Trowse Bridge
Trowse Bridge | |
---|---|
May Gurney | |
Opened | May 1987 |
Location | |
Trowse Bridge is a single-track railway bridge which carries the Great Eastern Main Line over the River Wensum just outside Norwich in England at grid reference TG245076.
The bridge was originally built in 1845 by
It is notable for being the only
The bridge is also the home of Trowse
Construction
The current single track rail bridge on the electrified railway line in to Norwich was designed by the
The bridge was fabricated and fully trial erected, including a slewing motion trial, inside the Butterley Engineering Company's workshops known as "The Bridge Yard" at Butterley Hill, Ripley in Derbyshire during 1986 and was delivered to site and installed during the winter months of November 1986 to January 1987.
The swing bridge section is approximately 26 metres (85 ft) long, with an off-centre slewing bearing and an underslung counterweight box. The total slew bridge weight was 354 long tons (360 tonnes; 396 short tons), including the counterweight. The counterweight was made from almost 90 long tons (91 t; 100 short tons) of cut up railway track used to precisely balance the structure during the commissioning works. It was necessary for the swing bridge to be balanced about the centre of slew to give equal loading of the 4 main lifting jacks and the span was accurately weighed by 4 x 100 long tons (100 t; 110 short tons) electronic load cells (certified to ±0.5%) February 1987, during the bridge's final installation and commissioning trials.
There are three fixed approach spans at the Norwich city end and the main swing bridge section. The swing bridge raises some 300 millimetres (12 in) on 4 main jacks, mounted on to substantial sub-frame in the turning pit. The swing bridge raises to clear the fixed span and land abutment's scarfed rail joints and to also clear the fixed overhead conductor rails, which are gantry mounted to the swing bridge and the approach spans. The bridge "slew" is provided by 2 hydraulic motors driving against the main slewing ring bearing, manufactured by Robello. The swing bridge section is constructed to be a flat span in the open to rail/service position and not cambered, as are many other bridges.
The old twin-track centre-slew bridge remained in service during the installation and trials of the new bridge until the date the live rail was diverted over the new bridge. The closure and removal of the old bridge in end of February 1987, was during the river's closure to navigation for the bridge replacement, provided for under a specific act of UK Parliament.[5]
References
- ^ a b "Bridge heights and openings". www.broads-authority.gov.uk. Retrieved 26 March 2023.
- ^ Redivivus, Brunel (October 1905). "The New Swing Bridge at Trowse". The Railway Magazine. Vol. 17. pp. 316–321. Retrieved 18 April 2019.
- ^ "Statement to EDP". NetworkRailMediaCentre.co.uk. Network Rail. 21 February 2003. Retrieved 18 April 2019.
It weighs around 350 tonnes and works on a system of computer controlled jacks and hydraulic pumps that raise the structure and rotate it to allow river traffic to pass through. It is locked back into place to rejoin the track.
- Broads Authority. pp. 8–9. Retrieved 18 April 2019.
From October 2003 to February 2013 Trowse Bridge has been operational 1591 days and has failed 1852 days.
- ^ Trowse Swing Bridge problems Rail issue 78 March 1988 page 15