SSpecialpecial editionedition paperpaper Development of Method for Improving Equipment for Implementation of Stable Current Collection at High Speed Kunio Ikeda*

JR East built the test train car Fastech 360 working toward implementation of a world class high speed train and started high speed on- track testing in June of last year. During this test, the test train car was driven at 360 km/h. Data concerning running stability and burden on the environment were collected and the purpose of this data is to contribute to implementation of 360 km/h commercial operation.

In order to implement stable electricity collection while traveling at 360 km/h, significant improvements must be made to the overhead wiring equipment. A method for enabling improvements to be made inexpensively and in a short period of time was developed. The system thus developed has been introduced in a test section between Sendai and Kitakami and it will be introduced by this paper.

• Keywords: Shinkansen, increasing speed, current collection efficiency, overhead line equipment

1 Introduction Table 1: Overhead line for high speed sections of JR East Shinkansen Me Ax Tr V The standard heavy compound overhead line for the Shinkansen is St180 Cu150 Cu170 limited to travel at roughly 240 km/h and even for a running test, in Tension- increased 275km/h order to drive at 360 km/h improvements to the overhead line overhead line 24.5kN 11.8kN 17.6kN equipment are essential. St240 Cu150 CS110 CS compound overhead line 365km/h In the current running test there was a limited period of one year from 24.5kN 9.8kN 19.6kN

when the test was scheduled to when it was started. As the overhead line Upper row : Line type / Lower row : Overhead line tensile force over a large area needed to be improved, development of a new method Me : Messenger wire / Ax : Auxiliary messenger wire of construction enabling shortening of the construction period and in Tr : Contact wire / V : Recommended running speed 1) addition providing resolution to the issue found during testing using a CS : Steel covered copper contact wire business car conducted in 2003 was implemented. Messenger wire Support member

Dropper Overhead line equipment suitable Auxiliary 1st 2 messenger 2nd 3rd 4th 5th for increasing speed wire Hanger

As is well known for targeting increase in speed, increase in the wave Contact wire Pull-off arm propagation velocity c of overhead line given by Eq. (1) is effective; Fig. 1: Compound overhead line therefore, high tension and weight reduction of the contact wire used to

handle the increase in speed. Performance equivalent to that provided by the “CS compound 1 2 ...... C= (T /ρ) * 3.6 [km / h] (1) overhead line” is a requirement for this high speed test as well. Here T is tensile force (N) and ρis weight per unit length (kg/m) However, the test area covers a long distance from Sendai to Kitakami The overhead line used for high speed sections of our Shinkansen are giving an area of approximately 60 km (60 drums) needing shown in Table 1 and Fig. 1. modification to overhead line and it was feared that it would not be In Table 1, the “Tension-increased overhead line” is the overhead line possible to complete this modification within the 1 year period. improved for increasing speed to 275 km/h in conjunction with introducing E2 and E3 series to the and the “CS Issues with modification of compound overhead line” is the overhead line improved for the running 3 overhead line test for the test train car “STAR 21” that reached a maximum speed of 3.1 Issues with current collection system performance 425 km/h on the . In the running test using “CS compound overhead line” implemented in 2003, a very large contact wire deflection (stress) of a contact wire

※ Technical Center, Research and Development Center of JR East Group JR EAST Technical Review-No.8 37 Special edition paper

exceeding 1,000μst was observed at 360 km/h 1). tensile force at 53.9 kN, the total tensile force of the the messenger wire Compounding of: and for the auxiliary messenger wire must be lowered. In the STAR 21

● Through changing to one pantograph collector head, stress is test, the messenger wire tensile force was left the same and only the concentrated, tensile force for the auxiliary messenger wire was reduced and this leads

● The distance between pantographs on the test train car is small, to the issues described in section 3.1. In addition, as the contact wire

