MEP Subcontractor for T5D Rail Tunnel Attenuator Overhaul Survey

This is an expression of interest for a Mechanical, Electrical, and Plumbing (MEP) subcontractor to conduct surveys and design support for replacing four end-of-life attenuators in the T5D Rail-tunnel Ventilation Shaft at Heathrow. The project involves surveying the shaft during non-operational hours to gather comprehensive information on MEP systems, fan and attenuator components, and structural elements within the air path. The subcontractor will work under the direction of the Design Consultant to support RIBA design stages 4ii and 4iii. The attenuator replacement aims to reduce debris entry into fans and tunnels, improve fire safety performance, enhance ventilation and smoke clearance capabilities, and reduce future maintenance requirements. Each of the four attenuators weighs approximately 1,160 kg per unit (four quadrants). The subcontractor must demonstrate capability in understanding attenuator replacement requirements within the constraints of an operational rail network, conducting thorough surveys to inform design development, and reviewing MEP systems for compliance modifications. Note: Construction activities (RIBA stage 5 onwards) are excluded from this scope.