Talk:Lock (water navigation)/Archive 1

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Archive 1



The title of this article

The title of this article should be Lock (water transportion), since the VERB "transport" is a lazy man's way of writing the NOUN "transportation". 98.67.106.30 (talk) 23:33, 8 January 2012 (UTC)

WRONG - "transport" is both a noun and a verb, for example Department for Transport, "transportation" either means sending criminals to Australia, or is an ugly Americanism for "transport". TiffaF (talk) 16:02, 6 August 2013 (UTC)

Hiram M. Chittenden Locks

re: the pictures and paragraph of discription of the Hiram M. Chittenden Locks... does this add anything to the article? To me, the section seems disjointed and not relevant to the rest of the article. I am hesitant to revert, though, as it is usefull information. Perhaps it would fit in better at the Hiram M. Chittenden Locks article? Iain 11:38, 29 Nov 2004 (UTC)

This makes sense. It should be moved. Paranoid 18:31, 1 Dec 2004 (UTC)

I saw a notice that the above lock was going to be drained for maintenance. The notice stated that one should come and see how a lock works. I took advantage of the rare opportunity to take the pictures as locks normally contain water. I put the pictures at the bottom of the "Operation" section with an explanation of what the pictures were about. I guess I was thinking someone would incorporate them into the article. My current thinking is that I should put them along with a paragraph on how they work just below the picture of "A plan and side view of a generic, empty canal lock".

staircase lock

this was added: "This is because climbing steps can involve the loss of lockfuls of water from the upper level and sluice operations, which is much worse than separate locks. "

Even if this was true the preceeding sentence said that bargees consider these locks nightmares. Why would bargees care how much water was used? Isn't the issue the amount of work required? Rmhermen 02:38, Feb 26, 2005 (UTC)

A true staircase is difficult to operate because it is necessary to ensure the emptying of a lock at the wrong time can cause difficulties. In descending, one must ensure that the lock below is empty before you start to fill it. Peterkingiron 17:47, 13 March 2006 (UTC)

Bargees might not worry about how many lockfulls of water they used, but the canal proprietors might, because they had to ensure that there was sufficient water in the summit level for it to be nevigable. Peterkingiron 17:50, 13 March 2006 (UTC)

Due to not normally being able to pass in the middle of staircase flights ensured many delays, and hence their main dislike by boatmen. Once a direction is chosen the delay between locks is less than a flight due to the closeness of the next lock. On a normal lock flight the next lock has to vacated of the boat in front before filling any way. Mykaskin 16:51, 1 April 2006 (UTC)

Is it really not possible for boats to pass in the middle ? I've never been in anything bigger thena a two-rise - and my mnd hurts trying to visualise this without a model in front of me! Chris Jones

Would it be a good idea to separate Staircase lock to a new page, or is that not very wiki-like? Mykaskin 16:51, 1 April 2006 (UTC)

Stop lock

I think the reason is slightly incorrect, and needs to be clarified. Stop locks were created to stop the newer canal stealing water. I've also never heard of the second meaning - I've always known them as Flood Gates. After consultation with other canal users I will rewrite it unless someone disagrees or can fill in more information. Mykaskin 16:51, 1 April 2006 (UTC)

Industrial Lock

Looking south toward the Lower Mississippi River
Length: 195 m (640 ft)
Width: 22.9 m (75 ft)
Type:
Maximum lift: 6 m (19.6 ft)
Sill: 9.6 m (31.5 ft)
Waterway(s): Lower Mississippi River, Industrial Canal
Year built: 1923
Geolocation: 29°57′54″N 90°01′38″W / 29.965°N 90.02735°W / 29.965; -90.02735
These are footnotes

Lock infobox

Since there are a few Wikipedia articles about navigation locks, it occurs to me there could be an infobox template for them. I'm starting an article about the Industrial Lock in New Orleans, and have manually cobbled together the accompanying infobox, but if somebody knows how to make an actual template, that would be cool. I'm sure there could be additional parameters for it that I'm not thinking of. Anyway, does anyone here know how to code such a thing? -- Muffuletta 18:08, 2 April 2006 (UTC)

Complaint

Buddainabucket appears to have vandalised a very useful big chunk for some dogmatic reason of his own - can someone restore the text and bar him from doing this again?