● The weight of the pull-off arm is large, and the like are considered to weight is reduced yet the tensile force of the messenger wire was not be the cause of the issue. changed, all of the droppers had to be replaced to maintain the height of the contact wire, increasing the workload of construction and leading Among these, the tensile force of the auxiliary messenger wire is low and to the issue in section 3.2. has not been able to maintain sufficient wave propagation velocity and this is causing obstruction to transmission of the wave motion. Here, the method adopted was to reduce the tensile force in the messenger wire to counterbalance the weight reduction of the contact 3.2 Issues with construction wire, making it unnecessary to change the droppers. At the same time, If the improvement method for the overhead line for the STAR 21 test the reduction in tensile force was added to the auxiliary messenger wire is taken as an example, improving of one drum (length of roughly and this enabled increasing the wave propagation velocity*2 to the level several hundred meters to 1.5 km) took 3 days (Table 4) and if the same needed for the test speed (360 km/h). construction method is used this time, it would require an entire half a year, even if construction is performed every day. However, if other Eq. (2) shows calculation of slack D that occurs in a catenary curve (Fig. 2) competing maintenance work is considered, it would have been X*(S-X)*ρ D= [m]...... (2) impossible to complete the construction before starting the test unless 2*T /9.8 this construction period was greatly shortened. Here S is span length (m). T is tensile force (N) and ρ is weight per unit length (kg/m), in the same way of Eq. (1). Development of overhead line that can be easily modified 4 and that has superior current collection performance D Here, working towards use of overhead line with increased tensile force X S X for this test in the vicinity of 360 km/h, in order to increase current collection performance and proceed with construction effectively and Fig. 2: Slack in a catenary curve smoothly, construction was moved forward with based on the following conditions. Through changing the contact wire to 110 mm2, the weight per unit (1) Ensure a contact wire wave propagation velocity of roughly 500 length of the overhead line system goes from 4.33 kg to 3.83 kg; km/h*1 therefore, if simply calculated from Eq. (2), roughly 21.6 kN is desirable (2) In order to prevent having to modify support structures, the total for the messenger wire tensile force. Therefore, the modified overhead overhead tensile force will not be changed line for the current test train car Fastech 360 is as shown in Table 2. (3) Shorten the construction period to 2/3

Table 2: Fastech 360 test overhead line As stated previously, due to confliction with other maintenance work, it Me Ax Tr V is desirable to be able to hold the number of construction days required Fastech 360 St180 Cu150 Cu110 to roughly 100 days. Here, targeting shortening of the construction test overhead 360km/h period for modification of the overhead line to roughly 2/3, it was line 21.6kN 12.7kN 19.6kN considered best to proceed such that modifications to support structures would not be required. Verification of construction work efficiency and current 5 collection performance In order to satisfy (1), the contact wire was reduced from 170 mm2 to 110 mm2 reducing diameter and weight and tensile force was increased 5.1 Verification of construction work efficiency from 17.6 kN to 19.6 kN. First, the lengths of the droppers for the “tension-increased overhead In conjunction with (2), in order to maintain the total overhead line line” and for the “Fastech 360 test overhead line” were verified. Comparison where span length is 50 m is shown in Table 3.

※1: Train speed ≦ wave propagation velocity × 0.7-0.8 is desirable 2) ※2: If the tensile force in the auxiliary messenger wire is set to 9.8 kN, the wave propagation velocity becomes roughly 300 km/h.

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It follows that there was very little adjustment needed after the Table 3: Dropper length before and after modification modification. 12345st nd rd th th Prior to modification 1,118mm 856mm 768mm 856mm 1,118mm 29D between Ichinoseki After and Mizusawaesashi modification 1,119mm 856mm 768mm 856mm 1,119mm Wear

For span lengths other than 50 m, the difference is within few Deviation millimeters.

