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L&L Staircase locks.


dmr

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As full length boaters the L&L is out of bounds, but just had the chance to do a bit on a friends boat. On the Leeds side of the summit most of the locks are done as staircases. Why? Staircase locks are not the easiest to work and can be slow. I would have thought a canal hoping to see a lot of traffic (as they all did) would avoid them.

I don't think its related to the profile of the land, the Bingley 3 and 5 are quite close to each other so a conventional flight would have been an option?

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dunno, fewer gates, but they are very big gates which must have posed some challenges. And other flights  (Rochdale, Caan Hill etc) chose not to use them.

Maybe just a whim of the engineer? or a desire to make a mark and build something a bit dramatic???

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25 minutes ago, dmr said:

dunno, fewer gates, but they are very big gates

But no bigger than the bottom gates of a single lock of the same width and fall - its just that with a staircase lock you can see the whole gate, whereas the lower part of a normal bottom gate is always below the lower water level.

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@Pluto will be along soon with the full L&L story no doubt, but in summary... 

Most staircase locks are early in canal development* - they fall into the "seemed like a good idea at the time" category - some were later removed (on the L&L at Greenberfield for example, and several places on the Trent and Mersey, Church Lawton and Meaford to name two). They have two fundamental advantages - they are cheaper and steeper. A three rise has only four sets of gates and four wing walls, rather than six of each, for example. And a well laid out flight needs four to six times as much length as a staircase to achieve the same climb. 

 

They have two significant disadvantages - when traffic flow is reversed they use more water than a flight - the first ascending boat in a three rise needs three lock full of water from the top of the flight - and boats can't pass in them.

Most canals seriously underestimated how much traffic they would have, and thus staircases became something of a nuisance as traffic grew. 

As regards being difficult to work - if you were an L&L boatman doing the run regularly you wouldn't notice that - a boat that snugly fits the lock, and a crew that was well used to the locks means they'd hardly notice.  

*Staircases are also a feature of canal restoration - for pretty much the same reasons - cheap and steep. 

 

A few oddities amongst staircases

 

There are two- and three-rises on the Chesterfield Canal that have the rise of a single deep lock - 10-12 feet in total

Bratch and the pair at Stourbridge were staircases when built, and adapted to save water - they remain a bottle neck for traffic

Foxton and Watford were built as staircases to save money, but with side ponds to save water

Caen Hill is an example of how to squeeze locks in to a short distance without using a staircase, but it was never that busy and I'm not sure how it would have coped with BCN type traffic levels as the passing places between the locks are very tight if two K&A barges met 

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1 hour ago, magpie patrick said:

*Staircases are also a feature of canal restoration - for pretty much the same reasons - cheap and steep. 

Also back pumping is now much cheaper with electric pumps, so the extra water usage is less of a problem. Back in the 18th/19th century, it would have meant a beam engine, a building for it and the boiler, lots of cast iron pipes and ongoing costs for coal and perhaps four to six employees to work it all. They only went to the expense and trouble of pumping when they had no choice, for example Crofton on the K&A. The space and cost advantages of staircases for restorations become more compelling for the modern restorer.

Pumping still isn't without its problems. On the Tinsley flight (conventional, not staircase) in Sheffield, the summit was originally filled via a cut from the River Sheaf. This was lost when the river had a railway and station built on top. After that, they used coal mine pumped water until around 1911 (if I remember right), water was pumped from the river Don. First by steam pumps, later by electric. The pumps were failing regularly, so were replaced a couple of years ago. Unfortunately, the new powerful pumps blew out the over a hundred year old pipe line several times, so this winter there is a towpath closure to replace the entire pipe, over a mile long.

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11 hours ago, dmr said:

As full length boaters the L&L is out of bounds, but just had the chance to do a bit on a friends boat. On the Leeds side of the summit most of the locks are done as staircases. Why? Staircase locks are not the easiest to work and can be slow. I would have thought a canal hoping to see a lot of traffic (as they all did) would avoid them.

I don't think its related to the profile of the land, the Bingley 3 and 5 are quite close to each other so a conventional flight would have been an option?

