Comparative Studies of Major Sea Routes

Abstract

A large amount of cargo is transported between European and Southeast Asian countries. Ships sometimes take different routes when sailing between ports due to the best commercial speed; navigational, economical, and hydrometeorological conditions; and political and military situations. Several routes are available for sailing between Europe and Southeast Asia: sailing the Suez Canal, sailing around the African continent, sailing the Panama Canal, as well as sailing the Northern Sea route. This article analyzes the possible sailing routes between Southeast Asia and Europe and presents a developed methodology for the evaluation of sailing routes. This sea route evaluation methodology is based on a comparative mathematical model that evaluates the main factors of cargo transportation by sea: transportation cost and time, possible maximum ship parameters, transportation energy (fuel) demand, and other possible factors, such as the probability of various restrictions. This paper presents a case study of cargo transportation between Rotterdam (The Netherlands) and Shanghai (China) using different possible sea routes. Assessments of various possible routes are presented; the main topics of discussion and conclusions are formulated.

1. Introduction

The maritime transport of goods is a very important part of global logistics, and most of the world’s exports and imports are transported by sea vessels, especially between the main economic locations of Southeast Asia, North America, and Western Europe. In this way, sea routes are very important for the world economy and global logistics [1,2].

The choice of ship routes, if there are possible alternatives, depends on many factors, such as navigational safety of shipping; safety of the whole ship; hydrometeorological conditions; conditions of navigational equipment; and various navigational, economic, and political restrictions [3,4]. There are several important industrial zones in the world, between which intensive transportation of large quantities of goods takes place. Several such important regions can be singled out: North America, Southeast Asia, and Western Europe. Among the aforementioned regions are several global shipping regulatory sites, such as the Suez and Panama Canals. Also, other very important sea routes can connect the mentioned industrial areas; these are the sea routes around the African continent, as well as the Northern Sea route and the Northwestern Sea route, and the discussion of which is very important [5].

The analysis of the aforementioned main sea routes and their application to the transportation of large cargo flows is important. By the beginning of 2024, about 13 percent of the world’s export and import goods were transported through the Suez Canal. The Panama Canal carries relatively large volumes of cargo, and a significant portion of cargo is transported by sea routes around the African continent, especially after the start of the 2024 conflict situation in the Red Sea off the coast of Yemen [6,7].

An analysis of the main advantages and disadvantages of the existing and proposed and potential major sea routes is essential. The Suez Canal is one of the most important sea routes, as it allows for the passage of ships with a draft of up to 18 m and a deadweight of up to 250,000–300,000 tons. The main disadvantages of the Suez Canal are the relatively low sailing speed (up to 12–14 knots, in some places lower), rather long waiting time for ships, and the one-way (single) movement of ships in individual sections of the canal. There is always a risk of major disruptions in areas with one-way (single) movement of ships, as happened with the container ship ”Ever Given“ in 2021 [7,8,9].

The Panama Canal, after the new locks came into operation in 2016, is very important and allows for the passage of ships up to 365 m long, 50 m wide, and up to 16 m draft. Such container ships have a container capacity of up to 15,000 TEU [10]. The length of the canal is about 82 km, and ships cover this route in 10–12 h, including lock operations. At the same time, we can mention the main disadvantages limiting the use of this sea route: ship size restrictions, i.e., NEW PANAMAX container ships and similar-sized bulk cargoes and tankers are able to pass through; before sailing the Panama Canal for the first time, additional time is required to complete the procedures for obtaining the Panama Canal certificate—this takes up to 12–18 h in individual cases (depending on the waiting time); operations in the locks are complex and require very precise actions and the use of tugs, which also require additional costs [10,11,12,13].

A common advantage of the Suez and Panama channels is their geographical location, i.e., no very frequent storms or ice conditions, and great experience of canal administration staff [14].

When sailing around the African continent, the parameters of ships are not limited, i.e., ships of all sizes can use this sea route. The main disadvantages of this sea route are the hydrometeorological conditions in the southern parts of the Indian and Atlantic Oceans (around the southern Horn of Africa), where storms often occur and extremely large waves are encountered, which make it difficult for ships to navigate, often requiring a reduction in the speed of sailing ships, and due to the large swaying of ships, increases ship safety and cargo damage risks. Due to the increased distances between the coastal ports of Southeast Asia and Europe and the East American continent (compared to sailing through the Suez Canal), the time of goods transportation and the cost of transportation increase [15].

