The role of construction of the Angren-Pap railway line in the plans of international transport and economic relations

ABSTRACT

The article deals with the construction of the Angren - Pap electrified railway line in the plans of international transport and economic relations, the reasons that contributed to the start of the construction of this line, the justification of technical solutions, the throughput and carrying capacity of the site, the competitiveness with road transport in terms of national economic transport.

АННОТАЦИЯ

В статье идёт речь о строительстве электрифицированной линии Ангрен – Пап в планах международных транспортно-экономических связей, причинах способствовавших началу строительства данной линии, обоснование технических решений, пропускной и провозной способности участка, конкурентной способности с автомобильным транспортом в плане народнохозяйственных перевозок.

Keywords: Angren-Pap railway line, Kamchik Pass, throughput, carrying capacity

Ключевые слово: линия Ангрен – Пап, перевал Камчик, пропускная способность, провозная способность

Introduction

The implementation of the construction of the Angren-Pap railway line in the long term is planned for 2030. However, recently, serious problems have arisen in the field of transportation between the Fergana Valley and the rest of the regions of Uzbekistan due to the economic development of the natural resources of the eastern sections. The Fergana Valley is connected with other regions of the republic by the only motor road laid between the Tashkent and Namangan regions. Since the road passes through the high-mountain Kamchik Pass, in winter, due to difficult natural conditions, as well as frequent avalanches, the highway on this section is periodically blocked. In addition, due to the insufficient throughput for the present time, the existing Tashkent-Namangan highway cannot cope with the growing volume of cargo transportation. Earlier (until the year of 2000), between the Fergana Valley and other regions of Uzbekistan, the railway communication was carried out only through the territory of Tajikistan (Bekabad – Kokand section). Subsequently, due to the problems of increasing tariffs for the carriage of goods on its own sections of the railway, transit when passing through Tajikistan along the Bekabad-Khujand-Kanibadam-Kokand route was reduced, and later in 2001 was fully stopped [1].

The Government of Uzbekistan, considering the issue comprehensively, came to the conclusion that without the creation of a railway connection between the Fergana Valley and the rest of the regions, it is impossible to speak of any satisfaction of the need for the continuous growth of the national economy of the Republic, as well as to ensure the socio-economic and political security of the Fergana Valley. 

Analysis of the current technical condition of the Angren - Pap railway line when switching transit freight flows between China, Central and South Asia

The prospect of the development of the existing Angren-Pap line as a link between China and South Asia may not provide large transit freight flows between China, Central and South Asia, since there are “bottlenecks” on this railway line, which significantly reduce the throughput and carrying capacity. This determines the need to increase the capacity of certain directions when switching transit traffic flows between China, Central and South Asia.

In this regard, an analysis of uncertainties and risks is required when justifying the increase in the capacity of the Angren-Pap railway line in order to switch transit traffic flows between China, Central and South Asia, in particular when assessing the increase in the capacity of the 19-kilometer tunnel of the Angren-Pap line. A correct risk assessment will make it possible to save construction and operating costs and increase the competitiveness of the specified railway direction with alternative modes of transport.

The railway line Angren - Pap with a length of 124 km and consisting of 7 sections with a length from 13 km to 24 km (Fig. 1) is fully electrified. It was laid in difficult topographic conditions under the Kamchik pass (2200 m above sea level). A project was created for the construction of a tunnel on the stretch of Sardala St. – Turn-out 2, 19 km long.

Figure1. Scheme of the Angren - Pap railway line

Calculation of the throughput and carrying capacity of the Angren - Pap railway line

Initial data of thrust calculations are presented in tables 1-4 [2-4].

1. Freight train:

Table 1.

Initial data

Table 2.

Initial data of freight cars

2. Passenger train:

Table 3.

Initial data

Table 4.

Initial data of passenger cars

Calculations were made in accordance with the “Instruction for calculating the throughput and carrying capacity of railways”. With a pair non-batch train schedule, the throughput of single-track runs can be determined by the formula (1) [2-4]:

where  - technological windows allocated for the production of work on the current maintenance and repair of the track and its infrastructure (contact network, signaling systems, etc.). On the basis of statistical data,  is taken equal to 75 minutes on single-track lines.

 is the reliability factor, taking into account the failures of the rolling stock as a whole, the reliability factor when calculating the available capacity is taken on electrified single-track lines 0.93;

 - station intervals in minutes;

, - travel time of the train along the haul, respectively, in even and odd directions in minutes.

