Fifteen Years' Experience with Synthetic sleeper


Takaharu NAGAFUJI , Noritsugi ABE
For the purpose of protecting global environment and to improve the function of wooden sleeper, especially its durability, a synthetic sleeper which consists of hard type polyurethane foam and continuous long glass fiber, has been developed. In the basic tests on physical properties, it was found that synthetic sleepers are almost similar or superior in their properties to wooden ones, and in additon, they have great resistance to strength drop and shape change arising from water absorption, which is the major reason for sleeper renewal. In order to confirm, therefore, the durability of synthetic sleepers, they were tentatively laid on the operating lines fifteen years ago. It has been proved through basic property tests on and fifteen years' experience with synthetic sleepers that they could be a practicable alternative to the impossible ideal of permanent sleeper with no decay nor crack on its surface.