A. Site exhibition

In terms of the site exhibition, while the mechanical devices in the forging workshop have been shut down for many years, they have not been damaged, and it is possible for many machines to resume operation. The spring coiling machine (A13) and the forging hammer (A32) are representative of the machines, and are expected to perform manufacturing activities in the in situ exhibition. However, the above studies of the processes show that the helical spring billets must be heated at a high temperature of hundreds centigrade before winding. In addition to workpiece heating, the sound produced during forging is more than 100 decibels; hence, the operation mode must be adjusted to accommodate the performance in the museum. For example, if the wire billets for coiling springs are changed to tin or other soft metal, the cool coils can be directly made without heating, which

can also reproduce the production process and the shapes of the finished products, although the finished products will have none of the functions of shock absorbing springs. In addition, many forging hammers are driven by steam, thus, boilers that produce steam are needed, and fuels, exhaust emissions, and other relevant problems of boilers shall be considered. However, according to the results of the object study, there is a forging machine (A28) driven by electricity, and it will be given priority if demonstration cooperation is required.

## B. Computer models and animations

Due to the limitations of machine restoration, the computer-aid techniques had been widely applied to the research and exhibitions of industrial sites, such as 3D reconstruction, animation, and virtual reality. With the help of the techniques, the visitors are able to jump out of a plane perspective and observe the full picture of the field and the details of each machine. Moreover, the analysis in the area of mechanism and materials are also helpful to realize the technology level in the ancient period, and their educational potential is clearly shown [7–12,17–21].

In this study, 3D simulation models are established with the assistance of computers, in order to record the functions, appearances, and locations of the machines and tools in the forging workshop in detail, as shown in Figure 22b,c. Moreover, in cooperation with the historical photo (Figure 19) and the present situations of the workshop (Figure 20), 3D images can also be used for visitors to understand the information of the on-site objects, such as production roles, production procedures, mechanical principles, and operation modes. In this study, the simulation models of the machines are established from the perspective of mechanical engineering, which is helpful to clarify the machines' operational principles and improve the accuracy and rationality of the models, as based on the background knowledge of the mechanical processes. The results will be helpful to the subsequent animation production, which is expected to show reasonable working methods in the workshop, including the animations of mechanical operations and parts production.

#### C. Experience activities

The large machines in the workshop are dangerous in operation, thus, even if they can be restored for demonstration, it is not suitable for visitors to operate practically. Hence, this study intends to make scaled-down machines, and reduce their forces and speeds correspondingly, in order that a miniature table production line can actually work with electricity or air compressors. This activity takes the abovementioned machine parts manufacturing process and the motion relationship between the parts, as clarified by 3D models, as the reference. By operating miniature machines, visitors can experience the original process of the forging workshop to make machine parts.

With various experience activities, in addition to the function of education, the public's understanding of the Taipei Railway Workshop will be enhanced, and public attention and interest in Taipei Railway Workshop will be aroused. Moreover, the public's review rate will be improved according to the experience of various themes in different periods, and cultural heritage can be preserved and sustainably developed.

**Figure 22.** Computer-aided 3D models. (**a**) Part of machines in shaping area and forging area, (**b**) shearing machine (A22), (**c**) steam hammer (A45).

## **5. Conclusions**

The Taipei Railway Workshop was in operation from 1885 to 2011, and reflects modern history, railway construction, and the mechanistic technology development processes of Taiwan, and thus, has significant cultural and technological value. After its shutdown, planning started to change the Taipei Railway Workshop from a machine plant to a railway museum; therefore, this study conducts object investigation and exhibition planning for the forging workshop.

In addition to searching literature, this study interviewed retired workers, and focused on the interviewees' working processes in the forging workshop, with particular attention paid to the manufacturing technology of train bogies and metal springs. Moreover, this study registered 85 items stored in the forging workshop, including machines, tools, and peripheral accessories. Regarding the forged parts, by considering their mechanical manufacturing procedures and cooperating with the site environment, the roles that the machines and peripheral objects played in the production of train parts are connected in accordance with the order of use. Moreover, the experiences and descriptions of site workers are integrated into the object research by referencing the interviews and survey results. In terms of object research, this study clarifies the manufacturing processes of helical springs and leaf springs in the forging workshop, as well as the site, machines, and configurations of spring manufacturing. Regarding the oldest machine, the information about the steam hammer made in 1889 coming to Taiwan is still being traced.

In situ preservation efforts are focused on preservation with the minimum intervention or permanent use. The features of the railway industry in the Taipei Railway Workshop are saved through maintaining, studying, and exhibiting the in situ museum, in order to complement the historical jigsaw of Taiwan's industrial and transportation developments. Moreover, the benefits received from exhibitions and activities will be used to maintain the museum, in order that the life of this industrial site can be sustained and cultural heritages can play their valuable roles and be sustainably managed.

**Author Contributions:** Data curation, C.-T.W., C.-L.L., Y.-R.C., and K.-H.H.; formal analysis, Y.-H.C., G.-C.C., C.-T.W., C.-L.L., Y.-R.C., J.-F.H., and K.-H.H.; funding acquisition, J.-I.L.; investigation, C.-T.W., C.-L.L., and K.H.H.; methodology, Y.-H.C., G.-C.C., and K.H.H.; project administration, G.-C.C., C.-L.L., K.-H.H., and J.-I.L.; resources, J.-F.H. and J.-I.L.; supervision, J.-I.L.; writing—original draft, Y.-H.C.; writing—review and editing, Y.-H.C. and G.-C.C. All authors have read and agree to the published version of the manuscript.

**Funding:** This work is funded by the Ministry of Culture (Taipei, Taiwan) and the Taipei Railway Workshop (Taipei, Taiwan) under the approved document, No. 1081023005, entitled "Investigation and Research on the Forging and Metallurgy Shop and the Engine Room of Taipei Railway Workshop."

**Acknowledgments:** The authors are grateful to the assistance provided by the Taipei Railway Workshop and Taiwan Railway Administration, especially Fugang Vehicle Depot (Taoyuan, Taiwan), Kaohsiung Railway Workshop (Kaohsiung, Taiwan), the respondents Shi-Zhou Lin, Tsan-Huang Liu, Qiu-Long Chen, Ming-Zhou Kang, Jiang-Lang Chen, and Ming-Hsun Hsieh. We would like to thank the following people who participated in this survey: The conservators Jiong-Gang Ruan and Yun-Ru Huang, the scholar Yu-Yu Huang, the assistants Bo-Hong Lin, Hao-Tian Gu, Zhen-Yu Wang, Xuan-Zhan Chen, Jung-Fang Cai, Hong-Yan Gu, Yu-Yan Li, Wan-Rong He, Chia-Ling Chen, Yen-Wen Wang, Yu Tao, Yu-Qi He, Chao-Chen Chang, Cheng-En Lee, and Hsuan-Ming Wang.

**Conflicts of Interest:** The authors declare no conflict of interest.
