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Black Lion Bridge - Pont Llew Ddu

At some point the tramway crosses the existing railway line, the 1875 Ordinance Survey plan shows it in this area. It was therefore necessary to provide a bridge to cross the railway which was the largest engineering Job on the trail, it has also replaced the existing crossing point which was very dangerous.

Concrete being poured into the pile cap with 50mm cover to the steel Concrete Finished Drill Rig at Darren Las
During excavation the remains of a Tram Wheel were found Final Ramp being Lifted Main Span being lifted into place using a 250t crane at 1am

Pile foundations were required to support the bridge as the ground below was very soft. Roger Bullivant Ltd carried out the work with their purpose built drill Rig .

A permanent steel casing was drilled 15m through the fill ground onto the rock head, the pile was then filled with a grout mix through the centre of the augers as they were retracted, Steel reinforcement was then inserted into the pile.

Pile Foundations Second Ramp being Lifted Side View of Bridge
Steel reinforcement cage to provide tensile strength in the base Temporary formwork being built around the steel into which the concrete is poured View of Bridge Looking South

A pile cap was constructed on each set of piles using reinforced concrete to support the main trestles of the bridge. The pile cap distributes the loads from the bridge to the piles.

On the 13th and 20th of April the bridge was lifted into place. The three trestles and one ramp was put in place on the first weekend with the main span and the two ramps on the east side of the railway on the following weekend.

The initial design of the bridge was done by Mark Robinson with Rowecord carrying out the detailed design and the fabrication of the structure. The foundations were designed by Carwyn Morris and constructed by Alun Griffiths Ltd, with Roger Bullivant Ltd as the sub contractor.