The Northern Sea route has only one advantage because the sailing distance between ports in Southeast Asia (Shanghai, Nimbo, Buasan, etc.) and Western Europe (Rotterdam, Hamburg, Antwerp, etc.) is shorter compared to the sea routes through the Suez Canal, Panama Canal, or around the African continent [15]. The Northern Sea and Northwestern Sea routes were highly promoted as early as a decade ago, but without theoretical and small practical tests, especially in container shipping, nothing has been achieved [16,17]. At the same time, the Northern Sea route has many disadvantages: ships sailing on this sea route must have an ice class, and usually a reinforced ice class; the help of an icebreaker must be used, which increases the cost of transporting goods; the sailing speed of ships from the Bering Strait to the gateway to the Kara Sea with or without icebreaker escort is relatively low, which significantly increases the sailing time and at the same time the advantage of sailing distance becomes insignificant compared to the sea route through the Suez Canal, and during the winter period (from November until May) sailing times of ships become similar; the main waterway (from the Sea of Japan to the Barents Sea) has practically no ports and even minimal service (if necessary); and there are limited ship parameters (can sail only up to PANAMAX-type ships).

In this way, the assessment of sea routes and a convenient, multi-factorial, and, at the same time, easily applicable methodology are very important from both a theoretical and practical point of view, and this article is focused on the creation of such a methodology. The main factors that are taken into account when comparing sea routes are the following: transportation costs, transportation time, possible maximum ship draft, request of transportation energy (fuel), ideal (best) seaway factors, correlation coefficients, factor weight coefficients, and other possible factors. Conducted theoretical and experimental research, especially the navigation of ships on the Northern Sea route, allow us to evaluate the advantages and disadvantages of different sea routes and at the same time search for optimal solutions for transporting goods between very important economic regions, which is the innovativeness and novelty of this article.

The novelty and innovation of this paper is the creation of a Benchmark index of major sea routes and its application to the assessment of sea routes, as well as a broader and more accurate assessment of individual sea routes, especially the Northern Sea route. The novelty of the comparative index assessment methodology is based on technical, economic, shipping safety, and environmental impact factors, which makes it, using the Benchmark index, a universal means of assessing sea routes. The main factors mentioned above, as well as additional factors such as technical service, ship supply capabilities, and other factors, are taken into account for the Benchmark index calculations.

The developed methodology can be used to evaluate other sea routes, adapting it to specific conditions.

2. Analysis of the Main Sea Routes Situation and Review of the Literature

Sea routes connecting the main economic regions of the world are very important for the development of economic relations and influence the development of the world economy [1,4,14]. The main global sea routes have their advantages and disadvantages, so it is very important to study them not only as economic “engines” but also to study their risks and disadvantages. Figure 1 shows the main sea routes of the ships sailing in the world, including the main shipping routes between Southeast Asia and Europe via the Suez Canal, around the African continent, the Panama Canal, and the North Sea route [18]. The main sea routes and distances between the primary Southeast Asian port of Shanghai and the European port of Rotterdam are [19]:

• Via the Suez Canal (distance about 10,800 n.m.);
• Around the African continent (distance about 14,100 n.m.);
• Via the Panama Canal (distance about 14,000 n.m.);
• Using the Northern Sea route (distance about 9000 n.m.).

Land (railways) or combined (sea transport to Russian or Iranian ports and railways) routes can also be used, using the Trans-Siberian railway or the railways of China, Kazakhstan, Transcaucasia, Russia, and Central and Western European countries. The main problems in using the possible specified transport corridors are associated with additional cargo transshipments, insufficiently developed land transport infrastructure for the transportation of large cargo flows between the selected regions, and, in many cases, political problems.

The analysis of sea routes combines many factors, the most important of which are the economic and world trade situations [1,2,7,11,15], the safety of ships and shipping as a whole [3,6,9], navigational and hydro–meteorological conditions [16], energy (fuel) consumption on a specific sea route [20], environmental impact assessment [21,22,23,24], and others.

The sea route through the Suez Canal has been in operation since the middle of the 19th century and has been reconstructed several times in the last 150 years, and it currently allows for the passage of ships of unlimited length, a width up to 75 m, and a draft up to 20 m [21] (Figure 2). For the analysis of the situation, it is appropriate to take the major port in Southeast Asia, Shanghai, and in Western Europe, Rotterdam. The distance between the specified ports is about 10,800 miles. With ships sailing at an average speed of 18 knots, the sailing time is about 600 h (without intermediate port calls). The sea route through the Suez Canal is also important because it passes through relatively good geographical and hydro–meteorological conditions. The main drawback of this sea route is the unstable political situation in the regions of the Red Sea and the Suez Canal, and as a result, navigation is complicated or stopped [21,22].

