Network Rail is updating a section of rail track that runs through a busy main station on the south coast of England with more durable fiber-reinforced polyurethane foam (FFU) sleepers. These fiber-reinforced polyurethane foam (FFU) sleepers are manufactured by Sekisui (Water Chemistry) in Japan.

This section of railway track in the United Kingdom originally used wooden sleepers, which are currently being replaced by fiber-reinforced polyurethane foam (FFU) sleepers. The fiber-reinforced polyurethane foam (FFU) sleeper is said to extend its service life by 30 years while requiring less maintenance.

Fiber-reinforced polyurethane foam (FFU) sleepers are made by reinforcing thermosetting hard polyurethane foam with long glass fibers. This makes it lightweight while providing durability, weather resistance and processability. In addition to rail systems, it has a wide range of applications, including construction and civil engineering, truck compartments and ship decks, manufacturing plants and aquaculture facilities, as well as sports facilities and parks.

Fiber-reinforced polyurethane foam (FFU) has been used as a railway sleeper material for more than 40 years and is currently used by various railway companies in Japan. The material was first used in Europe in 2004 and since then Europe has become a major market, with increasing demand expected in Germany and the United Kingdom.

Sekisui of Japan is a leading manufacturer of fiber-reinforced polyurethane foam (FFU) sleepers. In 2023, the company opened a production plant in Roermond, the Netherlands.