It is recorded (see here) that Robert Weldon (b:?1754 to d:1810) from Sunderland had a demo. half-sized model of the caisson lock on the Ketley Canal (near Oaken Gates) in working order in Sept. 1792. (The patent is believed to date from June 1792).This obviously impressed the SCC committee. However it seems likely that, being a native of Lichfield, he came across the writings of Charles Darwins' famous Grandfather - Erasmus - another native of this town. Erasmus published, in 1777, details of a wooden box, capable of receiving a boat which could be raised or lowered between the upper and lower levels of canals (Not in a water-filled well though).
The expression "Caissoon" ... means "a large water tight chest" ... The Caisson became a subject of interest to researchers in the Telford area when we read the details of a letter by John Ward written from Leeds to Thomas Gilbert of Cotton Hall, Staffordshire which reads "I saw Mr Thomas Gilbert at Cotton on Tuesday night. He was very earnest in recommending it to our committee to send to John Rennie (Civil Engineer:1761-1821) into Shropshire to see a "cassoon" (sic) which is calculated to raise and sink boats from one level to another without waste of water. Weldon the patentee and the cassoon is at Wrockwardine, near Lilleshall in Shropshire.
Where was it? "Wrockwardine", above, probably means Wrockwardine Wood, where the canal ran, not the village several miles away.
It could have been at the Wrockwardine Wood Inclined Plane, but I have neither seen nor heard of any remains.
It could have been at Hugh's Bridge, near Lilleshall, where there was a tunnel-and-shaft arrangement before the inclined plane there was built - was it considered as an option?
It could not have been at Oakengates, where there is no change of level, but could it have been at Red Lake, at the top of the Ketley Inclined Plane (only a couple of miles from Oakengates).
Could it, conceivably, have been at Brierley Hill, miles away at the other end of the canal system near Coalport, where there is an unexplained shaft: see The Old Wynd Tunnel (is this link defunct?)?
The uncertainty is driving me daft, and a source of frustration to the Somerset Coal Canal Society who are restoring a caisson lock. Does anyone have any information? Please contact me!
Top of this page
Exploring Telford