Koningshaven Bridge (Rotterdam)
Koningshaven Bridge, commonly known as De Hef ('the lift'), is a vertical-lift railway bridge over the Koningshaven (Kings Harbour) channel at the port of Rotterdam, Netherlands. Built in 1927, the bridge was part of the Breda–Rotterdam railway line until it was decommissioned in 1993. [1]
See here for a 1927 film of the bridge in service. Another early film here shows close-ups of the bridge in operation [2]
The lifting bridge replaced a swing bridge, built in 1876-8. The central pier was restrictive to river traffic. The two side spans were retained for the lifting bridge. See photograph here.
The lifting span uses two distinct sizes of steel cables. The moving span is counterbalanced by concrete weights using 40 mm diameter cables passing over large diameter sheaves. There are 48 balancing cables. The others are 26 mm diameter: four lifting cables, 225 m long; four lowering cables, 185 m long; four 'straightening' (level maintaining) cables, 105 m long.[3]
The motor room and control room are housed in the south tower structure.
The original electric motors were supplied by Willem Smit and Co of Slikkerveer[4]
As an 'iconic' structure, the internet provides vast numbers of images of the bridge, but there appears to be little information in the public domain to show details of construction and operation.
The lifting span is guided against longitudinal and lateral movement by guide wheels engaging with vertical rails attached to the vertical legs of the towers. The south corners of the lifting span each have three guide wheels. One of the rails on the south tower, and one of the three wheels (the one for lateral guidance) are visible in the bottom right-hand corner of Photo 5. The north corners probably only have a single roller, preventing transverse movement (it would be over-constrained with three rollers at both ends).
The south end of the lifting span's bottom chord has a pair of cast steel brackets, each having a semi-circular groove on the underside (photo 6). This engages with a bar at the top of a pedestal fixed to the pier (photo 7). In the lowered position (for trains to pass), the bracket and the bar engage to provide positive location against longitudinal movement resulting from expansion and contraction and from reaction to moving loads. They also serve as hinges. At the northern end, the span sits on rolling supports which allow expansion and contraction (photos 8 & 9).
When lowered for trains to pass, the lifting deck and the fixing deck were engaged by interlocks to ensure alignment and security of the rail tracks. It is not clear how these interlocks operated.
Photo 10 shows the southern fixed span straddled by the vertical legs of the column. Just visible at the top are four buffers, and four return pulleys for the 26 mm diameter operating cables.
After passing over the large sheaves, the 40 mm counterbalance ropes are connected to the lifting span via a system of compensating (equalising) levers to ensure even load sharing. Photo 11 shows that there are flat bars between the cables and the compensating levers. The compensating levers are provided with 'rams' horns'. These presumably allow temporary rigging cables to be attached when replacing the main cables.