A significant disadvantage of the Suez Canal is that until now, individual parts of the canal are one-way (Figure 3), and in the event of a navigational accident in such a part of the canal, as happened in 2021, the movement of ships in the canal is completely halted [7,8].

The sea route around the African continent is important because, in theory, there are no special navigation restrictions and it can be used by any vessel. The total distance from Shanghai to Rotterdam is about 14,100 nautical miles, and if the ship can sail at an average speed of 17 or more knots, which is acceptable for large container ships, the sailing time is about 780 h. At the same time, the sea route around Africa has serious disadvantages related to hydro–meteorological conditions since, in the southern parts of the Indian and Atlantic oceans, there are frequent storms, and there is a high probability for ships to encounter particularly strong waves [25]. Extremely large waves are dangerous for smaller ships, as well as dangerous for large ships and their cargo [25].

The sea route between Shanghai and Rotterdam via the Panama Canal is also used to transport cargo between Southeast Asia and Western Europe. The total distance between Shanghai and Rotterdam is about 14,000 nautical miles, and at an average speed of about 18 knots, the average sailing time for such ships is about 790 h, taking into account the reduced speed of the ship through the Panama Canal itself. The sea route through the Panama Canal has restrictions on the parameters of the ship because the maximum length of the ship when sailing through the Panama Canal is up to 365 m, the width is up to 50 m, and the draft is up to 16 m. Due to limitations in ship length and width, the maximum capacity of such a container ship is up to 15,000 TEU, limiting the use of large container ships in this seaway [10,11].

Currently, attempts are being made to promote the Northern Sea route as an alternative to other sea routes [16,26]. The total distance on the Northern Sea route from Shanghai to Rotterdam is about 9000 nautical miles. For about 2500 nautical miles, ships navigate the Arctic Ocean, where ships must be accompanied by icebreakers. It is theoretically possible for ships to use this sea route, but in practice, it is quite difficult, especially for large ships; the ships must have an A1 or A1 Super ice class and their container capacity can only reach up to 4000 TEU [27]. Observations of ships sailing on the Northern Sea route using the AIS system showed that the average sailing speed of vessels up to 180 m in length and up to 27 m in beam (excluding purpose-built LNG tankers with Arctic 5 and Arctic 7 ice classes corresponding to the A1 Super ice class) is between 5 and 14 nodes [28].

An analysis of vessel navigation in the Northern Sea route over the past few years using the “Marine traffic” website [18] allowed us to obtain the average number of ships sailing with and without icebreakers (without icebreakers, the sailings of LNG tankers with Arctic 5 or Arctic 7 ice classes were analyzed in summer and autumn months) and their speeds, which were between 4 and 12 knots on average (in the wintertime, they mainly did not use this sea route).

The sailing of two ships “Pugnax” and “Audax” (ship length 206 m, width 43 m) on the Northern Sea route in 2024 in January and February (sailing from the Bering Strait to the northern tip of Novaya Zemlya took 35 days) using the most powerful available icebreakers “50 Let Pobedy” (power plant about 57 MW) and “Arktika” (power plant about 62 MW) clearly proved that larger ships using this sea route are very expensive during the winter period and economically and technically complex. It took about 35 days for these ships to sail with the escort of icebreakers on the Northern Sea route [18]. For example, in 2024, after the sailing of the mentioned vessels in January–February, until the middle of June, the Northern Sea route was not used at all for more than 4 months [18].

In this way, the main sea routes connecting Southeast Asia and Europe are very important and are in fact the “arteries” that transport most of the goods between the aforementioned regions.

3. Theoretical Basis of the Evaluation Sea Routes

Various methods can be used for the analysis of sea routes but comparative methods are the most appropriate as they can be used to objectively assess the advantages and disadvantages of specific sea routes and to evaluate the differences based on selected factors.

3.1. Steps of Research Methodology

The following research methodology steps were used to conduct this study: sea route analysis, literature review, and data collection; mathematical model development; conducting calculations using a developed mathematical model; carrying out experiments on real ships using the AIS platform [18]; drawing up the discussions and conclusions (Figure 4). A mathematical model was created after a literature review and an analysis of sea routes and actual ship routes between Southeast Asia and Western Europe.

