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Vandalism on the Leeds Liverpool


TheBiscuits

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OK,

 

the mode of failure on Lock 11 is clearly speculative, but what I describe below is something that is seen in other structures of a similar age.

 

Essentially, we now build things be laying a concrete raft that everything sits on (foundations). Back then, they didn't.

 

They simply dug holes deep enough into the clay to provide adequate support. Such foundations work well, provided the clay remains intact. If the clay is allowed to dry out too much, the foundations can fail. You sometimes see it on old Victorian houses with concrete driveways that prevent rainwater reaching the foundations.

 

So, whilst a lock is periodically filled with water, keeping the clay wet, it will be OK. Let the clay dry out, and the foundations fail.

 

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18 minutes ago, billh said:

Since when was 6ft 10ins  a standard? Are you saying all those boats over that width will be barred from using the narrow canals because CRT can't be bothered  with proper maintenance? Have they rebuilt Marple Lock 15 to this new standard? Most historic NBs are over this "standard" ,looks like they may be consigned to museums then?

I seem to recall it was a decision by BW - someone else might have more details.  They consider a lock OK if it can take a 6' 10" beam with 1 inch of clearance.

 

The rebuild on lock 15 at Marple was to full size, but they don't usually attempt to fix lock chambers unless there is not 6' 11" clearance in the lock.

 

On the Rochdale canal, we have seen several signs saying "Narrow lock - only one boat at a time to use this lock."  This is a bit concerning if a lock nominally built for 14' 2" boats can't take two 6' 10" boats (13' 8").

 

 

 

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4 minutes ago, mayalld said:

OK,

 

the mode of failure on Lock 11 is clearly speculative, but what I describe below is something that is seen in other structures of a similar age.

 

Essentially, we now build things be laying a concrete raft that everything sits on (foundations). Back then, they didn't.

 

They simply dug holes deep enough into the clay to provide adequate support. Such foundations work well, provided the clay remains intact. If the clay is allowed to dry out too much, the foundations can fail. You sometimes see it on old Victorian houses with concrete driveways that prevent rainwater reaching the foundations.

 

So, whilst a lock is periodically filled with water, keeping the clay wet, it will be OK. Let the clay dry out, and the foundations fail.

 

Agreed, but it's what the bloke working us through lock 11 was telling me the day they reopened Marple.

 

He was also saying that they have learnt a lot from rebuilding 15, so they have a better plan for rebuilding 11.  

 

It's the ground drying out around the empty locks that concerns me about the L&L this month - I don't think freezing is going to be too much of a problem at current temperatures!

 

I'm also predicting we will have heavy enough rain while the locks are disabled that the bywashes won't be able to cope with the runoff ...

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8 minutes ago, TheBiscuits said:

I seem to recall it was a decision by BW - someone else might have more details.  They consider a lock OK if it can take a 6' 10" beam with 1 inch of clearance.

 

The rebuild on lock 15 at Marple was to full size, but they don't usually attempt to fix lock chambers unless there is not 6' 11" clearance in the lock.

 

On the Rochdale canal, we have seen several signs saying "Narrow lock - only one boat at a time to use this lock."  This is a bit concerning if a lock nominally built for 14' 2" boats can't take two 6' 10" boats (13' 8").

 

 

 

The Leeds and Liverpool and the Peak Forest stayed in use without a break from working through to leisure days. The section of the Rochdale with the worst of the narrow locks was out of use for decades and then restored with the minimum amount of money being spent to get something navigable. 

 

Through parts of Manchester the channel had been culverted in concrete. Only enough was dug out to allow a single wide beam to pass. If I remember right, most of the badly distorted lock chambers are on the West side that was restored. In addition to drying out there is also mining subsidence as well that affected parts of this canal. The volunteer who helped us come up through Manchester a few years ago said that the prevoius week a 12' beam boat had come through OK, to the surprise and delight of many!

 

Jen

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7 hours ago, Jerra said:

If you are going to the trouble of half opening the second gate why not fully open it.

obviously because I can easily get out without damaging the mitre with 1 gate fully open and the other half open.

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9 hours ago, Midnight said:

If boaters played their part by opening 1 gate fully and the other about half this damage could be avoided. Anyone who says they can enter/exit through 1 gate without touching every time is dreaming

A lot is down to bad boat design and wide chines...And it’s perfectly possible to enter or exit a wide lock without scraping the gate...perhaps you need more practice? 

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2 hours ago, Midnight said:

obviously because I can easily get out without damaging the mitre with 1 gate fully open and the other half open.

Most of the double locks I know, the gates don't sit half way anywhere, they either close back up or swing fully open. This is down to poor balancing when being installed.

