2. Requirements of carriers for railway infrastructure capacity

The allocation of railway infrastructure capacity is a complex product of the infrastructure manager, which consists of a number of sub-services. The infrastructure manager is obliged to publish the conditions of access to the infrastructure (the so-called Network Statement [5]) and to determine the free capacity of each line section. Consequently, it is intended to allow nondiscriminatory access for railway undertakings.

The Network Statement contains mainly the technical characteristics of the railways, conditions for the allocation of rail capacity to applicants, including procedures for the lack of rail capacity, conditions for access to the network, information on the price for the allocation of rail capacity and pricing for the use of the infrastructure, requirements for the application for the allocation of rail capacity, etc.

The allocation of capacity is the sale of a particular train path(s) on specific line sections in a specific time window. From a technological point of view, it is important to correctly determine the technical capacity of the track section, that is, to determine the extent of train traffic for a given track section, to show sufficient stability of train traffic even during operational irregularities. The charging of capacity is one of the tools for number of train path regulation [6–8]. The economic aspect of capacity takes into account also the risk of paying sanctions to railway undertakings for failure to comply with the RU due to poor organization of train transport (see the introduction of the European Performance Regime (EPR) [9]). The process demands the reconciliation of the requirements of all RU with regard to the technological nature of rail transport, requiring railway undertakings to anticipate traffic flows and commodity flows in the medium term.

The line capacity, that is, the ability to insert the required train paths for a given part of the infrastructure in a certain time period, is expressed by the number of train paths that can be determined over a certain time window with given technical, operational, and personnel equipment and with the necessary transport quality achieved [1, 10, 11].

Capacity definition in UIC 406 Capacity [12] represents some consensus among individual infrastructure managers on this specific issue and suggests that a clear definition of capacity cannot be established. The International Railway Union (UIC) defines railway infrastructure capacity as "the total number of possible paths in a defined time window, considering the actual path mix or known developments, respectively, and the IM's own assumptions; in node individual lines or part of the network, with market-oriented quality" [1].

In principle, capacity (throughput permeability) can be determined by the following approaches [12, 10]:

• graphically;

Railway Infrastructure Capacity in the Open Access Condition: Case Studies on SŽDC… DOI: http://dx.doi.org/10.5772/intechopen.88929


The main objective of this chapter is to define the processes of managing the capacity of railway infrastructure with the aim of achieving high-quality operative management of traffic due to the efficiency of transport flow on the infrastructure. These objectives fully respect EU transport policy, which provides a framework for creating transparent conditions and minimizing risks in accessing transport infrastructure and ensuring the growing transport needs of the company at the required time and quality. The scientific contribution is proven in the application of theoretical knowledge in the field of railway transport technology in terms of a case study

2. Requirements of carriers for railway infrastructure capacity

The allocation of railway infrastructure capacity is a complex product of the infrastructure manager, which consists of a number of sub-services. The infrastructure manager is obliged to publish the conditions of access to the infrastructure (the so-called Network Statement [5]) and to determine the free capacity of each line section. Consequently, it is intended to allow nondiscriminatory access for

The Network Statement contains mainly the technical characteristics of the railways, conditions for the allocation of rail capacity to applicants, including procedures for the lack of rail capacity, conditions for access to the network, information on the price for the allocation of rail capacity and pricing for the use of the infrastructure, requirements for the application for the allocation of rail

The allocation of capacity is the sale of a particular train path(s) on specific line sections in a specific time window. From a technological point of view, it is important to correctly determine the technical capacity of the track section, that is, to determine the extent of train traffic for a given track section, to show sufficient stability of train traffic even during operational irregularities. The charging of capacity is one of the tools for number of train path regulation [6–8]. The economic aspect of capacity takes into account also the risk of paying sanctions to railway undertakings for failure to comply with the RU due to poor organization of train transport (see the introduction of the European Performance Regime (EPR) [9]). The process demands the reconciliation of the requirements of all RU with regard to the technological nature of rail transport, requiring railway undertakings to antici-

The line capacity, that is, the ability to insert the required train paths for a given part of the infrastructure in a certain time period, is expressed by the number of train paths that can be determined over a certain time window with given technical, operational, and personnel equipment and with the necessary transport quality

Capacity definition in UIC 406 Capacity [12] represents some consensus among individual infrastructure managers on this specific issue and suggests that a clear definition of capacity cannot be established. The International Railway Union (UIC) defines railway infrastructure capacity as "the total number of possible paths in a defined time window, considering the actual path mix or known developments, respectively, and the IM's own assumptions; in node individual lines or part of the

In principle, capacity (throughput permeability) can be determined by the fol-

pate traffic flows and commodity flows in the medium term.

network, with market-oriented quality" [1].

on the corridor's lines.

