Oxford Canal Locks - a bit of a conundrum

[GilesMorris]

>why did Telford fit double TOP gates on the Shroppy?

 

Wait... What? It's been a long time, but I don't remember double top gates on the main line, Llangollen or Middlewich branch. The only place I remember them is on the Macclesfield.

 

I remember that you could operate the one on the far side of the lock with a boathook, but couldn't really understand what advantage there was in them.

 

[magpie patrick]

>why did Telford fit double TOP gates on the Shroppy?

 

Wait... What? It's been a long time, but I don't remember double top gates on the main line, Llangollen or Middlewich branch. The only place I remember them is on the Macclesfield.

 

I remember that you could operate the one on the far side of the lock with a boathook, but couldn't really understand what advantage there was in them.

 

The double top gates went a long time ago. I've seen no record of when but my guess is within 30 years of opening. Whatever advantage they were thought to offer obviously proved illusory.

 

A few survived on the Montgomery canal until it's closure in the 1940's - one set from Welshpool was preserved at Stoke Bruerne

[Tacet]

So, some genius decided that it was quicker to open two gates than one? He'll go far.

 

Well, you can open a smaller gate against a greater head of water, which makes a noticeable difference.

[Athy]

 

Well, you can open a smaller gate against a greater head of water, which makes a noticeable difference.

...which will be at least counteracted by having to walk round to the other side to open the other one (unless you do death-defying leaps, which I don't). This is assuming a crew of two, one steering, one locking. Obviously if the crew is more numerous, then having two gates becomes much quicker as both can be opened simultaneously.

[Derek R.]

A 'shunters pole' comes in very handy for managing the far gate of narrow locks. They move easy.

[Pluto]

So, some genius decided that closing two gates was quicker than closing one? He'll go far.

Saving twenty seconds per lock would save half an hour when crossing the L&LC, which is just about what HS2 is expected to save on a journey from London to Birmingham.

[Athy]

Saving twenty seconds per lock would save half an hour when crossing the L&LC, which is just about what HS2 is expected to save on a journey from London to Birmingham.

...if it's built, which I sincerely hope it won't be.

But, as I've said, having two bottom gates doesn't save time. Even using Derek's (very good) suggestion I'm sure that opening one gate will always be quicker than opening two.

 

I did try Derek's way, pushing the far gate open with the boathook, this summer, it worked but one had to perch precariously on the near gate to do it. The long shaft/ pole would be too long and unwieldy for this purpose, I reckon.

[alias]

I did try Derek's way, pushing the far gate open with the boathook, this summer, it worked but one had to perch precariously on the near gate to do it. The long shaft/ pole would be too long and unwieldy for this purpose, I reckon.

 

I find it easier to stand on one bottom gate and push the other open with a foot, then you have both hands free to hold on to the handrail.

[Athy]

 

I find it easier to stand on one bottom gate and push the other open with a foot, then you have both hands free to hold on to the handrail.

Worth a try. Peter, I suspect that some gates will respond to that pressure and others won't, but I would be happy to be proved wrong.*

 

 

* It's not often you'll see a Northerner saying that!

[ditchcrawler]

 

I find it easier to stand on one bottom gate and push the other open with a foot, then you have both hands free to hold on to the handrail.

That is how lots of people do it

[magpie patrick]

Back to the original theme: I called on Lutine to check on her and Dukes Cut Lock is drained for new gates.

 

 

It was nearly dark and I've played with contrast and colour to bring the detail out, but the cill of the "top" gate for locking up from the Thames is fairly obvious

 

 

 

 

And in this one shows the paddle hole for the now redundant ground paddle at the canal end. It's obviously blocked but I couldn't see a hole in the lock (I could easily see the one for the ground paddle at the other end, but it was way too dark to photograph) Has it been bricked over or is it under the residual water in the lock? I wonder how much further down the invert is and what the typical lift into the canal was when it worked that way round?

 

Finally, CRT are keeping a close eye on Lutine...

 

[Tacet]

 

I find it easier to stand on one bottom gate and push the other open with a foot, then you have both hands free to hold on to the handrail.

 

 

That is how lots of people do it

 

But then much of the leverage is lost - so you won't be able to open the gate against the same head of water.

 

Unless you have more than one crew person lock-side, the step-of-faith is the quickest for double gates. In general, I reckon with this technique one person can usually open a pair of gates earlier than a single gate. You do need to exercise care and discretion before making the jump. Three points of contact is sometimes recommended - but I can never quite see how that can be done and realistically you're down to single foot and no hands for a short time.

 

Or maybe you could leap the lock in one.

