Railway Buffer Stops Planning Guidelines

ISRAEL RAILWAYS LTD.

RAILWAY BUFFER STOPS PLANNING GUIDELINES

JULY 2009

YENON PLANNING CONSULTING & RESEARCH LTD. Civil engineering, roadways, steel tracks, traffic, imaging, Landscape architecture, constructions, measurements and project management

RAILWAY BUFFER STOPS PLANNING GUIDELINES Page 1 ISRAEL RAILWAYS LTD.

RAILWAY BUFFER STOPS PLANNING GUIDELINES

Members of the Steering Committee: Dr. Arkadi Rabinovich Engineering Branch Supervisor, Planning Division, Israel Railways Ltd.

Edited By: Eng. Selva Kaplanovich YENON PLANNING CONSULTING & RESEARCH LTD. Eng. Alex Lerner YENON PLANNING CONSULTING & RESEARCH LTD. Eng. Imad Zidan YENON PLANNING CONSULTING & RESEARCH LTD.

YENON PLANNING CONSULTING & RESEARCH LTD. Civil engineering, roadways, steel tracks, traffic, imaging, Landscape architecture, constructions, measurements and project management 4 HaYozma st., Tirat HaKarmel, P.O. Box 444, 30200 Tel: 04-8569000 Fax: 04-8569010 Email: [email protected] http://www.yenon.co.il

RAILWAY BUFFER STOPS PLANNING GUIDELINES Page 2 Table of Contents 1.Introduction...... 5 2.General...... 5 3.Classification of Buffer Stops...... 6 3.1.Arresting Devices...... 6 3.2.Fixed Buffer Stops...... 7 3.3.Friction Buffer Stops...... 7 3.4.Hydraulic Buffer Stops...... 11 3.5.Wheel Stops...... 12 3.6.End Impact Walls...... 13 4.Braking Distances...... 16 5.Collision Speeds...... 17 6.Geometric Conditions...... 18 7.Calculation of Kinetic Energy and Braking Work...... 19 7.1.Kinetic Energy...... 19 7.2.Braking Work...... 20 8.Criteria for the Design and Placement of Buffer Stops...... 22 8.1.Designing of Buffer Stops...... 22 8.2.In-station Buffer Stops...... 22 8.3.Special Areas...... 23 8.4.In-tunnel Buffer Stops...... 23 8.5.Temporary Arrangements...... 24 9.Buffer Stop Requirements...... 25 9.1.Adjustment of Buffer Stops for Rolling Stock bumpers...... 25 9.2.Buffer Stop Markings...... 25 9.3.Buffer Stop Color...... 26 10.Buffer Stop Risk Assessments...... 27 10.1.Definition of Risks to which Buffer Stops are Exposed...... 27 10.2.Calculation of Weighted Coefficients (Table 2)...... 27 10.2.1.Integrated Collision Potential Coefficients (Table 3)...... 28 10.2.2.Integrated Buffer Stop Coefficients (Table 4)...... 29

RAILWAY BUFFER STOPS PLANNING GUIDELINES Page 3 10.2.3.Integrated Train Type Coefficients (Table 5)...... 29 10.2.4.Integrated coefficients for Areas Located Behind Buffer Stops (Table 6)...... 29 10.3.Undertakings for reduction of Risk Levels...... 30 10.4.Reassessment of Risk...... 30 11. List of Place-markers ...... 37 12. List of Appendices...... 38

List of Figures Figure 3.1: An arresting device ...... 6 Figure 3.2: Fixed buffer stop for marking of track end …...... 7 Figure 3.3: Friction buffer stop without additional brake …...... 8 Figure 3.4: Friction buffer stop with additional brake …...... 9 Figure 3.5: Length of profile designated for reinforcement of track …...... 10 Figure 3.6: Hydraulic buffer stop …...... 11 Figure 3.7: Stop wheel with arresting device …...... 12 Figure 3.8: End impact wall of passenger train track …...... 13 Figure 3.9: End impact wall for freight trains …...... 14 Figure 4.1: Braking distance …...... 15 Figure 9.1: Marking of buffer stops with light reflectors …...... 24

List of Tables Table 1: Calculated Kinetic Energy Values E [kJ] of Colliding Trains …...... 18 Table 2: Assessment of Buffer Stop Collision Risk …...... 30 Table 3: Assessment of Integrated Collision Potential Coefficient …...... 32 Table 4: Assessment of Integrated Buffer Stop Coefficient …...... 33 Table 5: Assessment of Integrated Train Type Coefficient …...... 33 Table 6: Assessment of Integrated Coefficient for Areas Behind Buffer Stop …...... 34 Table 7: Recommendations for Execution of tasks to Reduce Risk Level …...... 35

RAILWAY BUFFER STOPS PLANNING GUIDELINES Page 4  Introduction The Israel Railways Planning Division instructs its planners to design tracks in accordance with “Guidelines for Planning of Steel tracks” This document, “RAILWAY BUFFER STOPS PLANNING GUIDELINES”, constitutes an important part of the instructions for planning of steel tracks and focuses on the design of different buffer stop types in optimal locations as a derivative of the required safety level. The instructions for placement of buffer stops shall serve both the planners and Israeli Railways employees as a guiding document when determining buffer stop location and type. The guidelines for placement of buffer stops are based on European standards such as : German DS 800 01, English GC/DT 5033, Italian, Austrian and Greek. All manufacturer names, supplier names and the names of any other equipment specified herein are provided for convenience purposes only.

