MASS-PRODUCTION OF SYNTHETIC SLEEPER - Fabrication, works for sleeper and recycling Chuou Line Tokyo Staion JR East Yoshihiko SATO, Dr.Eng Railway Track System Institute Koji MOTOI Sekisui Chemical Co.

Contents 1. Introduction Use and specifications of synthetic sleeper Fabrication Inspection Works for sleepers 5.1 Turnout 5.2 Sleepers on bridge 5.3 Sleepers in directly fastened track Reuse and recycles Concluding remarks

Production of synthetic sleepers Introduction Production of synthetic sleepers Laying work in Austria Synthetic sleeper is composed of long grass fibre and hard foamed urethane. It was developed and fabricated in Japan in 1980, to ameliorate the characteristics of the wooden sleeper, especially, durability and environmental protection.

Turnout of #38 at Takasaki Uses of synthetic sleeper Turnout of #38 at Takasaki Bridge over Tone river Kammon tunnel Curve in Guangzhou Metro

Specification High mechanical strength little water absorption High electrical insulation High fastening force for dog and screw spikes Notes: JIS Z2110 (Methods of tests for wood -1994), JIS C2110 (Testing methods for electric strength of solid insulating material -1994), JIS K6911 (Testing methods for thermosetting plastics -1995)

Fabrication (1) – FFU plate - Fibre reinforced Foamed Urethane

Surface grinding of FFU plates Painting of sleeper surface Fabrication(2) - From FFU plates to sleepers Accumulation of FFU plates Surface grinding of FFU plates Cure after gluing Painting of sleeper surface

Product bending strength Glued shearing strength Inspection – Bending strength and glued shearing Product bending strength Glued shearing strength

Dog spike pull-out test Screw spike pull-out test Inspection – Dog spike and screw spike pull-out test Dog spike pull-out test Screw spike pull-out test

Test piece bending test Inspection – Test piece test, specific gravity and sizes Test piece bending test Specific gravity Thickness Width Length

Setting of turnout on synthetic sleepers

NC Processing of sleepers Preparation of sleepers for bridge NC Processing of sleepers

Reuse and recycling

Evaluation Excellent Good Fair Poor FFU Concrete Sleepers Cost Environment Delivery Time Productivity Repairing Workability Durability Strength Wooden Sleepers Concrete Sleepers FFU Synthetic Sleeper Item

Concluding remarks The historical developments and fundamental characteristics of the synthetic sleeper were introduced in reference [1]. As having documented and demonstrated so far, the supply of mass produced synthetic sleepers is being introduced in a controlled manufactured environment to ensure precision and accuracy of the finished product. Further, the number of different applications and uses of synthetic sleepers have been outlined in the paper. Finally, the reuse and recycling of them are introduced. In the future more developments for actively decreasing the vibration and noise from railway track and for the specific use of synthetic material are expected.

Reference [1] Takai H, Sato Y & Sato K, Japanese experiences of using and fabricating synthetic sleepers, Railway Engineering 2005. [2] Ohi, S & Nagafugi, T, Performance of synthetic sleeper, Rail International pp. 35-42, 1990.05.

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