Application and Development of Firefighting Technologies in Industrial Heritage: Experiences and Insights from Macau

Abstract

Due to the irreversible nature of the consequences of fire, fire protection is a major challenge and source of problems for all types of built heritage. This study aims to establish sustainable fire protection technology strategies by generalizing fire prevention and control technologies and measures against extended burns. This study aims to explore Macau’s industrial heritage’s historical development and technological applications in the field of fire protection using literature analysis, field investigation, and spatial information visualization methods. It will be carried out using the industrial heritage of Macau as the object and systematic analyses from the screening and processing of fire protection historical data, fire risk assessment, and the migration of fire protection focus. The results show that (1) the fire protection of the industrial heritage of Macau has gone through a total of three phases: passive fire protection, transition of fire protection methods, and active fire protection, and the relied-upon fire protection technologies have been iterated and renewed continuously during this period. (2) When the fire load factors of industrial heritage increase, the fire vulnerability assessment substantially changes, and the center of gravity of heritage fire protection shifts from controlling the scope of disaster to reducing the fire risk. (3) The construction of a suitable and effective ecological model of fire protection technology can provide appropriate fire protection solutions for the preservation and reuse of Macau’s industrial heritage in a complex cultural context. Therefore, this study will help to solve the current dilemma of sustainable application and development of fire protection technology for industrial heritage. This study hopes to provide ideas and strategies for reference on industrial heritage fire protection issues in the development of similar world heritage cities.

1. Introduction

As an important place for industrial production, product transportation, and personnel operations, industrial heritage has a direct impact on buildings’ floor plan layout, structure, streamlined organization, and process characteristics. It is one of the important indicators for measuring urban competitiveness and economic development levels [1]. However, the city has undergone historical changes and industrial transformation, and early industrial production can no longer meet current development needs. The architectural images that once proudly displayed the city’s industrial style have gradually been diluted, and their fate has been either relegated to a corner or transformed into other uses, forming a unique urban traditional industrial heritage landscape. At present, this kind of heritage landscape is constantly being eroded by modern advanced technology and craftsmanship, and its status tends to be marginalized, which is regrettable. Urban industrial heritage faithfully witnesses and records the development of the local industrial economy and has both production and cultural significance [2]. It retains the typicality of industrial architectural style and the authenticity of spatial functions and is also full of traditional wisdom in facing complex production processes and dealing with many potential risks. It includes industrial fire safety management and response measures, which can be regarded as a good reference for the contemporary urban industry to carry forward the past, open the future, and maintain vitality and sustainable development, and it should therefore receive the necessary attention and systematic induction.

Urban fire protection is an important issue related to the social economy and people’s livelihood. The occurrence of fires seriously affects life, health, safety, and property. It has obvious disaster scalability and process uncertainty, and the resulting harm is irreversible. In particular, architectural heritage with historical and cultural value poses more severe challenges. As a world heritage city, Macau is also an important port hub in history. It once had matches, firecrackers, and incense as its three pillar industries. As a result, related manufacturing plants supporting storage docks and other industrial building types were built. The time trajectory of these buildings covers the period from 1910 to 1980 and has gone through nearly a century of development including construction, expansion, and renovation. Due to the close relationship between industrial properties and fire, industrial buildings in Macau have always faced severe fire prevention challenges. Currently, as the land space in Macau continues to shrink, early industrial buildings and residential buildings are mixed, and the high-density urban environment has increased the difficulty of regional fire prevention. Therefore, how to conduct a comprehensive assessment of the potential fire factors of industrial architectural heritage (hereinafter referred to as industrial heritage) and how to improve the response level of Macau’s urban buildings accurately and efficiently, especially industrial heritage, to fire risks have become important issues in current urban development.

1.1. Complex Social Environment and Industrial Development

As an island city, Macau’s early industry has been around since its opening in the mid-16th century. From the mid-sixteenth century to the mid-seventeenth century, Macau was a transit port and trade center for international trade between the East and the West. But at that time, its development was relatively slow. Before the Opium War, overseas trade was the mainstay of Macau’s economy, but the Opium War brought great challenges to Macau. The following aspects mirror this: (1) the formation of a “trading port” system led to a northward shift in China’s foreign trade; (2) the ascent of Hong Kong and its alignment with South China’s economic hub dealt a severe blow to Macau’s deteriorating economy; (3) the Portuguese in Macau sought to take control of Macau’s governance, resulting in political tensions that inevitably affected Macau’s fragile economy. Therefore, Macau made numerous efforts for economic transformation during the Opium War crisis, including the implementation of the industrial prosperity plan. After the Opium War, Macau’s modern industry gradually emerged and reached a certain scale. Especially after the success of the Portuguese Democratic Revolution in 1910, the Portuguese Republic government began to pay attention to the industrial development of overseas colonies. For example, Presidential Decree No. 985, issued on 28 October 1914, improved the existing industrial laws, stipulated the laws for the establishment of new industries, and strongly supported the industrial development of overseas colonies [3]. The then Governor of Macau also proposed to develop Macau’s industry and commerce, and formulated a series of measures to develop industry, for example, (1) reclaim land, increase the land area of Macau, and establish industrial zones on the newly reclaimed land to develop industry; (2) protect Macau’s local industry, implement tax exemption or tax reduction policies for industrial products produced locally in Macau, and increase the tax rate on foreign industrial products; (3) host industrial exhibitions to publicize and promote Macau’s industry and industrial products, attract industrialists from all over the world, and strive for manufacturers from all over the world to invest in Macau and build factories. Additionally, Macau’s relatively cheap labor market and relatively small investment in its main investment areas attracted a large number of wealthy businessmen from the Chinese Mainland and Hong Kong to invest in Macau’s industry. Throughout the hundreds of years of the development history of Macau’s industry, the following characteristics appear: First, the industrial capital structure is dominated by Chinese capital with a small amount of foreign capital participation. Second, the industrial production system is dominated by manual production, micro-factory clusters, and light industrial products. Third, the industrial development model aims at producing and exporting products to satisfy overseas markets.

The period from the 1920s to the 1980s was a period of real development and prosperity for Macau’s industry. During this period, a total of about 35 categories of relatively large-scale industries in Macau appeared [3] (

Table 1. Macau’s industrial categories from the 1920s to the 1980s.

Type	Specific Industrial Categories
Logging Industry	Quarrying	Casting	Plating	/	/
Food processing	Salted fish processing	Vegetable oil	Can	Winemaking	Candy cookies
	Seasoning	Grinding powder	Rice milling	Bird’s nest processing	/
Manufacturing	Textile	Electricity	Architecture	Cement	Tile
	Print	Glass	Big wood	Candle making	Tanning
	Ice making	Papermaking	Making cigarettes	Copper making	Scale making
	Shoemaking	Pharmaceutical	Making rice	Shipbuilding	/
Chemical industry	Firecrackers	Matches	Incense	Opium processing	/

Source: Author’s statistics.

). These categories are compiled based on the statistics of the Macau Industrial and Commercial Yearbook over the years. Among them, “matches, firecrackers, and incense” occupy a dominant position in terms of the number of employed people and the total value of exports. They are considered the three main types of Macau’s early industries. Based on the industrial distribution and port shipping at that time, industrial building forms such as firecracker factories (production space), dock construction areas (transportation hubs), and shipyards (means of transportation) were built. With the development of the social economy, considering that such industrial products are mostly flammable and explosive items from raw materials to the production process, there have been many explosion and combustion accidents in history (26 cases are not fully counted; see Appendix A for details). In 1961, the Portuguese government decided to set up a fortune gambling company in Macau, and the number of foreign tourists to Macau increased sharply. The huge gambling monopoly tax revenue and the general preferential tax system granted by the European Community countries and the United States created a low-tax environment for the development of all walks of life in Macau. Under this circumstance, some processing industries in Hong Kong began to transfer to Macau, forming a labor-intensive industrial structure led by clothing, textile, and toy production, and Macau’s economy began to enter a period of high growth. However, since 1993, the export processing industry, which relied on quotas and tariff preferences, has lost its advantages. Coupled with the insecurity before the handover of power and the impact of the Asian financial crisis, Macau’s economic growth began to slow down, and from 1996 to 1999, it even experienced negative economic growth (up to −4.6% in 1998). With the Macau government’s liberalization of gambling rights in 2002 and the implementation of individual travel between Hong Kong and Macau in 2003, Macau’s gaming industry ushered in a new round of prosperity and once again became the leading industry in Macau’s economy. Most of the industrial buildings that occupied a large area in the early days naturally became the government’s main targets for land acquisition due to the huge pressure from the lack of market and labor shortage and were forced to be demolished until they disappeared.