Gongoozlers

I've deleted the part about gongoozlers under basic construction and operation as it seems irrelevant and inappropriate. – SolitaryWolf

Not the best of calls, in my opinion. Whilst the section within which it was presented may have been the wrong one, mention of the concept is appropriate. Added it to "see also" for now untill it can be worked into the article again. LinaMishima 14:37, 10 September 2006 (UTC)
Ok, thats fair - SolitaryWolf
Speaking of which, I've cleaned up the humourous mess that was the Gongoozler article and made it much more serious, albeit a little lacking in direction (as to be expected for a colloquial term without lots of good references). Feel free to take a look at it and tell me what you think. LinaMishima 16:01, 10 September 2006 (UTC)
Sounds good - SolitaryWolf

Yes, very serious. CJ

Caisson Lock

I've added a short piece about the Caisson Lock on the Somerset Coal Canal. This appears to be the only example of one ever being built and I'm not sure how relevant it is under alternatives - could anyone advise. Also if anyone has the engineering expertise to describe it in a better way than I've done on either article that would be great. — Rod talk 17:55, 6 October 2006 (UTC)

I would argue that they have more in common with boat lifts than locks.Geni 19:52, 7 October 2006 (UTC)

Agree with Geni - but a short mention should be made here, if only because of the name. Chris Jones

Water usage in transit of locks

One thing missing from this article is the usage of water when a lock is used. I recall that it is: 

  differential volume of lock +/- displacement(s) of vessel(s) passing

depending upon whether the vessel is going "up" or "down". Recall that, on canals at least, additional water must enter the summit flight of a canal, and much of it is due to the passage of boats through locks! Comments? Hair Commodore 20:20, 2 February 2007 (UTC)

There is a section on "Use of Water" which discusses this in qualitative terms. A well-written sub-section on how different types of lock use different amounts of water (with or without side ponds etc ) could be useful, but not if it was too dry, which would spoil the easy-to-read nature of this page. Too many Wikipedia articles are completely accurate, completeley comprehensive, and completely unreadable to anyone but a specialist. Chris Jones 07/02(Feb)/2007

Stop Locks - "newer canal higher" rule question

I always believed that at a junction where there is a stop lock, the existing canal owners would always insist that the newer canal was at a higher level (even if only inches) than the older one - to prevent the newer one stealing water. Then I realised that this is NOT true at Autherley (newer Shroppie - B&LJ - is LOWER than the S&W, at least according to Nicholson). Perhaps this "rule" is a myth, and the only really important thing was that there WAS a difference (in EITHER diretion) so that pressure would keep the stop lock gates shut. Anyone know of other "exceptions" to this (now only tentative) "Rule". CHRIS JONES 12/02(FEB)/2007

Locks and sluices - merge or explain?

A question from a stupid Swede,
I hope to considerably expand the article Slussen but got stuck on the distinction between these two English words. Is a lock exclusively used for transport and a sluice only for controlling water flows? If so, what to do you people call a canal and its devices when they are used for both purposes? Both words translates to the Swedish word sluss, so its less than obvious from my point of view. Maybe the two articles should be merged?
/ Mats Halldin (talk) 17:36, 10 March 2007 (UTC)

I wrote Karl Johanslussen today, and called the thing both a lock and a sluice. I hope someone knows better than me what to call it.
/ Mats Halldin (talk) 14:22, 11 March 2007 (UTC)

It is very rare on the English waterways for the word "sluice" to be used for device to allow boats to change levels. I think there may be one or two locks in East Anglia, where the engineering was done by Dutch engineers ("sluis" is the Dutch word for lock OR sluice) , called "something sluice", but not anywhere else. Normally a sluice is something to control water flows, and probably only has one gate. Perhaps it would be true to say that something is called a "sluice" if it is primarily to control water flows, and SOME sluices have two gates where passage by boats is required as a secondary purpose. But since some (most?) sluices only have one gate, it is definitely misleading to think of a sluice and a lock as generally the same thing. Chris Jones (not logged in)
(Indented section above) OK, thanks. Apparently, the distinction is lost in translation, that's all... I guess.
/ Mats Halldin (talk) 16:48, 17 March 2007 (UTC)

Caisson lock variation

A 21st century variation on the Caisson lock: There is a new design which, as before, has a tube sealed closed (see comment below) at the top and bottom with watertight gates. The difference is that the tube is completely drained at each passage. The vessel is guided up and down in the tube by floating pontoons shaped to fit the tube walls, rather than within a sealed box, and is probably less scary. Less excavation is required as the tube, of concrete rather than stonework as originally, can lie on the slope. The disadvantage will be water use: although side ponds are envisioned, water use will not be eliminated completely, as it was with the original concept. A new section to follow, when I find some usable citations, unless anyone wants to jump in sooner!--Old Moonraker 17:11, 15 May 2007 (UTC)

