Beccles Swing Bridge
1927 Designed by John Miller and C. J. Brown
This bridge, and the nearby St. Olave's Swing Bridge, were constructed to replace two older railway swing bridges.
Contracts for both bridges were let to the Horseley Bridge and Engineering Co [1]
The bridges were were designed to be turnable through 360 degrees, for even wear, and this favoured operation using electric motors rather than hydraulic rams. However alignment problems prevented this, so they were restricted to 90 degrees.
The bridges turned on 29 cast steel conical rollers. A 30 HP motor turned the bridge via herringbone bevel gearing, with a final drive spur gear acting on a 28ft. 6in. diameter cast iron rack. When opened for rail traffic the swing bridge was supported at four corners by wedges with a 1 in 6 inclination, actuated by a 7.5 HP motor at each end. When aligned a single locking bolt was engaged by a geared 1.5 HP motor. There was no local electrical supply, so power was generated on site, by a two-cylinder two-stroke vertical oil engine driving a generator to charge batteries.
The above information is condensed from The Engineer 1927/02/18.
See here for an I.C.E. Discussion Paper on the reconstruction of the bridges.[2]
See Also
Sources of Information
- ↑ The Engineer 1927/02/18
- ↑ [1] Discussion of the Reconstruction of two Railway Swing Bridge: Minutes of Proceedings of The Institution of Civil Engineers, Vol. 225. Session 1927-28, Part I