The main sea routes are very important for the world economy, but at the same time, for various reasons, they are sometimes restricted or conditions arise when the normal sea routes cannot be used due to natural disasters or for other reasons; for example, the sea route through the Suez Canal being blocked due to political unrest in the Red Sea. In such cases, it is very important to find another sea route.

Based on the presented principal methodology (Figure 4), a theoretical model of sea routes was created and experiments were carried out with real ships. Finally, the theoretical model was improved on the basis of real ships and the experimental results [18]. After determining the possible sea routes, the main factors—transportation costs, transportation time, possible maximum ship parameters (mainly draft), request (use) of transportation energy (fuel), and other possible factors, such as the probability of the restrictions, were calculated to assess the different advantages and disadvantages of each sea route.

The transportation costs are an important factor and market conditions are taken as a basis in transportation processes (transportation prices, which are not always based on the income–cost principle). Transportation time is important in many cases, but in modern production chains, when the arrival of components and other goods is precisely regulated, the transportation time and especially the accuracy of the arrival of goods in relation to time is particularly important. In all sea routes, the possible geometrical parameters of the ships are very important; in many cases, the maximum draft of the ships is possible. Energy consumption (fuel) of ships directly influences the price of transportation, and therefore, relatively lower energy consumption when transporting the same amount of cargo is an important factor and cargo owners and ship operators always pay close attention to this. Other factors, especially those that influence the transportation time, such as political unrest or military conflicts in individual parts of sea routes or difficult hydro–meteorological conditions in individual parts of sea routes, do not allow for the optimization of transportation processes. To evaluate the accuracy of the calculations and experimental results, the maximum distribution method was used using data obtained from real experiments. The maximum distribution method can be applied if at least five measurements of the sea routes’ elements are taken.

In order to verify the accuracy of theoretical calculations and the practical application of the developed methodology, the results of experiments obtained with the help of the Automatic Identification System (AIS) [18] of real ships were used.

Then, the results were analyzed, discussions were planned, conclusions were prepared, and suggestions for further research were presented.

3.2. Mathematical Model

A review of the literature, the available information on the main sea routes and their characteristics, and the navigation of real ships on the main sea routes (the Suez and Panama Canals, the sea route around the African continent, and the Northern and Northwestern Sea routes) were used to develop mathematical models of the efficiency of sea routes. In the development of mathematical models, it was assumed that the largest possible ships navigate specific sea routes. To use the Northern and Northwestern Sea routes requires icebreaker assistance or else ships cannot navigate these sea routes at all.

The types of ships and their geometric dimensions depend on cargo flows and transportation distances. Cargo flows focused on the largest possible ship types, oil and oil products, long-distance bulk transport, and containers transported between the main industrial regions (Southeast Asia, North America, and Western Europe). In this way, a mathematical Benchmark model was created that evaluates the main factors: transportation price and time, possible maximum ship parameters (mainly draft), request of transportation energy (fuel), and other possible factors, such as the probability of the restrictions, and can be expressed by the following formula:

$$I_T={\displaystyle \frac{1}{{\eta }_T}}\left(k_P{\displaystyle \frac{P_T}{P_0}}+k_T{\displaystyle \frac{T_T}{T_0}}+k_D{\displaystyle \frac{D_T}{D_0}}+k_E{\displaystyle \frac{E_T}{E_0}}+k_A{\displaystyle \frac{A_{Ti}}{A_{0i}}}\right),$$

(1)

where ${\eta }_T$—correlation coefficient; $P_T$—transportation costs of the analyzed sea routes; $T_T$—transportation time of the analyzed sea routes; $D_T$—possible maximum ship draft of the analyzed sea routes; $E_T$—request of transportation energy of the analyzed sea routes; $A_{Ti}$—other possible factors of the analyzed sea routes, including environmental impact; $P_0$, $T_0$, $D_0$, $E_0$, $A_{0i}$—ideal (best) sea routes factors; $k_P$, $k_T$, $k_D$, $k_E$, $k_A$—factor weight coefficients.

