Concrete sleepers combined with heavy section flat bottom rail came into widespread use on mainline routes from the 1960s.
The concrete sleeper version of Pecos' O gauge Streamline flexitrack usins the same code 143 flat bottom rail as the wood sleeper base flexitrack and points and points denoted by the FB suffix. The sleepers are finely moulded with Pandrol type rail clips and the angled pofiles of the sleepers recreated.
Each length of track is 1 yard / 3 feet (914mm) in length and features nickel silver rail for excellent electrical conductivity. SL-710FB metal and SL-711FB insulated joiners are required.