[Heartland]

The Dukes Cut, built for the Duke of Buckingham, according to Canals of East England, was completed in 1789 and was a private waterway. The link to the Thames provided a means to join up with the improving navigation of the Upper Thames and the junction with the Thames & Severn Canal. This link enabled coal traffic to pass off the Oxford onto the wharves along the Upper Thames. The Oxford Canal wharves and basin in Oxford, did have a barge lock link to the Isis (Thames) before Isis Lock was made. In May 1794 the Oxford Canal Navigation published a notice in local papers quoting rates for

 

(1) Barges (20 tons) with coal from Oxford wharf passing Abingdon Lock but not Beeson Lock 10d per ton, 1s 3d for a 50 ton barge

(2) Barges (20 tons) passing Beeson Lock but not Whitchurch 1s 8d per ton, 2s 6d for a 50 ton barge

(3) Barges (20 tons) passing Whitchurch Lock 2s 6d per ton, 3s 6d for a 50 ton barge

 

The differential in charge depending on barge size is of interest, could this be due to water level and Thames charges?

[Scholar Gypsy]

I always thought it was the Duke of Marlborough (who is more local - Blenheim). Wikipedia agrees, but may be wrong of course...

[ditchcrawler]

 

 

 

But then much of the leverage is lost - so you won't be able to open the gate against the same head of water.

 

Unless you have more than one crew person lock-side, the step-of-faith is the quickest for double gates. In general, I reckon with this technique one person can usually open a pair of gates earlier than a single gate. You do need to exercise care and discretion before making the jump. Three points of contact is sometimes recommended - but I can never quite see how that can be done and realistically you're down to single foot and no hands for a short time.

 

Or maybe you could leap the lock in one.

An awful lot safe since BW decided to put anti slip surface on all walkboards on their locks. Probably the biggest single thing BW ever did to improve boaters safety.

[magpie patrick]

The Dukes Cut, built for the Duke of Buckingham, according to Canals of East England, was completed in 1789 and was a private waterway. The link to the Thames provided a means to join up with the improving navigation of the Upper Thames and the junction with the Thames & Severn Canal. This link enabled coal traffic to pass off the Oxford onto the wharves along the Upper Thames. The Oxford Canal wharves and basin in Oxford, did have a barge lock link to the Isis (Thames) before Isis Lock was made. In May 1794 the Oxford Canal Navigation published a notice in local papers quoting rates for

 

(1) Barges (20 tons) with coal from Oxford wharf passing Abingdon Lock but not Beeson Lock 10d per ton, 1s 3d for a 50 ton barge

(2) Barges (20 tons) passing Beeson Lock but not Whitchurch 1s 8d per ton, 2s 6d for a 50 ton barge

(3) Barges (20 tons) passing Whitchurch Lock 2s 6d per ton, 3s 6d for a 50 ton barge

 

The differential in charge depending on barge size is of interest, could this be due to water level and Thames charges?

 

Very interesting, that's the first time I've heard of a link prior to Isis Lock. I wonder where it was? Into the Castle Stream from the now vanished terminal basin?

 

Isis lock looks like an afterthought, it's squeezed into a narrow strip of land between the canal and the river: it's actually quite practical save for the near U-turn on exit to go UP the Sheepwash Channel (in times past going down the Castle Mill stream was doubtless possible but probably ill advised, low bridges and a weir await) and I understand the Sheepwash Channel itself had to be improved for the link - or perhaps that was for the barge lock?

 

It's quite possible the Thames steams in the area were configured differently in the 1790's I guess, at least with weirs in different places and even the odd now vanished stream.

 

I had thought that perhaps there was no lock initially on the basis that cargo being forwarded between canal and river would have to be transhipped between barge and narrowboat anyway so no point in connecting the two. Was a "barge (20 tonnes)" actually a narrow boat?

[Scholar Gypsy]

 

Very interesting, that's the first time I've heard of a link prior to Isis Lock. I wonder where it was? Into the Castle Stream from the now vanished terminal basin?

 

Isis lock looks like an afterthought, it's squeezed into a narrow strip of land between the canal and the river: it's actually quite practical save for the near U-turn on exit to go UP the Sheepwash Channel (in times past going down the Castle Mill stream was doubtless possible but probably ill advised, low bridges and a weir await) and I understand the Sheepwash Channel itself had to be improved for the link - or perhaps that was for the barge lock?

 

It's quite possible the Thames steams in the area were configured differently in the 1790's I guess, at least with weirs in different places and even the odd now vanished stream.

 

I had thought that perhaps there was no lock initially on the basis that cargo being forwarded between canal and river would have to be transhipped between barge and narrowboat anyway so no point in connecting the two. Was a "barge (20 tonnes)" actually a narrow boat?