Transportation Systems Analysis and Assessment

railway undertakings.

capacity, etc.

achieved [1, 10, 11].

lowing approaches [12, 10]:

• graphically;

68

• simulation modeling.

An overview of the most preferred methodologies for capacity estimation is elaborated in the work [13]. The most comprehensive approach is to use simulation tools to evaluate the capacity of a railway infrastructure based on a real-world traffic model. Capacity assessment using simulation modeling methods provides a comprehensive assessment of the capacity characteristics of the transport infrastructure being solved. The result provided is only suboptimal in terms of the general approach depending on the course of the simulation. A problem here is the range of input data required for a simulation model (a detailed description of the infrastructure and dynamic properties of the vehicles), as well as the time data required for the simulation assessment. On the other hand, the new possibilities offered by simulation modeling are a prerequisite for its successful implementation in cases where it is justified. The criterion used here is primarily the stability of the timetable (the ability not to increase or decrease the input delay).

### 2.1 Relevant data for capacity allocation in the case study

The capacity assessment is based on the evaluation of the existing timetable. Infrastructure dimensioning, operational performance, and quality of service are interdependent. If two variables are known, the third can be derived. Security requirements, general economic framework conditions, and environmental constraints are given by the external environment.

The following factors influence the capacity of a given infrastructure [11, 14]:


The overview of the preferred methodologies among European Infrastructure managers is elaborated in the work of Kontaxi and Riccci [13]. The resulting average value of the stability coefficient (ratio of the output and input delays of the train on the monitored infrastructure in the simulation run) is the basis for assessing whether the infrastructure under investigation corresponds to the expected traffic range.

The train path is defined for the purposes of EP and ER 2012/34/EU directive establishing a single European railway area for the allocation of railway infrastructure capacity [15] as "the infrastructure capacity needed to run a train between two places over a given period." The train path is defined by important parameters, such as train type, days of operation, routing, scheduled speed, arrival times, departures times, and transfer times at stations and stops.

The timetable shows the paths of all regular trains, trains as needed (on days of deployment), and canceled trains (they travel on specified days and their paths

cancel other train paths where the regular train must be waiting in the event of the jamming train being introduced). The insertion of train paths to the graphical timetable must be in accordance with the technological procedures of the station operation processes and traffic safety. The insertion of train paths to the timetable under SŽDC and ŽSR Railway infrastructure manager is performed gradually according to the following basic types [5, 11]:

Three requirements summarize the kit's technical data, that is, the transport weight and the length of the train, tractive vehicle order in the train, and the requirements for technological procedures at the stations. The transport mass and train length shall be determined in tonnes and meters. The set values must comply with the instructions of SŽDC and ŽSR [11]. If a useful track length is less than the train length norm at the station, this shall be taken into account in the timetable. The transport weight of the train in relation to the regular driving times and consequently the technical norms of weight differ according to the types of driving resistance of individual types of trains. The established driving resistance types (marked as M, R, S, T, and U, for example) are indicated with the train weight normative value. If a freight train path is to be constructed in which the transport weight of the train vehicles is higher than the technical weight standard, then the number, type, and method of deployment of other active traction vehicles (loco-

Railway Infrastructure Capacity in the Open Access Condition: Case Studies on SŽDC…

It is important to precisely determine the binding travel time of the train

and numerical solutions to the train equation. It is necessary to construct the tachogram of the train, that is, the algorithm or simulation of the ride, which is tasked with compiling the track and time waveforms by means of the train's differential equations, which result in a graphical dependency of the driving speed on the trajectory v = f (l) as well as dependency of the driving time on the trajectory

The methodology for determining the theoretical driving time assumes graphical

At each stage of the train movement, the traction resistances that are overcome by the tractive force exerted by the driving axles of the tractive vehicle must be

This section discusses overcoming the traction resistances that occur when starting, running at inertial speed, running, and braking as described in these

where Ft is the locomotive pulling force, its graphical representation in relation to speed is traction characteristic Ft = f (V); Fa is the resistance of mass inertia [N]; F0L is the driving resistance of the traction vehicle [N]; F0V is the driving resistance of trailers (loads or wagon set) [N]; Fb is the braking resistance [N]; and FS is the

For the driving resistance coefficient, which is specified for each tractive vehicle and load separately, the empirical relationship applies, where a, b, and c are the

C

These are the quadratic dependencies and formulas applicable to approved

tion of train movement, assuming that the velocity is constant when the

The calculations use the so-called inertial slope, which is defined as the slope that is numerically equal to the slope of the line on which a particular train moves at a constant speed. In determining the inertia slope, we proceed from the basic equa-

Ft ¼ Fa þ F0<sup>L</sup> þ F0<sup>V</sup> þ FS þ Fb ½ � N (1)

<sup>G</sup> � <sup>V</sup><sup>2</sup> <sup>¼</sup> <sup>a</sup> <sup>þ</sup> <sup>b</sup> � <sup>V</sup> <sup>þ</sup> <sup>c</sup> � <sup>V</sup><sup>2</sup> ½ � � (2)

motives) must be agreed.

f (l) [16].

taken into account.

physical equations [10]:

slope resistance [N].

