Talk:Falkirk Wheel

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Can we get a new picture of the wheel that doesn't cut off half of it? -R. fiend 21:39, 5 May 2005 (UTC)

Added 2, with different view points. If thats overkill I'm happy if anyone removes one. SeanMack 11:22, 8 May 2005 (UTC)

Contents

[edit] Great article

I came across this at semi-random, and just wanted to compliment you folks on a well-done article. It's a cool topic that is clearly explained. --William Pietri 22:52, 12 November 2005 (UTC)

Well, it's the best we can dae!--81.156.131.229 00:16, 25 February 2006 (UTC)

I concur. I think the pictures included in this article are especially well-photographed... that wheel is one of the neatest contemporary engineering constructions I've seen in a long time. -- S.R.G. (Some Random Guy)

Good pictures, is the first pic fotoshopped? Very (in a sense) futuristic... (~*~<Unreali.4>~*~)

[edit] More info on boat lift

The matter included in here is ideal.But could someone please explain me what boatlift actually is?We don't have any in India.My email: supernova_robin@yahoo.com demeanor.kid@gmail.com Thanks --Demeanor kid 05:37, 12 January 2006 (UTC)

See boat lift. —Lowellian (reply) 08:31, 18 February 2006 (UTC)

[edit] Kilowatts or Kilowatt-hours?

Power consumption should be stated in Kilowatt-hours. The article says that in 4 minutes it consumes "just 22.5 kilowatts". Perhaps it is mistated and it should read 22.5 kilowatt-hours. But it also might mean that the motors draw 22.5 Kilowats of power to operate. If the motors require this much power that would equal a consumption of 1.5 kilowat-hours of electricity. Whatever the case, this should be made clear. The first case would just require changing Kilowatts to Kilowatt-hours. The second case (which is what I suspect) should read something like "The 22.5 kilowatt motors consume only 1.5 kilowatt-hours of electricity in 4 minutes." I see this type of confusion all the time in the media. Most reporters do not understand physics and don't get it right. It might be hard to determine what the actual numbers are for this reason. -- Samuel Wantman 11:51, 18 February 2006 (UTC)

If 22.5 kilowatts is two boiling kettles, that's 11.25 kilowatts per boiling kettle, which is not plausible. A typical North American electric kettle plugs into a circuit limited to 120V 15A, for a maximum possible power consumption of 1.8 kilowatts (ignore power factor and other complexities of AC electricity - the kettle is close enough to a plain resistor). Even if it were kilowatt-hours, it would take 6.25 hours to get to 11.25 kilowatt-hours at 1.8 kilowatts, which is clearly much longer than it takes for a kettle to boil. And I'm not sure that kettles typically max out their circuits anyway. I think the comparison given in the article has to be off by a factor of at least ten. Note, however, that 22.5 kilowatts for four minutes (which you calculate to be 1.5 kilowatt-hours) is probably about as many kilowatt-hours as two kettles consume in the time it takes them to reach a boil. Maybe that's where the comparison comes from; if you, you're quite right that it's misleadingly stated.69.63.62.226 13:40, 18 February 2006 (UTC)
The falkirk wheel site says "Despite the scale of this power, each turn of The Wheel uses virtually no water and the same energy as just 8 boiling kettles (22.5kW)" I assume they mean 22.5kWh. This means 1 kettle is about 3 kWh, which seems more reasonable allowing for the site wanting to exagerate the wheel's efficiencey. --212.183.128.185 14:16, 18 February 2006 (UTC)
The "Engineering" page on the Falkirk wheel site claims a power of 1.5kW, notwithstanding that that contradicts the 22.5kW figure given on the main page of the same site.129.97.79.144 18:14, 18 February 2006 (UTC)
I think the statement should be taken out until we can clear this up. I gonna do it now. If people disagree, it can always be reverted. --Nathan (Talk) 19:49, 18 February 2006 (UTC)