 General Buffer stops are placed at the end of steel tracks for: - Marking of track ends (terminus). - Prevention of railroad car derailment and rolling. - Stopping of trains in order to prevent injury, protect nearby structures and prevent damage to rolling stock. Buffer stops are not designed to replace the normal braking process of trains. The braking work of buffer stops is limited due to technical and economic reasons. Buffer stops must be designed such that they are able to absorb the kinetic energy of the train running into them.

RAILWAY BUFFER STOPS PLANNING GUIDELINES Page 5  Classification of Buffer Stops 31. . Arresting Devices Buffer stops include several subsystems. Of these, arresting devices are one of the most important. Arresting devices hold the track rail head for braking and it is this part which connects the buffer stop to the track rails. Arresting devices include the following components: 1. A plate for holding of the arresting material and track rail, 2. A nut for holding of the arresting material, the holding plate and the track rail on which the buffer stop is installed, 3. Arresting material, 4. An arresting rod, 5. A track rail, 6. and the track rail on which the buffer stop is installed.

These components hold the rail as illustrated in Figure 3.1 below.

Figure 3.1: An arresting device

All arresting device components are adjusted in accordance with the height and type of track on which it is installed. The braking force of arresting devices changes according to the type of device in place. The forces fluctuate between 32 kN and 40 kN per device. The final braking force of all arresting devices installed on the buffer stop depends on the braking distances [1].

RAILWAY BUFFER STOPS PLANNING GUIDELINES Page 6 32. . Fixed Buffer Stops Fixed buffer stops are placed at track ends before the end-loading platform in locations such as factory complexes, ports, train yards, terminals, tail flank protections, etc. There are two types of fixed buffer stops – those of steel and those of concrete. Steel fixed buffer stops are placed on track ends in fixed form and do therefore not create braking work. Such buffer stops only serve as track end indicators and are equipped with red signal lights which work on a permanent basis (see Figure 3.2).

Figure 3.2: Fixed buffer stop for marking of track end

Concrete fixed buffer stops (see Appendix F') are placed in stabling tails, track ends in factories and branches and of course in loading / unloading platforms. In the event of collision between a train having a greater kinetic energy than the rolling stock bumpers into which it collides, the rolling stock and arresting device shall sustain damage.

33. . Friction Buffer Stops Friction Buffer Stops are placed on main lines of terminal stations, in track yards, on secondary lines of functional tracks and in places where there is sufficient distance for gradual braking of the trains (braking distance). There are several types of friction buffer stops: - Friction Buffer Stop (without additional brake)  Friction Buffer Stop with additional Brake 

RAILWAY BUFFER STOPS PLANNING GUIDELINES Page 7 Friction buffers include of the following components: 1. A collision triangle, 2. Braking devices, 3. Bumpers, 4. A holding device for returning the buffer to its former position following a collision, 5. A reinforcement cross.

Figure 3.3 illustrates one main type of friction buffer stop without additional brakes.

Figure 3.3: A friction buffer stop without additional brake

When constructing friction buffer stops, it is necessary to ensure the track section located behind the buffer stop is perfectly straight and sufficiently long to allow unobstructed backward movement of the buffer stop (braking distance). Upon collision between a train and the buffer bumpers, all of the kinetic energy forces created pass through the various buffer parts to the arresting devices and from there down to the track rails. As a result of the friction created between the arresting device and track rails, the train stops in a gradual manner. The buffer moves away from the colliding train in the direction of the train's travel until it finally stops.

The addition of brakes nz, as illustrated in Figure 3.4, involves the installation of additional brakes behind the buffer on top or below the existing rails using an extra set of rails which are installed between the two primary track rails. In cases where the kinetic energy is greater than the buffer stop's maximum braking

RAILWAY BUFFER STOPS PLANNING GUIDELINES Page 8 work, additional brakes are installed (See Figure 3.4). The added brake system includes the following parts:  Additional arresting devices for added braking,  A Steel profile below rails for reinforcement of the track,  Jointed connection belts between arresting devices,  A lateral connection between the arresting devices.

Figure 3.4: Friction buffer stop with additional brakes

For each additional brake there are two arresting devices positioned in parallel and connected to one another. The added brakes are connected to the buffer stop and to each other using joint connection belts – see Figure 3.4. When constructing friction buffer stops with additional brakes, it is necessary to ensure the track section behind the buffer is perfectly straight and sufficiently long such that there is enough space for unobstructed backward movement of the buffer stop (braking distance) for the extra distance which is required for the addition of post-impact arresting devices. For examples of friction buffer stops see Appendix C'. The arresting forces offered by buffer stop arresting devices and the added brakes result in the creation of pull and torque forces on the track rails. In order to prevent the track rails from rising as a result of torque forces which are created directly in front of the buffer stop, to an extent that may surpass permissible levels, it is necessary to ensure the friction buffer and added brakes are installed on track rails which are held together using steel profiles, where the profile type is selected according to the type of buffer stop and number of arresting devices which are installed. The length of steel profiles used for strengthening is divided into the following sections

RAILWAY BUFFER STOPS PLANNING GUIDELINES Page 9 – see Figure 3.5: ▪ The front part – 3.5 meters long, ▪ Length of Buffer stop, ▪ Length of additional brakes, ▪ The back part – 0.5 meters long.