1.2. Architectural Heritage and Fire Protection after the Decline of Industry

Under the guidance of an industrial economy dominated by tourism and gaming, the past glory of Macau’s industry has gradually been forgotten, and many remaining industrial heritage sites have been abandoned, and some are even overgrown with weeds. In 2005, the Historic Center of Macau was listed as a World Cultural Heritage. Various architectural heritages have become an important support for the development of Macau’s cultural tourism industry, and heritage protection has become a consensus in society. However, judging from the demarcation scope of Macau’s historical and cultural city, the core area is mainly dominated by religious and residential buildings, and its fire protection facilities, landmarks, and other fire protection levels are the highest. Early industrial buildings are widely distributed around the core area, including the inner harbor–dock complex and former manufacturing plant sites. These building types generally receive insufficient attention. It should be realized from the actual situation that due to the characteristics of Macau’s high-density urban environment, the relationship between various urban areas is interactive. Therefore, disaster situations, especially fire threats, do not have obvious divisions, and there is an objective relationship of “all prosper, and both suffer losses”. Considering the limited stock of heritage and the extent of possible fire damage, fire protection measures for industrial heritage in Macau should also be elevated to a higher level to actively avoid uncontrollable and irreversible potential fire risks. Unfortunately, so far, few relevant research results have focused on the historical development of fire protection in Macau’s industrial heritage, lacking an overall review and systematic summary. This is also one of the starting points of this study.

The research team compiled and sorted out historical data from relevant websites such as the Macau Fire Department and Macau historical events to obtain the main fire conditions in the city’s history: we found that fires in Macau have continued since the 19th century, which has had a great impact on the local economy and social stability. For example, in 1835, a fire destroyed the Church of “Mater Dei” (Church of St. Paul). Only the front wall of the church remained, which is now called the “Ruínas de São Paulo”. This archway is now a landmark building in Macau, but in fact, it is also a warning to Macau’s firefighting. In 1856, the largest fire in history broke out in the main city of Macau, causing damage to more than 1300 shops and houses, and killing more than a hundred people. On the other hand, the most serious industrial explosion in Macau’s history was the one at the Toi San Electric Firecracker Factory on 30 December 1925, which killed more than 100 people and injured more than 300 people. At that time, the firecracker factory was located in a residential building, so when a big explosion occurred, it affected surrounding residential buildings. Following this incident, the Portuguese government in Macau intensified its management and supervision of the firecracker industry and explosives. They mandated the relocation of high-risk firecracker production procedures to Taipa for supervision. At the same time, Taipa also has a fire brigade for disaster relief. In addition, each factory also has safety facilities, such as pools and rammed earth walls, for firefighting and explosion-proof purposes. Located far away from the factories, the most dangerous pharmacies prioritize early morning work. However, it is worth noting that from 1910 to the present, there have been a total of 38 fires in Macau firecracker factories, docks, shipyards, and other industrial buildings over the past century due to explosions, lightning, man-made and other factors (limited to the currently available data, the actual number may be more) (Appendix A). Although these buildings were initially designed with potential fire hazards in mind, how to prevent and mitigate disasters has always been one of the problems faced by Macau’s industrial buildings over the past century.

In the post-heritage era, Macau’s industrial buildings have become an integral part of Macau’s cultural heritage. With the renovation and design of the Iec Long Firecracker Factory in 2022 and the revitalization of the Lai Chi Vun Shipyards in 2023, actual projects mean that Macau’s industrial heritage has regained the favor of the government after many years. There must be many differences in fire protection strategies between these old and new industrial buildings, which also provides good material for comparative research on the development of fire protection methods. Against this background, this article starts with the types of industrial buildings attached to the three main industries in Macau and corresponds to the complete industrial chain of product production–transportation hub–transportation. The only remaining firecracker factory in Macau, the Inner Harbor Pier Building Complex (17 buildings were selected as samples), and the Lai Chi Vun Shipyard Area, the largest shipyard in Macau, were taken as the objects (Appendix B). On the premise of protecting Macau’s industrial heritage, the research team will conduct discussions on early fire protection and post-heritage era fire protection strategies for this type of building. This study attempts to establish the specific methods and effectiveness of historical fire protection measures from a temporal and spatial comparative perspective. It will intuitively explain the factors and practical logic that affect the entire process of fire generation, spread, and fire extinguishing mechanisms, which will help to summarize the history of Macau’s industrial heritage firefighting experience. At the same time, spatial information and architectural modeling are widely used to visually analyze the new issues and challenges currently faced by Macau’s industrial architectural heritage, to gain a deeper understanding of the current fire protection status and vulnerability of industrial buildings. Combined with historical experience, traditional wisdom and new scientific methods are combined to optimize modern fire protection strategies and technical methods, to learn from the past and realize the fire safety design and management of contemporary industrial architectural heritage.

1.3. Problem Statement and Objectives

Industrial heritage fire safety protection involves the collection, collation, analysis, and fire management and technological innovation of fire risk elements. The Macau Industrial Heritage is the historical epitome of the early industry in Macau. Although it has long been statically affected by urban construction, the continuity of industrial culture is deeply imprinted on these heritages. At present, the Macau Industrial Heritage has a complex background. In terms of the research object of this paper, eight of the inner harbor dock buildings continue the function of the docking hub and remain in use, while seven of them have been left unmanaged and unused. The Iec Long Firecracker Factory and some dock factories have been activated and utilized. Although these industrial heritage fire methods have undergone tremendous changes, there are traces of fire measures from the past, and a complete database is required to summarize. In addition, unlike general historical buildings, in addition to considering the building itself and moving fire loads, the industrial heritage also has strict requirements for the industrial environment, material facilities, safe evacuation, and rescue. Fire control is generally based on industrial materials, operating space, and behavioral paths; otherwise, the negligence of any link may have great consequences.

Overall, given the special context and cultural significance of Macau’s Industrial heritage, several key issues need to be clarified before further developing and optimizing this type of fire protection model:

(1)

How many periods have the fire protection of Macau’s Industrial heritage gone through? What are the strengths and weaknesses of the fire protection experience during its historical development?

(2)

What are the aspects covered by the origin of fire in the industrial heritage of Macau? How do the spatial, material, and use aspects of industrial heritage affect its fire conditions?

(3)

As the development of fire prevention and control strategies is an iterative process, what are the new issues and challenges facing the fire protection of Macau Industrial Heritage, and how can the existing fire protection technologies cope with the current fire safety dilemmas?

Therefore, the goal of this research is to solve the above problems based on field surveys and empirical research, based on big data induction and combined space information visualization technology. It is expected to reach the following goals:

(1)

Using literature historical materials and on-site investigation work on the fire data of the Macau Industrial Heritage, including classified induction, attribute recognition, analysis, and inspection, and confirming fire risk assessment factors and influencing factors.

(2)

Explore the transformation of the origin of fire, fire load, and fire mode of industrial heritage in Macau, and propose the similarities and differences between the new and old fire protection theories and technologies, and the migration characteristics of the fire.

(3)

Establish a spatial model for industrial heritage, fully understand the analysis of fire prevention status and fire vulnerability, promote the integration of traditional fire protection wisdom and modern fire technology, and alleviate the current fire safety dilemma.

(4)

The distribution of comprehensive industrial heritage optimizes emergency management of urban fire space. This maintains the integrity of the historical architectural heritage of Macau’s urban city and promotes the high-quality development of the cultural tourism industry.

This paper organizes the remaining sections as follows: Section 2 is a literature review, analyzing the existing results between industrial architectural heritage and fire protection technology. Section 3 introduces the research area, methods, and processes. In Section 4, the researchers delve into a detailed analysis of the underlying causes of fire disasters in industrial heritage, the significance of fire protection in this context, and the advancements in fire protection technology and strategies, using Macau as a case study. Section 5 is a discussion summarizing the adaptive relationship between the functional transformation of Macau’s industrial heritage and fire protection methods. Section 6 presents our conclusions.

2. Literature Review

Fire safety is one of the main problems that affect the full life cycle of buildings from early design to post-period operation and maintenance [4]. Different from the performance of the performance of focusing on fire materials, such as the effects of thermoplastic materials on the spread of fires [5], etc., this review is more concerned with the fire safety of many historical buildings, including industrial heritage. This must not only consider fire prevention in the building itself but also involve the cultural significance of protecting intangible assets. How to balance the relationship between historical fire resistance and fire prevention requirements, and the relationship between traditional fire protection and modern fire involvement [6], has become a hot spot. Related research has been continuously explored from theoretical methods and technical experiments.