The number of freight trains on sections with predominant freight traffic is determined by the formula (2) [2-4]:

 ,   (pairs of trains/twenty-four hours);  (2)

where n is the throughput of the section, train pairs / day;

,  - removal rate for passenger and groupage freight trains 1.7 and 1.8, respectively;

, - the size of movement (trains, pairs of trains) of various categories; passenger and groupage trains 2 and 1 pairs of trains per day, respectively.

The possible carrying capacity of the road, determined by the amount of cargo that can be transported with a given technical equipment in one direction or another, is determined by the formula (3) [2-4]:

where  is the number of freight trains that the railway can pass in this direction;

γ - coefficient of uneven traffic 1.2;

The gross weight of a freight train with two sectional locomotive VL80s on the Angren-Pap line is determined by the formula (4).

where  - the calculated traction force of the two-section locomotive VL80s is 51200 kgf;

P - the mass of the VL 80s locomotive is 184 t;

- leading bias;

are the main specific resistances to the movement of the locomotive and the train of cars, kgf / t.

The main specific resistance to the motion of the VL 80s locomotive, kgf / t, is determined by the formula (5) [5,6].

where  is the speed of movement, km / h;

The main specific resistance to the movement of loaded freight cars, kgf / t, is determined by the formula (6) [5,6]:

Respectively:

Traction service for the freight traffic of the Angren-Pap railway line is provided for by two sectional electric locomotives VL80c (2 locomotives), then the mass of the train is 2 1600 = 3200 tons.

As a result of processing information on the structure of freight traffic, it is known that freight trains will handle the following types of cargo on the Angren-Pap line: (oil products, GM Uzbekistan cars, gasoline, coal, cement, cotton, grain, fertilizers, etc.) ), formed from 4-axle wagons with a carrying capacity of up to 60 tons, with an average wagon tare weight of up to 22 tons. The average value of the coefficient of utilization of the carrying capacity of wagons is 0.80.

The ratio of the net mass of the composition to the gross mass will be:

Then, obviously, the net mass of a freight train for two two-section VL80s will be  =0,68·=0,68·3200=2176 t;

The results of traction calculations showed that the capacity of the Angren-Pap railway line assumes the passage of freight trains in the amount of 21 pairs of trains per day and the maximum possible carrying capacity of 13.9 million tons (Table 2). Limiting runs are “Sardala St. – Turn-out 2 "," Turn-out 2 – Turn-out 3 "and" Turn-out 3 – Koshminar St. ". On the stretch “Sardala St. – Turn-out 2 " there is a tunnel with a length of 19 km.

Table 5.

Calculation results of the throughput and carrying capacity of the Angren – Pap railway line

Analysis of the decisions made in the context of the uncertainty of the initial information of the Angren - Pap railway line and its complex structures

According to traction calculations, the maximum possible carrying capacity of the Angren-Pap line is 13.9 million tons. In 2018, cargo traffic through the Kamchik pass amounted to 8.60 million tons. According to statistical data, the volume of freight traffic of China and South Korea between Central and South Asia in 2018 amounted to 6.10 million tons. By 2020, when switching transit cargo from China and South Korea to Central and South Asia along the Angren-Pap line, which will exceed the possible carrying capacity of the line under consideration. In this regard, already in 2020 the line will not meet the required carrying capacity. This gives rise to the need to strengthen the Angren-Pap line shortly after its commissioning and to rebuild it in the future as traffic grows. Obviously, additional investment will be required soon.

The main indicators of the Angren - Pap railway line are given in table. 3.

Table 6.

Main indicators of the Angren – Pap railway line

As noted, the calculation results showed that the limiting sections are “Sardala St.- Turn-out 2 "," Turn-out 2 – Turn-out 3 "and" Turn-out 3 – Koshminar St.”, where the difference in the possible carrying capacity is insignificant. The above stages are analyzed in more detail below:

"Sardala St. – Turn-out 2 "- a stretch of 23.6 km is located on a complex profile, hump-shaped and large artificial structures (tunnel). The construction of the tunnel was carried out in cooperation with the joint stock company “Uzbekiston Temir Yullari” and the Chinese company “China Railway Tunnel Group”. The total cost of the tunnel was 999.38 billion soums. The tunnel in accordance with the project has a gable shape (+20; +10; +5.4; and -5.5 ‰). The tunnel starts at a distance of 3.2 km from the station. Sardala and has a maximum slope of 25 ‰ on this site. From the eastern portal to sect. 2 (1.3 km) maximum slope 20 ‰ [98] (Fig. 3).

