Stanton Bonna Supplies Twin Block Sleepers To Manchester Metrolink

One of the most successful light rail systems in the UK, carrying nearly 20 million passengers every year, Manchester Metrolink’s new £575M (Phase 3A) project includes the 3.9 mile (6.3 km) upgrade to the East Manchester Line extension to Droylsden, which will run from Manchester Piccadilly to provide a link to the City of Manchester Stadium and the National Cycling Centre. Phase 3A also includes a new 3-stop, 1.7 mile (2.7 km) South Manchester Line extension from Trafford Bar and reconstruction of the 14 mile (22.5km) Oldham Loop Line to Oldham and Rochdale.

Stanton Bonna is close to completing the supply of its lightweight Twin-Block Concrete Railway Sleepers to MPT for the £575M Phase 3A extensions to Manchester’s Metrolink network.

The contract, which includes over 50,000 VAX U21 Twin-Block sleepers, follows successful light rail systems installations of Stanton Bonna sleepers in Birmingham, Nottingham and Sheffield – as well as High Speed 1 (formerly the CTRL) and previous phases of Manchester Metrolink since 1998.

Five variants of the VAX U21 Twin-Block sleeper were supplied with Pandrol Fastclip, E-clip and VIPA baseplates for both the ballasted and slab track sections.

The adaptability of the twin block sleeper meant that sleepers could be easily matched to suit the existing trackforms on Metrolink. The principal quantity of sleepers was set for BS113A rail and Fastclip fastenings, with smaller quantities of sleepers also being provided with E-clip fastenings for both BS113A and 80A rail sections. Weighing only 160kg and with a depth of 170mm at the rail seat, the sleepers are lighter than traditional monoblock sleepers - and the steel tie bar also makes them easier to handle on site. Increased lateral stability is another key reason why the twin block sleeper has been used on so many UK LRT projects.

Two variants of the sleeper were supplied with Vipa baseplates, one with hold down assemblies using plastic inserts and the other with cast iron inserts to be used on the tighter radius curves. The sleepers have Vipa baseplates fitted at the Stanton Bonna factory before being delivered to site ready for installation.

The construction method consists of laying out the sleepers on a concrete slab; then rails are fitted and the track is raised using levelling bolts, which pass through the body of the sleeper blocks. Once the track is aligned, concrete is poured around the sleepers to form the upper slab. Once the initial set has taken place, the levelling bolts can be removed and reused on the next section of track.