Height

Table 4: Comparison of overhead line modification methods

CS compound overhead line Fastech 360 test overhead line Prior to modification

Yscale= 1v/div File name: IchinosekiPHC.wm3 (Subtitle) 1 Replacement of first and (Lemma: Left) (Lemma: Center) (Lemma: Right) second yokes Power pole position Stretching of new contact 2 Shock

First day wire(110 )

250mm 0 3 Pre-stretch Deviation 1 Wear

Replacement of hangers 5025mm 1 Pull-off arm replacement 4 Trolley height 5000 and pull-off arms etc. Deviation

50m/s~2 Winding up of old contact 0 5 Shock 1 wire(170 ) Height 2 Attaching new droppers 6 Overlap adjustment #2 results #4 results

165 170 175 180 185 190 195 Time (sec) Xscale= 1sec/div 1 Replacement of first yoke Shock After 2004/0721 12:02:43 WM3 Ver2.21 (byRTRI) modification 2 Stretching of new contact wire(110 ) Second day Fig. 3: Comparison of inspection train car chart before and after modification 3 Pre-stretch 5.2 Verification of current collection performance 4 Replacement of hangers 1 Pull-off arm replacement and pull-off arms etc. The evaluation items for current collection performance were primarily Cutting and removal 5 ● of old droppers Contact loss rate ● Contact wire uplift 6 Winding up of old contact wire(170 ) ● Contact wire deflection 7 Overlap adjustment 2 Adjustment to overhead line These 3 items were used for evaluation; however, this is primarily a Third day 1 Up/down movement countermeasure for reducing the large “contact wire deflection” of moveable bracket previously observed. 2 Removal of dropper clip

3 Adjustment to overhead line Here, as one method, through raising the tensile force of the auxiliary messenger wire and increasing the wave propagation velocity, reduction It follows that, as shown in Table 4, through making replacement of of the contact wire stress was tried. droppers unnecessary, the process is greatly simplified compared to the construction method used for modifying the “CS compound overhead The results were verified using simulation 2). A portion of the results are line” and it became possible to complete switchover of the overhead line shown in Fig. 4. in 2 days, where it previously required nearly all of 3 days. Note, in the results of the simulation, similar to the contact force the Note, in order to change the tensile force on the messenger wire contact wire uplift was greatly reduced from 70 mm to 35 mm and as (replacement of first and second yokes), a cooperation company was anticipated, it is considered that this reduced fatigue damage (stress) developed special tooling enabling shortening of construction time. to the the contact wire.

Fig. 3 is a comparison of the data for the overall electric railway test On the other hand, an increase in contact loss rate is seen; however, it is train car for the conditions before and after the modification. As can be still within 30% of the permissible range. seen the conditions of height and deviation of the overhead line prior to the modification have been recreated very well. It has also been confirmed that contact loss has been greatly reduced through use of a “multi-segment contact strip” which reduced the mass

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of the moving portion of the pantograph and increased performance of method” are being performed through high speed running tests. overhead contact line following ability1) and the actual percentage is Last of all, I would like to thank all who cooperated with this considered to be only a few percent. development.

800 PMAX Ax=1t PMAX Ax=1.3t PDIV Ax=1t PDIV Ax=1.3t

Contact force (N) References 600 1) Ikeda: Current collection performance for tests at speeds higher than 300 km/h using a commercial train car” JREA, 2004 11 400 (Vol. 47, No. 11)

200 2) The Railway Technical Research Institute report: “Train car electric wires and pantograph characteristics”, 1993 10 0 300 320 340 360 Speed (km/h) Sample pantograph: PS207 (yield direction of 1 pantograph) 30 Contact loss rate Ax=1t Contact loss rate(%) Contact loss rate Ax=1.3t 20

10

0 300 320 340 360 Speed (km/h) Sample pantograph: PS207 (yield direction of 1 pantograph)

Fig. 4: Simulation results

6 Conclusion

A summary of the development of overhead line equipment that has superior current collection performance and that can be improved efficiently in a short amount of time targeting implementation of commercial travel at 360 km/h has been introduced.

This overhead line system was introduced as improvement to equipment in the high speed running test area between Sendai and Kitakami on the Tohoku Shinkansen and construction of approximately 60 km over one year in 2004FY was completed.

Currently the running test that is being implemented is being performed to verify the effectiveness of this system and we would like to refine this to develop a standard for equipment to be used for starting business at Shin-Aomori.

Note, introduction in this paper is not provided; however, in conjunction with targeting increase in speed, development of “lightweight pull-off arm that reduces contact wire stress”, “a new overhead line stress control method”, and “a contact loss rate evaluation

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