Someone's posted it—thanks. [1]. Any volunteers to incorporate it into the article?--Old Moonraker 08:29, 30 June 2007 (UTC)
It's called the "Diagonal Lock" and it is most intruiging. You really need to download the videos to understand how it works (and they are big files) but you can quickly see why the inventor is so excited by his idea. I can't help keep thinking that there must be some kind of snag to it, like keeping the bottom gate watertight against such a large head of water, but nothing else springs to mind, and the accompanying article from Towpath Talk includes opinions from several experienced engineers. BTW, the top of the tube is open to the atmosphere, not sealed; the top-end 'seal' being provided by a pair of conventional lock gates.
EdJogg 00:38, 1 July 2007 (UTC)
Added. --Old Moonraker (talk) 15:36, 17 June 2008 (UTC)

Question removed from article

Cill [should this and all other instances on this page be spelt "Sill" [2] —Preceding unsigned comment added by 193.113.57.167 (talk • contribs)

--Old Moonraker 11:38, 16 July 2007 (UTC)

"Cill" is the common usage on canals. See, for example, BWB publications about repairs and stoppages, works on canal history etc. --Old Moonraker 11:41, 16 July 2007 (UTC)

Pointing Doors

Are they really commonly called that? I only ever hear them called mitre gates or doors. Single gates are also called clapper gates. Mayalld 12:37, 23 August 2007 (UTC)

Never heard the term. This page [3] mentions them in the context of flood protection near Witham. Also on the fens, [4]. Again here [5] in East Anglia. Note the instructions to always leave the guillotine gate raised and the doors closed, perhaps suggesting some waterlevel control function? Anyway, it definitely seems to be a regional term so i am changing it to mitre gates.Derek Andrews 17:48, 13 September 2007

"Pointing doors" is the official usage for mitre gates on the River Nene and used in EA notices. Always at the head of locks, occasionally at the bottom as well instead of the guillotine. The reason for them is that at times of flood the doors are chained open and the guillotines raised to provide an additional overflow weir. This is obviously impossible with mitre gates at both ends. --Hymers2 (talk) 11:31, 7 February 2008 (UTC)

Drop locks

New addition to page: could do with some examples. I remember reading about a couple of examples being installed on certain UK restoration projects, but cannot remember which ones. I know that the Wey and Arun Canal has a pound that has been lowered below the original level (can't remember why), but cannot remember if the level is raised again at the following lock, or if the fall at that lock is merely reduced.

Are there any instances of canals being built with these 'from new' (as opposed to a restored or re-routed canal section negotiating a later-built obstruction)?

How do they stop all the water piling-up in the dropped section? (or rather, how do they maintain the correct water level in the dropped section?)

EdJogg 09:12, 21 September 2007 (UTC)

Real life example added! Mayalld 11:29, 21 September 2007 (UTC)

Large Locks using pumps to speed the filling process

Hello. The article says there are some locks that use pumps to speed up the filling and emptying process, but does not list which locks use this type of aid. I was under the assumption that all the canals moved water by gravity. Can somebody list some of the canals or locks that use pumps to speed up lockages.

Thanks

168.77.204.182 19:12, 8 November 2007 (UTC)

Raoul

Photographic Sequence of a Russian Lock in Action

Picture sequence of a lock in action.

http://englishrussia.com/?p=1676#comment-223769 —Preceding unsigned comment added by Root Beers (talk • contribs) 04:55, 12 December 2007 (UTC)

About Adding a Link

Earlier today I added a link to a page listing the deepest canal locks in England. It is on a site that I run. I have just spotted elsewhere that it is considered "bad form" to link to one's own site!

Would others care to approve the link? Perhaps someone would like to remove it and add it again themselves, to keep things within the "rules"?

Or is it okay just to leave it where it is?