Figure 3.5 – Length of profile designated for reinforcement of track

34. . Hydraulic Buffer Stops Subject to approval of Israel Railways, terminal stations which do not offer sufficient distance for gradual braking of trains (braking distance), require installation of buffer stops with hydraulic braking systems which are in fact a type of combination between fixed and friction type buffer stops – see Figure 3.6. Hydraulic systems are designed to absorb, in part, the kinetic energy which is released during impact and to stop the train in a gradual manner. For this reason, the extent by which the maximum braking work is dependent on the speed of collision and the system length is limited.

RAILWAY BUFFER STOPS PLANNING GUIDELINES Page 10 Figure 3.6 – Hydraulic buffer stop

Hydraulic buffer stops consist of two parts: The back part, which includes the hydraulic system, from which the two arms which are tied to the front part extend. The back part is fastened at the track end to a concrete plate in a rigid manner that does not allow movement. The front part, which is connected to the two hydraulic arms, is also connected to the track rails. Upon collision of a train with this front part, the hydraulic arms move in the direction of the train's travel and gradually slow the train down to a complete stop.

35. . Wheel Stops Wheel stops are designed for use inside rail yards and garages whenever the track is frequented by a small number of trains which are moving or being moved at extremely low speeds. Stop wheels are designed to stop rolling stock, railroad cars, locomotives and other rail vehicles during shunting. They are installed whenever there is a need to absorb small amounts of kinetic energy or when there is not enough space for the installation of buffer stops which would have been required for proper absorption of the kinetic energy required.

RAILWAY BUFFER STOPS PLANNING GUIDELINES Page 11 Such devices are not designed to absorb high levels of energy. Stop wheels are installed onto tracks in pairs, with both devices standing in parallel to one another. Stop wheels are fastened onto the rails using arresting devices to which they are fastened using screws – see Figure 3.7. Stop wheels consist of three parts: 1. A collision plate, 2. An underside, 3. An arresting device.

Figure 3.7 – Stop wheel with arresting device

The braking work of stop wheels is relatively low and only works on the train's front axle. For this reason, light-weight trains are able to rise above the wheel stop and derail off the tracks.

36. . End Impact Walls End impact walls are positioned behind buffer stops and are used for the protection of people, structures, and other special constructions located in areas with high probability of a colliding train which may damage such structures, constructions, or even cause injury or fatalities as specified in Chapter 8. In places where end impact walls protect structures which may be destroyed, collapse on top of a train, or which may potentially result in human casualties, stop walls are implemented in order to push the train sideways during the collision, thus increasing the distance between the colliding train and structures. The myriad of buffer stops and end impact walls constitutes a single train stopping

RAILWAY BUFFER STOPS PLANNING GUIDELINES Page 12 system.

End impact walls are categorized into two groups: ▪ End impact walls for passenger trains inside stations. In tracks carrying passenger trains, on which minimum braking capacity buffers of 2,500 kNm are installed, impact walls should be designed for compliance with lateral forces of 5,000 kN at a collision height of 1 meter above the tracks rails. The height of such end impact walls, as illustrated in Figure 3.8, shall be 1.5 meters [2, 4].

Figure 3.8: End impact wall of passenger train track

▪ End impact walls for freight trains and trains traveling on secondary lines. In tracks carrying freight trains, in secondary lines or shunting, on which minimum braking capacity buffers of 2,500 kNm are installed, the impact walls are planned

RAILWAY BUFFER STOPS PLANNING GUIDELINES Page 13 for compliance with lateral forces of 10,000 kN at a collision height of 1 meter above the tracks rails. The height of end impact walls, as illustrated in Figure 3.9, shall be 2.0 meters. In order to ensure the wall's ability to withstand a collision of magnitude that is typical of heavy trains, the wall design must take the concrete plate which connects to it into account [2,4].

Figure 3.9 – End impact wall for freight trains

RAILWAY BUFFER STOPS PLANNING GUIDELINES Page 14  Braking Distances The braking distance is defined as the distance which is required in order to ensure the gradual stopping of a train which collides with a friction buffer stop – see Figure 4.1 which illustrates the braking distance.

Figure 4.1 – Braking distance Where:

lw - Maximum braking distance

lb - Buffer stop length

lv - The maximum distance intended for placement of the device and for ensuring braking distance

It is necessary to ensure the track section which is within range of the braking distance is straight and free of any obstacle which may interfere with proper functioning of the buffer stop. The track rails must be continuous, without any joints or welds which may cause the rails to bend. The braking distance depends on the buffer stop's braking forces. Longer braking distances require buffer stops with lower brake forces than those of shorter braking distance. It is for this reason that buffers having longer braking distances are more economical. The recommended braking distances for friction buffer stops are as follows:  Minimum braking distance for passenger trains approaching the track end - 8 meters [1]  Minimum braking distance for all other train types. - 4 meters [1]  Recommended maximum braking distance for all train types - 12 meters [1]

In special cases, when the 12 meter maximum braking distance recommended for all trains is insufficient, a longer distance of 16 meters may be implemented subject to Israel Railways authorization. Recommended wheel stop braking distances - - 1.5 – 2.0 meters [6] Shortening of a track's usable length due to the planning of a buffer stop and the required distances must be coordinated with the Israel Railways Operations Division Design Unit.