71

infrastructure manager's table values:

<sup>p</sup><sup>0</sup> <sup>¼</sup> <sup>F</sup><sup>0</sup>

<sup>G</sup> <sup>¼</sup> <sup>A</sup> G þ B <sup>G</sup> � <sup>V</sup> <sup>þ</sup>

vehicles, as measured by actual measurements on vehicles.

concerned for the construction of the train path.

DOI: http://dx.doi.org/10.5772/intechopen.88929

2.2 Driving time calculation presumptions


The RU submits timetable capacity requirements along with mandatory data summarized in Table 1. Only three of the twelve required data affect the calculation of train running times and thus the line capacity. At the same time, the RU communicates other specific data whose operational nature allows the train to assign the particular type and traffic calendar in particular. Although this is not data directly affecting infrastructure utilization, it is data that allow the capacity allocator to decide on the allocation or nonallocation of railway capacity from a legislative perspective.


#### Table 1.

Required data in rail capacity allocation request.

Railway Infrastructure Capacity in the Open Access Condition: Case Studies on SŽDC… DOI: http://dx.doi.org/10.5772/intechopen.88929

Three requirements summarize the kit's technical data, that is, the transport weight and the length of the train, tractive vehicle order in the train, and the requirements for technological procedures at the stations. The transport mass and train length shall be determined in tonnes and meters. The set values must comply with the instructions of SŽDC and ŽSR [11]. If a useful track length is less than the train length norm at the station, this shall be taken into account in the timetable. The transport weight of the train in relation to the regular driving times and consequently the technical norms of weight differ according to the types of driving resistance of individual types of trains. The established driving resistance types (marked as M, R, S, T, and U, for example) are indicated with the train weight normative value. If a freight train path is to be constructed in which the transport weight of the train vehicles is higher than the technical weight standard, then the number, type, and method of deployment of other active traction vehicles (locomotives) must be agreed.

It is important to precisely determine the binding travel time of the train concerned for the construction of the train path.

The methodology for determining the theoretical driving time assumes graphical and numerical solutions to the train equation. It is necessary to construct the tachogram of the train, that is, the algorithm or simulation of the ride, which is tasked with compiling the track and time waveforms by means of the train's differential equations, which result in a graphical dependency of the driving speed on the trajectory v = f (l) as well as dependency of the driving time on the trajectory f (l) [16].

At each stage of the train movement, the traction resistances that are overcome by the tractive force exerted by the driving axles of the tractive vehicle must be taken into account.

#### 2.2 Driving time calculation presumptions

This section discusses overcoming the traction resistances that occur when starting, running at inertial speed, running, and braking as described in these physical equations [10]:

$$F\_t = F\_a + F\_{0L} + F\_{0V} + F\_S + F\_b \text{ [N]} \tag{1}$$

where Ft is the locomotive pulling force, its graphical representation in relation to speed is traction characteristic Ft = f (V); Fa is the resistance of mass inertia [N]; F0L is the driving resistance of the traction vehicle [N]; F0V is the driving resistance of trailers (loads or wagon set) [N]; Fb is the braking resistance [N]; and FS is the slope resistance [N].

For the driving resistance coefficient, which is specified for each tractive vehicle and load separately, the empirical relationship applies, where a, b, and c are the infrastructure manager's table values:

$$p\_0 = \frac{F\_0}{G} = \frac{A}{G} + \frac{B}{G} \cdot V + \frac{C}{G} \cdot V^2 = a + b \cdot V + c \cdot V^2 \text{[--]}\tag{2}$$

These are the quadratic dependencies and formulas applicable to approved vehicles, as measured by actual measurements on vehicles.

The calculations use the so-called inertial slope, which is defined as the slope that is numerically equal to the slope of the line on which a particular train moves at a constant speed. In determining the inertia slope, we proceed from the basic equation of train movement, assuming that the velocity is constant when the

cancel other train paths where the regular train must be waiting in the event of the jamming train being introduced). The insertion of train paths to the graphical timetable must be in accordance with the technological procedures of the station operation processes and traffic safety. The insertion of train paths to the timetable under SŽDC and ŽSR Railway infrastructure manager is performed gradually

• feeder freight service trains on line sections before determining the final

• interfering train paths (regular train paths with special path construction, these trains are operated in dedicated days during the week or daily during a specific

The RU submits timetable capacity requirements along with mandatory data summarized in Table 1. Only three of the twelve required data affect the calculation of train running times and thus the line capacity. At the same time, the RU communicates other specific data whose operational nature allows the train to assign the particular type and traffic calendar in particular. Although this is not data directly affecting infrastructure utilization, it is data that allow the capacity allocator to decide on the allocation or nonallocation of railway capacity from a legislative

