Case Studies



East London Line Extension - Tunnel Telephone Design

East London Line Extension - Tunnel Telephone Design image East London Line Extension - Tunnel Telephone Design image

A £363M project to extend the existing East London Line to Dalston Junction in the North and New Cross Crystal Palace and West Croydon in the South. It was completed in 2011. The works including track, signalling, telecommunications and electrification, and major civil engineering works including the construction of two large new bridges, new stations and a new depot at New Cross Gate.

Fourway provided the engineering consultancy to design the new traction discharge system (tunnel telephone). In collaboration with rolling stock, p-way and civil engineers we developed the system engineering requirements and CDS around LU standards and HMRI legislation. We surveyed all tunnel sections with a structure gauge, designed and built by the team to determine track cant, curvature and the effect on car position and throw.

The design was further developed by 3D modelling the train window and tunnel wall interface. As the open wires were operated from the train cab window we modelled a range of human percentile scenarios to demonstrate 'train operator's reach' remained within the human factors criteria established at outset. We undertook structural assessments and calculations for all steelwork and affected tunnel structures. Due to the age of the tunnel construction bracket design varied considerably from situation to situation. The design also needed to mitigate water ingress problems in many of the tunnel sections. A range of galvanising treatments were investigated to ensure the maximum coating weights were obtained. We provided detailed design for bracket metal work and piece-part assemblies for fabrication.