RAILWAY BUFFER STOPS PLANNING GUIDELINES Page 15  Collision Speeds The 'collision speed' is defined as the maximum permissible speed in which trains may travel when colliding with a buffer stop. The arresting forces of friction buffer stops are calculated based on the collision speed and weight of the train. Collision speeds classification based on train type:  Passenger trains - 15 km/h [1]  Freight trains - 10 km/h [1] Collision speeds classification based on track type:  Mail line trains - 15 km/h [6]  Empty passenger trains or fright in shunting - 10 km/h [6]

In order to ensure compliance with maximum train speed limits, Israel Railways operates a signalling system which monitors all train speeds. Israel Railways determines the maximum speed limits at the approach to track ends, secondary lines, train yards etc. on the basis geometric conditions and current state of track. In order to ensure trains stop before hitting the buffer stop located at the track end, it is necessary to install a Indusi System, with the final speed sensor being positioned 25 meters before the buffer stop. In flanks, rail yards, garages and shunting tracks it is not necessary to install an Indusi System for monitoring of train speeds unless there is need for additional protection of adjacent areas as specified in section 8.

Any Collision between trains and buffer Stops is considered a Rail Accident In order to prevent the occurrence of accidents involving collisions between trains and buffer stops, a minimum safety distance next to which trains are supposed to stop in the buffer stop approach was set. The minimum safety distances of the buffer stop approach are classified based on the type of buffer stop used, as detailed below:  Stop wheel - 1 meter  Fixed buffer stop - 2 meters  Friction buffer stop - 5 meters  Friction buffer stop with additional brake - 5 meters  Hydraulic buffer stop - 7 meters

RAILWAY BUFFER STOPS PLANNING GUIDELINES Page 16  Geometric Conditions Horizontal Alignment The angle by which a train collides with a buffer stop influences the manner by which the kinetic energy is transferred to the buffer stop and subsequently to the track rails. Accordingly, correct design of the horizontal alignment of the track section leading up to the buffer stop is of vital importance. The alignment of all buffer stop approaches must accordingly have no less than 20 meters of straight track (tangent track) before the buffer stop itself. In track ends, it is recommended the length of straight track leading up to the buffer stop be greater than the length of the longest train using that track.

Vertical Alignment When designing buffer stops, it is necessary to take the vertical alignment into account. Tracks having a negative approach gradient (descending) when running in direction of the buffer stop increase the kinetic energy released by the trains while tracks having a positive gradient (ascending) decrease it. It is for this reason recommended:  To place buffer stops of tracks with a positive approach gradient (ascending) towards the stop.  To avoid placing buffer stops in vertical inclinations. In some cases, when there is need of protection, in protective flanks and based on field conditions, it may be necessary to examine the type of buffer stop based on the analysis of various criteria as specified in Section 8, subject to Israel Railways authorization.

RAILWAY BUFFER STOPS PLANNING GUIDELINES Page 17  Calculation of Kinetic Energy and Braking Work The calculation of kinetic energy in trains which run on track rails which have a buffer stop installed on them is considered as the first step in the design and selection of the correct type of buffer stop based on the existing or planned conditions.

71. . Kinetic Energy Kinetic energy is calculated using the following formula:

Formula 1: Calculation of Kinetic Energy [1]

Where:

[kJ] Ekin – The kinetic energy of the train colliding with the buffer stop, [ton] m - The weight of the train colliding with a buffer stop, see Appendix B', For more information regarding the weight of rolling stock, it is necessary to coordinate with Israel Railways in order to obtain data pertaining to the type and weight of trains which are owned by Israel Railways and which make use of the track which is located nearby the planned stop. When calculating the weight of passenger trains, it is necessary to add the weight of all passengers based on the maximum capacity of each given train. [m/s] V - Collision Speed.

The calculation of kinetic energy is based on the assumption that the train crashes into the buffer stop without any braking whatsoever. For calculated kinetic energy values of different train weights and two permissible collision speeds - 10 km/h (2.8 m/sec) and 15 km/h (4.2 m/sec) - see Table 1.

Table 1: Calculated Kinetic Energy Values E [kJ] of Colliding Trains Speed (M/sec) Weight (tons) of colliding train 80 120 150 200 250 300 400 500 600 700 800 900 1000 2.8 m/sec 314 470 588 784 980 1176 1568 1960 2352 2744 3136 3528 3920 4.2 m/sec 706 1058 1323 1764 2205 2646 3528 4410 5292 6174 7056 7938 8820

RAILWAY BUFFER STOPS PLANNING GUIDELINES Page 18 Weighted kinetic energy is calculated by multiplying the calculated kinetic energy by the safety coefficient. The safety coefficient 'K' is graded on the basis of the required level of protection and the type of trains as follows:  For passenger trains - 1.5 [6]  For freight trains and shunting maneuvers in yards - 1.2 [6]  For freight trains and shunting maneuvers in yards, when it is necessary to protect various systems which are located behind or nearby buffer stops - 1.5 [6]  For freight trains and shunting maneuvers in yards, in cases where there are traffic zones, structures or residential houses located behind or nearby buffer stops which require protection. - 1.8 [6]  For preventing the fall of any train or track vehicle into an abyss - 2.0 [6]

The selection of a specific buffer stop type requires compliance with Condition No. 1, when the buffer stop's braking energy 'W' is equal to or greater than the maximum

weighted kinetic energy Ekin * K of the various train types using that track:

W ≥ Ekin * K Condition No. 1 [6, 1]

For an example of a typical buffer stop calculation, see Appendix D'.

72. . Braking Work The maximum braking work of buffer stops is calculated based on the number of arresting devices installed on the buffer stop and on the additional brakes. The braking work depends not only on the type and braking force of the arresting devices, but also on the maximum braking distance permitted. The braking work 'W' of friction buffer stops without additional brakes is calculated using Formula 2:

W = nB * FB * lw [kJ] Formula 2: Calculation of Braking Work [1]

Where:

nB [-] - No. of arresting devices

RAILWAY BUFFER STOPS PLANNING GUIDELINES Page 19 FB [kN] - The braking force of a single arresting device as stated by the manufacturer,

lW [m] - Length of maximum permissible braking distance.

