Double track on a viaduct, laid on composite sleepers

Applications

Rerawa sleepers
on live track

Rerawa sleepers are in revenue service in several Turkish cities; dozens of trains pass over them every day. Every photograph below was taken on those lines.

Composite sleepers on a curved track, the date 22.10.25 stencilled in yellow — The laying date is stencilled on the sleeper.

Kayseri

Light-rail
line

Timber sleepers on a curved section of the line were replaced with composite. The existing rail profile and coach-screw fastening were retained; nothing else on the track was touched. Possession time was kept short.

Sleeper replacement on curve geometry
Direct fit to the existing coach-screw fastening — no steel baseplate
Drilling and adjustment carried out on site
Continental climate: winter temperatures fall into the minus twenties, and the sleepers remain dimensionally stable

Adana

Metro
viaduct

The viaduct section of the metro was laid on composite sleepers and is in revenue service.

Continuous track on the viaduct
Full-length, one-piece sleepers in the turnout zone
Reduced transmission of noise and vibration on the structure
Mediterranean climate: rail temperatures exceed 50 °C in summer, and the sleepers remain dimensionally stable

Aerial view of a multi-track turnout zone laid on composite sleepers — Turnout zone, from above.

Bursa

Urban
rail line

A composite-sleeper installation is under way on the Bursa urban rail line. Sleepers of different lengths were produced in the same set-up; dimensions and hole layout were taken from the line’s existing fastening system.

Different sleeper lengths, one production set-up
Hole layout matched to the existing fastening
Marmara climate: humid seasons and frost nights together

Climate

The same dimension
in heat and in cold

Rerawa sleepers are in service in three distinctly different climates. In Adana, summer days exceed 40 °C and the sleeper surface in the sun runs hotter still. In Kayseri, winter temperatures fall into the minus twenties. In Bursa, high humidity and frost nights occur together.

The first demand a sleeper must meet on any of these lines is to hold gauge across that temperature range. The Rerawa formulation was developed for low thermal expansion and dimensional stability. Expansion and contraction stay limited as the sleeper heats and cools; coach-screw holes stay where they were drilled.

Unlike timber, it does not take up moisture and swell, or dry out and split. The dimensional play that loosens fastenings through the seasons is removed.

From the field