Steel Lock Gates?

[John Liley]

I find myself involved with pressure to change the material with which lock gates are made. Oak gates last between 20 and 25 years. Steel ones, though marginally more expensive, last far,, far longer.

 

The present replacement rate is not keeping up. So, given the parlous state of C&RT finances, moving to steel seems a no-brainer. Two worthy members of the Kennet & Avon Trust put the case for modular steel gates in a recent issue of 'Waterways World' and I have supported this, commenting that if the heritage issue emerges, the Canal du Midi in France makes a useful precedent. This canal started, long ago, with wooden gates throughout, but nowadays has them made of metal. The Canal du Midi was inscribed as a UNESCO World Heritage site in 1996 and nobody seems to have noticed the difference.

 

However ...

 

A letter in the latest issue of Waterways World points out that 25 years ago a steel replacement pair of gates was rejected by the Daventry Conservation Officer. A Heritage Advisor I have spoken to tells me that this is an ambiguous matter, that some officers would say OK, and others No. Some kind of central directive would be of help here. Any ideas on how to achieve this?

 

It may seem arcane, but, long term, our canal system will descend into more and more stoppages through lock gate collapse. And then, ultimately, closure.

Edited October 3, 2020 by John Liley
Mis-spelling

[ditchcrawler]

How do these new steel gates differ from all the old steel gates dotted around the system complete with steel balance beams?

[Guest]

27 minutes ago, John Liley said:

I find myself involved with pressure to change the material with which lock gates are made. Oak gates last between 20 and 25 years. Steel ones, though marginally more expensive, last far,, far longer.

 

The present replacement rate is not keeping up. So, given the parlous state of C&RT finances, moving to steel seems a no-brainer. Two worthy members of the Kennet & Avon Trust put the case for modular steel gates in a recent issue of 'Waterways World' and I have supported this, commenting that if the heritage issue emerges, the Canal du Midi in France makes a useful precedent. This canal started, long ago, with wooden gates throughout, but nowadays has them made of metal. The Canal du Midi was inscribed as a UNESCO World Heritage site in 1996 and nobody seems to have noticed the difference.

 

However ...

 

A letter in the latest issue of Waterways World points out that 25 years ago a steel replacement pair of gates was rejected by the Daventry Conservation Officer. A Heritage Advisor I have spoken to tells me that this is an ambiguous matter, that some officers would say OK, and others No. Some kind of central directive would be of help here. Any ideas on how to achieve this?

 

It may seem arcane, but, long term, our canal system will descend into more and more stoppages through lock gate collapse. And then, ultimately, closure.

Forgive me for not knowing but who are you and what is your interest in this matter?

 

I'm guessing others will know but im aftaid I, and possibly others wont know.

[dmr]

Making changes to heritage and listed structures really is the thin end of a big wedge.

More importantly I see very little financial advantage in this. If gates need replacing now then spending even more now to make a potential saving  in 25 years time is just daft. In 25 years time the canals might be very well financed, or more likely, due to banning diesel, boating may well have ended and the canals filled in to be cycle ways.

 

How will changing to steel improve the current replacement rate? 

 

..................Dave

[matty40s]

Given the state of Daventry as a historical market town devastated by development, non sympathetic architecture and the fact that the oldest bookstore in town was given zero finance in help when it was on the cusp of falling down.....the owner taking on massive debts to secure its future....and Covid finishing him off....

 

I dont really think Daventry should be taken as a rule of thumb.

[StephenA]

59 minutes ago, dmr said:

Making changes to heritage and listed structures really is the thin end of a big wedge.

More importantly I see very little financial advantage in this. If gates need replacing now then spending even more now to make a potential saving  in 25 years time is just daft. In 25 years time the canals might be very well financed, or more likely, due to banning diesel, boating may well have ended and the canals filled in to be cycle ways.

 

How will changing to steel improve the current replacement rate? 

 

..................Dave

It wont but it does mean that in 15 years or so you're not replacing gates. Some of the steel gates on the Llangollen date from 1976.

 

 

[Tam & Di]

2 hours ago, The Happy Nomad said:

Forgive me for not knowing but who are you and what is your interest in this matter?

 

I'm guessing others will know but im aftaid I, and possibly others wont know.