The braking work of additional brakes which are installed behind buffer stops is calculated using Formula 3 which includes reference to the number of arresting devices

nZ installed and the braking distances of each arresting device in separate.

Formula 3: Calculation of Braking Work with additional brakes [1]

Where:

nB [-] - The no. of additional arresting devices.

FBi [kN] - The braking force of a single arresting device 'i' based on the braking distance

lWi and manufacturer specifications.

lWi [m] - The length of braking distance of a pair of arresting devices 'I'.

The braking work of stop wheels is calculated using Formula 2, Where:

nB [-] - The No. of arresting devices on a single stop wheel.

RAILWAY BUFFER STOPS PLANNING GUIDELINES Page 20  Criteria for the Design and Placement of Buffer Stops 81. . Designing of Buffer Stops When designing the type of buffer stop required, the following criteria must be taken into account:  Type of train  Minimum and maximum weight of trains running on the given track  The buffer stop approach gradient  Frequency of trains on the track  Local conditions such as location of structures, pedestrians, etc.  Location of light signals and distances of visibility  Signalling system for control of train speeds (Indusi System)  Permissible collision speed  The buffer stop's braking distance  Assessment of existing state of track surface, falling leaves and impact of weather on braking  Visibility and lighting conditions  Information regarding previous train collisions  The type of coupler connecting the railroad cars  Isolation of track joints and buffer stop electrical systems  Transport of hazardous materials and their type

Following analysis of the above criteria and as required by Israel Railways, the planner shall be required to fill out a Buffer Stop Order Form – Appendix A'. The planner shall be required to submit the form, Appendix A', to the Israel Railways Track and Environment Division for the purpose of placing the order as required.

82. . In-station Buffer Stops The exact location in which buffer stops are placed constitutes a main criterion when designing the type of buffer stop required. When planning buffer stops, the following criteria shall serve as the basis for the design:  The type of track rails used within range of the buffer stop and additional brakes include no joints or welds which may result in curving of the rails. It is necessary to ensure a minimum safety distance of 3 meters between the buffer stop and the nearest joint.

RAILWAY BUFFER STOPS PLANNING GUIDELINES Page 21  Within limits of the braking distance, it is necessary to maintain the dynamic vertical clearance of trains free of all obstacles.  It is prohibited to erect new buildings, support elements, or any other structure such sales kiosks, ticket booths and food stalls within the following limits [1, 2]: ▪ At least 20 meters behind the front end of the buffer stop. ▪ At least 5 meters from each side of the track axis. ▪ At least 5 meters behind the front end of the buffer stop, at the platform end. Subject to the approval of Israel Railways, waivers of these distances shall be allowed in stations or track sections in which a signalling system is used for monitoring train speeds.

83. . Special Areas Areas in which the integration of additional safety measures must be considered are those special areas in which the following conditions are met:  Based on the assessment of criteria specified in section 8.1, there is a high probability of derailment.  Based on the assessment of criteria specified in section 8.1, there is a high probability of serious damage in the event of train derailment.  There are various critical structures, pillar supported structures, work places, shops or crowd concentrations within a 5 meter radius around the buffer stop.  When shunting, there is a chance freight or passenger trains may roll down into an abyss or lower level.

Additional safety measures:  Construction of end impact walls as specified in Section 3.6  Improvement of lighting conditions in the buffer stop approach.  Installation of signs displaying distances to the buffer stop.  Limitation of train speeds when approaching buffer stops.  Identification and removal of nuisances / obstacles.

84. . In-tunnel Buffer Stops In terminal station tracks and secondary lines that run through tunnels it is necessary to verify the tunnel length is extended to the required length in accordance with the braking distance specified in Section 4 plus 3.0 – 5.0 meters.

RAILWAY BUFFER STOPS PLANNING GUIDELINES Page 22 85. . Temporary Arrangements Temporary buffer stops which are installed due to various railway works must comply with all of the criteria detailed above. In addition, the following conditions must also be taken into consideration:  Duration of the temporary works  The existence of work sites or temporary structures behind the buffer stop

RAILWAY BUFFER STOPS PLANNING GUIDELINES Page 23  Buffer Stop Requirements 91. . Adjustment of Buffer Stops for Rolling Stock Bumpers All types of rolling stock used by Israel Railways are equipped with front end bumpers. The position and height in which the bumpers are installed depends on the type of rolling stock in question. Bumper height is defined as the vertical distance from the track rails to the center of the bumper plate. Israel Railways operates rolling stock having one of two bumper heights:  Side height 1,060 ± 20 mm  Center height 865 ± 10 mm When designing buffer stops, the height and position of rolling stock bumpers must be taken into account for any one of the following cases:  When different types of rolling stock use the same rail it is necessary to design the buffer stops such that they comply with both heights.  When only a single rolling stock type uses a given track, there is no need to design the buffer stop for both heights.

92. . Buffer Stop Markings The position in which buffer stops are installed must ensure proper visibility and clear identification of the stop by all train drivers. For this reason it is necessary to install a red lighting fixture and bright-colored light reflectors on the front side of the buffer stop – see example in Figure 9.1.