From the discussion so far, I think it is reasonable to assume that the motors use 22.5kW of power and consume 1.5kWh of energy in the 4 minutes they are operating. The site says 8 tea kettles. I'm going to assume that an English tea kettle draws about 15 Amps of current at 220 Volts which equals roughly 3kW of power. Times 8 would be very close to the 22.5kW figure. The total energy consumed would be the 1.5 kWh that I calculated. Since this figure was at the site, that makes it pretty clear. The problem, is that "Power", "Power consumption" and "Energy" are often used differently by physicists than by ordinary language. The motors take 22.5 kW of power. The energy used is 1.5 kWh. Power consumption usually implies energy (kWh), though sometime it is used to mean power (kW). To make all of this clear in the article, I am going to say. "It takes just 22.5 kW to power the electric motors, which consume just 1.5 kWh of energy in 4 minutes, roughly the same as 8 tea kettles." --Samuel Wantman 22:09, 18 February 2006 (UTC)

Ah, those figures make sense. I was confused by the fact that the article said 22.5 kWh. I make it as 7.12 times as much as a British kettle (on a 13A fuse at 240V), so eight is a fair estimate. --Nathan (Talk) 02:44, 19 February 2006 (UTC)

[edit] Archimedes' Principle?

I'm wasn't understanding why the explanation of how Archimedes' Pricinple works in this system is correct until I looked it up via Google and found a description. It wasn't obvious to me how the principle applied, as a it wasn't obvious to me from the article what water was being displaced. After looking at web page, which states that "[w]hen a boat enters the caisson it displaces its own weight of water and effectively there is no change in the overall weight." Should a similar sentence be added to the description? Thanks! Don 15:33, 18 February 2006 (UTC) (To clarify what I wasn't understanding, I at first thought that the principle was being applied to the caissons and not to the boats; I imagined that water would be drained or added to the caissons to balance them. Don 15:38, 18 February 2006 (UTC))

Yes, I think the sentence you propose should be added. The clever point (the one The Wheel people are trying to make) is that there are no pumps, negligible interchange of water between the two canals, and very low use of power to run the whole thing. The latter of locks which The Wheel replaces used no power at all, but each transit moved a lockfull of water down from the higher to the lower canal. -- Finlay McWalter | Talk 15:59, 18 February 2006 (UTC)
Snazzy. I just added it, though the language feels a little disjoint to me. Cheers! Don 19:46, 20 February 2006 (UTC)
I don't think the bit that you added is really needed, Don. Me and a couple of others did our best to make it clearer since this was brought up, and I think that suffices. It's not so much the language that's disjointed, it's that the detailed explanation is a bit out of place. I'm going to revert, but if others prefer your version, or you (or anyone else) think you can do better, it can always be changed again. --Nathan (Talk) 20:59, 20 February 2006 (UTC)
Sounds good, Nathan. I'm going to suggest "In accordance with Archimedes' principle, a boat entering one of the caissons does not change that ciasson's loaded weight." If anybody would like to insert that instead of the "According to ..." sentence, feel free. If not, I'm leaving the article as is. I tend to be nitpicky and over-precise sometimes. Either way, it's a great article. Don 02:03, 25 February 2006 (UTC)
Okay, as an attempt at an improvement to solve the disjoint, while not adding the extra details, I've simply joined the sentences together to try and connect the two facts more closely (weight is constant/Archimedes principle), as I also felt that having it as a standalone sentence felt a little disjointed. MartinRe 11:29, 25 February 2006 (UTC)

[edit] Questions

I've never seen a boatlift, and I'm a little confused. The article doesn't actually say what happens to the boats after they get in the lift. I guess maybe the wheel stops at the top, the lock opens, and then the boat moves horizontally down that bridge-like structure? Is the other canal on the other side of that grassy hill? What does it look like at the other end? Is the bridge filled with water naturally from the higher canal, or with pumps? Or is it even filled with water at all? Do the boats traverse it under their own power, or are they towed? From the photos, as far as I can tell, it just looks like a ferris wheel for boats, picking them up and dropping them off at the same spot. So what exactly happens at the top, and where is the second canal? Thanks - Kafziel 15:45, 18 February 2006 (UTC)