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12 minutes ago, matty40s said:

Well with the hosepipe ban being lifted before it comes into place perhaps the paddle gear will be welded back on tomorrow. ......

I'm not holding my breath on that one. 

 

Would this month be a good time to get DEFRA to check how well CRT are maintaining the assets in trust? 

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On 01/08/2018 at 11:02, Ace 01 said:

We are on the K and A and some locks are signed as to be left empty. These are the ones without by wash weirs and the excess water goes over the top paddle culvert into the lock chamber then exits via the open bottom paddles or gates. These can cause water loss if anyone going down goes to fill a lock without noticing the bottom paddles have been left open by a previous boater.

 

Cheers

 

David

don't. we were on the VM at the pumping station yesterday and someone had all four paddles open and within minutes we were sat on the bottom.

 

luckily CRT were then in an hour or two and restored levels

 

the pound below croften top lock was left completely empty too.

 

they are left empty because there are no  lock weirs. comibg down a few pounds were overflowing the tow path because people don't leave a paddle up. the same at caen hill.

On 01/08/2018 at 11:02, Ace 01 said:

 

On 01/08/2018 at 11:02, Ace 01 said:

 

Edited by thebfg
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On 31/07/2018 at 22:52, TheBiscuits said:

20180731_193738.jpg.1a76643e6b92a747216bdc58f7e8ef5c.jpg

 

The lock flights at Wigan (locks 65 to 85), Johnsons Hillocks (58 to 64), Blackburn Flight (locks 52 to 57), Barrowford Locks (45 to 51), Greenberfield Locks (42 to 44), Bank Newton Locks (36 to 41) and Gargrave (locks 35 to 30) will be padlocked closed and the gates will be ashed up to reduce leakage.  To prevent unauthorised access though vandalism, measures will be taken to make the locks inoperable.

 

Ground paddle shafts removed and gate paddle shafts cut off is vandalism!

This is pretty extreme! Is there some history of people cutting off the chains they use to shut locks in these areas? Can't recall anything like this on any other canals when they have been closed for lack of water?

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1 minute ago, Dave123 said:

This is pretty extreme! Is there some history of people cutting off the chains they use to shut locks in these areas? Can't recall anything like this on any other canals when they have been closed for lack of water?

We thought they would just put the stop planks in to stop people using the locks by cutting chains off, but no.

 

I'm assuming they have not done this on the Rochdale as @dmr has been told they can move a few miles on Monday.

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I see no reason why leaving a lock empty should be detrimental to the integrity of the structure. Each side wall is a gravity retaining structure that must be designed to withstand the pressure of the earth on the external side while the lock chamber is completely empty. There are thousands of such structures of contemporary design in the UK which never 'benefit' from having water pressure applied to the opposite face. All locks spend prolonged periods completely empty as part of the maintenance programme. They don't routinely suffer.

 

JP

Edited by Captain Pegg
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7 hours ago, Captain Pegg said:

I see no reason why leaving a lock empty should be detrimental to the integrity of the structure. Each side wall is a gravity retaining structure that must be designed to withstand the pressure of the earth on the external side while the lock chamber is completely empty. There are thousands of such structures of contemporary design in the UK which never 'benefit' from having water pressure applied to the opposite face. All locks spend prolonged periods completely empty as part of the maintenance programme. They don't routinely suffer.

 

JP

But a lot of these locks were built in the infancy of civil engineering when methods for calculating the forces involved were not available. There’s also MtB’s point about clay foundations drying out. It’s not unusual to see locks on abandoned canals awaiting restoration with acroprops across them the hold the walls in place.

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8 hours ago, TheBiscuits said:

We thought they would just put the stop planks in to stop people using the locks by cutting chains off, but no.

 

I'm assuming they have not done this on the Rochdale as @dmr has been told they can move a few miles on Monday.

Probably easier and quicker to remove the gear mechanism and therefore cheaper than use stop planks.

8 hours ago, Dave123 said:

This is pretty extreme! Is there some history of people cutting off the chains they use to shut locks in these areas? Can't recall anything like this on any other canals when they have been closed for lack of water?

I’m guessing that’s what happened last time.

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22 minutes ago, BruceinSanity said:

But a lot of these locks were built in the infancy of civil engineering when methods for calculating the forces involved were not available. There’s also MtB’s point about clay foundations drying out. It’s not unusual to see locks on abandoned canals awaiting restoration with acroprops across them the hold the walls in place.

I deliberated on whether I should add to my post or even delete it as I knew it would trigger a riposte.

 

Just dealing with the issue at hand I don't believe there is any good reason why leaving the water at the lower level on the locks in question (they are not empty) should be detrimental.