A general formula for sea transportation can be used to calculate the cost of freight transportation, based on different sources [29,30]:

$$P_T=P_{OTHC}+P_{BAF}+P_{CAF}+P_{ISPS}+P_{WRS}+P_{CONG}+P_{PORT}+P_{THC}+P_{DOC}+P_{IMP/EXP}+P_{S/P}+P_{RF}$$

(2)

where $P_{OTHC}$—sea freight factor; $P_{BAF}$—bunker adjustment factor; $P_{CAF}$—currency correction factor; $P_{ISPS}$—the International Ship and Port Facility Security factor; $P_{WRS}$—war risk factor; $P_{CONG}$—cost of transshipment in ports factor; $P_{PORT}$—port dues factor; $P_{THC}$—terminal handling fee factor; $P_{DOC}$—fee for preparation of documents factor; $P_{IMP/EXP}$—export/import tax factor; $P_{S/P}$—Panama/Suez Canal Fee factor; and $P_{RF}$—fee for connecting the referred container, etc.

The cost of transportation, using Formula (2), must be adapted to the specific conditions of transportation; i.e., part of the ingredients presented in Formula (2) can be omitted or supplemented.

Transit (transportation) times depend on various factors and, similarly, calculating the cost of transportation can be broken down into various time factors depending on the specific conditions of transportation, such as waiting before entering the Panama or Suez Canals, icebreaker waiting time, etc. The following components can be used to calculate the transportation time: the average (commercial) speed of the ship, the waiting time before entering the canals if the Suez or Panama Canals are used, possible interruptions due to weather conditions, technical and organizational problems, and other problems; i.e., the following formula can be adopted for calculating the sailing time of the ship:

$$T_T={\displaystyle \frac{{\eta }_k\left(T_K+T_w\right)}{\left(1-\frac{Q_1}{T_K}\right)\left(1-\frac{Q_2}{T_K}\right)\left(1-\frac{Q_3}{T_K}\right)}},$$

(3)

where ${\eta }_k$—correlation coefficient depends on similar factors or processes and can be taken from 0.95 to 1.0 (if there are no similar factors or processes or only one factor or process is evaluated); $Q_1$, $Q_2$, $Q_3$…—adverse time factors, such as hydro–meteorological conditions, ship maintenance or breakdown problems, and organizational problems while waiting for entry into ports, canals, etc., expressed in days (can be taken from statistical data); $T_w$—average waiting time when entering ports or channels, waiting for icebreaker escort, etc., expressed in days (can be taken from statistical data); $T_K$—the vessel’s commercial sailing time, which can be calculated using the following formula:

$$T_K={\displaystyle \frac{S_S}{v_K}},$$

(4)

where $S_S$—sailing distance of the ship, in nautical miles; $v_K$—commercial vessel speed, in knots.

The possible maximum ship draft of the analyzed sea routes is especially important for certain parts of the sea routes. The limitations of the main parameters of ships, especially the draft of ships, do not allow for the efficient use of cargo transportation by sea.

The required amount of energy (fuel) when transporting goods from Southeast Asia to Europe is important not only from an economic point of view but also from the point of view of environmental impact since fuel consumption and engine working time are directly related to the generated amount of emissions [23,31]. Ship engine power ($N$) and the amount of fuel consumed ($q_f$) over a given period of a ship’s active working time, during which the ship is sailing between ports; time ($t$), e.g., an hour; and the relative fuel consumption ($q_f^{\prime }$) correlate to the following formula, as seen in Refs. [32,33]:

$$N=q_f/\left(q_f^{\prime }t\right)$$

(5)

The fuel consumption of a ship can be calculated using the following formula [34]:

$$q_f=\int q_f^{\prime }{N}_{av}dt,$$

(6)

here, $N_{av}$ is the average engine power of the ship during the sailing between ports.

Emissions from ships while sailing between ports directly depend on the quantity and quality of fuel used, engine power, and engine running time [33,34,35]. The main emissions from ships constitute carbon dioxide ($C{O}_2$), nitrogen oxide ($N{O}_x$), carbon monoxide ($CO$), sulfur oxide ($S{O}_x$), and particulate matter ($PM$) [33,35]. Thus, the carbon dioxide emissions, for example, are calculated according to the following formula [33]:

$$C{O}_2=k_{C{O}_2}{q}_f,$$

(7)

here, $k_{C{O}_2}$ is carbon dioxide coefficient for petroleum products (diesel, fuel oil) is between 3.0 and 3.5, and for LNG, between 2.5 and 2.9.

Other emissions generated by the ship can be calculated using the methodology presented in Ref. [33] or other similar methodologies.