Fire risk assessment is considered the primary consideration of fire safety in historical buildings, which is related to pre-disaster prediction and post-disaster reconstruction plans. The assessment content is mainly concentrated on the two levels of the judgment of the fire source before the disaster source and the simulation of fire in the disaster. The evaluation method formulation will be different according to the historical buildings of different backgrounds. Commonly used methods include fire risk index (FRI) [7], establishing a fire influence database (DAFI) analysis of spatial distribution and quantitative characteristics [8], and building a 3D model as the evaluation tool to retrieve the source data of the fire source [9]. Scholars attempted to reconstruct and evaluate LULC changes and fire history in six case studies of the Central Mountain System (Spain) using historical geography, socio-spatial systems analysis methods, archival documentary sources, and historical cartography. This study aims to assess the interaction between landscape dynamics and fire regimes in a fire-prone and humanized Mediterranean region since the mid-19th century. Compared with traditional methods, three-dimensional models have significant advantages and better results in predicting fire behavior. For instance, (1) a 3D model allows for a more realistic simulation of fire behavior. Traditional methods may be based on simplified assumptions and theoretical models, and the description of fire scenes is relatively rough. Three-dimensional models, on the other hand, can construct complex and realistic building structures and spatial layouts, including details such as room shape, door and window location, and ventilation ducts. For example, when simulating fires in high-rise buildings, 3D models can accurately present the mutual influence between different floors and the flow path of smoke. (2) Accurate heat transfer and airflow analysis: 3D models can more accurately calculate heat transfer processes and airflow movement. They can take into account the thermal properties of different materials, the diffusion of heat in space, and the convection of air. In contrast, traditional methods may not be able to handle these factors so meticulously. For example, in a fire simulation of a large factory, a 3D model can show the flow of hot air in different workshops and passages, helping to predict the direction of fire spread. (3) Comprehensive consideration of multiple factors: It can simultaneously consider multiple factors that affect fire behavior, such as the distribution of combustibles, the location and actions of personnel, and the layout of firefighting facilities. Traditional methods may have difficulty comprehensively integrating these factors for analysis. Taking a shopping mall fire as an example, a 3D model can provide a more accurate prediction of the development of a fire by combining the placement of goods, the status of personnel evacuation passages, and the location of the automatic sprinkler system. (4) Good visualization effect: Through intuitive 3D images and animations, firefighters, decision-makers, etc., can more clearly understand the fire’s development trend. This is often difficult to achieve with traditional methods because traditional methods may rely mainly on data tables and charts. For example, when introducing fire plans to firefighters, 3D models can allow them to more intuitively understand the possible development path and key areas of the fire. It should be noted that these methods need to be based on literature surveys, many on-site collections work, and a good fire management data system [10] to form a relatively complete data foundation. Of course, by constructing GWLR (Geographically Weighted Logistic Regression), the fire risk assessment model can also confirm the regional fire risk probability and influence of fire risk [11], and the use of a fire dynamics simulator (FDS) predicts fire conditions [12,13]. These methods provide our ideas for our in-depth understanding of the cause of fires in historical buildings, and we discuss key measures that can be taken [14]. There are already many cases that can be demonstrated; for example, in Beijing, China, the fixed fire load (FFL) (fire loading is a combustible material that may be burned in the fire) and mobile fire load (MMF) are determined. The corresponding fire prevention plan is proposed [15]. The rapid advancement of satellite remote sensing technology has made it a common tool for detecting forest fires, including methods such as brightness temperature detection and smoke detection [16]. In order to reduce the losses caused by fires, some scholars have proposed an intelligent fire monitoring system based on multi-sensor data fusion [17]. They designed temperature, smoke, and flame sensors, fused data from similar and heterogeneous sensors using weighted least squares (WLS), and improved fuzzy support. They then designed a fire remote monitoring alarm device based on the ZigBee wireless network for monitoring, and added local storage and emergency modules. In addition, some scholars have proposed an end-to-end, two-stream neural network model to detect fires, trained the algorithm using fire videos on the Internet, and then tested it using a fire database [18]. The proposed method, when compared to existing fire detection algorithms, demonstrates good practicality and versatility, serving as a valuable reference for the advancement of fire detection technology. A large number of cases and data show that to maintain the limited assets of historical buildings, plans during the fire and post-disaster response should be considered. However, preventive measures should be paid for [19].

Secondly, at the micro level, the problem of fire-related issues seems to be relatively intuitive. Researchers have found that architectural materials, structural forms, fire habits, and fire loads are vital to improving single historical buildings’ fire resistance performance [20]. This is reflected in the fire treatment of the Tianjin Qunju Courtyard [21], and the fire treatment of the Master of Paris [22]. In addition, at the meso level, the environmental characteristics of the surrounding area of historical buildings are also important content of fire management. This kind of environment includes the prediction of fire value assessment and risk forecast in historical areas [23], and various types of heritage cities, villages, and other fire management of fire management “compliance” and “safety” [24,25]. For example, George Town, Penang, Malaysia, effectively identifies fire hazards in the environment and develops fire contingency plans to eliminate fire hazards [26]. Dangjia Village [27] and Chengkan Village [28] in China established the sensitivity of heritage value, village fire hazard, and fire evacuation accessibility. They utilized these three levels for fire risk control of heritage villages and their historic buildings. Misi Village in Turkey achieved heritage sustainability through fire control of environmental resources [29]. These case studies jointly show that strengthening environmental fire protection planning and fire resistance assessment is a powerful measure to protect the inheritance of land and historic buildings from fire [30]. But we should also review the impact of people’s activities in the fire prevention process [31]. At the macro level, the fire measures of historical buildings and their environment are mainly used in policy and regulations, such as formulating legal frameworks and planning of fire safety venues [32]. For example, the National Fire Protection Association (NFPA) formulates the exclusive fire safety specifications and standards of historical architecture to meet the fire safety needs of historical buildings [33], which is considered progress at the institutional level. It should be added that although the impact of land use and covering fire is not in the scope of research and discussion in this article, land use is related to urban space resources, and urban space is related to historical building fire resistance. To this end, we believe that land use and land coverage as the urban space landscape will also become the main driving factor of fire behavior, which should be paid attention to. As scholar Iyai D. A. once pointed out, in agricultural production, we should pay attention to the cultural productivity of the land. The same is true for the land occupied by industrial heritage buildings and their cultural output [34].

At this stage, we cannot ignore the phenomenon that research on fire protection techniques for minimum damage during firefighting in historic buildings is also a major contribution to fire protection in historic buildings. This type of research has responded to many difficult problems at the level of technical experimentation. For example, it was found that hand-held portable fine water mist extinguishers are potential fire protection means for historic buildings in terms of extinguishing mechanism and impact of use [35], the smoke detection system of historic buildings was optimized by temperature distribution, flame, and smoke behavior paths of wood fires [36], and clean fire extinguishing technology using fluorochemical gases can quickly extinguish historic building fires in the initial stage [37]. There are also studies on integrating passive flame retardant and active fire warning into a single fire protection system that will greatly improve the performance of early fire warning sensors in historic buildings [38,39], as well as the use of artificial intelligence deep learning for flame detection [40], construction of fire protection decision-making models [41], and fire prediction [42,43]. The development and utilization of these technologies have enriched the means of firefighting in historic buildings, making early fire prevention and accurate rescue in disasters possible.

This article studies the target industrial architectural heritage as one of the many types of historical buildings, but it cannot be denied that industrial buildings have their complexity and independence. First, the evaluation of fire risk should pay more attention to historical data and empirical research, and comprehensively inspect and evaluate the fire protection strategy [44]. Pay attention to people, materials, equipment, environment, management, and fire protection facilities as the main indicators of evaluation [45], which are different from general historical architectural fire assessment content. Secondly, in terms of fire management, Pakistan builds a list-type system framework covering the type of inheritance, the property, the characteristics of the space, and the significance of the value of the industrial heritage fire. At the same time, intelligent inspection technology has been used to improve safety inspections and intelligent management problems in the protection of industrial heritage [46]; finally, fire technology is also different from other historical buildings. For example, the new flames and smoke detectors [47] and the basic principles and suppression mechanisms of fine water fog should also be revised according to the industrial application situation of the industrial application situation [48]. These point to the industrial heritage fire protection system and management system that meets its attributes, and there is insufficient research on this.

In addition, the research team also noticed that the current focus on industrial heritage is mainly concentrated on transformation design and reuse. The effective reuse of historical buildings has become the basic content of the European Architectural Heritage Management and Protection Plan. The industrial heritage has provided huge possibilities for the redemption and transformation of its internal space, showing the plasticity of changes and performance renewal [49]. In this regard, the evaluation framework has three dimensions of basic, advanced, and challenging needs, and the success of industrial heritage for public buildings is evaluated and analyzed [50]. However, labels such as “high fire” are key issues that such buildings should pay attention to during the protection of protective transformation [51]. Therefore, based on a full investigation, we should pay attention to the adaptability of industrial heritage, and strive to empower the current fire safety toughness of the current industrial heritage from the perspective of absorption, disaster, and recovery ability.