IIRC the L&L spent pretty much the entire budget for the canal building Bingley 5-rise and had to penny-pinch everywhere else, the large number of swing bridges (much cheaper than proper bridges) are one sign of this and the staircase locks (cheaper than separate ones) are another.

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2 hours ago, magpie patrick said:

@Pluto will be along soon with the full L&L story no doubt, but in summary... 

Most staircase locks are early in canal development* - they fall into the "seemed like a good idea at the time" category - some were later removed (on the L&L at Greenberfield for example, and several places on the Trent and Mersey, Church Lawton and Meaford to name two). They have two fundamental advantages - they are cheaper and steeper. A three rise has only four sets of gates and four wing walls, rather than six of each, for example. And a well laid out flight needs four to six times as much length as a staircase to achieve the same climb. 

 

 

Interesting - three locks would require twelve wing walls rather than six, so helping more with the cost saving.  But I can't see that the total length of the flight of staircase will be a prime issue generally speaking; neither changes the distance between Leeds and Liverpool.  It is quicker to work a staircase than a flight - but not if you have a long wait for the staircase to be cleared by a boat travelling in the opposite direction.  So probably an advantage when there was little traffic.

 

It is the greater use of water that makes the adoption of the conventional staircase surprising; that must have been understood the time - and having regard to the overriding issue of sufficient water supply, the staircase is best avoided.

 

The fall in the surrounding land may have been an issue; where the canal can follow the levels it would help reduce engineering work.  Where it is is particularly steep (Foxton?) separate locks would have required a greater length over which to achieve the same fall - and perhaps some cutting at the top and embankments at the bottom would have been necessary.  But at Bingley, for example, it looks as thought more earthworks would be required to suit the staircases than would be needed to accommodate separate locks - which rather undermines that theory.

 

 

 

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7 minutes ago, Tacet said:

Interesting - three locks would require twelve wing walls rather than six, so helping more with the cost saving.  But I can't see that the total length of the flight of staircase will be a prime issue generally speaking; neither changes the distance between Leeds and Liverpool.  It is quicker to work a staircase than a flight - but not if you have a long wait for the staircase to be cleared by a boat travelling in the opposite direction.  So probably an advantage when there was little traffic.

 

 

I don't have all the answers - most is supposition based on the fact we can't deny what is actually there. Bingley Five Rise may not make any sense but it was built! The length matters for fitting in with the gradient and, occasionally for total length - e.g. the Staircase on the Ribble Link makes the canal shorter. I haven't done a topo survey around Bingley but from memory it is on sidelong ground and roughly level with the surrounding land at the top. For whatever reason it seems a decision was made to drop to the valley floor here - perhaps ahead of crossing the river at Dowley Gap. 

 

13 minutes ago, Tacet said:

It is the greater use of water that makes the adoption of the conventional staircase surprising; that must have been understood the time - and having regard to the overriding issue of sufficient water supply, the staircase is best avoided.

 

 

 I don't think ideas on water supply and consumption were that well developed, and even now when I'm looking at canal restoration it is often leakage and evaporation that are the biggest concern. If a flight of locks is used three times a day it's consumption may have been inconsequential, not so much once traffic exceeded all expectations. There are other instances where water supply seems to have been given less thought - compare the variance of depth on the Staffs and Worcs locks with the uniformity of the Shropshire Union locks

 

15 minutes ago, Tacet said:

The fall in the surrounding land may have been an issue; where the canal can follow the levels it would help reduce engineering work.  Where it is is particularly steep (Foxton?) separate locks would have required a greater length over which to achieve the same fall - and perhaps some cutting at the top and embankments at the bottom would have been necessary.  But at Bingley, for example, it looks as thought more earthworks would be required to suit the staircases than would be needed to accommodate separate locks - which rather undermines that theory.

 

 

Tyrley locks, built much later, drop into a cutting and are a good example of why earlier engineers squashed their lock flights

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The post-5-rise cost-saving measures (swing bridges and staircase locks) are mentioned both in one of the recent TV programs on canals, and the book by Mike Clarke on the history of the L&L which is sitting in front of me as I type...

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Incidentally I've just measured from the top of Bingley five to the bottom of Bingley 3 - it's about 2000 feet for the canal fall 100 feet, or 1 in 20. That's rather steeper than Marple Locks (about 1 in 25) which are amongst the steepest in the country. The fall probably could have been done in 8 single locks but it would have been quite an undertaking - I guess the real question is why the top and bottom of the locks are where they are, because that's what was driving the formation 

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26 minutes ago, magpie patrick said:

Incidentally I've just measured from the top of Bingley five to the bottom of Bingley 3 - it's about 2000 feet for the canal fall 100 feet, or 1 in 20. That's rather steeper than Marple Locks (about 1 in 25) which are amongst the steepest in the country. The fall probably could have been done in 8 single locks but it would have been quite an undertaking - I guess the real question is why the top and bottom of the locks are where they are, because that's what was driving the formation 

Possibly existing buildings in the area constrained the place where they could climb up the valley side? I am guessing Bingley would still be fairly built up at that time, though it would need a check on a contemporary map. Looking at the current contour map, there the Dowley Gap crossing of the Aire below Bingley and a valley coming in from the side above Bingley, (Bradup Beck), where you would want to be on the right sort of level to minimise the height of embankments to cross, but these are both a relatively long way away and don't explain why the height was gained in such a short space.

Edited by Jen-in-Wellies
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Riser locks were probably seen as useful in the 18th century as they allowed several locks to be controlled by one person. They may also have been cheaper to build. L&LC locks were considered deep at the time of their construction, at between nine and ten feet, and the widespread use of ground paddles was certainly a factor in the use of 'deep' locks  across the country. The depth of locks on canals was certainly more than on contemporary river navigations. I am sure the builders realised that riser locks would use more water than individual locks, but with the volume of trade expected, this was not seen as a problem. However, trade seems to have developed far more than expected, and this created a water supply problem, with the result that Greenberfield two-rise was removed by the 1820s, just thirty years after construction, and the bypassing of other riser locks was considered at various times. The increase in traffic was also a factor in replacing swing bridges, used from the start to keep down costs on the L&C. The 1790 Act prohibits their use unless local land owners did not object, and many existing swing bridges were replaced after the 1790s, particularly in those areas where road traffic was also increasing. The general rise in trade encouraged by the opening of inland waterways was far greater than originally expected, and this rise did have an effect on what was built after the 1790s. On the L&LC, there were no more riser locks after Greenberfield two-rise was built between 1790 and 1794.

 

When our canals were first proposed in the 176os, riser locks were considered a suitable solution, both financially and operationally. By the 1790s they had been shown to be a failure operationally, and few were built subsequently, except in very specific circumstances. For example, on the Caledonian Canal, where water supply was not a major problem and where the number of boats using the canal was not likely to be a problem.

 

On the location of locks on the L&LC in the Aire Valley, it is important to remember that this is a valley with glacial morains, such as at Dowley Gap, at the lower end of a very shallow section of the Aire Valley. Lock building would try to avoid morains as they would be difficult areas for foundations, with Dowley two-rise being above the morain. Good solid rock at Bingley may have been one reason for riser locks there, though the availability of land would have been another. Canals tend to use the cheapest land, and consequently avoid the older town centres, such as at Burnley and Blackburn on the L&LC. 

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6 minutes ago, Pluto said:

and many existing swing bridges were replaced after the 1790s, particularly in those areas where road traffic was also increasing.

 

I knew the meister would be along soon! Thanks @Pluto

On swing bridges, the only other canal I have detailed knowledge of, the Coal Canal, was built with swing bridges that were later all replaced with fixed bridges - it got the canal open and earning toll revenue

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and whilst Pluto is here?

 

Why are all the swing bridges operated from the non-towpath side?

You said that a single person could maybe handle multiple boats on a staircase, but the swing bridges tie up a person who can then take little part in boat moving.

The only thing that I can think off is it makes it marginally easier for the horse and rope to pass???.

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36 minutes ago, dmr said:

and whilst Pluto is here?

 

Why are all the swing bridges operated from the non-towpath side?

You said that a single person could maybe handle multiple boats on a staircase, but the swing bridges tie up a person who can then take little part in boat moving.

The only thing that I can think off is it makes it marginally easier for the horse and rope to pass???.

That’s pretty much the case everywhere else too. 
I always thought it was something to do with the land owner’s  right of access?

Edited by Goliath
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3 hours ago, Tacet said:

 Where it is is particularly steep (Foxton?) separate locks would have required a greater length over which to achieve the same fall.

Foxton is only steep because the builders made it so. The summit clings to the contour until the last minute when there's nowhere else to go and then drops steeply.  There's a lovely gentle slope from the as built line for at least the last half mile where the canal could have descended more slowly.

 

MP.

 

 

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3 minutes ago, magpie patrick said:

 Not marginally easier - a LOT easier

 

Maybe,  as long as the handrails are not too high getting the rope over would not be too bad (some bridges have a tall upright post) though getting any boat past the end of an open bridge is a bit stressful.   I reckon Goliath might be right.

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1 hour ago, dmr said:

and whilst Pluto is here?

 

Why are all the swing bridges operated from the non-towpath side?

You said that a single person could maybe handle multiple boats on a staircase, but the swing bridges tie up a person who can then take little part in boat moving.

The only thing that I can think off is it makes it marginally easier for the horse and rope to pass???.

A lot easier for horse towing as there is nothing on the towpath side for the rope to snag on, and the person leading the horse can nip over the bridge to open it, wait on the offside while the horse pulls the boat through, then close up again and catch up with the horse.

No doubt swing bridges on the towpath side could have been configured with fence 'ramps' to lift the tow rope over the structure, but it would have been messy and not foolproof. For lift bridges it would be impossible.

Edited by David Mack
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2 minutes ago, David Mack said:

A lot easier for horse towing as there is nothing on the towpath side for the rope to snag on, and the person leading the horse can nip over the bridge to open it, wait on the offside while the horse pulls the boat through, then close up again and catch up with the horse.

No doubt swing bridges on the towpath side could have been configured with fence 'ramps' to lift the tow rope over the structure, but it would have been messy and not foolproof. For lift bridges it would be impossible.

 

I have seen the horseboat on the K&A many times, if the owner nipped over a swing bridge then the horse would stop, eat a bit of grass then turn round and head for home. 😀

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Following @dmr query I started thinking where staircase locks were replaced with conventional locks*, as this was a solution when the problem proved too great

 

*Note - staircases replaced and the canal remaining open, not just closed staircase locks

 

Ones I can think of - I'm sure there were others

 

L&L, Greenberfield - 2 rise and a single replaced by three new single locks

Calder and Hebble - Salterhebble (2 rise? or 3 rise?)

Caldon (Hazlehurst 3 rise, replaced by three single locks and had itself had replaced two single locks

T&M - Meaford - three rise replaced by three single locks

T&M - bottom three of Church Lawton - three rise replaced by three single

[I think there were at least two more on the T&M - Etruria?]

 

Plus the rather odd ones at Bratch on the S&W and the double lock at Stourbridge - both converted from staircases to close formation separate locks. Related to these the middle seven at delph were close formation and replaced with what is now six locks

I think there was one built on the K&A but removed before the canal was finished, and also I think a really odd one on the royal were a three rise with short chambers was converted into a two rise with proper length chambers - again before the canal was finished

 

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Interesting. There is a two chamber staircase on the Grand Union, after Calcutt and heading down to Leamington. (can't remember its name)  Why just one amongst lots of conventional locks?, and why did it not get replaced? I assume it was once a narrow lock and so got rebuilt as a wide????  so a busy canal....so why keep a staircase lock?

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4 minutes ago, dmr said:

Interesting. There is a two chamber staircase on the Grand Union, after Calcutt and heading down to Leamington. (can't remember its name)  Why just one amongst lots of conventional locks?, and why did it not get replaced? I assume it was once a narrow lock and so got rebuilt as a wide????  so a busy canal....so why keep a staircase lock?

Bascote

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