Friday, 6 July 2018

An Historic Double Decker In Bristol (1)

Tidal Troubles : Trendy Trains!
Bristol was, for hundreds of years, an important port with access to the sea via the River Avon. The river wiggled through the developing town ...
... and collected wharves and shipyards building high quality vessels. (Hence "all shipshape and Bristol fashion"). The River Frome also acquired significant amounts of harbourside business.

But there was a problem. The River Avon was tidal all the way through the town, so, as boats got bigger, the restrictions on water depth began to hamper the trade. 

The limitations of Bristol's docks were causing problems to business, so in 1802 William Jessop ...
... proposed installing a dam and lock at Hotwells to create the harbour. The £530,000 scheme was approved by Parliament, and construction began in May 1804. The scheme included the construction of the Cumberland Basin, a large wide stretch of the harbour in Hotwells.

To preserve the flow of the Avon, a cut was built from Hotwells to just past today's Temple Meads Station. A simplified sketch plan is shown below ...
And here is a more accurate plan (click on the maps for an enlargement).
The engraving below shows the Cumberland Basin and its locks in 1825 ...
... but the entrance from the Avon Gorge was enlarged and re-aligned by one Isambard Kingdom Brunel. To get from one side to the other, the man with the tall hat and cigar installed his swing bridge.
Until the ultimate decline of the shipping trade, with the bigger and bigger boats docking at Avonmouth, the Cumberland Basin remained much the same as when Brunel improved it.
One of his swingers still remains, hidden in obscurity under the modern road bridge.
Like (almost) everything IKB turned his hand to, its design was revolutionary.
The main load bearing structure was formed by two curved girders - but they were hollow to maintain strength but reduce weight.
Its pivot is asymmetrically paced (close to one end!) with gurt chunks of weight to counterbalance the whole thing. When it was first installed it was opened/closed by a man winding a handle; subsequently it was joined to the area's hydraulics systems. In this picture ...
... you have a rare view of it having been swung. Proposals by the City council to repair and reinstate it as a "feature" appear to have sadly foundered on the rocks of austerity. Boo! But volunteers continue to work on a long-term restoration project.
Local folk refer to it as Brunel's other bridge, clearly less well known than the dangly one over the Gorge itself!
But technology rushes on apace and soon "they new fangled" railways arrive.

Trains reached the harbourside from Temple Meads ...
... via a tunnel under St Marys Redcliffe. The remnants are in this clump of undergrowth ...
... and the western portal is still visible from the banks of the Bathhurst Basin.
It is this branch, and the railways serving the docks that will enthrall blog readers on the morrow.

 Next Double Decker blog : Saturday 7th July 

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