Finally, it should be noted that although we have summarized several contents of industrial heritage fire protection, these studies are insufficient to constitute a systematic analysis of industrial heritage fire protection, and there are no related results for the fire protection of Macau Industrial Heritage. Therefore, given the affiliation of industrial heritage and historical buildings, the above-mentioned more comprehensive review discusses the development of historical buildings in the aspects of fire risk assessment, fire management, and fire technology innovation, which is believed to help provide lessons for industrial fire safety protection. This is why this article mainly uses historical buildings as a review object, and it is also the motivation to firmly carry out fire research in Macau Industrial Architecture Heritage.

3. Methods and Study Area

3.1. Methodology

This study aims to have in-depth discussions on the historical development and technical application of Macau’s industrial heritage fire protection in the use of literature analysis, field surveys, and space information visualization methods.

First, the literature analyzes the historical data of the Macau Industrial Fire, including types of industrial heritage, fire events, early fire protection facilities, fire prevention, fire extinguishing methods, etc. The data of this study are sorted into historical documents, maps, photos, and newspapers. The meticulous review of the relevant records of the research object is an important way to understand the early fire situation of industrial heritage.

Second, empirical research. Through field investigation, the samples of building complexes in the Inner Harbor Pier of Macau, Iec Long Firecracker Factory, and Lai Chi Vun Shipyards were analyzed. The content of the survey includes two parts: one is the research object itself, including the current situation of samples, fire protection facilities, evacuation channels, and fire risk assessment, fully understanding the current harmful ingredients (industrial materials, operating behavior, etc.) and vulnerable components (building materials, fire loads, etc.). The other is the spatial relationship between the spatial distribution of industrial heritage and the urban environment, including building safety and the resistance of fire protection distance. To obtain real and reliable field images, all the field survey images in this study are taken from the dock, block, and factory buildings in person.

Third, use spatial information data to conduct a model visual analysis. Using modeling software such as Autodesk CAD software (2018 version) and Sketch Up software (2020 version), we first combined surveying and mapping technology to complete 3D architectural models of some docks, firecracker factories, and dockyards, thereby clarifying the firefighting facilities and safety distances between buildings. Then, we sorted out the distribution of Macau Fire Stations from historical records and used GIS (10.8 version) to create the spatial layout of firefighting facilities, which included the number and geographical location of fire stations in different periods. This will allow for a more intuitive interpretation of the environmental characteristics of Macau’s industrial heritage firefighting sites, the distribution of firefighting equipment, and the current status of firefighting planning.

3.2. Material Preparation

3.2.1. Study Area: The Macau Peninsula, Taipa Island, and Coloane Island

Macau is situated on the north shore of the South China Sea and the west side of the Pearl River Estuary. Zhuhai City, Guangdong Province, connects to Macau in the north, while 63 km separates it from neighboring Hong Kong in the east, with the South China Sea on its other two sides. It is one of the central cities in the Guangdong–Hong Kong–Macau Greater Bay Area. Macau consists of four areas: the Macau Peninsula, Taipa, Cotai, and Coloane (Figure 1). After 2000, the reclamation between Taipa and Coloane formed Cotai City, which is mainly based on the gambling industry. The Macau Peninsula is the core of Macau. Chinese Mainland connects a small portion of Macau’s northeastern land. Taipa and Coloane were originally two outlying islands. They later became Cotai City due to reclamation. Moreover, Macau and Guangdong Province collaborate in managing Hengqin Island and have the authority to enforce Macau laws in specific domains such as ports and the University of Macau. Simultaneously, the new urban area is being developed through land reclamation, and the artificial island of the Macau Port, located near the Hong Kong–Zhuhai–Macau Bridge, has undergone development. However, the land reclaimed after 2000 has rarely included the distribution of traditional industrial buildings. Therefore, this study exclusively concentrates on the three traditionally developed islands in Macau: the Macau Peninsula, Taipa Island, and Coloane Island. The research team obtains the terrain map of the research object from the Macau Capital Bureau and processes the bottom diagram. This study uses a building entity associated with a complete industrial industry chain as the object. The relevant areas include Inner Harbor Pier in the Macau Peninsula, Iec Long Firecracker Factory on the Taipa Island, and Lai Chi Vun Shipyards in the Coloane Island. The involved areas are concentrated in the west of Macau city, which is the concentrated area of Macau’s traditional industrial production and transportation and meets the setting of the scope of this study (Figure 2).

3.2.2. Data Collection and Basic Information on the Study Sample

Sample selection and screening are necessary measures to ensure the authenticity, science, and integrity of this study. The first step in this study is to establish a data set of the Macau Industrial Heritage type. The Inner Harbor Pier in the Macau Peninsula, Iec Long Firecracker Factory in the Taipa Island, and Lai Chi Vun Shipyards in the Coloane Island are selected. Among this industrial heritage, there are early architectural forms and later intervention transformations to form new industrial heritage landscapes. Given the complexity of the sample data, researchers summarize the samples from construction, structure configuration, function types (divided into early function and contemporary use), usage, and other contents (Appendix B). A total of 569 photos were taken on the spot. Due to poor viewing angles, obstructions, and blurred quality, 194 copies were removed, leaving 375 copies, and four related statistical tables were completed as the basic material for this study. In addition, to better compare the comparative analysis of the time and space of the Macau Industrial Heritage, we have also analyzed whether there is renovation and utilization in the form. Unfortunately, because some buildings failed to enter the room for observation due to property rights and actual conditions, the research team conducted a detailed investigation of the fire protection of the underlying space, including the location of the fire facilities, the smooth flow of the evacuation channel, the fire loads, etc.

The sample data were initially arranged, and we found that the current fire protection system of this industrial architectural heritage is still minimal, and the equipment facilities are elementary. Some of them only provide infrastructure fire extinguishers. There are still many tasks to strengthen the industrial heritage fire system. Macau Industrial Heritage elements are valuable and should not be lost in possible fires.

3.3. Material Treatment

As Macau has experienced the integration and changes of multiple cultures in history, its architectural style, fire protection facilities, and environmental characteristics have shown complex and diverse characteristics. Reasonable materials are guaranteed to ensure the accuracy and effectiveness of this research. The researchers classify the attributes of various samples in the region. The single buildings are placed in each category according to the architectural characteristics, fire protection facilities, environmental characteristics, and fire loads. At the same time, the researchers also used different colors to mark the relevant images according to the characteristics and factors that affect fire safety. For example, in some traditional commercial areas in Macau, there may be random stacking of dangerous goods; in some old building areas, there may be a lack of eye-catching safety signs; and in some industrial sites, there may be irregular operations. Our precise identification of these issues can provide clear guidance for subsequent in-depth analysis. To strengthen the visualization of space fire protection, the research team has rebuilt the building model in the research area according to a certain proportion. The basis for constructing the 3D model comes from the research team’s on-site investigation and measurement data.

3.4. Research Strategy

This research mainly relies on survey data obtained to analyze and build a fire protection model for industrial heritage in Macau. In this study, (1) researchers will comprehensively complete historical data. Based on fully interpreting the history of Macau’s fire protection, we will summarize early fire prevention technology and anti-extension measures and summarize the useful fire safety designs. (2) We will discuss the fire risks of the Macau Industrial Heritage through empirical research, manually label images, including specific distribution and quantitative conditions such as fire protection facilities and fire loads, and objectively evaluate the current fire protection situation of industrial heritage. (3) Based on the traditional fire protection wisdom and modern fire protection technology, we will optimize the industrial heritage fire protection management model and alleviate the fire safety dilemma that is being faced. All in all, the institute’s strategy is not an experiment, simulation, or calculation formula. On the contrary, this study pays more attention to the essence of regression, that is, the research path of discovering problems and analysis of problems—proposing solutions is a primary and very practical scientific research procedure. This article emphasizes the inherent fire protection characteristics of industrial heritage. At the same time, we actively accept new fire protection technology, communicate with each other, and use the minimum and reasonable improvements to meet the goals of fire safety (Figure 3).

4. Results

4.1. The Root Cause of Industrial Heritage Fires: The Complexity and Diversity of Fire Sources

4.1.1. Fire Statistics

Fire source recognition, combustion, and burning are the basic elements that affect fire factors. Combined with the current statistics of the historical fire data of the research region (as of December 2023), there have been 26 fires involving bamboo factories (3 of which were affected by the surrounding fires) and fire incidents in dock buildings started from 2 fires (

Table 2. Total fires for history of industrial heritage in Macau.