I'm not sure why that is important, but you can click on his name to get some idea of his interests. He's been boating longer than most people on this forum, both in the UK and on the continent, and written books about it - I think "Journeys of the Swan" was probably the first https://www.amazon.co.uk/Journeys-Swan-John-Liley/dp/0043860052

 

Most recently he has contributed several photos to the "Tonic Required" thread here.

 

Tam

Edited October 4, 2020 by Tam & Di

[mrsmelly]

8 hours ago, dmr said:

Making changes to heritage and listed structures really is the thin end of a big wedge.

More importantly I see very little financial advantage in this. If gates need replacing now then spending even more now to make a potential saving  in 25 years time is just daft. In 25 years time the canals might be very well financed, or more likely, due to banning diesel, boating may well have ended and the canals filled in to be cycle ways.

 

How will changing to steel improve the current replacement rate? 

 

..................Dave

Dont be daft Dave. We all know that within ten years of now we will all have binned our diesel engines for the fantastic cheap to buy with a bank of cheap batteries electric motors. A complete network of charging points will have been built at thousands of spots around the country that just like water points now no one will ever take this piss by mooring on when not being used for their original intention.. Also the sun has given notice that it now intends to shine brightly every day for ever over the UK and not shut down for six months of the year, you only have to look at the vast amount we have had over the last three days to understand we can run all electric appliances and propel the boat for several hours every day with only a couple of solar panels.

[Jen-in-Wellies]

Here are the questions I'd want to investigate.

With steel lock gates, does it decrease the frequency of maintenance required? Are the cills and mitre surfaces still made of oak? If so, do these bits still need replacement on a 20 to 25 year basis. The Llangollen steel gates are from 1976, but how often has the lock had to be drained and them lifted out for fettling and part replacement in that time? Since with modern elth'n'safety, the lock has to be scaffolded and fenced, sealed off, drained and a crane bought in to do this, is it any cheaper in maintenance than having to do this to replace a set of oak gates?

The average cost of running a lock with steel versus oak needs working out over a 25 year period. A bit more complex than comparing the straight up build cost of the two materials, but not impossible. Not averse to the idea. Steel gates have been around for a long time now that their use is "historic", just not everywhere.

 

I remember it being said that oak gates are more resistant to being accidentally rammed than steel. Not sure how true this is. Again, the Llangollen ones have survived over 40 years of novice boaters, so they can't be too fragile.

 

On conservation, I'd worry about a dispensation to change lock gate material over cost could be the thin end of the wedge. What if, say a snake turnover bridge on the Macc needed rebuilding? Could it be replaced with a cheaper concrete, or steel one? The same arguments could be used.

 

With the present Cycling and Rambling Trust senior management, would a decrease in maintenance cost lead to more locks getting maintenance, or a further cut in the maintenance budget?

 

Jen

 

Edited October 4, 2020 by Jen-in-Wellies

[Tracy D'arth]

I can support function over aesthetics.  I don't live on the canals for the view. I want to continue being able to move.

There are many precidents for modern construction and materials being used in past maintenance, may it continue and the canals remain open and usable.

Edited October 4, 2020 by Tracy D'arth

[blackrose]

I

47 minutes ago, Jen-in-Wellies said:

Here are the questions I'd want to investigate.

With steel lock gates, does it decrease the frequency of maintenance required? Are the cills and mitre surfaces still made of oak? If so, do these bits still need replacement on a 20 to 25 year basis. The Llangollen steel gates are from 1976, but how often has the lock had to be drained and them lifted out for fettling and part replacement in that time? Since with modern elth'n'safety, the lock has to be scaffolded and fenced, sealed off, drained and a crane bought in to do this, is it any cheaper in maintenance than having to do this to replace a set of oak gates?

The average cost of running a lock with steel versus oak needs working out over a 25 year period. A bit more complex than comparing the straight up build cost of the two materials, but not impossible. Not averse to the idea. Steel gates have been around for a long time now that their use is "historic", just not everywhere.

 

I'd have thought the ANT would have some data on steel lock gate maintenance for comparison. Although they're not as heavily used as the canal locks, most (all?) of the gates on the Avon are made of steel. In terms of operating them some are almost impossible to open if you're single handing, but that's probably due to design rather than material. 

[matty40s]

49 minutes ago, Tracy D'arth said:

 

There are many presidents for modern construction and materials being used in past maintenance, may it continue and the canals remain open and usable.

To many Presidents spoil the lockth. 