Other possible factors of the analyzed sea routes are mostly associated with political factors, such as sanctions; particularly difficult hydro–meteorological conditions when the navigation of ships becomes too difficult or inappropriate, such as, for example, particularly dangerous waves in the area of the island of Madagascar or the southern Horn of Africa; and by other similar factors.

Weight coefficients of the factors could be defined by calculation methods (in cases where large amounts of data are available), by experts’ methods in cases of limited data, or by other methods. Cases of many relative factor weight coefficients could be similar but in any case, the sum of the weight coefficients must be equal to 1 [36,37].

In this way, using the mathematical Benchmark model presented in this chapter, it is possible to evaluate the parameters of sea routes between Southeast Asia and Europe, and the advantages and disadvantages of specific sea routes.

4. Case Study of the Sea Routes between Southeast Asia and Europe Evaluation

The Port of Shanghai (China) and the Port of Rotterdam (The Netherlands) were selected as the largest ports in Southeast Asia and Europe for a practical evaluation of the major sea routes between Southeast Asia and Europe. Sea routes through the Suez Canal, around the African continent, the sea route through the Panama Canal, and the Northern Sea route were also selected for analysis [38,39].

The length of the sea route that passes through the Suez Canal is about 10,800 n.m. and goes through the Pacific and Indian Oceans, Red Sea, Suez Canal, Mediterranean Sea, Atlantic Ocean, English Channel, and the Northern Sea [18,19] (Figure 5).

When ships sail at an average (commercial) speed of about 14 knots (bulk carriers) or about 17 knots (container ships) [40,41], and adding the additional waiting time for passage and the sailing time itself through the Suez Canal, the total sailing time for bulk ships is about 33 days, and for container ships about 27 days. Evaluating the capacities of energy devices of bulk cargo and container ships, a bulk cargo ship consumes an average of about 2400 t using petroleum product fuel, while a container ship consumes about 3050 t using petroleum product fuel, on average [42,43]. According to the available statistical data, the average cost of transportation of one container is around EUR 1500 [44]. At the same time, the Suez Canal has restrictions on ship parameters, which are as follows: ship length up to 450 m, ship width up to 75 m, and ship draft up to 19 m. In this way, G-class container ships currently in operation and under design can use the Suez Canal. The main problem with the Suez Canal is the unstable political situation in the Red Sea and Suez Canal area, for example, and from the end of 2023 until now (middle of 2024), ships and especially container ships avoid sailing through the Suez Canal and mostly choose the sea route around the African continent. In terms of emissions generated by ships [45,46], a conditional bulk carrier generates about 7700 t of carbon dioxide using petroleum product fuel, or about 5500 t using LNG fuel. A container ship currently generates about 9800 t of carbon dioxide when using petroleum product fuel, or about 7000 t when using LNG fuel [33].

The sea route around the African continent, which is currently chosen by most container and other ships due to the insufficient safety of ships in the Red Sea, is about 3300 miles longer than via the Suez Canal and is about 14,100 nautical miles [18,19] (Figure 6).

The sea route around the African continent goes through the Pacific, Indian, and Atlantic Oceans; the English Channel; and the Northern Sea. Considering the commercial speeds of ships (bulk carriers about 14 knots and container ships about 17 knots, respectively), the sailing time of bulk carriers is about 42 days and the sailing time of container ships is about 35 days. The average energy (fuel) consumption per average bulk cargo per ship is about 2800 t using oil product fuel and the energy (fuel) consumption of an average container ship is about 4900 t using oil product fuel [42,43]. The current market price of one container on this sea route is about EUR 2200 [44]. The sea route around the African continent does not have any limitations of ship parameters, but very complex hydro–meteorological conditions are often encountered in the southern part of India (Madagascar island region) and the Atlantic Ocean in the region of the southern tip of Africa. In terms of emissions generated by ships, a conditional bulk carrier generates about 9000 t of carbon dioxide using petroleum product fuel, or about 6500 t using LNG [45,46]. A container ship currently generates about 15,000 t of carbon dioxide when using petroleum product fuel, or about 11,200 t when using LNG fuel [33].

The sea route through the Panama Canal is not currently widely used by ships that sail between Southeast Asia and Europe, but this route could potentially be used [18,19] (Figure 7).

