Rail Replacement System

The requirement for this procurement is four Rail Replacement Gantries systems for use on the HS1 route. The gantry system must be able to deliver the following requirements and conform to particular interfaces: Key requirements: System must deliver renewals in CP4 System must operate in single-bore tunnel environment System must perform rail replacement activities in weeknight shift System must be capable of exchanging both S&C assets and CWR System must deliver rail, exchange rails, and collect scrap in the same working shift Key considerations for interface groups: Permanent way: The track gauge is 1435mm.

The rail type is UIC60 (aka CEN60) on mainly ballasted track with twin block sleepers, and ~50km single track on slab track. The maximum installed cant is 160mm.

The maximum gradient is 1 in 40 (2.5%). Open sections have a maximum speed of 300km/h, with track centres spaced at 4.5m.

The infrastructure is predominantly built to GC gauge. UIC GB+ gauge applies to the Ashford connecting lines on the NR Network.

The most restrictive, W6a gauge applies to a small number of locations on NRHS-managed infrastructure. Buildings & Civils: Several tunnels exist on HS1 including twin tunnels under London from Stratford westwards towards St Pancras and eastwards towards Dagenham.

Tunnel depth varies between 24m and 50m. The two London tunnels are 7.5km and 10.1km long and split by Stratford International station.

Other major tunnels include the 3.1km tunnel under the Thames at Thurrock in Essex and the 3.2km North Downs Tunnel near Maidstone in Kent. HS1 features several major viaducts with three exceeding 1km in length: Medway Viaduct carries the line over the river Medway adjacent to the M2 motorway, Thurrock Viaduct takes the line over the A282 Dartford Crossing and Ashford Viaduct takes the fast lines over Ashford International station.

Signalling & Telecoms (S&T): TVM430 in-cab signalling is used across the infrastructure - except at Ashford and St Pancras International stations which are equipped with the KVB train protection system. Electricfication & Plant (E&P): Catenary compliant with the Energy (High Speed) TSI supplies 25kV at 50Hz AC.

Maintenance Depot: The infrastructure maintenance depot for HS1, Singlewell Infrastructure Maintenance Depot (SIMD), is located at Singlewell, near to Gravesend, Kent. Storage, maintenance and overhaul of the proposed system would need to take place at SIMD. The contract will also includes the provision of training for Network Rail High Speed personnel to operate and maintain the Gantries once they are delivered to site.