Required data under the Network Statement Influence on driving

1. Identification data of the RU N 2. Position route guidance N 3. Timing of train path N 4. Train type N 5. Train set data specifications Y 6. Technical data on traction vehicles including their number and function

7. Train driving calendar N 8. Type of railway transport operated N 9. Required tariff and nontariff conditions N 10. Type and extent of services provided in the train N 11. RU requirements for technological operations in stations Y 12. Known extraordinary of the train N

time

Y

according to the following basic types [5, 11]:

Transportation Systems Analysis and Assessment

• passenger trains to and from employment;

position of the running freight trains; and

• long-distance passenger trains;

• freight express trains;

time period).

perspective.

in the train

Source: authors on the ground of [4].

Required data in rail capacity allocation request.

Table 1.

70

• international and national expresses and fast trains;

acceleration resistance is zero. The graphical dependence of inertia on speed is the so-called s0/V diagram. It is unique to the type of traction vehicle, the type of vehicle resistance, and the weight of the wagon set. Traction characteristics for each traction vehicle (locomotive and motor car) are constructed to obtain a traction force-speed dependence. The vertical y-axis shows the tractive force, and the x-axis shows the speed. The tractive effort curve in the traction diagram indicates a lot about the locomotive's operating characteristics.

The construction of graphical methods to determine the technical normative weight of a train set is based on the theory of nomograms. In practice, SŽDC and ŽSR most often use the Koreff intersection nomogram, constructed under the condition V = const. The tractive force values of the coupler for a given traction vehicle are given by the traction characteristic, and the coefficient of vehicle resistance can be determined from empirical relationships. The slope of the track is given by the parameters of the track. It follows from the equation of motion (3) that the left side corresponds to the linear dependence on the resistance of the tractive vehicles, and the right side of the linear dependence on the slope. Relations after adjustment for the weight determination of the transported vehicles are represented by two equations of lines whose relationship can be solved graphically.

$$F\_{\rm tr} - G\_{\rm D} \cdot f\_{\rm 0V} = (G\_{\rm L} + G\_{\rm D}) \cdot f\_{\rm S} \tag{3}$$

methodological postulates for new approaches in capacity management in the fol-

• lack of efficient train paths for freight trains on transit corridors;

Railway Infrastructure Capacity in the Open Access Condition: Case Studies on SŽDC…

• an increase in the demand for "ad hoc" freight paths.

further reduce line capacity (and in addition, unproductivity).

transport are implemented on the line;

examination without stopping.

for the station (source: elaborated on ground of [11]).

line; and

trains.

Figure 1.

73

• application of the integrated tactic timetable for passenger trains; and

3.1 Lack of efficient train paths for freight trains on rail corridors and nodes

the individual railway stations, where insufficient capacity of railway tracks at stations can cause a train to be rejected and wait at intermediate stations, which will

line between railway stations A and B was chosen, which is characterized by:

short station and track operational intervals as well headways;

The capacity of the lines as a line construction is closely related to the capacity of

For a short case study on the 4th transit corridor, a section of the double-track

• track equipped with a fully automatic track and station security devices, with a

• both regional passenger transport and long-distance express and interregional

• international freight trains and relational freight trains are established on the

• most trains pass through both stations bounding the interstation section under

The typical timetable for that line is shown in the segment in Figure 1. Due to the preference of passenger transport in the allocation of timetable routes, the assumption can be made that any freight train can only be traced when it does not restrict the movement of passenger trains. The problem is the time taken by a freight train in a timetable, which is significantly longer compared to passenger

In the timetable, the driving times for this section are of the order of Ex 4.5–5.0 min, regional passenger trains 11.0 min, freight expresses 7.5 min, and relational freight trains 9.5 min. To do this, there is need to add a start and stop

Headway for train sequence in odd direction (line with odd numbers) stopping freight express-passing express

lowing areas are defined:

DOI: http://dx.doi.org/10.5772/intechopen.88929

where Fts is the tractive effort of the locomotive on coupler [kN]; GD is the weight of wagon set [kN]; GL is the tractive vehicle weight [kN]; f0V is the driving resistance coefficient of transported vehicles [—]; and fS is the slope resistance coefficient [—].

The practical expression of Koreff nomograms for transport practice is tables of the technical normative mass. Tables are compiled for each type of traction vehicle; at the intersection of a certain slope (track class) and the mass of the train set, there is the value of inertial speed that the traction vehicle of the given series is able to haul on a given inertia slope and with a given weight of trailer vehicles. Calculated driving time values are called theoretical driving times, rounded off to at least 0.1 min. Regular driving times rounded to 0.5 min are used for the timetable construction [1, 2, 10].
