Pedestrian Guardrail, A38 Queensway Road Tunnel

The A38 St Chads and Queensway tunnels were undergoing a major programme of refurbishment and upgrade lasting several weeks. The tunnels are over 40 years old and the works were intended to enhance their appearance, improve safety and prepare them for the future. A new government safety standard meant that improvements had to be in place to meet the new directive by April 2013.  During the works the tunnels were closed to all traffic in order to make structural modifications, upgrade fire protection, install new LED lighting and also improve their general appearance. Further refurbishment works will include new emergency, control and communications systems.

Advance assessment works included a number of night-time closures, where many different contractors were bused on to the carriageway site to carry out their specific assignments.

Alpha Rail were appointed to survey and measure defined sections of the road in the Queensway tunnel. At the time, concrete structures ran along the central reservation to divide the north and southbound carriageways. During the same closure, the concrete was being surveyed and Alpha Rail were asked to complete their survey such that should the concrete still prove to be fit for purpose, steel posts and solid in-filled metal panels could be added on top of the concrete central reservation to provide additional safety protection to motorists.

The team used a combination of total station measuring instrument and tape measure to calculate the distance between the existing concrete dividers and the rake and radius of the road curvatures at 5m intervals in order to obtain precise measurements for the manufacture and supply of the solid metal in-fills and posts should they be required.