Some time has been spent researching this list and it uses information supplied to me by a number of sources, including BW and Waterways World. I have even measured some of the locks myself! —Preceding unsigned comment added by Pennine (talk • contribs) 20:20, 12 December 2007 (UTC)

You can link to your site (and I have done so to mine), however you must be careful. I would say not in your case - you have click through adverts (for Amazon) on your site, that's a no-no - someone will say that adding a link to wikipedia will be spam (seen it very recently, even less obvious than yours - not my chemistry site of course, there are zero adverts and no other means of spending money within it). I would suggest that you create a similar table in wiki and make a new page of it - but you must follow WP:DCP if it's a copy or it will get speedily deleted (been there)! Ronhjones (talk) 22:26, 12 February 2009 (UTC)

Winding gear / paddle gear - citation request

The incident mentioned (4 people drowned in lock) is certainly true. The following links provide verifiable cites:

The Coroner's Report (accidental death), was publlished nearly a year later:

But the clinching link is the report of the Marine Accident Investigation Branch into the incident

Page 21 of the report identifies a delay in obtaining the key to the handcuff lock as a contributory cause. However, on reading the report you will see that this was a very minor factor, and the MAIB did not include mention of handcuff padlocks in their recommendations.

So, the text needs to be re-written, and cites provided...

EdJogg (talk) 17:47, 25 January 2008 (UTC)

Anyone looking at the history of this page will see that this has been bugging me!
Having mulled-over the facts (having now read the report), the existing article text contains several factual errors. The canal name was wrong (fixed earlier today) and the victims were mentally disabled, not wheelchair bound; the boat caught its front fender between the lock gate and the balance beam, it was not caught on the cill; the angle of the boat meant that water was taken on board aft, causing it to sink further.
Although an inability to locate the handcuff key caused a delay, the act of opening the top paddle protected by the lock actually made matters worse by allowing water to enter the boat's cockpit.
All-in-all, I don't think that the incident is sufficiently related to the use of handcuff padlocks to need to remain in this section of the article. I leave it to other editors to decide whether the incident should be mentioned elsewhere instead.
EdJogg (talk) 18:08, 25 January 2008 (UTC)

Staircase Locks

I haven't changed anything, but I feel that the section on staircase locks needs to distinguish between real staircases, like Bingley and Grindley Brook and apparent ones like Foxton and Watford. The difference is that on real staircases the water leaves one chamber to go into the one immediately below, whereas on Foxton etc where there are sideponds the water leaving the chamber goes into a sidepond, from which the next chamber is filled. This means that it is only on real staircases that it is necessary to have the whole flight full or empty before you start. It also means that on apparent staircases passage of the locks still only uses a single lockful of water. It is still the case that it is quicker for boats to follow each other through the flight rather than alternate; the usual rule applied by the lock keepers is "three up, three down". Bratch locks on the Staffs and Worcs is also an "apparent" staircase, but differs from Foxton in that each chamber has both top and bottom gates, although they are only a few feet apart. —Preceding unsigned comment added by Hymers2 (talk • contribs) 14:54, 7 March 2008 (UTC)

I have now rewritten this along the lines indicated, since no-one commented.Hymers2 (talk) 10:20, 17 April 2008 (UTC)

Are the terms real and apparent official terminology? Also, you need to adjust the rest of the section to match your new edits, since it is inconsistent in places. EdJogg (talk) 12:10, 17 April 2008 (UTC)

This "apparent" staircase terminology is surely too single person POV ? To anyone other than that editor, a staircase is about the arrangement of GATES, not paddles. A staircase is a staircase if your boat goes from one chamber to another with no intervening pound, regardless of the water-transfer arrangements. To call something an "apparent" staircase means "it might appear to be a staircase, but you are mistaken - it only looks that way". To say that Foxton Locks, one of the most famous examples of a staircase (OK, two staircases) in the UK is "not really" a staircase because it has side po(u)nds is perverse in the extreme. I really do sympathise with what the author is trying to do - they are trying to find some terminology to make it simple to categorise different methods of water saving / water transfer, but I think this way of doing it is just too singular. Unless there are objections within the next three weeks saying "the original author was right, and there are no 'real' staircases on the Leicester Line" I will have my own go (fresh from a trip to Foxton and Watford as it happens). I may use the "apparent staircase" terminology, but to mean "something that looks like a staircase but isn't" (probably because of intermediate pounds, eg "Foxton is an apparent 10-rise staircase but in fact is two 5-rise staircases separated by a short pound whose level does not vary significantly".) Chris Jones, 11:17 GMT 2010-05-16 —Preceding unsigned comment added by 86.153.55.190 (talk) 11:16, 16 May 2010 (UTC)

Merge this article into pound lock and create new Lock (water transport) article/dab page?

This article is misnamed, as its subject is really just one sort of water transport lock, the pound lock. The original sort of water transport lock, the flash lock, does not meet the criteria for a lock laid down in the lede for this article.

Also, we already have a pound lock article, which overlaps with this one.

