Plastic Sleepers (ISO 12856-1)
"Plastic sleeper" is a general term for a sleeper which is shaped using synthetic resin. Synthetic sleepers, which were composed of complex materials including continuous glass fiber and rigid urethane foam resin, were developed in 1980 in Japan. Its features are as follows;
  • Enough toughness necessary for sleepers is provided,
  • Advantage over concrete sleepers in being light weight, with higher elasticity and electrical insulation,
  • Advantage over wooden sleepers in durability and decay-prevention properties.

Because of these features, synthetic sleepers are applied as sleepers on steel bridges and at switch and crossing sections. Moreover, superior technology is leading to the increase in application cases not only in Japan but around the world.

Concerning standards for plastic sleepers, JIS E 1203 "Synthetic sleepers" was published in 2007, at a time where there were very few related standards outside Japan. Therefore, ISO/TC 61 "Plastic" (member body: JPIF = the Japan Plastic Industry Federation) started to discuss standardization for plastic sleepers in 2008 for the purpose of further diffusion of the technology concerned with synthetic sleepers globally. Subsequently, Japan has played a key role in developing the standard by undertaking the role of convenor in ISO/TC 61/SC 11/WG 9. As a result, ISO 12856 part 1 "Materials" was published in March 2014.