Figure 9.1 - Marking of buffer stops with light reflectors

RAILWAY BUFFER STOPS PLANNING GUIDELINES Page 24 All light reflectors must be red-white in color and have the following dimensions:  Paint strip width - 10 cm  Minimum paint strip height - 20 cm In cases where the buffer stop shape does not allow the installation of light reflectors as specified above, it is necessary to install the reflectors such that they maintain the principle and order of colors in similar dimension proportions. The intensity by which light is reflected must ensure complete identification of the buffer stop by all rolling stock drivers. The material from which the reflectors are made must be of third generation Diamond Grade that is specifically designed for signs, with the highest possible light reflection, in full compliance with all Israeli Standard SI 2247 Grade 02 requirements. Excluding the following cases, all buffer stop lighting fixtures must be red in color.  When the buffer stop is placed at the end of a shunting rail.  When the red light may confuse rolling stock drivers who are driving on nearby tracks. In both cases it is permitted to install white lighting fixtures [5].

93. . Buffer Stop Color Buffer stops must be galvanized and colored in silver-gray RAL 9023 color shade or any other color approved by the customer. Paint shall be applied in two coats – primer and cover coat. The cover coat must possess the following properties:  High external durability.  High resistance to UV radiation.  Long-term preservation of color shade and shine (many years).  High resistance to corrosive industrial environments.  High resistance to wear / fragmentation.

RAILWAY BUFFER STOPS PLANNING GUIDELINES Page 25  Buffer Stop Risk Assessments 101. . Definition of Risks to which Buffer Stops are Exposed Buffer stops are devices which are designed to play an important role during incidents involving the collision of trains. When assessing their performance, it is necessary to take the following criteria into account:  Risk of injury to bystanders.  Risk of damage to nearby structures.  Type and state of buffer stop.  Information regarding previous collisions. All risk assessments must account for the range of incidents involving derailing of trains during low speed travel - which may result in light damages only - and during higher speed travel which is less likely but would probably result in devastating damages. Based on the model developed by 'Rail Safety & Standards Board Limited, London' which is described in Document GC/RC5633 [3], a set of risk assessment criteria which determine a weighted coefficient for hazardous events which buffer stops may experience once per hundred years has been defined. Based on the value of the weighted coefficient for hazardous events which buffer stops may experience once per hundred years, various activities which are required for the reduction of risk are determined in accordance with Section 10.3. The Risk Assessment Model serves as an aid to planners and maintenance crews when determining buffer stop placement conditions and maintenance levels. An example for definition of a buffer stop risk coefficient is presented in Appendix E'.

102. . Calculation of Weighted Coefficients (Table 2) The weighted coefficient for a hazardous event per buffer stop per 100 years relies on the weighting of various parameters such as the buffer stop type and location, the frequency of traveling trains, the type of rolling stock in question etc., as defined in Table 2. When calculating the weighted coefficient for a hazardous event per buffer stop per 100 years the following coefficients must be multiplied:  Average number of trains approaching the buffer stop.  Average number of passengers on trains approaching the buffer stop.  The integrated coefficient of the potential for collision – which specifies collision incidents.  Integrated buffer stop coefficient – which specifies the physical state of the buffer stop.

RAILWAY BUFFER STOPS PLANNING GUIDELINES Page 26  The combined train type coefficient – which specifies the type of trains approaching.  The combined coefficient for areas behind the buffer stop – which specifies the areas located behind the buffer stop.

The average number of trains approaching the buffer stop per day may be obtained from the Operations Planning Branch of the Israel Railways Operations Division. The average number of passengers on each approaching train may be obtained from the Israel Railways Passengers Branch or by calculated assessment using the maximum capacity of all rolling stock types. All weighted coefficients shall be calculated by choosing the correct categories of each influencing factor as specified in Tables 3 and 6. In cases where it is not possible to properly assess category coefficients, it shall be necessary to assess them by interpolation based on predefined coefficient values of the given category. The general weighted risk coefficient is calculated by multiplying the number of trains approaching per day by the average number of passengers per train and by the integrated coefficients calculated in Tables 3, 4, 5, and 6. The risk index is the value derived from the RSSB's Safety Risk Model which was developed by the Rail Safety and Standards Board, London, and is required in order to calculate the weighted coefficient for a hazardous event per buffer stop per 100 years. The weighted coefficient for a hazardous event per buffer stop per 100 years is calculated by multiplying the risk index by the general weighted risk coefficient. The weighted coefficient for a hazardous event per buffer stop per 100 years is the sum of all category coefficients.

10.2.1. Integrated Collision Potential Coefficients (Table 3) The integrated collision potential coefficient is obtained by multiplying the weighted risk coefficients of the influencing factors. Listed below are several clarifications for the calculation of influencing factor values:  A list of all collisions in which buffer stops were involved may be obtained from the Israel Railways Safety Inspection Branch.  Among other things, post-collision changes include plans for improvement of driver training, infrastructure and maintenance.  The definition of buffer stop approach speed limits is carried out based on the buffer stop type and position.

RAILWAY BUFFER STOPS PLANNING GUIDELINES Page 27  Example of driver nuisances – advertising billboards, trees, and any other nuisance which may interfere with the driver's attention.  Selection of the coefficient is based on Israel Railways - Safety, Security and Environment Division data regarding the state of rail surfaces and fallen leaves. 10.2.2. Integrated Buffer Stop Coefficients (Table 4) The integrated buffer stop coefficient is obtained by multiplying the weighted risk coefficients of all influencing factors. Listed below are several clarifications for calculating influencing factor values:  In the event the repair is required for improvement of safety level, it must be implemented on an immediate basis.  When assessing risks, it is necessary to specify the urgency for immediate execution of the required repair.