I propose therefore, that we should merge this article, and pound lock, into a new article under the latter title. And then create a new short summary article / dab page with the name Lock (water transport) pointing out the two fundamental types of locks. Then fix up all the links.

So long as we also put two entries (flash lock and pound lock) into the existing dab page lock, this shouldn't serious incomode searchers.

Thoughts -- Chris j wood (talk) 18:46, 30 July 2008 (UTC)

Sounds like a lot of work, but I think you're probably right. EdJogg (talk) 18:02, 13 August 2008 (UTC)
I agree too, but there are a few other types of locks which are in this article. A new article for staircase locks should probably be created. A link to the caisson lock can go on the dab page too. And I'm not sure whether the diagonal lock deserves its own article. MSGJ (talk) 18:19, 13 August 2008 (UTC)
On further reflection I might suggest to create a new section for water transport on the lock dab page and then redirect Lock (water transport) to that section. Then there are not two dab pages to be maintained! MSGJ (talk) 18:21, 13 August 2008 (UTC)

I would agree - there are only two types of lock, flash and pound and the former is obsolete. All the others (staircase, diagonal etc) are simply special cases of pound lock. I would suggest, however, that the caisson lock is really a form of boat lift and not a lock at all, since it requires a power source to make it work. A pound lock works entirely by gravity, even if machinery is nowadays sometimes used to open gates, sluices etc. Hymers2 (talk) 13:12, 27 November 2008 (UTC)

It would be very useful to have one article to refer to. Renata (talk) 23:26, 13 August 2008 (UTC)
Lock (water transport) should be rewritten. It would be a mistake to make it a disambiguation page. pound lock, flash lock, and possibly other varieties of lock are specific instances of Lock (water transport).
Okay, I just checked lock -- it lists Lock (water transport) -- but under "Mechanical devices" -- not technology. The current description is broad enough to include lift locks and canal inclined planes. Geo Swan (talk) 18:57, 16 December 2008 (UTC)
I agree - I was looking for Canal lock - that took me to Lock (water transport), and I was expecting to find Pound lock. Ronhjones (talk) 22:11, 12 February 2009 (UTC)

Merge into Lock (water transport), I think. That's where the links to Canal lock go. Pound lock describes the pound as the chamber of the lock, between the two lock gates, but I thought the pound was the water between the locks, as the Lock (Water transport) article says. It might be useful to clear up that confusion between any more work gets done. Abouthalfthree (talk) 13:48, 26 February 2009 (UTC)

They are called Pound Locks as they are a lock that separates two pounds. Previously we had flash locks, but a flash lock drains the upper level (and raises the lower one), so those levels are always changing, whereas with pound locks the levels of the upper and lower pounds remains (almost) constant. One can easily find references outside Wikipedia that refer to these locks as Pound Locks, a Google search for "Pound Locks" (with the quotes) with find plenty - e.g. http://www.the-river-thames.co.uk/locks.htm - (caption to a picture) "The original flash lock capstan used at the Hurley flash lock, prior to the first pound lock being built at this location in 1773, is the last surviving flash lock capstan in existence on the Thames and is situated next to the River in the grounds of Wittington House between Henley and Marlow" - so the term has been around for a very long time, and I think we need to keep the data with name. Ronhjones (talk) 20:05, 26 February 2009 (UTC)

I don't think so. OED says that it is used in the sense "body of still water, pond". That is, they are called pound locks because they contain a stretch of still water between the sets of gates, which a flash lock does not. The name is also used (confusingly) for the stretch of water between locks on canals for the same reason; it is still (more or less) water. Significantly the word is not used for lengths between locks on rivers -reach is the usual (though not universal) term.Hymers2 (talk) 13:42, 27 February 2009 (UTC)

This article should be merged into Lock (water transport)). The latter article covers other locks, which are also notable. It is also more thorough and higher in quality.  dmyersturnbull  ⇒ talk 19:15, 2 May 2010 (UTC)

New diagram

I found this diagram on Flickr ([6]) which is free for use in Wikipedia. Do you think it should be added to the article?--Natl1 (Talk Page) (Contribs) 20:39, 2 August 2008 (UTC)

It's an interesting diagram, but I'm not convinced that it is free for use on WP. The photo may be free for use, but there is no indication of who drew the diagram in the first place, and hence there is the question of who owns its copyright. Without knowing this, we wouldn't be able to use the photo here (or at Commons). EdJogg (talk) 18:01, 13 August 2008 (UTC)