[Tracy D'arth]

2 minutes ago, matty40s said:

To many Presidents spoil the lockth. 

Oooops! Corrected, my brain trumped.  What's a lockth?

[magpie patrick]

10 hours ago, John Liley said:

I find myself involved with pressure to change the material with which lock gates are made. Oak gates last between 20 and 25 years. Steel ones, though marginally more expensive, last far,, far longer.

 

The present replacement rate is not keeping up. So, given the parlous state of C&RT finances, moving to steel seems a no-brainer. Two worthy members of the Kennet & Avon Trust put the case for modular steel gates in a recent issue of 'Waterways World' and I have supported this, commenting that if the heritage issue emerges, the Canal du Midi in France makes a useful precedent. This canal started, long ago, with wooden gates throughout, but nowadays has them made of metal. The Canal du Midi was inscribed as a UNESCO World Heritage site in 1996 and nobody seems to have noticed the difference.

 

However ...

 

A letter in the latest issue of Waterways World points out that 25 years ago a steel replacement pair of gates was rejected by the Daventry Conservation Officer. A Heritage Advisor I have spoken to tells me that this is an ambiguous matter, that some officers would say OK, and others No. Some kind of central directive would be of help here. Any ideas on how to achieve this?

 

It may seem arcane, but, long term, our canal system will descend into more and more stoppages through lock gate collapse. And then, ultimately, closure.

Okay - this is the sort of thing I advise on professionally, both from the canal point of view and the heritage/conservation point of view - these are my thoughts and I'm very happy to keep posting if you have more questions. 

 

Until fairly recently wooden gates were de riguer  for many reasons, including but not limited to conservation. The technical reasons even came into the type of wood. Steel gates transfer more of any shock load (e.g. a boat hitting them) into the lock structure, but so do gates made of eki. Steel gates are more resilient when hit, they tend not to break, but in extremis they bend and don't bend back afterwards. 

 

The Monmouth, Brecon and Abergavenny Canal Trust trialed steel gates that look like wooden gates and also have buoyancy (a major failing of previous steel gates) , not only will they last far longer but they are modular and can be brought to site in sections and assembled by volunteers. Both are big issues on restoration of isolated waterways. A K&A gate might see 50,000 boat movements or more in a 25 year period, one on the Neath Canal might not see 500 boat movements in that time.These gates got Heritage Lottery Fund approval. 

 

There is also the issue of the amount of wood a pair of wooden gates need (six trees a lock?), and the quality - this results in them not being as "green" nor as durable as might be supposed. A pair of flood gates at Ebley (also HLF funded) were cracking less than a year after installation for example. I suspect this issue has generally shortened gate life as well, looking at how intact gates are on the North Walsham and Dilham Canal (last used 90 years ago) - not usable, but substantially intact, and made from timber around 110 years ago, I suspect many modern wooden gates will be dust after 110 years. 

 

C&RT should, sensibly, look at a mix. The steel lookalikes would serve well in many cases, but I'd be reluctant to see them on Bingley five rise for example, but I really don't see why they shouldn't be on the locks at Soulbury or Bank Newton

Edited October 4, 2020 by magpie patrick

[Tam & Di]

8 minutes ago, magpie patrick said:

C&RT should, sensibly, look at a mix. The steel lookalikes would serve well in many cases, but I'd be reluctant to see them on Bingley five rise for example, but I really don't see why they shouldn't be on the locks at Soulbury or Bank Newton

Can't give greenies, but this looks to me an extremely useful answer and I'm sure John will note it.

 

Tam

Edited October 4, 2020 by Tam & Di

[Bee]

Hardly ever see a wooden lock gate across the channel. Once they've been in for a few years they get a good covering of greenery and moss and don't look much different. If you used a timber balance beam you would hardly know. After all not many of us have wooden boats these days.

[roland elsdon]

Having done a fair amount of boating this summer I surmised, in general lock condition.

 

Locks on the oxford canal are dangerously worn and rotten. To the point of wondering if lock will survive a passage.

 

Coventry canal is variable but generally better, but I guess 2 flights are easy to concentrate on.

 

Grand union, mostly ok but buckby flight bad. Mainly I suspect because balance has always been bad, and hence they get abused. Foxton and Watford good ( halo effect and volunteer operation?)
 

Staffs and Worcester generally very good, but also keen volunteers present.
 