10.2.3. Integrated Train Type Coefficients (Table 5) The integrated train type coefficient is obtained by multiplying the weighted risk coefficients of all influencing factors. Listed below are several clarifications for calculating influencing factor values:  Data regarding the type of rolling stock entering the track may be obtained from the Israel Railways Operations Planning Branch – appendix B'.  Full conformity is achieved when the height of the buffer stop head corresponds with the height of the train bumpers.  Partial conformity is achieved when the height of the buffer stop head corresponds with the height of the train bumpers but the train is equipped with a coupling device for connection of railroad cars.  No conformity is achieved when the height of the buffer stop head does not correspond with the height of the train bumper.

10.2.4. Integrated coefficients for Areas Located Behind Buffer Stops (Table 6) The integrated coefficient for areas located behind buffer stops is obtained by summing up the product of all weighted risk coefficients which are influenced by public/work-team characteristics and the product of all weighted risk coefficients which are influenced by structure characteristics. Listed below are several clarifications concerning the calculation of influencing factors:  All crowd values are based on the number of people situated in the area

RAILWAY BUFFER STOPS PLANNING GUIDELINES Page 28 behind the buffer stop, excluding all persons located inside buildings.  A safety system including an Indusi System for monitoring of train speeds.  The assessment of coefficients for structures which are not defined in the list shall be carried out by taking the number of people located inside the building into account and calculating an intermediate value based on the coefficients specified in the Table.

103. . Undertakings for reduction of Risk Levels Risk Assessment Systems determine the value of the weighted coefficient for a hazardous event per buffer stop per 100 years. It is according to this coefficient that various tasks which are required for lowering the risk level, as specified in Table 7, are determined.

104. . Reassessment of Risk A reassessment of buffer stop risks shall be carried out for each planned and existing device within 10 years. Pursuant to Israel railways instructions or following infrastructure changes in the buffer stop and/or its immediate environment, it shall be necessary to conduct a reassessment of the buffer stop risk. Inter alia, changes which may influence the risk assessment include the following:  A change in track layout  A change in the type of trains using the track  A change in the number of trains using the track  A change in approach speed  A Railway Signaling and Indusi System  A change in usage of areas located behind buffer stops  The addition of structures or supports behind buffer stops

RAILWAY BUFFER STOPS PLANNING GUIDELINES Page 29 Table 2: Assessment of Buffer Stop Collision Risk Hazardous Event Weighting Coefficient Risk Category Average No. Average No. Integrated Integrated Integrated Integrated General Risk Index Weighted of Trains of Passengers Collision Buffer Stop Train Type Coefficient for Weighted coefficient for a Approaching per Potential Coefficient Coefficient Areas Located Risk hazardous Per Day Approaching Coefficient – See Table – See Table Behind Buffer Coefficient event per Train – See Table 4 5 Stops buffer stop per 3 – See Table 100 years 6

Incidents without X X X X X No = X -6 = 3.9 * 10 serious implications on buffer stops / rolling stock when crossing safety distances

Risk to Train + Passengers Incidents having X X X X X No = X -6 = serious implications on 7.0 * 10 buffer stops / rolling stock when crossing safety distances

+ Risk to public, Incidents having X No X X X X No = X --5 = 8.1 * 10 passengers, serious implications on staff located in buffer stops when areas behind crossing safety buffer stops distances

+ Incidents without X No X X X X No = X -5 = 9.9 * 10 serious implications on buffer stops / rolling stock when crossing safety distances

+ Incidents having X No X X X X No = X -4 = serious implications on 2.7 * 10 buffer stops / rolling stock when crossing safety distances

Table 3: Assessment of Integrated Collision Potential Coefficient

Factors Influencing Chance Category Weighted Risk Assessed for Collisions Coefficient Value

No previous collision incidents during past 5 years 0.8 Information regarding or major changes implemented since last collision. previous collisions One single collision during past 5 years without 2.0 major changes following the collision. More than one collision during past 5 years 10.0 without major changes following the collisions. X > 10 meters 0.8 Standard safety distance 5-10 meters 1.0 before buffer stop < 5 meters 1.5 X Longitudinal gradient of buffer 1.2 stop approach 1.0 1.1 X 10 k/h 0.8 20 k/h 1.0 Speed limit nearby buffer stop 30 k/h 1.1 40 k/h 1.2 50 k/h 2.0 X Visibility Direct Approach. Proper lighting 1.0 Curved approach or insufficient lighting 1.2 X Markings of distances to Yes 0.9 buffer stop during approach No 1.0 X Driver nuisances No possible nuisances exist 1.0 Possible nuisances exist 1.1 X State of track surface No proof of possible adhesion problems 1.0

RAILWAY BUFFER STOPS PLANNING GUIDELINES Page 32 Proof of possible adhesion problems 1.2 = Integrated Coefficient for Potential Collision

RAILWAY BUFFER STOPS PLANNING GUIDELINES Page 33 Table 4: Assessment of Integrated Buffer Stop Coefficient Factors Influencing Buffer Category Weighted Risk Assessed Stop Risk Coefficients Coefficient Value

Fixed (Concrete, Steel) 1.8 Buffer stop type Energy absorbing (friction, hydraulic) 0.8 Integrated energy absorbing (friction + hydraulic) 0.6 X < 10 years 0.8 Buffer stop age 10 - 30 years 1.0 > 30 years 1.5 X 6 months 0.8 Frequency of Inspections 1 year 1.0 2 years 1.5 X No repair required before next inspection 1.0 Condition of buffer stop, Repair required within 3 months 1.5 track and track joints Repair required within 1 month 2.0 Immediate repair required 4.0 =