Offering pictures

Hello, the photos I have are of relatively low quality, but I have a few pictures taken inside 19th century American lock chambers located @ http://home.comcast.net/~corey.sciuto/lowell18.htm . If anyone thinks anything here would be of use, I'd be more than happy to donate :-) Thanks, CSZero (talk) 21:54, 19 August 2008 (UTC)

Rideau Canal

The image in the river navigations section is described as "on the Ottawa River" in the caption, but is actually on the Rideau Canal. Should we change it? The river is visible in the background. --Old Moonraker (talk) 13:12, 8 February 2011 (UTC)

Thanks for the fix.--Old Moonraker (talk) 20:56, 1 March 2011 (UTC)

Too many pictures in lede

There are five pics at the top of this article. This looks OK on a PC, where they neatly fill the large white space next to the TOC; however, when viewing the article from the mobile portal, all five will be displayed before the lede text, which is not good.

Two pictures would be OK, but I don't think any of the present set are really representative -- there are many lock pictures on Commons, so there must be better pictures available. I would suggest a good photo of a traditional English lock (in the countryside...) and a suitable image of a much larger commercial lock, would be more than enough.

EdJogg (talk) 13:21, 23 May 2011 (UTC)

Concur—it's gradually been getting more and more cluttered. Lower down the images illustrating various topics, showing next to the relevant text on a full-size screen, are useful but again it's getting very crowded. --Old Moonraker (talk) 14:01, 23 May 2011 (UTC)
Been bold. Found new pic of an English lock (among the literally hundreds on Commons) -- this clearly shows the whole lock, is rural and pretty, and is also fairly small, so a nice contrast to the commercial lock shown below. (I didn't look for replacements for this one. It's not too bad, showing the whole of the lock, and looks suitably 'industrial') -- EdJogg (talk) 22:56, 23 May 2011 (UTC)
The contrast between the two works well: aesthetic and relevant. --Old Moonraker (talk) 07:25, 24 May 2011 (UTC)

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merge two sections?

The "Bi-directional gates and locks" and "Tidal locks" sections seem to contain essentially similar information, perhaps they can be merged (or one simply deleted - the former seems pretty complete to me)? Huw Powell (talk) 22:42, 12 June 2011 (UTC)

Staircase locks (again)

I think the use of the terms "real" and "apparent" for staircase locks is a case of poor use of English. "Foxton Locks and Inclined Plane", published by Leicestershire CC in 1982 uses "riser" lock to describe two locks which share a set of gates, and "staircase flight", where there are a number of riser locks, but the water is transferred to a side pond, rather than directly to the next lock. So Bingley five-rise are risers, while Foxton has two staircase flights. McKnight (1981) makes a similar distinction, but not quite so clearly, and Edwards (1985) also uses the term risers. Shall I alter the section? Bob1960evens (talk) 17:52, 7 February 2012 (UTC)

The trouble with "riser" is that the term is not in current use and very few people would recognise it - after all, all locks are in a sense "risers". The use of "real" and "apparent" was an attempt to highlight that there are two different sorts of staircase; they may look similar to the operator, but they require different techniques. Any attempt to operate Bingley or Grindley Brook etc in the same way as Foxton or Bratch will lead to problems - in the first case overfilling a chamber will lead to flooding, in the second case it will not. Hymers2 (talk) 14:37, 1 March 2012 (UTC)

I am not convinced that "apparent" is in current use either, or that many people would recognise it, since I cannot find it in any sources. Nor am I convinced that all locks are risers, since the term is nowhere used to describe a single lock, but used in several sources to describe locks in a staircase. Staircase has a specific meaning in the context of canals (as opposed to houses), as does riser. I agree we need to distinguish the two types, but "apparent" appears to me to be a case of making up a word to fit the occasion, particularly since it has to be in quotes. I'll keep looking to find another authoritative source. I was just hoping to introduce some references to an article which seems to be largely unreferenced. Bob1960evens (talk) 10:01, 2 March 2012 (UTC)
I have just found an article by Jim Shead, published in Waterways World in 1998 and available online ([7]), which uses riser, but does not specifically name those with side ponds and those without. Jo Gilbertson for the IWA describes them similarly in 2010. ([8]).Bob1960evens (talk) 10:32, 2 March 2012 (UTC)