Worcester and Birmingham . Several beams with metal splints on, for short term repair. Lots of leaks, looks like proactive repairs.

 

Stratford canal South very wobbly condition like Oxford, but suffers from its historical years of neglect
 

Northern Stratford lapworth ok. Rest of the canal is the dumping ground of Shirley and Solihull  Kings norton etc.

I suggest that it’s the 3 day hire casual honeyspot canals with heavy use that are suffering damage . Steel gates on the oxford and southern Stratford?

 

[Jerra]

I have no objection to steel gates I just wish they looked a bit more "normal".   I don't find the narrows balance beams pleasing to the eye, probably because I am so used to seeing the wooden ones..

[Rose Narrowboats]

On the one hand I'm uncomfortable with the notion that a local authority can tell a navigation authority how to manage it's assets (how did BWB lose so many of its powers?) but at the same time there's no-one else to hold the current set-up to account.

 

If steel piling is acceptable (though there were those in BW such as Peter White who hated it) then surely steel gates are acceptable - to a point. Likewise much original paddle gearing has gone (eg Coventry Canal bottom gates) with barely a murmur of protest

 

I agree that it needs to be considered on a case by case basis. On some the lesser used bits of the BCN for example, I think steel gates and balance beams would be no brainer - at least until the phantom balance beam hacker trades his chain saw in for an angle grinder. Other places could be composite: wooden balance beams are much more tactile, and changing the balance beam is not a big job. I doubt many people would even notice the steel gate. Finally places such as Foxton should be kept as original as possible. I'd suggest that there should be a minimum of say one lock per flight or stretch of canal that is kept in original condition so that the original appearance and construction skills are not lost for the time in the future when steel gates go out of favour again.

 

I'm not sure bouyancy is a major consideration on narrow locks - the cast iron ones on the Oxford work well - there just needs to be enough weight in the balance beam to er, balance it....

 

Anthony Grantham

[Rob-M]

I generally find steel gates with the thin steel beams very hard to open compared to wooden gates. I think if the beam was more substantial and better balanced then operation wouldn't be as difficult.

[Guest]

8 hours ago, Tam & Di said:

I'm not sure why that is important, but you can click on his name to get some idea of his interests. He's been boating longer than most people on this forum, both in the UK and on the continent, and written books about it - I think "Journeys of the Swan" was probably the first https://www.amazon.co.uk/Journeys-Swan-John-Liley/dp/0043860052

 

Most recently he has contributed several photos to the "Tonic Required" thread here.

 

Tam

It was a simple question posted in a perfectly polite manner because I didn't know and was curious.

 

I now have the answer so thankyou.

[Jerra]

25 minutes ago, Rose Narrowboats said:

places could be composite: wooden balance beams are much more tactile, and changing the balance beam is not a big job. I doubt many people would even notice the steel gate.

To me that would be the perfect answer.  Long lasting gate and an aesthetic and pleasant to handle balance beam.

[Captain Pegg]

We should lose any assumption that a steel gate needs to look like the standard design for narrow locks of the 1970s.

 

Steel gates - or at least balance beams - are not uncommon on broad locks. I seem to recall they are universal on the Erewash. If the detailing of the fabrication is done sympathetically, such as having 45 degree chamfers rather than square edges then they can be fairly indistinguishable from timber beams.

 

Composite construction certainly offers solutions as may synthetic wood which is becoming available as an engineering material.

 

JP

[Guest]

3 minutes ago, Jerra said:

To me that would be the perfect answer.  Long lasting gate and an aesthetic and pleasant to handle balance beam.

They were fitting composite (wood and metal) gates as a trial on the K&A last year, not sure if the balance beam was timber though.

Edited October 4, 2020 by The Happy Nomad

[Phoenix_V]

Gates are always steel in France they seem to last forever, even canals closed many years ago have seemingly sound gates on locks. Often they are galvanised I believe. Interestingly though in Belgium (Flanders at least ) even quite large gates  and all smaller ones are timber. I don't know how that works though on the one closed canal we did look at there are no signs of the gates surviving. IMHO nothing wrong with steel gates but regional variation in paddle gear is a far more important issue and we need to retain trad gear.

There is also the unsustainability of continuing to use tropical hardwood for the gates, the newer ones seem to last less long so the quality of the wood may be going down too.

 

Perhaps some fake rivets would help.

Edited October 4, 2020 by Phoenix_V