Caunton are working on a new £20million depot to house twenty new Supertrams for Blackpool after the tramway’s upgrade.
The building comprises four high level and four low level roof units. Each high level unit alternates with a low level one - working down the building. A high level unit in plan is 66 metre span and 12 metre wide. The low level units are the same. The photograph shows the half way stage for the steelwork ahead of the sheeting and cladding operations.
The overall roof is supported by rafters which in the main are curved in elevation; comprising two distinct curves in two opposite directions to create the appearance of a flowing wave effect imaginatively designed in order to reflect the proximity of the sea.
The rafters, for both high and low level units, span directly between similar columns. The high level rafter comprises a single universal beam (albeit spliced) – the profile is a concave curve meeting a convex one. The low level comprises also a single universal beam (similarly spliced) – but the profile in this case comprises in the first place a straight section, before meeting first a concave profile and finally a convex. (Numerically - the radii of curvature for high level are 100 metres and 115 metres and the low level 200m and 75 m).
Manufacture of the rafters required highly sophisticated modelling, engineering and fabrication techniques. These Caunton Engineering have developed most successfully over the years.