Dyer & Butler
Bridge Deck Replacement
Dawsons Rail Underbridge was originally a wrought iron structure with a very low overall construction depth due to the use of longitudinal timbers instead of normal ballasted track. Crouch Waterfall was asked by Dyer & Butler to support them in the Design & Build contract for this structure.
The conforming design was to utilise the Network Rail standard composite U-decks (as the most slender underbridge type in the Network Rail standard design suite). Due to the additional thickness in the conforming deck and the proximity of the station, this design required a reduction in the soffit level of the bridge. This obviously increased the risk of vehicular impact.
The alternative design developed for this location by our Bridge Design Team, is an all steel design, ultimately costing more than the standard composite designs to fabricate but offering a reduction in construction depth and therefore the risk to the operational railway.
The new design incorporated Network Rail standard walkways, service ducts and a cill unit that resembled the historic padstones. The scheme was delivered by the team, on time and within budget.