Research Object	Firecracker Factory Industry	Dock Industry (17 Representatives)	Lai Chi Vun Shipyard
Number of fires	26	10	2

(Table note: For the specific situations of the fires in this table, please refer to Appendix A).

). Through preliminary analysis of statistics, since the establishment of the Macau Fire Brigade in 1919, the 1920–1980 period was used as a period of prosperity in Macau’s traditional industry. Due to the limitation of fire prevention technology and the poor fire extinguishing facilities, this period is also a stage of high fire incidence. The location of the fire was relatively concentrated, and the fire caused a wide range of fires, which caused a serious degree of disaster. From the perspective of overall data, the fire threats faced by the cannon factory are very severe. What is more surprising is that there are fewer industrial fire records in the shipyard with more flames such as wood. To understand this phenomenon, we conducted a detailed investigation and analysis of the causes and influencing factors of these industrial heritage fires.

4.1.2. Analysis of Fire Influencing Factors

(1)

Production space—potential fire source of the cannon factory

This is the most serious and most complicated type of fire in the Macau Industrial Heritage. In 1881, Macau established its first firecracker factory. In 1930, there were a total of ten firecracker factories in Macau. At that time, Macau was an important firecracker production center, and its products were mainly exported to Singapore, the Philippines, the United States, and Europe. In the 1950s, there were about 12 firecracker factories in Macau. In 1953, firecrackers became Macau’s main export commodity, with production reaching 3 tons with a value of MOP 7 million. In the 1980s, there were only Iec Long Firecracker Factory and Po Sing Firecracker Factory. After the 1970s, Macau’s firecracker industry gradually declined due to competitors’ price advantages and safety concerns, and the last firecracker factory closed down in the 1990s. Now, only the Iec Long Firecracker Factory District can be fully preserved.

The production of artillery firecrackers from material configuration and gunpowder is adjusted to the finished packaging. The production process is relatively simple but the whole process is very dangerous (Figure 4). According to historical records from the Archives of the Central Library of Macau, the process of making gunpowder in a firecracker factory requires using the appropriate amount of powder, which is one of the most dangerous stages in the production of firecrackers. The ingredients of gunpowder are a mixture of materials such as white medicine (i.e., potassium chlorate), silver powder, sulfur, nitric acid, and carbon powder. We can divide the production process into two steps: “mixing gunpowder” and “preparing medicine”. European countries transport the raw materials for gunpowder to Macau after a lengthy journey; 80% of them are from Chinese Mainland, and the rest are from Japan, China’s Taiwan, and other places. The process may pose a risk of explosion. The firecracker factory transports most of the raw materials in solid block form, as powder is more stable than blocks. Workers need to crush raw materials such as silver, sulfur, and nitric acid into powder to facilitate the subsequent mixing of medicine. Originally, workers stood on wooden sticks and used seesaws to manually grind the raw materials into powder. The 1960s saw the mechanization of powder grinding, where engines powered the machines, thereby reducing costs and accelerating work progress. After the powder is mixed, the workers mix the raw material powders, such as white medicine, silver powder, sulfur, and nitric acid, according to the appropriate proportions. Generally, workers mix one catty of silver powder, two catties of sulfur, and three catties of white medicine. This process is called “mixing medicine”. The mixing process is the most dangerous work in firecracker production. If workers make a mistake during the mixing process, slight friction could ignite a spark, potentially leading to a large-scale explosion. Because of this, many workers who mix medicine have died. Therefore, the number of workers who mix medicine cannot be too large. Generally, there are about six or seven workers who mix it at the same time. The raw materials must enter Macau from the pier through maritime transportation, but they are hazardous chemical products. This is one of the main sources of fire in the firecracker factory. Secondly, from making paper shells to putting them into gunpowder, it is necessary to regulate the gunpowder and the drug access process. This process is the most dangerous process of the entire firecracker factory, and it is also another potential explosion risk for early firecracker factories. Finally, with the packaging of the shells and the strict requirements of the surrounding environment during the export period, such as drying, ventilation, avoiding impact and high temperature, etc., a little carelessness can become a huge threat. In summary, the fire source of the early firecracker factory is the firecracker product itself. This potential fire source covers the entire process of the production of gun caster.

At present, the Macau Firecracker Factory industry is gradually falling, and firecrackers are no longer produced in Macau. The firecracker factories closed and even disappeared, and the early potential fire sources no longer exist. As the only industrial heritage of the firecracker industry in Macau, the Iec Long Firecracker Factory has now been transformed into an industrial exhibition place. However, the dry weeds, the exposed wooden frames, and the broken structure, although presenting the early industrial landscape (Figure 5), have become a new challenge regarding fire. These features clearly show that the main fire factors have emerged in new forms, that is, starting from the Turkish product itself to risks from external factors.

(2)

Transportation Hub—Fire Factors of Dock Buildings

The dock is an important hub for the industrial development of Macau, including a series of industrial products such as firecrackers and other industrial products. In the early days, the three islands of the Macau Peninsula, Taipa, and Coloane had not yet reclaimed the sea and the bridge. The people and items were transported by the pier. Among them, the Inner Port Pier is an important node connecting Chinese Mainland and Taipa, Coloane, and other countries. It has an office, reception, warehouse, and other functions. The complex use of the surrounding area increases the risk of fire in the dock. Through the survey of newly built and early dock buildings and combined with the main fire incidents of history, it was found that the influencing factors of fire in the dock building include three aspects:

First, the component of the docking architecture itself. The scene shows early existing dock buildings such as No. 23, No. 25, No. 26, 29, No. 30, and No. 31, as well as their connection platforms, flooring, beams, ceiling, etc. (Figure 6); these materials have been treated a certain amount but still have a certain flammability. But according to the historical fire data of the dock, this factor obviously cannot be the main fire source.

Second, travel ships. Earlier ships used wood as the main material, and the effects of onboard equipment, electric lights (or oil lamps), and fuel can easily form a fire source. According to dock fire statistics, four fires were caused by the fire from vessels exploding during stopping. It can be considered that this is the main factor affecting fires in the dock building. Because Macau is a transshipment hub, ships frequently pass by. Ships have become a potential fire hazard for mobile docks. This is a problem faced by new and old dock buildings.

Third, goods and equipment. The flammable degree, burning nature, stacking location, equipment operation, and aging of the goods will affect fires in the dock building. According to statistics, two cases of fire have affected the dock building due to goods and equipment. Although the proportion is not very large, it has shifted over time, and only certain dock building, loading, and unloading products are still in use. The proportion of aging equipment is higher, which will inevitably increase the fire risk.

In addition, whether in the early or current industrial environment, we cannot ignore the influence of fire, intentional arson, or occasional situations (such as lightning strikes) due to personal contradictions and trade competition.

(3)

Transportation Hub—Fire Factors of Shipyard Buildings

Lai Chi Vun Shipyards is the largest ship manufacturer in Macau. The heyday of the shipbuilding industry was around 1938, and there were 45 shipyards in Macau. Now only the industrial relics of Lai Chi Vun Shipyards are left. The Lai Chi Vun Shipyards, which are roughly the same size, are mainly spread out in a row along the coastline to form a group, and some spaces extend onto the adjacent water surface, forming a unique landscape combination that integrates artificial and natural environments. The proximity to water sources and wooden shipbuilding are factors that lead to a low incidence of fire. Because of the historical fires of the shipyard, the data of the shipbuilding industry and the judgment of the ship’s production process indicate that the potential fire source of the shipyard is similar to the firecracker plant, that is, there is a clear stage difference. Early shipbuilding used wood as the main raw material. Wood chips and dust were generated by the process of wood processing; once they encountered fire, it was extremely dangerous. Secondly, shipyards make it easy to generate fire points while cutting, becoming a potential source of ignition. Therefore, shipbuilders need to maintain a high sense of safety in their work, which may be the reason why there are fewer fire records in shipyards. In addition, human behavior may be an important influencing factor for the source of the Firefall, including the heating of shipwrights, cooking, and smoking. For shipyards mainly based on wood, the hidden dangers are large. However, since the 1990s, Macau’s shipbuilding industry has gradually declined due to factors such as the decline in the fishing industry and the entry of competition from neighboring regions. The shipyards in Lai Chi Vun Village have ceased operations one after another, and most of the shipyards have basically stopped carrying out activities related to shipbuilding purposes. Although the Lai Chi Vun Shipyards area is currently deserted, transformation and improvement are underway. But for the state of the shipyard today, the new fire problems cannot be ignored, for example, retaining wooden-based building structures, deodorous woods, dead wood in the shipyard, and temporary houses covered with iron in the surroundings (Figure 7). In addition, the location is relatively remote, and it is not easy to detect outsiders. Compared with the industrial heritage of the Iec Long Firecracker Factory, which is located in Taipa City, the Lai Chi Vun Shipyards are currently facing a greater potential fire risk.

