The Somerset Coal Canal, and the mildly terrifying world-first caisson lock

In the late 1700s a canal was constructed to transport coal to market from the Somerset coalfield. Its innovative but scary caisson lock, which saw boats sealed inside a box, underwater, inside a box, to be transported up and down hills, did not catch on, but makes for an interesting story, with a supporting role by William 'strata' Smith, the so-called father of English geology.
0:00 - Introduction and context of the Somerset Coal Canal
3:40 - The water shortage / elevation change problem
4:58 - The caisson lock
9:27 - The inclined plane
11:00 - The lock flight
14:35 - Railways arrive and the canal closes
17:44 - Outro and credits
Sources, credits and transcript: pedestriandive...

[@richardstevens8548]

Thanks; a good summary. Just two points...1. There was a quay on the southern end of the canal after the road was diverted to serve the inclined plane (if one looks carefully the path of which can still be seen -probably best in winter). 2. Fuller's earth (clay) was used for fulling sheeps' wool and later cats' litter - the point being it swells when in contact with water. My reading is that the caisson failed because the pressure of the wet clay pushed the stonework of the outer chamber inwards, not the water pressure inside the chamber forcing the stones outward. (But who knows...?). Thanks again.

[@hushpuppies17]

Oh man when you search an obscure subject on KZbin and find this its liable to make your day!

[@OutbackCatgirl]

The youtube suggestion algorithm brought me here and I thoroughly enjoyed this video. Hopefully more people get suggested this way.

[@PedestrianDiversions]

It's sent this vid a couple of thousand in the last week or so! Thanks for watching, glad you enjoyed

[@bengriffiths442]

Great video. Thanks for putting it together! I'd love to watch something about the Bristol coalfields if you ever decide to make that one. Also feel free to keep posting these to /r/bristol if you'd like to. Even ones like this that stray a little out of the area.

[@dobrussell]

As a former resident of Red House Farm (now Wick House) Radford (between Paulton and Camerton) I found this a wonderfully informative video. However, I must take issue with one thing; the area is not part of the Cotswolds, it is part of the Mendip Hills.

[@PedestrianDiversions]

Combe Hay sneaks inside the boundary of the Cotswolds AONB! however I was quite surprised to discover that; I don't think I would have considered anywhere south of Bath as Cotswolds geologically or culturally, left to my own devices. So I'm not surprised you disagree with the cotswold label. I did too but I "stood corrected" by official borders. I shall now stand corrected by local knowledge!

[@hughtierneytierney3585]

It does indeed seem most un-cotswold-like.

[@stevehill4615]

Thanks for the video, the Whitewicks on their channel had mentioned the caisson locks your explanation made clear how the system should have worked.

[@simonmcowan6874]

That was brilliant, love the dour voice description suits you perfectly, lots of info, little chat too, the use of map graphics are fine and much used by others, I may borrow your style for a 1798 waggonway in Shropshire with an incline that had been overlooked until i found it.

[@PedestrianDiversions]

thanks Simon. I guess you are one of the many people youtube has suddenly decided to recommend this video to this afternoon, for no particular reason I can fathom. The algorithm works in mysterious ways! An undiscovered wagonway sounds very cool, give me a shout if you get a video up about it for sure

[@andrewhotston983]

Fascinating. I read about the caisson lock in the book about the GWR Camerton Branch railway. I couldn't quite believe they thought they could make it work with the technology they had at the time. Well done for not mentioning the Titfield Thunderbolt, too. Hope you get around to making a video about the Bristol coalfield.

[@SageThyme23]

Great video. Cheers for the subtitles. If you ever need B-roll or footage from Bath or nearby areas, I'd be happy to help you out.

[@gerryholland7274]

The Southern Arm of the Canal was quite extensively built with sections of it still visible from Wellow westward including Aquaduct at Stoney Littleton. Further section can be seen at Single Hill, Shoscombe and a little further on past Paglinch Farm. If travelling westwards to Radstock from Shoscombe Vale the Canal can be seen on the RH side of Sustrans 24, next to S & D Track direction. At Single Hill there is a Swivel Bridge footings. I have lived 50+ years at the Railway Cottages, part of the Shoscombe and Single Hill Halt. Cottages were built on Canal Base with Tow Path now our Driveway. Our Garden has a quarry at the rear with stone from it creating pillar stones for the subsequent Tramway. It's an interesting area!

[@stevenmetzger3385]

Thanks from Arizona USA 🇺🇸

[@David-tb9rf]

The C and O canal running from Cumberland, Maryland to Georgetown, Washington D.C. had caisson locks like these as well

[@PedestrianDiversions]

I knew there was a reason I put "(?)" after the word "only"! Thanks for adding this

[@Gndlf_TheOrange]

Loving your channel! I'd love to know more about the coal industry in Temple Cloud and Clutton. Clutton especially as there is a giant derelict tower on the old railway line footpath and I'm really interested to find out what it was for or what it even is! Keep up the good work.

[@PedestrianDiversions]

No idea offhand I'm afraid! And I'll be honest, I'd be surprised if I did more coalfield vids any time imminently, I think part of the reason I swerved this one toward the canal is I couldn't find any books etc about the coalfield per se. But the railway line might get a look at. We shall see...

[@Gndlf_TheOrange]

@@PedestrianDiversions thanks for the reply! No problem. The rail would be fascinating though. The old station remnants are still there in Clutton and you can see bits of old track through the walk. Very cool!

[@jamstawildman]

Fascinating. Thank you for producing this and sharing. Could you tell me the source of the geological/ topological map you show around 7:35?

[@PedestrianDiversions]

I was going to say all sources linked on the website, but it seems I failed to include that map, oversight on my part...! It's File:Geological map Britain William Smith 1815.jpg on wikipedia, you can find it on the page for William Smith (geologist)

[@jamstawildman]

@@PedestrianDiversions Thank you for that :)

[@martinpook5707]

Whilst I can see your point that it doesn't go anywhere, I think you might be surprised at the ability of canal fans to get the job done. Paul and Rebecca Whitewick also did a video on this subject.

[@vinawaldren6888]

Very interesting.👍

[@margaretrowe4261]

Why show a cart from transwhatever when there is a somerset one in Radstock museum

[@DavidBeardmore-i5q]

Sorry to be picky but while much of the canal is within the Cotswold AONB for planning purposes it is definitely not in the Cotswolds in a geographical or geological sense. The Cotswolds stops along the northern edge of Bath roughly on the Lansdown (no additional e please) scarp.

[@cliffwoodbury5319]

why didn't he just build a system were a tower was split in two and as one side went down the other side went up and when the ship got to the bottom the door closed and the ship left to the lower water level. And then the next ship just used the other side that was dried but was now full. I wish they had a video on Caisson Locks online.

[@olentangyriver1191]

do they still use these, i hope not

[@PedestrianDiversions]

not to my knowledge

[@wagwanbennydj6003]

🤘🤘🤘🤘

[@johnmightymole2284]

Good but maybe complete it with footage you didn't take because of the weather.