left: the west girder is shown during construction. It is parallel to the roadway removing the normal risks of working over traffic when dropping something as small as a bolt can be very dangerous to a vehicle below. The slab concrete had been finished several days earlier and the forms are shown ready for concrete placing in the webs. The cross-bracing can be clearly seen and was hardly designed to counteract any outward overturning of the two walls. Once concrete reached about half-way up the forms, additional ties had to be hastily introduced to keep the alignment true. The finished overpass shows that the sloped sides of the piers match that of the walls. They also share the same plane. The tops of all the piers were similar with the tallest pier therefore having a much narrower base than those of the shorter piers. The thru-girder configuration of the superstructure was necessary to maintain safe clearance between pedestrians and the overhead electricity conductors. The concrete was painted with a pigmented sealer to resist salt attack on the concrete. The galvanised steel rails were custom designed.
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Tom Martin
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