Through the above sorting and analysis (

Table 3. The historical development and changes in the fire factors of the Macau Industrial Heritage.

Industry Heritage	Stage	Raw Material	Construction Process	Building Structure	Transportation	Goods	Environmental Character	Occasional Disaster	Human Behavior
Firecracker Factory	Early	●	●	×	×	×	●	×	×
	status quo	×	×	●	×	×	●	×	×
Pier buildings	Early	×	×	●	●	●	×	×	×
	status quo	×	×	●	●	●	●	●	●
shipyard	Early	●	●	●	×	×	×	×	●
	status quo	×	×	●	×	×	●	×	●

(Table note: goods factors include warehousing goods and temporary stacking goods. Environmental characteristics refer to regional environmental conditions including vegetation and surrounding combustibles. Occasional disasters mainly refer to natural disasters, including lightning strikes and wind disasters. Human behavior includes improper operation and arson. ● This logo represents related; × this logo means unrelated).

), the influencing factors of the Macau Industrial Heritage Fire will be summarized from the historical development process. It can be found that the influencing factors of the dock construction industrial fire have continued to increase, and the main influencing factors have changed after the transformation and improvement of the firecracker factory and shipyards. The three fire-influencing factors of architectural structure, environmental characteristics, and human behavior have become the main concerns of the current Macau Industrial Heritage.

4.2. The Relocation of Fire Focus of Industrial Heritage: From Controlling the Disaster Area to Actively Reducing Fire Risk

The focus of fire protection of industrial heritage shall be judged according to the fire load and fire vulnerability in the region to judge what can affect the scope of fire and the duration of the fire. Based on this, the scientific defense focus is established.

4.2.1. Distribution of Fire Loads

As an important parameter that measures the number of combustibles in the building room, the fire load determines the changes in the duration of the fire and the changes in the indoor temperature, which is the main factor for assessing the comprehensive development of the fire. According to survey statistics from the fire load of the Macau Industrial Heritage, the factors that need to be considered are as follows:

First, fixed fire loads (FFLs). This type of load is an indispensable material for buildings, which exists in the development of industrial heritage in Macau. Regardless of whether it is a firecracker factory, a dock building, or a shipyard, wooden pillars, beams, platforms, smallpox, and fixed wooden boxes are the main combustibles. According to the research on wooden building fire, wooden materials will become rotten over time, causing reduced density, easy ignition and rapid fire spread, and possible flashes which cause fire [52]. Secondly, the decorated surface of the building is often plaster or white ash. Although it is not flawed, it is susceptible to thermal expansion to form a hidden danger.

Second, mobile fire loads (MFL). Due to historical development and changes in functional purposes and equipment demand, MFLs at different stages of industrial heritage in Macau are large. With the restrictions of early material conditions, the main MFLs of the firecracker factory and the shipyard include production materials, office furniture (tables, chairs, etc.), tools, and equipment (boilers, wood hammers, etc.). The dock buildings are mainly cargo. At this stage, MFLs are more complicated. In addition to the cargo container, there is the construction room, which includes a sofa, TV, air conditioning, foam box, rusty doors and windows, plastic fish bar, bucket, and billboard canvas. After the use of the firecracker factory and the shipyard, various types of exhibits, showcases (wood), and human activities are at risk of being mobile fire loads.

Therefore, it can be judged from the above analysis (Figure 8) that MFLs are actually at a much higher risk of fire than FFLs. The unpredictability of fires due to their large number and uncertain use needs to be taken seriously.

4.2.2. Fire Vulnerability Assessment

Fire vulnerability is defined as the likelihood of being damaged by fire, i.e., relative to the severity of the consequences of fire. Vulnerability evaluation includes physical, social, economic, and environmental factors that may affect danger. Unlike fire impact factors that focus on the source of ignition, fire vulnerability focuses more on the degree of being at risk when experiencing a fire hazard, with uncertainty and complexity [53]. The effective evaluation of fire vulnerability is related to the priority of rescue targets and determining more targeted protection measures when fire occurs.

Taken together with the above historical fire data and fire-affecting factors, all the facts seem to point to a degree of fire vulnerability: highest in the early days of the firecracker factories, lowest in the dock buildings, and medium in the shipyards, and in the present situation, highest in the dock buildings, medium in the shipyards, and lowest in the firecracker factories. This logical judgment, based only on the number of fire-influencing factors, is one-sided. This study found that the fire vulnerability of industrial heritage should be evaluated by taking into account the vulnerability of the object itself, the environmental space in which it is located, and the fire-accessible vulnerability.

Because of this, the research team mapped the distribution of the industrial heritage of Macau, the Macau Fire Station, and the environmental space (looking at the access to water and combustible materials in the neighborhood). Through the use of spatial information technology, these elements were plotted on a map according to the historical reality, to show the relevant data and results more visually (Figure 9 and Figure 10).

Fire-influencing factors are classified according to more, usual, and less. Firefighting accessibility is classified according to maneuver time, e.g., <500 m (or <10 min, the minimum time for firefighting to arrive at the scene, the same hereinafter) as good, average, or poor. The environmental space is divided into three levels: excellent, medium, and difficult, mainly examining the water resources in the environment and the surrounding combustible materials. In this way, a comprehensive evaluation of the fire vulnerability of Macau’s industrial heritage was constructed (

Table 4. Comprehensive evaluation of Macau Industrial Heritage fire vulnerability.

Industry Heritage	Stage	Fire Factors	Fire Station Accessibility	Environmental Space	Integrated Fire Vulnerability Assessment
Firecracker Factory	Early	More	Average	Medium	High
	Status quo	Less	Good	Difficult	Low to medium
Dock buildings	Early	Less	Average	Excellent	Medium
	Status quo	More	Good	Medium	Medium to high
Shipyard	Early	Usual	Poor	Medium	Low to high
	Status quo	Usual	Average	Medium	Medium to high

Source: Author’s statistics.

).

From the above comprehensive assessment of fire risk, the vulnerability of the firecracker factory at the production end has gone from the highest in the early days to the current medium due to the reduction in combustible materials. The dock buildings have been extended and altered during the development process, resulting in congested aisles, blocked fire escapes, and increased mobile fire loads in some of the buildings. Their vulnerability rating may be upgraded to the highest status from the earlier medium. The fire vulnerability of shipyards has shown a gradual increase because the shipbuilding industry has declined and most of the factory areas are unused and are mostly temporary tin houses.

4.2.3. Transfer of the Focus of Fire Protection in Macau Industrial Heritage

Industrial heritage is generally laid out in a regionally distributed, multi-story concentration, often with a “one fire, many dangers” approach. The urban landscape has also developed from a sparse spatial pattern in the early days to a high-density urban environment at the present stage, but fire is still the biggest challenge facing this type of building. It is not difficult to see from past fire data that, limited by the firefighting technology and methods of the time, the focus of fire prevention and control in the early days was more out of consideration for the impact of the industrial environment itself, i.e., to maximize the control of the fire’s reach, to minimize casualties and property damage. Whether it is a firecracker factory, a dock building, or a shipyard, the smaller and more concentrated the fire-causing area is, the more controllable the consequences are, and the less damage is done. This is influenced by the objective relationship between early fire load limitations and overall high fire vulnerability, but also by the fact that the sparse urban space allows sufficient buffer zones for the spread of fires in some industrial buildings.

At the present stage, due to the more complex urban environment and the large number of land resources occupied by urban construction, the buffer zone between the industrial heritage and contemporary settlements no longer exists, and fires can easily burn from the industrial to the residential concentration, i.e., from the concentration of objects to the concentration of people, resulting in incalculable losses. From the above analysis, we can also see that at this stage, the fire load, both in terms of capacity and quantity, has shown a variety and complex development trends. Narrow streets, limited access to fire engines, and insufficient open space in cities are factors that give rise to major risks of fire spread. Analyses of fire vulnerability in industrial heritage have revealed a general progression from medium to high risk. Although the level of firefighting technology and equipment has been qualitatively improved at the present stage, when facing the problem of fire prevention in industrial heritage, how to extinguish fires at the point of origin, i.e., actively adopting measures to reduce the risk of fires occurring, is the most urgent task of firefighting in Macau’s industrial heritage at the present stage.

