- Standard slab track which forms 80 per cent of the track on the new railway – 70 per cent complete;
- Direct fixed track using Australian Delkor two-holed baseplates to reduce dynamic stresses and installed throughout the Victorian Connaught Tunnel – 100 per cent complete;
- High-attenuation sleepers, similar to standard slab track, used in a few areas where noise and vibration need to be kept to a minimum – 25 per cent complete; » Floating track slab light, used to reduce noise and vibration in the Soho area – 50 per cent complete.
- Floating track slab heavy, with a high iron ore content which doubles the density of normal concrete, is being used in the most sensitive areas such as under the Barbican Centre – work just starting.
As autumn approached, Crossrail announced that, following a very intense and busy period, the project had reached yet another milestone – declaring that 75 per cent of the work was now complete. To understand better just what “75 per cent complete” actually means for the engineers involved, Rail Engineer caught up with Chris Binns, chief engineer for the £14.8 billion project. First, a recap on the project. Crossrail extends from Reading and Heathrow in the west to Abbey Wood and Shenfield in the east, a route that is 118km long. It includes a new central core consisting of 42km of new bored tunnels. There are 40 stations on the route, including 10 new Crossrail stations that are entering their final stages of construction. Some are in very complex locations – Paddington, Bond Street, Whitechapel and Liverpool Street to mention a few. In addition, there are complex, redesigned track layouts both west and east of the capital. Bombardier is currently building 66 new trains at its factory in Derby. Each train is 200 metres long and designed to carry 1,500 passengers. The first trains are now coming off the production lines for trials and testing, ready to be introduced to services on the route between Liverpool Street and Shenfield by May 2017. This deadline will be followed by further targets of May 2018 from Heathrow to Paddington then Paddington to Abbey Wood by December 2018. Myriad of system interfaces More than 35km of permanent track has been installed inside the new tunnels and the fitting out of the mechanical and electrical equipment for the stations, signalling systems and power supplies is now well underway. Engineering teams are being refocussed and are slowly moving away from production issues toward the intricate requirements associated with the testing and commissioning regime. Not only do the myriad of system interfaces need to be tested in the new tunnels but also with the different Network Rail environments both east and west of the capital. Chris was keen to point out that none of the fitting-out work of tunnels and stations can be carried out without the skill and support of a competent and innovative supply chain. Back in April 2013, Crossrail awarded the last major suite of contracts, valued at £300 million, to a joint venture comprising Alstom Transport, Costain and French track work specialist, Travail Sud Ouest (TSO). Normally referred to as ATC JV, it is the joint venture’s responsibility to ensure that the tunnels are fitted out with the necessary equipment for an operational railway system. When the tunnels were completed, the construction included a mass concrete base ready to receive the various track slab designs. The base has a raised curb either side, which can carry a specially built multi-purpose gantry. There are four gantries working on the project and each one has the capacity to carry and position 28 sleepers at a time ready to receive new continuously welded rail. A total of 70,000 sleepers are being installed. These are manufactured in Nottingham by SBC Rail and then stockpiled in bales at the railhead depots at Plumstead Logistics Centre in south east London and Westbourne Park temporary railhead in West London. Both locations are being used throughout the contract for providing engineer trains and for storing materials and equipment. The Plumstead railhead is going to be the permanent infrastructure maintenance depot for Crossrail. British Steel is supplying more than 57km of heat- treated, wear-resistant rail. The steel blooms are produced in its Scunthorpe plant but the slight surprise is that these blooms are then transported to Tata’s Hayange mill in northern France to be rolled and finished. Apparently, that’s where the heat-treatment furnaces are. Heavy and light track slab Chris stated that about 64 per cent of the track required in the tunnels has been installed. This is not an easy calculation because there are five different types of track being used, including: