Oddly shaped lock?

[luctor et emergo]

This oddly shaped lock (where the Oxford joins/leaves the Cherwell near Enslow) seemed very strange, as it is very short, and wide, but can only accomodate one boat at a time. Is there a reason for it's odd shape? There didn't seem a lack of space to site a full length narrow lock at the location.

 

 

 

Just wondering.

[magpie patrick]

The theory is (and the physics would support it) that the lock would carry more water than a proper narrow lock the same fall. Where a canal is intercepted by a river, the hydraulic continuity is lost, all water from above disappears down the river and in effect you start again on water supply. To offset this it is though that the Oxford Canal Company built locks (where the canal left the river) that carried a greater volume of water to feed the lock downstream.

 

The sums more or less work at Shipton Weir, at Aynho the lock isn't big enough to feed Somerton Deep, the next lock downstream

[Janet S]

That looks like Aynho Weir Lock, and you CAN get two boats in, as we shared it on our May cruise, the first time we've every shared a lock on a narrow canal!

 

Mind you, it did help that our boat was only 34 foot, so we could squeeze in at the side!

 

Janet

 

[luctor et emergo]

The theory is (and the physics would support it) that the lock would carry more water than a proper narrow lock the same fall. Where a canal is intercepted by a river, the hydraulic continuity is lost, all water from above disappears down the river and in effect you start again on water supply. To offset this it is though that the Oxford Canal Company built locks (where the canal left the river) that carried a greater volume of water to feed the lock downstream.

 

 

 

The sums more or less work at Shipton Weir, at Aynho the lock isn't big enough to feed Somerton Deep, the next lock downstream

 

Thanks Patrick,

I see, that makes sort of sense. But why make it shorter than all other locks? Why didn't they just build a wider, full length lock?

 

If only the designers would have written down there reasonings for all the different lock configurations...

[Athy]

Surely it isn't shorter than the other locks - if it was, the working boats for which it was built would not have been able to get through it. But its shape does make it lok shorter. We too have shared this lock with another boat; this was with our last boat 'Batto' which is 40 feet long: a longer boat pulled over to the side amd we were able to come in alongside it. Or vice versa, can't remember.

Edited August 26, 2010 by Athy

[mrsmelly]

This oddly shaped lock (where the Oxford joins/leaves the Cherwell near Enslow) seemed very strange, as it is very short, and wide, but can only accomodate one boat at a time. Is there a reason for it's odd shape? There didn't seem a lack of space to site a full length narrow lock at the location.

 

 

 

Just wondering.

 

Is that not Aynho weir lock rather than the lock near enslow which is Shipton weir diamond lock. They both take full length boats with ease and you can get a couple of tiddlers in at the same time.............

[RLWP]

That looks like Aynho Weir Lock, and you CAN get two boats in, as we shared it on our May cruise, the first time we've every shared a lock on a narrow canal!

 

Mind you, it did help that our boat was only 34 foot, so we could squeeze in at the side!

 

Janet

 

<snip>

 

We have managed three boats in that lock. I'm sure I posted a picture last year, I wonder where it is?

 

Richard

[magpie patrick]

Thanks Patrick,

I see, that makes sort of sense. But why make it shorter than all other locks? Why didn't they just build a wider, full length lock?

 

If only the designers would have written down there reasonings for all the different lock configurations...

 

Luctor, in the photo your boat is in the lower gate recess area, and your boat is three feet short, a 72 footer could only open the bottom gate by backing into the top gate bay

 

and there is no significant cill, so you can go down with your stern against the top gate

[RLWP]

Luctor, in the photo your boat is in the lower gate recess area, and your boat is three feet short, a 72 footer could only open the bottom gate by backing into the top gate bay

 

and there is no significant cill, so you can go down with your stern against the top gate

 

A 70 footer can touch the bottom gate and then slew the stern over enough to let another boat in

 

Richard

 

Where's that damn picture?

[magpie patrick]

A 70 footer can touch the bottom gate and then slew the stern over enough to let another boat in

 

Richard

 

Where's that damn picture?

 

but not, I'll venture, another seventy footer...

 

Narrow canals were built for full length boats, tis us modern users who have shorties

 

and I said 72 foot

 

 

If only the designers would have written down there reasonings for all the different lock configurations...

 

 

You have no idea how often I've thought this...

 

Why did coal canal locks have the top gate mounted on the non-towpath side? Why is lower lode lock shaped like a mace? Why did dudgrove two-rise on the Thames and Severn have the lower chamber with a fall of less than 3 feet while the upper chamber fell 9? The lock you show is one of the oddities still in use, the number of oddities no longer in use, like this...

 

 

is far greater

Edited August 26, 2010 by magpie patrick

[DHutch]

The theory is (and the physics would support it) that the lock would carry more water than a proper narrow lock the same fall. Where a canal is intercepted by a river, the hydraulic continuity is lost, all water from above disappears down the river and in effect you start again on water supply. To offset this it is though that the Oxford Canal Company built locks (where the canal left the river) that carried a greater volume of water to feed the lock downstream.

This is my understanding.

- Presumably the fall of a large/fulldepth lock was not required.

 

[

That looks like Aynho Weir Lock, and you CAN get two boats in, as we shared it on our May cruise, the first time we've every shared a lock on a narrow canal!

We have managed three boats in that lock.

you just messing up the SYSTEM!!!

[RLWP]

<snip>

 

[you just messing up the SYSTEM!!!

 

You're right of course, we've left a two lock water deficit in the bottom part of the Oxford Canal

 

 

Richard

[Stephen Sugg]

Is that not Aynho weir lock rather than the lock near enslow which is Shipton weir diamond lock. They both take full length boats with ease and you can get a couple of tiddlers in at the same time.............

That's Aynho lock (one of Bones favourite locks!) It's defo full length and I remember years ago having just left the now vanished Anglo Welsh boatyard sharing it with two other Anglo's. I'm trying to twist my Dads arm into scanning in his slides of that particular trip which shows the gathering.....

[magpie patrick]

Didn't some one on here (possibly Bones) ground her boat in one of the bays?

[furnessvale]

Thanks Patrick,

I see, that makes sort of sense. But why make it shorter than all other locks? Why didn't they just build a wider, full length lock?

 

If only the designers would have written down there reasonings for all the different lock configurations...

If they had built a wider full length lock then two working boats would routinely share it. At the next lock down they would have to lock separately and all the benefit of the wider upstream lock passing more water per use would have been lost.

 

Force the boats to pass separately and you get more water downstream which is the object of the exercise.

 

George ex nb Alton retired

[Stephen Sugg]

Didn't some one on here (possibly Bones) ground her boat in one of the bays?

don't know about that but I remember going through there a while back on Bones with the river getting up to the red bit of the boards. She had to give up some proper welly to get past the weir in a straight line. I took the cowards option and stayed on the towpath. We then only just got under Nell bridge.

[MartinClark]

the number of oddities no longer in use, like this...

 

 

is far greater

 

Where's that, then, Patrick?

[Mrs Tawny Owl]

We have managed three boats in that lock. I'm sure I posted a picture last year, I wonder where it is?

 

Richard

 

 

A 70 footer can touch the bottom gate and then slew the stern over enough to let another boat in

 

Richard

 

Where's that damn picture?

 

 

Now I'll have to correct him, got his geography wrong. The first one posted was Aynho Weir lock which I dont' think is 3 boats wide.

 

The one we got 3 boats in as the picture above is Shipton Weir lock.

 

It was quite fun, the main problem we put Tawny Owl in first, then pulled her to one side or the other to get the other two in. They should have gone in first, but we weren't sure they would all fit.

 

It amused the locals for a while, it was the end of the day and no one was in a hurry so it was fun playing.

 

The prop nut was falling off Tawny Owl, so Richard was down the weed hatch trying to secure it with a wire coat hanger donated by one of the other boats. It was just after that that I found out just how quickly the forum can work.

Richard still wasn't happy with his repair so we called Proper Job who we knew moors in Thrupp to see if he had a big spanner. He was on the Thames, so he tried to get a mate to help. The Mate wasn't available so he said he drive up form Abingdon to meet us. We limped in to Thrupp just as it got Dusk, to be greed by Maffi asking how she was.

 

We'd never met before, how on earth did he know. Turns out PJ had spoken to Bones who spoke to Maffi.

PJ turned up to help with his tool box, and someone else who I don't wandered along to help too.

 

Isn't the forum wonderful

 

Sue

[magpie patrick]

Where's that, then, Patrick?

 

14 locks, Crumlin Branch of the Monmouthshire Canal, allegedly (but disputed) a passing place in the middle of a bratch style three

[Janet S]

We'd never met before, how on earth did he know. Turns out PJ had spoken to Bones who spoke to Maffi.

 

Isn't the forum wonderful

 

Sue

 

 

Well, you should know, after helping us with our laptop problem back in May! It was very surreal to be accosted at all points along the journey asking if we'd had our computer fixed!

 

One quick text to Bones and the CWDF crew swung into action...I'm still amazed by it!

 

Janet

Edited August 26, 2010 by Janet S

[magpie patrick]

Now I'll have to correct him, got his geography wrong. The first one posted was Aynho Weir lock which I dont' think is 3 boats wide.

 

The one we got 3 boats in as the picture above is Shipton Weir lock.

 

Yes Sue, tell him you are right, for some bizarre reason, Shipton Weir Lock (fall 2 foot 6, feeding a 7 foot 6 drop downstream) is bigger than Aynho (fall 1 foot, feeding a 12 foot fall downstream). I suspect a 19th century rebuild but have no evidence for this.

 

I measured both, Aynho is a bare 21 foot, if two "juno's" were put either side you'd squeeze Tawny Owl down the middle. Shipton Weir is nearer 30 foot wide

[Keeping Up]

Didn't some one on here (possibly Bones) ground her boat in one of the bays?

There is a small ledge (about two inches wide) around much of Shipton Weir lock including by the gates, and it is easy to catch the edge of the boat on it. This is not dangerous as the lock as such a small drop, but is inconvenient and sometimes means you have to refill the lock.

 

I can confirm, you can definitely get a 67-footer and a 72-footer into the lock together.

[Duchess Omnium]

Pangolin is 62 ft and I have been in that lock with 2 (smaller) boats. In fact it is better with another boat, because it is a devil to keep straight in there. There ought to be a sign though, because I did it for a couple of years without waiting for another boat because I never thought you could get two (or more) in there.

[magpie patrick]

Pangolin is 62 ft and I have been in that lock with 2 (smaller) boats. In fact it is better with another boat, because it is a devil to keep straight in there. There ought to be a sign though, because I did it for a couple of years without waiting for another boat because I never thought you could get two (or more) in there.

 

:Don't take this too seriously smiley:

 

AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAARRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRGGGGGGGGGGGHHHHHHHHHHHHH

 

It's only supposed to take on boat at once, you screw the water supply by putting more boats in

 

:where's the head in hands smiley:

[Bones]

That's Aynho lock (one of Bones favourite locks!) It's defo full length and I remember years ago having just left the now vanished Anglo Welsh boatyard sharing it with two other Anglo's. I'm trying to twist my Dads arm into scanning in his slides of that particular trip which shows the gathering.....

 

I still remember that event every time I go through there! We did have fun didn't we!

 

Didn't some one on here (possibly Bones) ground her boat in one of the bays?

 

Yes, in Shipton Weir Lock, one side is slightly smaller than the other side and there is a ledge sticking out on one of them which you can, if you aren't sharp, get stuck on. It was easy to pull me off.

 

don't know about that but I remember going through there a while back on Bones with the river getting up to the red bit of the boards. She had to give up some proper welly to get past the weir in a straight line. I took the cowards option and stayed on the towpath. We then only just got under Nell bridge.

 

I remember the look we gave eachother as we came out of yet another lock that was under water and the beer was promptly cracked open to supress the histerior

 

I thought that the diamond shape lock at Aynho was something to do with Somerton Deep being so..er.. deep, but that doesn't explain the shipton one - so it all makes sense (I think).

 

I have often had 3 boats in Shipton and I have had 3 in Aynho, but tend to go with 2. putting more boats in does screw up the water supply thing I suppose... hadn't thought of that Magpie Patrick!