Integrated Buffer Stop Coefficient

Table 5: Assessment of Integrated Train Type Coefficient Factors Influencing Buffer Category Weighted Risk Assessed Stop Risk Coefficients Coefficient Value

Passenger train with push locomotive 1.6 Type of rolling stock Passenger train with pull locomotive 1.4 Freight train with push locomotive 0.9 Freight train with pull locomotive 0.8 X Conformity between rolling Full conformity 0.8

RAILWAY BUFFER STOPS PLANNING GUIDELINES Page 34 stock and buffer stop Partial conformity 1.2 Non-conforming 1.5 =

Integrated Train Type Coefficient

RAILWAY BUFFER STOPS PLANNING GUIDELINES Page 35 Table 6: Assessment of Integrated Coefficient for Areas Behind Buffer Stop Factors Influencing Buffer Stop Risk Category Weighted Risk Assessed Coefficients Coefficient Value

None 0 Gathering point for public and/or Low crowd concentration of 1-2 people 1 work teams in areas behind buffer on average stops Medium crowd concentration of 3-10 2 people on average High crowd concentration > 10 people on 5 average X

P < 10 meters 1.0 u

b Distance of crowd concentrations l

i 10 - 20 meters 0.5 c

areas from front side of buffer stop /

W 20 - 30 meters 0.2 o r k 30 - 50 meters 0.1

a 50 - 100 meters 0.01 m > 100 meters 0.0 X Train Protection System Yes 1.0 No 1.04 X End impact walls Yes 0.1 No 1.0 + Existing structures in areas located None 0 behind buffer stops Walking trail 1 Office areas 3 Commercial areas 5 S

t Support structures (piles) 10 r u c t

u X r e

s Distance from existing structures < 10 meters 1.0 to front end of buffer stop 10 - 20 meters 0.5 20 - 30 meters 0.2 30 - 50 meters 0.1 50 - 100 meters 0.01

RAILWAY BUFFER STOPS PLANNING GUIDELINES Page 36 > 100 meters 0.0 X Train protection system Yes 1.0 No 1.04 X End impact walls Yes 0.1 No 1.0 =

Integrated Coefficient for Areas Behind Buffer Stops

RAILWAY BUFFER STOPS PLANNING GUIDELINES Page 37 Table 7: Recommendations for Execution of Tasks to Reduce Risk Level Value of Weighted Means for Reduction of Risk Level Coefficient for Hazardous Event per Buffer Stop per 100 Years < 0.03 - Minor means at low cost 0.03 - 0.15 ▪ Change in buffer stop conditions based on criteria specified in Table 3: - Reduction of speed limit in buffer stop approaches to 30 km/h or less - Improvement of lighting systems in buffer stop approaches - Removal of any driver nuisances - Implementation of means for improvement of track surface condition ▪ Change in maintenance conditions based on criteria specified in Table 4: - Increase in the number of inspections carried out to at least once a year. - Implementation of all required repairs within 1 month 0.15 – 0.3 ▪ Significant changes in buffer stop conditions based on criteria specified in Table 3: - Reduction of speed limit in buffer stop approaches to 25 km/h or less - Improvement of lighting systems in buffer stop approaches - Removal of any driver nuisances - Implementation of means for improvement of track surface condition ▪ Change in maintenance conditions based on criteria specified in Table 4: - Increase in the number of inspections carried out to at least once every 6 months. - Immediate implementation of all required repairs. > 0.3 ▪ Implementation of required tasks for reduction of the aforementioned risk levels. ▪ If the weighted coefficient value remains at a constant level of above 0.3, it shall be necessary to consider execution of the following tasks based on costs involved. - Increasing of safety distance as specified in Section 4 (and Table 3) - Improvement of buffer stop type (Table 4) - Relocation of buffer stop in order to increase the distance to crowd concentrations located in areas behind the buffer stop (Table 6). - Implementation of an Indusi System for monitoring of train speed during approach (Table 6) - Erection of end impact walls (Table 6) - Relocation of existing structures which are located behind buffer stops (Table 6)

RAILWAY BUFFER STOPS PLANNING GUIDELINES Page 38  List of Place-markers (1) German Standard DS 800 01 (2) British Standard; GC/RT 5033; Terminal Tracks-requirements for Buffer Stops, Arresting Devices and Impact Walls, Issue 2, December 2007 (3) British Standard GC/RC 5633 Recommendations for the Risk assessment of Buffer Stops, Arresting Devices and End Impact Walls, Issue 2, December 2007 (4) UIC CODE 777-2, Structures built over railway lines - Construction requirements in the track zone. 2nd edition, September 2002 (5) British Standard GK/RT 0031 - Lineside signals and Indicators, Issue 4, February 2002 (6) Austrian standard DV B 53

RAILWAY BUFFER STOPS PLANNING GUIDELINES Page 39  List of Appendices Appendix A': Buffer Stop Order Form Appendix B': Passenger Trains and Locomotive Types Appendix C': Buffer Stop Examples Appendix D': Buffer Stop Calculation Example Appendix E': Example for Preparation of Buffer Stop Risk Coefficient Appendix F': Fixed Concrete Buffer Design Scheme

RAILWAY BUFFER STOPS PLANNING GUIDELINES Page 40