The sea route via the Panama Canal has a length of about 14,000 nautical miles; assuming the commercial sailing speed of ships indicated above (14 knots for a bulk carrier, 17 knots for a container ship) and considering the average waiting time of ships, for sailing through the Panama Canal (about 10 h), the total sailing time for a bulk cargo ship is about 42 days, and for a container ship about 35 days. During navigation, an average bulk carrier that can navigate the new locks of the Panama Canal consumes about 2900 t of petroleum product fuel, while a container ship uses about 5000 t of petroleum product fuel [42,43]. The cost of transporting a container by this sea route is about EUR 2200 [44]. The main limitation of ships using the sea route through the Panama Canal is the limited parameters of the ships, i.e., length of ships up to 365 m, width of ships up to 50 m, and draft of ships up to 15.5 m [47]. In terms of emissions generated by ships, a conditional bulk carrier generates about 9200 t of carbon dioxide using petroleum product fuel, or about 6600 t using LNG [45,46]. A container ship currently generates about 17,000 t of carbon dioxide when using petroleum product fuel, or about 11,500 t when using LNG fuel [33].

The Northern Sea route has recently been widely promoted as the shortest route between Southeast Asia and Europe [18,19] (Figure 8).

The distance between the ports of Shanghai and Rotterdam using the Northern Sea route is about 9000 nautical miles. At the same time, it should be noted that about 2500 nautical miles pass through the Northern Sea route, where ships have to use icebreaker services for most of the year [48]. It prevents them from maintaining the accepted commercial speed of ships; the ships are limited by their parameters, i.e., most vessels could only be up to PANAMAX size (mostly up to 250 m length, up to 30 m beam, up to 12 m draft, except for standard LNG tankers that have Arctic 5 or Arctic 7 ice class); and the vessels must have A1 or A1 Super ice class (which corresponds to no less than Arctic 5 ice class) [16,27,49]. Considering the need to sail with an icebreaker escort, the average sailing time of a bulk cargo ship is about 32 days in summer and about 37 days in winter; the total sailing time of a container ship between the indicated ports in the summer period is about 29 days, and in winter—about 34 days (provided that the ships do not have to wait for icebreaker assistance). At the same time, the average fuel consumption for a bulk cargo ship using oil products fuel in the summer period is about 2000 t, and in winter—about 2400 t [50,51]. The fuel consumption of a container ship is about 3300 t in the summer period and about 4200 t in the winter period [50]. The cost of transporting a container by this sea route is around EUR 2300, and additionally, the costs of icebreaker assistance, which amount to around EUR 300 per container in the summer period and around EUR 400 in the winter period should be considered [28,52]. The main limitations of the Northern Sea route are the ship parameters (ships could only be up to PANAMAX size and must have A1 or A Super ice class), the need to use icebreakers, and the high probability of ship damage due to ice. In terms of emissions generated by ships, a conditional bulk carrier generates about 6500 t of carbon dioxide in the summertime and 7700 t in the wintertime using petroleum product fuel, or about 4600 t in the summertime and about 5600 t in the wintertime using LNG [45,46,53]. A container ship currently generates about 11,000 t of carbon dioxide in the summertime and about 14,000 t in the wintertime when using petroleum product fuel, or about 7700 t in the summertime and about 10,000 t when using LNG fuel [33].

Conducted research on the navigation of ships on the Northern Sea route during the last 5 years in different seasons allowed us to evaluate the average speed of ships in different periods of the year when sailing without the aid of icebreakers (this is mostly performed by LNG standard tankers with Arctic 5 or Arctic 7 ice classes) and with the aid of icebreakers. The average sailing speeds of ships obtained on the basis of 5 years of observations are presented in Figure 9 [18,19].

In 2024, in January and February, ships “Pugnax” and “Audax” sailed via the Northern Sea route from the Bering Strait to the northern tip of the island of Novaya Zemlya using two of the most powerful nuclear icebreakers currently available. The total sailing time on the Northern Sea route was 39 days. The average daily sailing speed from 19 January 2024 to 27 February 2024 using the icebreaker “50 Let Pobedy” and from 2 February 2024 additionally using the icebreaker “Arktika” are presented in Figure 10 and Figure 11 [18,19].

In this way, the Northern Sea route can be theoretically analyzed, but for practical purposes, it is not suitable for connecting the largest economic regions.

In January 2024, a cargo ship (A1 ice class, DWT about 7000 t) sailing the Northern Sea route with the help of a nuclear icebreaker sailed from the Bering Strait to the northern tip of the Novaya Zemlya island (Figure 12) [18]; the sailing time was 14 days, the distance was about 2450 nautical miles, and the average speed was about 7.1 knots.

