Field Visit
Date June 1995
Event ID 1090850
Category Recording
Type Field Visit
Permalink http://canmore.org.uk/event/1090850
This railway swing bridge was constructed in about 1896 by the Lanarkshire and Dunbartonshire Railway Company, and carried a double-track railway across the mouth of the Forth and Clyde Canal basin at Bowling. The railway was heavily funded by the Caledonian Railway and was designed to link Glasgow with Dumbarton, thereby securing the business of the riverside industries and docks on the north bank of the Clyde where the North British Railway had previously dominated.
The main span consists of riveted steel structure 33.23m in length (see site plan), with concrete-built viaducts at each end. The engine house and the pump room were accommodated within the NW abutment of the bridge. All equipment has been removed from the pumphouse, as has the turning machinery. However, the main rams for lifting the bridge prior to the swinging procedure are still in position. These consisted of a total of five hydraulic rams, of which the main ram is located at the central pivot point , and is 0.99m (39-inches) in diameter. At each side of the main ram there is a ram 0.7m (28-inches) in diameter, with double rollers mounted above and at the north west end of the bridge, there are two smaller rams of 0.13m (7-inches) in diameter, each with a single roller above. When in operation, before the bridge could be swung, the five hydraulic rams lifted the structure by 0.1m (4-inches), allowing the rollers to travel along a circular iron track as the bridge pivoted into the open position, permitting canal traffic to pass.
The pivot point is situated 10.3m from the north west end of the bridge, and is contained within the north west abutment. The bridge is fitted with a counterweight which is built into the north west end end of the steelwork. This ensured that during the swing procedure, the bridge was balanced around the pivot point after the rams had lifted it out of the fixed position.
The surrounding viaducts are constructed from concrete, and are faced with a coloured layer of render to simulate red sandstone. The sides of the canal basin (especially the east) are constructed from a similar coloured and textured concrete. In contrast , the load bearing points of the structure are built from blocks of granite.
The hydraulic pumps were probably steam powered, but no boiler house equipment was noted. It is possible that the chimney to the north west of the bridge (on Ordnance Survey maps) was built for the boiler house. Note also that the control cabin for the bridge has been removed. The railway itself has been disused for many decades.
Photographic surveys and graphic surveys along with a record sheet, were completed for this bridge in 1988-9 (see MS/ST/DU/4, sheet 2 of 5).
Visited by MK Oglethorpe, RCAHMS, June 1995.