Figure 2. Schematic longitudinal profile of the “Sardala St. – Turn-out 2"

According to the project, the tunnel is supposed to carry out freight traffic for 21 pairs of trains per day. In the world ranking, in terms of its complexity, the tunnel, located in a mountainous area, takes the 8th place and the 13th in length. In addition, the tunnel is the most capital-intensive structure in the project (27% of the total construction cost) and the need for its early construction requires a more detailed analysis. It is obvious that increasing the capacity of the tunnel in the future is difficult and requires the involvement of foreign specialists. Difficulties arising when carrying out measures to increase the power of the tunnel directly during its operation, as a rule, are associated with a large volume of various works, for example, the construction of a double-track insert, the introduction of an automatic blocking or a second track in the tunnel. Therefore, with a reasonable approach, the capacity in the process of such activities should be increased to the maximum possible extent, so that the need for such activities does not arise in the future.

"Turn-out 2 – Turn-out 3" and "Turn-out 3 – Koshminar St.”- 28.2 km long railway tracks are located in difficult topographic conditions. Throughout the stretches, the stretches are designed with a tight run and 27 ‰ steering slopes. A significant part of the track has a radius of 300 m, and there are also separate points with a longitudinal slope of 12 ‰ (Fig. 3).

Figure 3. Schematic longitudinal profile of the tracks "Turn-out 2 – Turn-out 3" and "Turn-out 3 – Koshminar St."

The adopted project in the plan of which there are curves with a radius of 300 m, can provide a reduction in the volume of work and a reduction in construction costs. But at the same time, curves of small radii cause a deterioration in a number of operational ones. In addition, the intensive growth of traffic causes rapid deterioration of the main equipment of the power supply system, which creates difficulties in operational work on these lines. It can also be noted that steep slopes of the profile limit the mass of the train.

An increase in the power characteristics of structures and various devices with uninterrupted use of the line in some cases can be carried out without significant changes in the operated structures. In particular, this applies, for example, to sidings, if sections are already provided for them.

The main parameters of the projected railway line, including the number of main tracks, useful length of receiving and departure tracks, layouts of separate points and sections of traction service, steering slope and type of traction, placement of traction substations, power supply of electrified lines, as well as its main direction is necessary set in accordance with clause 3.7 of the current STN Ts-01-95 [7] based on the results of technical and economic calculations for the future, taking into account the savings in initial costs and ensuring further stepwise strengthening of the line as the volume of traffic increases [7].

If it is necessary to increase the capacity of a structure within a given period of t years, it is advisable to build it immediately at an increased capacity. If it is necessary to perform reinforcements after more than t years, a more profitable option is to build a structure at first in a smaller volume and then reinforce it during operation [7].

Conclusion

Analysis of the calculations allows us to conclude that the power characteristics of complex structures during construction should be at a maximum level. At the same time, it is necessary to take into account the possibility of development and operating conditions. This will allow avoiding reconstruction until the 15th year of operation. To maximize the efficiency of investments associated with such works, a project should be drawn up with taking into account the rate of operation of the road in the next few years. If we consider the Angren-Pap railway line as a model, namely the strengthening of the tunnel, then such measures here should be focused on the longest possible perspective.

References:

1. Report of the feasibility study “Construction of a new electrified railway line Angren - Pap”. - Tashkent, 2012 .-- 350 p.
2. Umarov X.K. Increase in the capacity of the limiting section of the Angren - Pap / X. K. Umarov, E. S. Svintsov // Izvestia. Petersburg University of Railways. - 2015. - Issue. 2 (43). – pp. 84-90;
3. Umarov X.K. Justification of measures to increase the capacity of the Angren - Pap / X. K. Umarov, E. S. Svintsov // Bulletin. Rostov State Transport University. - 2015. - Issue. 2 (58). – pp. 104-110;
4. Umarov X.K. Construction of the Angren - Pap railway line and its role in the formation of the railway network of the Republic of Uzbekistan / X. K. Umarov, E. S. Svintsov // Izvestia. Petersburg University of Railways. - 2014. - Issue. 4 (41). – pp. 80-86.
5. Grebenyuk P.T. Dolganov A.N., Skvortsova A.I. Traction calculations: Handbook. / Ed. P.T. Grebenyuk. - M .: Transport, 1987 .-- 272 p.
6. Rules for traction calculations for train operation. - M .: Transport, 1985 .-- 287 p.
7. Building technical standards. 1520 mm gauge railways. STN Ts-01-95. M., 1995, 87 p.