Using the sea route Benchmarking methodology presented in Section 3, a Benchmark index was estimated by analyzing the four main sea routes between Southeast Asia’s largest port, Shanghai, and Europe’s largest port, Rotterdam. In this way, the following Benchmark indices were obtained using initial statistical data presented in

Table 1. Basic sea routes between Shanghai and Rotterdam data for benchmarking and Benchmark indices.

Sea Routes Data	Sea Route via Suez Canal	Sea Route around Africa Continent	Sea Route via Panama Canal	Northern Sea Route
Total distance, n.m.	10,800	14,100	14,000	9000
Distance with limitations, n.m.	140	-	80	2500
Ship’s speed, kn	17	17	17	17
Ship’s speed on limitation sections, kn	12	-	8	8
Additional waiting time, hours	10	-	10
Total sailing time, days	27	35	35	29
Allowable draft of the ship, m	18	25	16	12
Transportation price per container, EUR	1500	2200	2200	2300
Additional price per container, EUR	-	-	-	300
Fuel consumption (diesel), tons	3050	4900	5000	3300
$C{O}_2$ generation, tons	9800	15,000	17,000	11,000
Benchmark indices	1.16	1.34	1.50	1.60

.

In the calculation, the following factor weight coefficients are taken: transportation price—0.3; transportation time—0.2; ship parameter limitations (draft)—0.3; fuel consumption—0.1; $C{O}_2$ generation—0.1. The correlation coefficient is taken as 0.98.

The Benchmark index of sea routes is important when choosing a specific sea route and when choosing possible freight rates and other factors that may be important in the case of the specific transportation of goods.

5. Discussion and Conclusions

The assessment of sea routes is important in many cases, and in cases where it is difficult to use a normal sea route for any reason, it is very important to be able to compare the used sea route with other possible sea routes (alternatives) in order to estimate the necessary additional transportation costs (transportation time, price, and other factors). For such evaluations, it is very important to have relatively simple but reliable comparative methodologies, so research and practical applications of such methodologies are of great importance to both cargo owners and carriers.

The methodology presented in this article was tested many times after the beginning of the unstable situation in the Red Sea when ship operators, especially container operators, chose other sea routes. When such changes occur, operators often raise the transportation price without any real basis (clear calculations) and the market adjusts it only after some time. Therefore, clear and relatively simple methodologies are important for both carriers and customers.

At the same time, it is necessary to expand this type of research in order to detect the “weak” points of any newly developed methodology, so similar research will be important in the future as well because when both the economic and political situation changes, new challenges and factors appear, such as, for example, pandemics, which must be evaluated.

The methodology developed and presented in this article is also important from the point of view that it can be adapted to other areas of transport as similar processes take place in road, railway, inland waterways, and air transport. Of course, each field of transport has its own specifics, so you cannot mechanically “transfer” any methodology created from one type of transport to another without first thoroughly studying the characteristics of a specific type of transport, but the principle itself can be used to create and adapt similar comparable methodologies.

One of the most complex elements of comparative methodologies is the factor weights, as they can be different for different types of transport or situations, so their further study is very important and the authors plan to extend the research depending on non-standard situations and when several types of transport modes are used.

Maritime transport and seaways must be safe and their improvement must be carried out in separate periods, and during it all, conditions must be adopted to ensure the safety of navigation [54], so this problem is important both from a scientific and practical point of view.

Supply chains and their optimization are important in logistics processes [55], so research in this direction is important and must be connected with the possibilities of testing new sections of sea routes using modern navigation systems and their separate components, such as Real-Time Kinematic (RTK) systems [56]; therefore, the use of separate sections of new main sea roads and optimizing logistics chains must be scientifically based and practically acceptable [57,58,59].

The main conclusion that is important when evaluating the methodology for the evaluation of maritime road comparative indices developed and presented in this article is that when using the presented methodology, it is possible to obtain quantitative results of specific maritime routes that are important for shipping companies and cargo owners (customers) and, in addition, may also be useful for administrative authorities. Finally, we have made the following conclusion: the best Benchmark index was attained for the Suez Canal route (1.16). The Benchmark index for the African sea route is about 16 percent worse, the Panama Canal sea route index is about 29 percent worse, and the Northern Sea route is about 37 percent worse compared to the Suez Canal route. Although the Benchmark index of the Suez Canal route is the best, some ships cannot use it in the event of military conflicts or other problems. A Benchmark index is important in that it provides a basis for changes in timing, price, and other factors.