4.3. Fire Prevention Techniques and Strategies for Industrial Heritage: From Reactive Prevention to Proactive Measures

4.3.1. Summary of Early Passive Fire Protection Techniques for Industrial Heritage

The early years of Macau’s industrial heritage were characterized by a diversity of fire-influencing factors, the uncertainty of fire loads, and low fire vulnerability, which, together with the usual absence of automatic fire detection systems and automatic fire extinguishing systems, made it difficult to detect and control the occurrence and development of fires promptly. It was determined that the center of gravity of firefighting at that time was dominated by the control of the disaster-causing area, i.e., the use of physical containment measures as the main means. In terms of subject participation, the best way of firefighting in the early industrial heritage relied mainly on human activity, focusing on the distance from the fire station to ensure that firefighters could reach the fire scene with the fastest possible maneuverability. To this end, the research team summarized the measures for the early physical defense of Macau’s industrial heritage against the effects of fire-causing hazards.

Firstly, rammed earth walls stop explosions and keep out fires. Macau rammed earth wall is composed of slaked lime, glutinous rice flour, and yellow mud, as well as aggregates (usually sand and gravel), with sugar water as a binder. The main practice is to use wooden boards to set up the enclosure, each time putting about 10 cm of mixed soil, using a wooden square to force downward tamping, and adding a layer of mixed soil. This is pushed forward until it is rammed to a certain height and hardness. The rammed earth walls formed in this way have good thermal insulation, fire and wind resistance, etc., and are widely used in Macau. Examples include the walls of the Macau Fortress and the Old City Wall. For instance, the historical photos of the Kwong Hing Tai Firecracker Factory clearly show the location of the rammed earth wall (Figure 11). The site’s status of the early Iec Long Firecracker Factory is still visible in several rammed earth walls. However, the difference is that, in addition to the rammed earth wall as part of the building enclosure structure in the firecracker factory, between the buildings, there is an independent masonry height of about 2.2 m on the top of the narrow point below the width of the rammed earth wall chapter. Because the rammed earth wall is inert to blast damage, it can block the radiation surface of the firecracker explosion and prevent the spread of fire (Figure 12). In addition, rammed earth walls are used as partition walls in some shipyard areas, also to control the extent of fire damage.

Secondly, the use of isolation zones to prevent prolonged burning. The establishment of fire separation zones can effectively slow down the spread of fire, provided that sufficient space is reserved at the beginning of the building design. The Macau Firecracker Factory and the Dock Building Industrial Heritage have reserved buffer space from the beginning of the design, from the plan layout, and between the functional rooms. In addition to the rammed earth walls separating the buildings in the firecracker factory, the distance between them effectively prevented the expansion of the fire. The dock buildings were also constructed with a space distance of 3–4 m between them (Figure 13), forming a theoretical fire buffer zone and facilitating the passage of goods vehicles.

Thirdly, firewall design. The design of firewalls is relatively simple compared to the early Macau Industrial Heritage. For example, the main structure of the walls of the firecracker factory buildings and the dock buildings was changed from brick and wood structures to concrete or reinforced concrete structures with higher fire resistance ratings, so that the good performance of the fireproofing could control the influence area of the indoor fires and buy more time for the arrival of fire trucks.

The fourth is the proximity of water sources to facilitate the use of water in disasters. Due to the insufficient number of fire stations in early Macau (

Table 5. The number of Macau Fire Stations in different periods.

Times	1912	1927	1954	1986	2024
No. of fire stations	3	4	2	3	10

Source: Author’s statistics.

; see Appendix C for details) and the fact that fire engines were mainly simple water trucks or small tankers, the ability to collect water for firefighting was limited. Therefore, proximity to water sources was the first choice for the location of industrial heritage in Macau. In the case of the dock building, the firecracker factory, and the shipyard, on the one hand, water is an essential resource for industrial production and life, and on the other hand, proximity to water prevents the dilemma of having to fetch water for firefighting. In the case of the firecracker factory, a waterway was dug at the time of construction to bring water from the surrounding area into the factory.

The above study shows that firefighting in the early days of Macau’s industrial heritage relied not only on a focus on limited facilities but also tended to favor human cooperation. The equipment was generally hand-cranked fire extinguishing pumps, sand buckets, hook-sharp knives, scaling ladders, and other traditional firefighting tools (Figure 14). Special attention is paid to controlling the scope of fire causation in the pre-fire stage, fighting for firefighting time, intervening, slowing down, and blocking the disaster to the greatest extent possible. These are the obvious characteristics of passive prevention.

4.3.2. The Positive Effect of Proactive Measures on Preventing Fires in Macau’s Industrial Heritage

Currently, urban development and the iterative updating of technology have raised the current level of fire prevention in Macau’s industrial heritage, with the center of gravity of fire prevention migrating from an early focus on the impacts of disaster to the reduction of the point of origin of the fire. Modern technological tools are constantly involved in the fire prevention work of Macau’s industrial heritage. Full use is made of the characteristics of building materials and the land environment to improve the resilience of building fire protection, thereby improving the environmental performance of the living landscape [54]. To this end, the research team compiled a list of current fire prevention tools and analyzed the benefits and risks of such tools for Macau’s industrial heritage.

The current fire protection measures in the Iec Long Firecracker Factory, the dock Building, and the shipyard are uniformly set up by the city’s fire protection regulations, with no major differences in facilities between buildings. This differs from the earlier situation where fire protection measures varied according to type.

Firstly, front-end warning devices, fire hydrants, and pipes are installed at a fixed distance. An alarm bell warning is currently the most frequently arranged equipment in Macau’s industrial heritage, which shows the importance of front-end warning of the source of the fire. With the early alarm bells needing to be manually struck differently (Figure 15), the alarm bells are set up indoors generally about 1.6 m above the ground, and those outdoors will be relatively higher, about 2.2 m, to be used the first time fire is detected and to maximize the range of sound diffusion. After the alarm warning, in addition to the standing fire extinguishers, fire hydrants and fire pipes are the first sources of water to extinguish the fire. Fire hydrants in Macau are also known as fire hoses, and fire pipes are installed both indoors and outdoors in industrial heritage buildings. There are “goose-head” hydrants and T-shaped hydrants on the interior and exterior walls, which can provide the necessary emergency response support to the relevant personnel at the initial stage of a fire.

Secondly, fire stations and fire engines. The number of fire stations in Macau has increased from 3 in the early days (1912) and 4 in 1956 to 10 nowadays, and their distribution has also been established from the centralized areas of the city to the peripheral areas. The increase in the number of fire stations and their distribution means that the mobility of Macau’s firefighting industry has increased, and the accessibility of front-end firefighting is higher. Coupled with the modernization and improvement of the fire engines, they have gotten rid of the insufficient water-carrying capacity of the earlier apparatus such as wooden manual pumps, hand-operated water pumps, and old fire pump trucks (Figure 16). The current fire trucks carry a one-time water volume of 10–30 tonnes but are also equipped with a variety of types of foam fire trucks, effectively solving the problem of timely access to water, but also conducive to quickly cutting off the point of fire origin. This enables a more flexible response to the changing fire situation.

Thirdly, intelligent firefighting and human initiative. Intelligent firefighting in Macau’s industrial heritage is mainly based on the automatic identification of fire sources by mechanical equipment, synchronized remote alarms (connected to fire stations), and timely intervention to extinguish fires. Specifically, it includes automatic smoke detectors, heat detectors, and automatic sprinkler systems, which are widely used in the renovation and upgrading works of shipyards and firecracker factories. When a fire occurs, a smoke detector, an intelligent firefighting system, will instantly feed back on the fire situation to the nearest fire station and synchronously activate the automatic sprinkler system to extinguish the fire. Of course, this set of equipment is currently only applicable to water fire extinguishing scenarios; other scenarios need to rely on human initiative. From this point of view, to strengthen fire prevention, the role of people should not be ignored, including personnel training in fire emergency simulation, skilled use of firefighting equipment, organizing collective evacuation, and having the ability to identify combustible materials and deal with the initial fire situation. Unfortunately, although there are relevant emergency escape exit signs in these existing Macau Industrial Heritage buildings, no evacuation floor plan for a comprehensive fire response was found, and the level of human judgment, supervision, and organization of firefighting and escape needs to be improved.

With the front-loading of fire prevention measures for Macau’s industrial heritage, reducing the point of origin of fires is currently the most important means of control. With the help of modern technology, proactive prevention is both an important reflection of the historical value of preserving industrial heritage and a consensus on regional fire protection.

