This is an interesting and no-doubt competent design avoiding Weldon's problem with completely covered watertight caissons. (3D picture of Weldon's caisson lock ) (These, as can be seen, were open at the top and thus similar to the Rowland and Pickering design)Sketch of R&P's design..
The chains slung underneath the caissons were to counteract exactly the change in mass of caisson plus boat as the top chain was wound or unwound around the giant wheels. The very top wheel has a shaft attached to it (see pic.) which could act as a brake. Movement of the dual caissons was made possible by increasing the mass of the top caisson through the introduction of sufficient water.
Seasoned sceptics will no doubt see the only real problem with this design is in the maintenance of watertight "doors' at the end of the caisson when it had to 'mate' with a similar door set into the brick-work at both levels. Fussell's patent suggests a mixture of leather wadding, close tolerances, and even levers etc as can be seen from a section from his patent (AD 1798; No.: 2284). read from line 20.....
and continued below. Here can also be seen Fussell's clever realisation that his patent could be used up a steep gradient made of hard rock as it could be adapted to the working of an inclined plane. (One wonders what the plan of the inclined plane at Combe Hay looked like...)
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Press SCC site for the pages dealing with the Somersetshire Coal Canal.
The writer is also a keen member of 2 Trusts engaged in keeping the memory of the Somerset & Dorset Railway open.
See: www.sdjr.co.uk
The writer's e mail is rtjstevens@btopenworld.com
This is an interesting and no-doubt competent design avoiding Weldon's problem with completely covered watertight caissons. (3D picture of Weldon's caisson lock ) (These, as can be seen, were open at the top and thus similar to the Rowland and Pickering design)Sketch of R&P's design..
The chains slung underneath the caissons were to counteract exactly the change in mass of caisson plus boat as the top chain was wound or unwound around the giant wheels. The very top wheel has a shaft attached to it (see pic.) which could act as a brake. Movement of the dual caissons was made possible by increasing the mass of the top caisson through the introduction of sufficient water.
Seasoned sceptics will no doubt see the only real problem with this design is in the maintenance of watertight "doors' at the end of the caisson when it had to 'mate' with a similar door set into the brick-work at both levels. Fussell's patent suggests a mixture of leather wadding, close tolerances, and even levers etc as can be seen from a section from his patent (AD 1798; No.: 2284). read from line 20.....
and continued below. Here can also be seen Fussell's clever realisation that his patent could be used up a steep gradient made of hard rock as it could be adapted to the working of an inclined plane. (One wonders what the plan of the inclined plane at Combe Hay looked like...) Return to Top of Page
Press SCC site for the pages dealing with the Somersetshire Coal Canal.
The writer is also a keen member of 2 Trusts engaged in keeping the memory of the Somerset & Dorset Railway open.
See: www.sdjr.co.uk
The writer's e mail is rtjstevens@btopenworld.com