 

As the map here shows, the main navigational channel used to be via Castle Mill steam, Hythe bridge St etc, and it was moved to the west when the channel was moved to Osney. The pound lock there was built in 1789, but I think the channel was moved over 500 years earlier.

 

http://thames.me.uk/s01800.htm (Medley weir)

 

http://thames.me.uk/s01760.htm (Osney)

[magpie patrick]

 

As the map here shows, the main navigational channel used to be via Castle Mill steam, Hythe bridge St etc, and it was moved to the west when the channel was moved to Osney. The pound lock there was built in 1789, but I think the channel was moved over 500 years earlier.

 

http://thames.me.uk/s01800.htm (Medley weir)

 

http://thames.me.uk/s01760.htm (Osney)

 

Ah, I knew what was there at Fiddlers Island, but I didn't know why

[ditchcrawler]

My daughter gave me this book (in paper back) a few years ago and lots of interesting bits in there about boaters. If I remember correctly the barges only came up as far as Oxford. https://www.amazon.co.uk/Fisher-Row-Fishermen-Historical-Monographs/dp/0198226497

[magpie patrick]

My daughter gave me this book (in paper back) a few years ago and lots of interesting bits in there about boaters. If I remember correctly the barges only came up as far as Oxford. https://www.amazon.co.uk/Fisher-Row-Fishermen-Historical-Monographs/dp/0198226497

 

Looks good, might get one second hand, I don't think my left over Christmas money will stretch to a new copy!

 

Edited to add, I'm not sure my original query has been answered in the slightest, but the picture that is emerging is that Dukes Cut allowed access upstream and Isis lockdownstream and that whilst the channel may have been moved from the Castle Mill Stream 500 years ago the Castle Mill Stream remained (and remains) navigable. Also that Oxford was, for some craft, the head of navigation on the Thames: in a way I suppose it still is given the height restriction at Osney Bridge.

Edited January 9, 2017 by magpie patrick

[ditchcrawler]

 

Looks good, might get one second hand, I don't think my left over Christmas money will stretch to a new copy!

 

Edited to add, I'm not sure my original query has been answered in the slightest, but the picture that is emerging is that Dukes Cut allowed access upstream and Isis lockdownstream and that whilst the channel may have been moved from the Castle Mill Stream 500 years ago the Castle Mill Stream remained (and remains) navigable. Also that Oxford was, for some craft, the head of navigation on the Thames: in a way I suppose it still is given the height restriction at Osney Bridge.

I passed my copy on to another ex boater, I can see if he has finished with it or even still has it if you like?

[Scholar Gypsy]

 

Looks good, might get one second hand, I don't think my left over Christmas money will stretch to a new copy!

 

Edited to add, I'm not sure my original query has been answered in the slightest, but the picture that is emerging is that Dukes Cut allowed access upstream and Isis lockdownstream and that whilst the channel may have been moved from the Castle Mill Stream 500 years ago the Castle Mill Stream remained (and remains) navigable. Also that Oxford was, for some craft, the head of navigation on the Thames: in a way I suppose it still is given the height restriction at Osney Bridge.

 

I've found some more on Wikipedia, very strange. But the references to barges above do now make sense, and as you surmised the link used to be further south,

 

"In central Oxford, the Oxford Canal and the River Thames were originally linked by a flash lock at Hythe Bridge.^[4] In 1795–97, David Harris replaced it with Isis Lock, a broad lock to allow Thames barges in and out of the Oxford Canal Company's Worcester Street wharves. Isis Lock was rebuilt as a narrow lock in 1844.^[4]"

 

A connection at Hythe Bridge might suggest that navigation to the Thames would have been to the south from there, along the old channel, rather than battling upstream along the Castle Mill stream to get to the Sheepwash?

 

https://en.wikipedia.org/wiki/Isis_Lock

[Heartland]

The lock came off the main basin- it is shown in Hugh Compton's book, I believe.

 

Actually reading the advert again it looks like these charges were drawbacks on people bringing coal along the length of the Oxford Canal, so it would appear that the Oxford was keen to export coal onto the Thames and failing this trade developing, a reason for Isis Lock may well have been the result. So if 50 ton of coal was sent on then the drawback was greater

[magpie patrick]

I've got a meeting and site visit next to the Sheepwash Channel in the morning, I'll have another look at Isis Lock and surrounds

[bookworm]

Fisher Row .Fishermen,Bargemen & Canal Boatmen in Oxford by Mary Prior. Try this site for a better price. http://Bookfinder.com