Bratch Locks

I note that Bratch Locks are listed in the staircase section, but they are not a staircase. They were originally built as a staircase and re-engineered as three separate locks according to Wikipedia! More seriously, Nicholson (2006) and Mosse (2010) both say that the tiny bit of water between the two sets of gates is a pound, which maintains its level because it is connected to the side ponds. Nicholson says "In fact, to work through these locks, boaters should simply treat each one as a separate lock, like any other." (p114). I think this could definitely be classified as an "apparent" staircase - it sort of looks like one, but it isn't. :-) Bob1960evens (talk) 20:47, 4 March 2012 (UTC)

You are quite right that they are not strictly a staircase; however, for operational purposes they are and have to be treated as a staircase. The Bratch locks, however, are unique in Britain, except for a pair that are part of the Stourbridge 16 flight. All other staircases have common gates between adjacent locks, but fall into two categories, depending on whether they employ side ponds (like Watford and Foxton) or not. The distinction is important because the operating techniques differ.Hymers2 (talk) 21:38, 4 March 2012 (UTC)

Do you have a source for that, because my sources say that they should be treated like any other locks? As well as Bratch and the Stourbridge locks, there are also the two new pairs recently re-opened at Fourteen Locks on the Monmouthshire Canal. The intervening pound is too short to hold a boat, but works as an intervening pound because it is attached to the side pond. (And when they finish restoring the flight, there will be five pairs and a triple.) Bob1960evens (talk) 23:22, 4 March 2012 (UTC)
PS just found File:Badgernet Bratch Locks.jpg, where British Waterways claim they are a flight, not a staircase. Bob1960evens (talk) 00:09, 5 March 2012 (UTC)
Sorry to bang on about stuff, but I think this article has serious problems with referencing (or at least the lack of it). It also mentions Ardnacrusha lock as having a fall of 100 ft, but in reality, there is a 60 ft drop, and then a second chamber that drops the last 40 ft (or so, as the bottom is tidal). (See Cumberlidge 2002 or Ardnacrusha). So it we count it as a single lock, then any lock flight or staircase could also be counted. Bob1960evens (talk) 23:55, 4 March 2012 (UTC)
bjg: I'm not sure whether I'm inserting this properly; I apologise if I've got it wrong. I've asked for my WP password to be re-sent to me, but it hasn't arrived yet. I noted your link to my page about Ardrnacrusha lock (above). You are quite right that the lock has two chambers, with falls of roughly 60' and 40' (the drop in the upper chamber varies too: it depends on the water level in the headrace, which is affected by the number of turbines running and, the lockkeeper tells me, can vary by up to four feet). However, the term 'staircase' is not widely used in Ireland: we talk of a 'double lock' (there are no extant locks with more than two chambers) and such a lock is treated, named, numbered and discussed as one lock, as the Guides to the Grand and Royal Canals and the River Barrow will show. Thus, while I accept that Ardnacrusha's twochamberedness should be made clear, I would not like to see Irish terminology overridden. bjg 194.46.167.226 (talk) 12:51, 23 March 2012 (UTC)
Hi, bjg. Your comments are welcome. The article (rather than this talk page) mentions Ardnacrusha in the context of locks with a large rise, and makes no attempt to describe it as a staircase. While it may have a single number, it still acts as two separate locks, since a boater descends through the top chamber, passes through the tunnel into the second chamber, and then descends again. The point I was trying to make was that this is not a single chamber with a rise of 100 ft. Regards. Bob1960evens (talk) 13:34, 23 March 2012 (UTC)

You don't say which sources but I suggest they're wrong. They are not like any other lock because they have to be treated as a group - once a boat has started it cannot be passed in flight, just like a real staircase. I suggest no source is required for this since it is an obvious fact verifiable on the ground. The other peculiarity of the Bratch is that if you prepare a chamber in advance by filling it and opening the top gate before drawing the lock above, as you could with a normal lock, you will flood the place as the open gate blocks the culvert and the water from the lock above flows straight on and over the towpath. You would be pressed to find a written reference for this, but it is a fact nevertheless - I've done it myself. Whether this feature is present at the 14 locks I don't know - it would depend on how the top gates are hung in relation to the culverts. I didn't know that the 14 were of this type - alter the above to "unique in England"!Hymers2 (talk) 10:05, 7 March 2012 (UTC)