 

The folks that built them had more than a basic grasp of forces and if they had got it fundamentally wrong the impact of that would have been felt long before now and quite probably before any water was put in the canal.

 

The reason that Victorian (and older) structures survive and still work two centuries after construction isn't so much that they were 'built to last' as the continuous maintenance that is undertaken to keep them serviceable. A lock on an abandoned  canal hasn't been subject to that or indeed any formal assessment of its soundness as is undertaken on locks on the operational network. Therefore you probably would be well advised to prop the walls before working in the chamber.

 

JP

 

 

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3 hours ago, Robbo said:

Probably easier and quicker to remove the gear mechanism and therefore cheaper than use stop planks.

Absolutely, but the exact opposite applies when reopening the locks.   It has to be easier and quicker to remove a dozen stop planks than it's going to be to rebuild all the paddle gear on the whole flight(s).

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1 minute ago, TheBiscuits said:

Absolutely, but the exact opposite applies when reopening the locks.   It has to be easier and quicker to remove a dozen stop planks than it's going to be to rebuild all the paddle gear on the whole flight(s).

Have all the locks been cut?  I woulld have thought the one at each end would have been enough.

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13 minutes ago, TheBiscuits said:

Absolutely, but the exact opposite applies when reopening the locks.   It has to be easier and quicker to remove a dozen stop planks than it's going to be to rebuild all the paddle gear on the whole flight(s).

Stop planks require craning in/out it will be alot slower to do that rather than remove and putting back the gear mechanisms.

Edited by Robbo
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On 01/08/2018 at 21:49, matty40s said:

Most of the double locks I know, the gates don't sit half way anywhere, they either close back up or swing fully open. This is down to poor balancing when being installed.

Surely that is good balancing. Gates should either stay closed or stay open. And it's not down to the gate installation. On many locks you can see that the quoins have been installed at an angle so that this happens.

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On 03/08/2018 at 11:15, Jerra said:

Have all the locks been cut?  I woulld have thought the one at each end would have been enough.

Good point - I went to have a look today.  It's only the top lock and the bottom lock that have had this treatment, which makes sense.  Oddly quiet on the flight though - no boats at all. :D

 

I have been doing CRT a disservice with my original post - the bottom lock clearly has had the rack disconnected rather than cut off the gate paddle shaft, but I couldn't see that on the top lock.  The bottom lock gates are new ones though, so it is more obvious. 

 

IMG_20180804_183826141.jpg.5e412b3cf0200d25273aa313fbad383f.jpg

 

It does look like they need bigger ashes on some of the locks though.  The ones they are using are not large enough to stop the water coming out!

 

IMG_20180804_184906282.jpg.29a0f7b8832ec4a79de992ff576bf62a.jpg

 

 

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12 hours ago, TheBiscuits said:

Good point - I went to have a look today.  It's only the top lock and the bottom lock that have had this treatment, which makes sense.  Oddly quiet on the flight though - no boats at all. :D

 

I have been doing CRT a disservice with my original post - the bottom lock clearly has had the rack disconnected rather than cut off the gate paddle shaft, but I couldn't see that on the top lock.  The bottom lock gates are new ones though, so it is more obvious. 

 

IMG_20180804_183826141.jpg.5e412b3cf0200d25273aa313fbad383f.jpg

 

It does look like they need bigger ashes on some of the locks though.  The ones they are using are not large enough to stop the water coming out!

 

IMG_20180804_184906282.jpg.29a0f7b8832ec4a79de992ff576bf62a.jpghe

 

 

Put the boat shaft down the mitre inside the lock and you can normally stop enough of this flow to fill a bad leaker.

 

CRT could do the same with a length of 3" x 3".

 

George

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13 hours ago, TheBiscuits said:

Good point - I went to have a look today.  It's only the top lock and the bottom lock that have had this treatment, which makes sense.  Oddly quiet on the flight though - no boats at all. :D

 

I have been doing CRT a disservice with my original post - the bottom lock clearly has had the rack disconnected rather than cut off the gate paddle shaft, but I couldn't see that on the top lock.  The bottom lock gates are new ones though, so it is more obvious. 

 

IMG_20180804_183826141.jpg.5e412b3cf0200d25273aa313fbad383f.jpg

 

It does look like they need bigger ashes on some of the locks though.  The ones they are using are not large enough to stop the water coming out!

 

IMG_20180804_184906282.jpg.29a0f7b8832ec4a79de992ff576bf62a.jpg

 

 

I thought that ashing would normally be done to top lock with the lock empty. (That's what I have seen, anyway)

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