The existing Sean Heuston Bridge over the River Liffey in Dublin is a listed stucture which required strenghtening in order to accommodate the new Dublin Light Railway. Watson supplied and installed the new steelwork which consisted of seven verendeel arches which were installed parrallel to the existing arches and then connected to relieve the load from the existing.

The works were further complicated by the requirement to protect the river from any pollution during the operations and this was achieved by the constuction of a substantial crasg deck under the bridge.