The St Ann Way Bridge Link at Gloucester Quays provides a
vital link to Gloucester’s transport infrastructure by linking the inner relief
road to the newly completed south-west bypass. The bridge will provide access to
the massive Gloucester Quays £250 million re-development scheme, as well as a
variety of other leisure, commercial and residential projects.
Bennett Associates were appointed by lead consultant White Young
Green, to provide the exemplar design for the mechanical, electrical and
hydraulic elements that would form the lifting mechanism for the road bridge.
The design brief was for a contemporary styled single span
bridge, with an efficient and reliable electro-hydraulic lift deck, typical of a
modern bascule design. The bridge not only serves a practical function in terms
of integrating the development around Gloucester Quays, it is also a striking
waterway gateway to the historic Gloucester Docks.
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28 metres long and 15.7 metres
wide. |
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The structure rotates 69° about a
horizontal axis to form a 12.5 metre wide, infinite height navigation channel. |
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Sitting 6 metres above the Gloucester to
Sharpness canal, most boats will be able to pass beneath without the bridge
needing to be raised. |
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The deck weighs approximately 200 tonnes
with an additional 100 tonnes of counter-weight situated behind the pivot in the
tail section of the bridge. |
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The counter weight reduces the load on the
two 420mm diameter bore, 200mm diameter rod lift cylinders which are extended to
cause the deck to rotate. |
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When in the lowered position, the tip of
the bridge rests on the approach span and two tail locks engage at the back of
the bridge to secure the deck in position. |
Constructed from steel with white concrete
abutments, the bridge was designed to be extremely low profile in order to
preserve the existing views of the city. The main bridge deck was built in five
separate sections and then welded together once on site. Once the concrete and
steel counter weight was added, the whole deck was launched into place using
special jacks and hydraulic pushing cylinders which slid the deck over the
canal.
Bennett Associates involvement continued throughout the
construction of the bridge in a supervisory capacity. They were on hand to
ensure that the design was executed as intended and in accordance with the
design drawings and specification documents that they produced.
The simple, minimalist design of the bridge also provides access
to new cycle and pedestrian routes being constructed along the canal towpaths.
The two canal banks were joined for the first time in mid-January 2008, as the
final section of decking was put in position.
The £10 million project is a joint venture between English
Partnerships, British Waterways and the developer, Peel Holdings.
For more information, contact us on
01709-373782.
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