Sateba UK (previously SBC Rail) were selected to provide a proven, quick fit, cost effective alternative to floating slab track on certain stretches of the Elizabeth Line, Crossrail project.

A joint venture called ATC comprising of Alstom, Transport Sud Ouest and Costain Limited won the Crossrail contract to deliver the Elizabeth Line.

Project

The Elizabeth Line runs from Reading and Heathrow in the West, to Abbey Wood and Shenfield in the East.

Up to 40 metres deep in places, the route covers 73 miles (117.5km) and includes 26 miles (42km) of tunnels.

Tunnelling began in May 2012 and the line was completed in May 2022.

Challenge

The line runs through some of the existing underground landscape and under some iconic historic buildings along its route. So the reduction of any noise and vibration was a key consideration for the design and installation, and selection of rail track products.

Floating Slab Track is traditionally used to help mitigate the vibration of trains running through populated areas, but ATC wanted something quicker and more cost effective system that would still help reduce noise and vibration.

Solution

Sateba invested time, resources and engineering experience in a 10 year program to develop a cost effective alternative to floating slab track. The result was the M312 Monoblock Booted Sleeper (previously known as the High Attenuation Sleeper or HAS). The sleeper is made up of a prestressed precast concrete block with a rigid boot and resilient pads sealed in.

This unique booted sleeper system is tuned to attenuate when a train runs over the track. The M312 can provide a high level of attenuation, up to 20dbs, so perfect for use under the more sensitive parts of the Crossrail project inside the tunnels.

The S312 twin block booted sleeper is the next generation of the original VAX U41  sleeper, that was successfully used on HS1 (CTRL), and can be tuned to attenuate between 5 and 15dbs. This was used on the entrances and exits of the tunnels.

Around 5,000 of the M312 sleeper and approximately 70,000 of the S312 sleeper were used on this project. They were installed around the entrance/exit of tunnels at Paddington in the West and Plumstead in the East, and inside other tunnels in between!

Deliveries of the sleepers were made in 11 slots over a 22 month period between May 2015 and March 2016.