This is why Wikipedia requires sources. I am afraid you do not count as an authoritative source, any more than I do, and it is not obvious, or we would not be having this discussion. My sources are Nicholson Waterway Guide, 2006 Vol 2 p.115, McKnight 1981 p.396, Mosse 2010 p.23, The British Waterways site ([9]), and the British Waterways signage at the site (see above). The definition for a staircase does not include the fact that boats cannot pass. They do pass in the middle of Neptunes staircase, for instance, which is definitely a staircase, and Limehouse Cut on the Regents Canal would count as a staircase on that definition, since it had a lock at both ends and was not wide enough for boats to pass when built. Again, the fact that it is possible to flood the lock below does not necessarily make it a staircase, but the fact that it has intervening pounds, however short, indicates that it is not. I was only trying to help. I recently assessed an article at "B" class, and someone wrote that there were two paragraphs without references, despite the fact that all the rest of the article was carefully referenced. The resulting discussion produced a much better article, and I would like this one to be correct, as I often find myself linking to it from other articles. Regards. Bob1960evens (talk) 20:23, 7 March 2012 (UTC)
Additional reference for the original point here. No new information, but it confirms that the original staircase was converted to a flight, by the addition of new top gates and the digging of side pounds to maintain the level in the extremely short intermediate pounds thus created. --Old Moonraker (talk) 13:24, 23 March 2012 (UTC)

Guard Lock

The article at present does not mention the term Guard Lock. They are possibly just another name for a Flood Lock which is covered. In which case a simple mention as an alternative name in the existing section is called for.

But if there is some other distinction, then a new section or subsection would seem appropriate. I encountered the term for Lock 60 of the Schuylkill Navigation, which was a series of canals and slack water pools, in the Schuylkill River. Lock 60 sits at the upstream end of one reach. It's possible a distinction is that the guard lock had to help maintain the water depth in the slack water pool at all times, and acted as a flood lock when the river was up. I've also seen the term used for Erie Canal locks, so maybe Guard Lock is just the American term.

I don't really know for sure, so I'd appreciate it if someone with more knowledge would sort it out and update the article. Thanks. --J Clear (talk) 14:49, 14 April 2012 (UTC)

Not having heard the term, I looked for a definition, and Merriam Webster says it is "a tide lock at the mouth of a dock or basin or a lock for preventing flooding of a canal", which implies it is much the same as a flood lock. Interesting, that dictionary does not include the term "flood lock", so it may be a case of different British and American terms for the same thing. I also found details of Erie Canal Guard Lock, which states "The guard lock doors were normally kept in the open position, but were closed in times of high water." Bob1960evens (talk) 17:37, 24 April 2012 (UTC)

Marine railway

This item leaves the impression that marine railways exist only because no one ever bothered to build a lock. The Big Chute railway was originally an expedient solution, but its form took on new significance when people realized that where a lock would permit the mingling of incompatible species, the railway - or more accurately, the ridge over which it ran - kept each in its place. This has taken on new significance as invasive species have entered the Waterway. Note that rather than building a lock, the authority has twinned this railway, with a higher capacity railway joining the original while retaining the barrier. Scuppersthesailordog — Preceding unsigned comment added by Scuppersthesailordog (talk • contribs) 00:49, 8 January 2014 (UTC)

Cills

The section on cills explains what they are and how they may be a problem but says nothing about why they exist. If they cause problems, why are they there? Do they have a function?Bill (talk) 19:01, 10 March 2015 (UTC)

Half tide dock might help (although it needs work).
The purpose of the sill is to keep water in place on one side of the sill, when water level on the other side drops (due to tide or canal levels). Generally the gates to a dock or lock are only just as deep as they need to be to let the maximum draught of vessel through. The main dock is deeper than this (which may just be to allow room for silt to build up) and the difference is made up by the sill height.
Particularly for canal locks, there's also the need for a sill just to make a solid bottom to the opening of the lock and give the gates something to close and seal against. A vessel can grind itself onto a sill, or for a canal boat hang up, tilt and sink itself; from the canal operator's view point this isn't good, but it's bettter to damage the boat than to scour the bottom of the lock out instead. Andy Dingley (talk) 19:34, 10 March 2015 (UTC)

Needham

Who or what is "Needham" as a citation? The work is cited multiple time but never properly referenced. Martin of Sheffield (talk) 09:46, 9 November 2015 (UTC)

Part of Needham's epic series on China. Volume 4 part 3 is the canals one. Andy Dingley (talk) 11:41, 9 November 2015 (UTC)
  • Needham, J (1971). "Civil Engineering and Nautics". Science and Civilisation in China. Vol. Volume 4:3. Cambridge: Cambridge University Press. {{cite book}}: |volume= has extra text (help)
Thanks Andy. I've pasted your reference into the main article. Martin of Sheffield (talk) 11:48, 9 November 2015 (UTC)
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