5. Discussion: Functional Transformation of Macau’s Industrial Heritage to the Adaptation of Firefighting Methods

Macau’s industrial heritage has evolved from its early focus on practical functions to its current use as a venue for performances and exhibitions, highlighting the cultural value of the heritage. This process of firefighting technology from the initial use of limitations to the current focus on proactive prevention is an inevitable trend in the development of urban firefighting methods. At the same time, due to Macau’s urban expansion, new industrial forms were born, with the gaming and tourism industries serving as the pillar industries, and the original industrial space gradually disappeared. The previous industrial chain of production–transport–traffic has been broken, and the specific functions of the firecracker factory, dock, dockyard, etc., have changed dramatically. For example, the firecracker factory now serves as an exhibition space, the shipyard as the cultural and creative bazaar of Macau, and some of the piers as the transshipment of goods operations such as fisheries, which are independent of each other and form their systems. The transformation of these new functions has had a variety of impacts on fire risks. (1) Population density and behavioral changes: As an example, exhibition spaces (such as those converted from firecracker factories) typically attract more tourists and visitors, and the flow of people is relatively frequent. They may engage in unsafe behaviors such as littering cigarette butts and illegally using electrical appliances, which increases the possibility of fire. Cultural and creative markets, which have been converted from docks, as well as docks used for fishery cargo operations, are likely to increase man-made fire hazards due to the increased complexity and volume of personnel activities. (2) Electrical equipment and wiring: A large number of electrical facilities, such as lighting and multimedia equipment, may be required in exhibition spaces, thereby increasing the electrical load. If the wiring is unreasonable or the equipment is aging, it is simple to cause electrical fires. Temporary stalls in cultural and creative markets may randomly pull wires, increasing the risk of electrical failures. (3) Goods and storage: Fishery cargo transit terminals store a large number of flammable and perishable goods, such as dried fish and fishing nets. Improper storage or handling of these goods may cause fires. (4) Activities and use of fire: Cultural and creative markets may have live performances, catering stalls, etc., which involve the use of open flames and flammable decorative materials, increasing the risk of fire. The emergence of these new functions has altered the characteristics and intensity of fire risks, necessitating adjustments and optimization of the corresponding fire prevention measures to safeguard life and property. The key considerations are as follows: (1) Firefighting facility renewal: It is necessary to re-evaluate and reconfigure firefighting facilities in places with changed uses, taking into account the new functions and fire risks. For instance, we need to equip exhibition spaces with more smoke detectors and automatic fire extinguishing systems, and equip fishery transit terminals with fire extinguishing equipment capable of extinguishing grease fires. (2) Safety exits and evacuation routes: Considering the changes in population density, it is necessary to re-plan and ensure sufficient numbers and widths of safety exits and evacuation routes to meet the needs of emergency evacuation. (3) Staff training: It is important to strengthen fire safety training for staff in new functional places to enhance their understanding of fire risks, fire prevention, alarms, and initial firefighting methods. (4) Formulate a special emergency plan for each independent new function, which should include personnel evacuation routes in the event of a fire, coordination with external rescue forces, and other necessary measures. (5) Fire separation: Since each is independent and self-contained, it is necessary to strengthen the fire separation between different functional areas to prevent the spread of fire between areas.

Therefore, from the above discussion, the research team can further conclude that, in the face of changing industrial demands and real problems, a complete firefighting response strategy should be established for the firefighting of Macau’s industrial heritage, i.e., the formation of a firefighting technological ecology that is fast-responding, strongly mobile, and high-efficiency. The study concluded that a complete fire technology ecosystem includes five processes: “routine maintenance—front-end early warning—rapid maneuvering—efficient fire suppression—effective (aftermath) management” (Figure 17). It is worth explaining that this is a closed-loop technology ecosystem.

First, routine maintenance addresses the issue of human awareness of fire prevention and eliminates the occurrence of fires due to negligent human behavior. The allocation and number of human resources, regular fire training, and expertise in fire suppression are closely related to the fire safety of the site. At the same time, the fire load and resources are equipped. The resources here refer to the firefighting media on the one hand. On the other hand, a census and strategic response to the location of objects of value in the building and their protection is based on a heritage conservation perspective. Clearly labeled evacuation routes, clearly defined entrances and exits, inspection plans, firefighting objectives, and the assessment of potential hazards are macro measures for firefighting in industrial heritage.

Second, front-end warning can detect fire in time and carry out firefighting work in the first instance, effectively blocking the further spread of the disaster and buying time for the arrival of firefighters. Therefore, the distance between the site and the fire station is also a necessary consideration in daily maintenance. Of course, the level of intelligence and automation of early warning can get rid of the dependence on human beings and inform the fire situation in time in the current heritage protection work.

Third, rapid maneuvering is for firefighting accessibility, which depends on the availability of firefighting equipment on site, such as hydrants and water sources. The effectiveness of rapid maneuvering is based on the timeliness of the front-end warning, and the two are positively correlated.

Fourth, efficient fire suppression relies on the synergy of multiple forces. This includes timely feedback of fire information from site managers, selection of firefighting options by firefighting professionals, and on-site management of the fire area to minimize casualties and property damage.

Fifth, effective management consists of two aspects: one is the aftermath of a fire, and the other is the necessary controls to be made for future preventive measures, for example, keeping fire escapes open, reassessing fire loads and fire vulnerability, and identifying possible fire risks. It also considers combining with traditional physical means of fire protection, such as the installation of rammed earth landscape walls, and incorporating them into the routine maintenance. This creates a techno-ecological closed loop of fire protection for Macau’s industrial heritage, leading to the establishment of a relatively effective fire response strategy.

6. Conclusions

Effective firefighting strategies for industrial heritage have been a major issue facing the field. This study traces the development process of fire protection for industrial heritage in Macau. It clarifies the fire load, assesses the fire vulnerability, summarizes the firefighting model, and alleviates the fire safety dilemmas through different strategies in response to the industrial context of different periods. With a dynamic development perspective, the study synthesizes the transforming characteristics of industrial heritage functions on fire protection needs, establishes the specific practices of reactive prevention and proactive measures for fire protection in Macau’s industrial heritage, and summarizes the main conclusions of this study.

(1) The protection of Macau’s industrial heritage has gone through three periods of development: the passive firefighting period, the firefighting transition period, and the active firefighting period. Passive fire protection is mainly oriented towards the needs of high-risk industries and compromises made in the context of technological constraints, while active fire protection relies on functional transformation and technological upgrading to make beneficial changes in terms of firefighting awareness, fire extinguishing media, and firefighting accessibility. The transition period of fire protection is not overly analyzed in this paper due to the existence of relatively ambiguous time nodes and the short coexistence phase of traditional technical means and modern fire protection methods, but it is necessary to explain it here. At present, Macau’s industrial heritage is in the period of active fire protection, and there are still many problems with the current fire protection situation, such as the emphasis on fire protection regulations, safety distances, fire protection accessibility, and the use of smart fire protection in dock buildings.

(2) The origin of fires in Macau’s industrial heritage varies in content and emphasis from one period to another. In the initial period, it was relatively easy to judge the fire load by the simple traditional industrial methods of production, transportation, and processing. However, with the increase in objective factors such as functional use, equipment demand, material materials, staffing, etc., the assessment of fire loads, especially mobile fire loads, is relatively more complicated and the resulting fires are unpredictable. The biggest factor in this change is the qualitative change in the function of industrial heritage. The Iec Long Firecracker Factory and Lai Chi Vun Shipyards have changed from producers to city exhibition halls, shifting their focus from production profits to the safety of people’s lives and property. This is in line with the new requirements of Macau’s cultural and tourism development, as well as an important manifestation of the positive shift in the focus of fire protection.

(4) We urgently need to establish a systematic firefighting model, taking into account the characteristics of traditional firefighting methods and the innovation of modern firefighting technology, without abandoning the traditional firefighting form. The design of isolation belts, fire walls, and rammed earth walls is still the most effective and economical firefighting method. This can be considered a priority in places with a relatively sparse population density. However, for buildings such as docks in relatively densely populated downtown areas, modern active firefighting technology should be the first choice.

(5) Macau’s industrial heritage is generally in a medium-to-high state of fire vulnerability. Compared to the early firefighting situation, the challenges associated with fighting fires have only escalated. Therefore, by establishing an urban firefighting space, building a firefighting technology ecosystem that includes daily maintenance, front-end warning, rapid mobility, efficient firefighting, effective (aftermath) management, etc., will help to assess and predict fire risks in advance. This way, we can deal with new problems and difficulties in the fire safety of Macau’s industrial heritage.

Finally, it should be recognized that the high-value cultural attributes of the place are an important element in the future intensification and diversification of experiences in the tourism industry of Macau. For this reason, a proactive approach should be taken to avoid the cultural loss of industrial heritage due to fires. The next step of the study will be to quantify the fire risk level of the industrial heritage based on the combination of the value of the specific industrial heritage and the probability of fire occurrence and to propose differentiated fire prevention recommendations. In this way, we can prevent fires from occurring at the root of the problem and maintain and protect the landscape of Macau’s industrial heritage.