Yes, a door opens and the boat sails down the bridge, which is indeed full of water. At the end of the bridge is a big pond, which is in turn connected to the higher of the two canals. The visitor centre's boat tours just go up, circle the big pond, and come right back down again. The bridge is part of the higher canal, and is filled under gravity by it. The visitor center boats have their own motors. Other boats (a few, really) travelling from one canal to the other also use The Wheel. I believe there is a towpath on the bridge, although I think in practice all boats travelling the canal system these days are motorised. -- Finlay McWalter | Talk 15:54, 18 February 2006 (UTC)
To be clear, the height through which The Wheel lifts boats is the difference in height between the two canals. -- Finlay McWalter | Talk 15:56, 18 February 2006 (UTC)
Thanks for the explanation. The only canals I've seen are here in New York; they just use a series of locks to raise and lower the boats as they move along. Compared to the Falkirk Wheel, the Erie Canal is almost shamefully uninspired (but forgivable, I suppose, considering its age). This wheel is quite a beautiful feat of engineering. I'd even go so far as to label it pretty damned kickass. I'll have to check it out someday, if I'm ever in Scotland. Thanks again. Kafziel 18:13, 18 February 2006 (UTC)
Most of our canals in Britain just have locks like you describe. That's all you really need when there isn't that much of a difference... or when the canals are far apart. It's necessity that turns an over-engineered solution into a great design. --Nathan (Talk) 03:05, 19 February 2006 (UTC)

[edit] Flange

What's the purpose of the flanges gutting out of the ends? That is, why are the ends not just round? Is it for aesthetics, or is there a function. BTW, This thing looks mighty beautiful! It reminds me of architectural elements found in the MYST computer game series (most of which are physically impossible, but downright magnificent!) --RealGrouchy

My guess would be that it's to allow the water to drip off rather than drip along it, in order to keep it perfectly balanced. If you imagine that the one coming out of the water would have lots of droplets of water on it, and the one descending would have much fewer, having had time to dry since it's last dip. Water dripping along the length of the wheel would be quite slow in evening out this inbalance, but if water is allowed to simply drip off the flanges, it would be rebalanced quite quickly. --Nathan (Talk) 20:52, 18 February 2006 (UTC)

Hi, I have also found this wheel very interesting and I am sure more of them are going to be used in future to solve various other problems too. I think the flanges may have been designed the way they have so that the wheel is more stable in the vertical position, so that if any of the mechanical components, ie the gears were to fail, it would stay upright. See Table Mountain in Cape Town and visit the external link Table Mountain Aerial Cableway Company which was visited by Princess Elizabeth and her father in 1947 to see how popular these initiatives are.. Gregorydavid 10:33, 21 February 2006 (UTC)

I don't understand how that would make it any more stable. It seems that my theory above has been dismissed by the fact that the wheel rotates in the opposite direction, so I can't see any rational reason for them. If the wheel is so precisely balanced, shouldn't it stay upright anyway? I then thought that they could make it travel through the water better, but my Fluid dynamics lecturer would say that's a load of rubbish, because at such low speeds, the difference would be unmeasurable. I give up. --Nathan (Talk) 12:13, 21 February 2006 (UTC)

Hi, obviously the whole structure and mechanism is stable, I was speculating that the two flanges with the caissons between them could ossillate like a pendulum, particularly if the top caisson was empty. If this were the case then I assume the maintenance people would like it to stop ossillating in a convenient position. Gregorydavid 13:48, 21 February 2006 (UTC)

Does this help any engineers out there?

It seems engineering meets, entertainment due to millenium money?

Regards SeanMack 15:04, 21 February 2006 (UTC)

Hi, thank you for all the links above.. I see architects are still more arty than engineers are.. We have lots of new facts, so I shall fix a few things.. Regards Gregorydavid 19:48, 21 February 2006 (UTC)

I am 99% sure from my visit to the centre that it said in the presentation the special flange shaping is purely aesthetic, and not of any real engineering or functional value. However unless someone can confirm this I won't edit the article, its just for the interest of those asking about it. :) Orion3T 13:39, 12 December 2006 (GMT)

I went to a presentation given by the Engineering Director of Butterley Engineering, Julian Bonfield, who stated that the 'beaks' are purely decorative and perform no structural or engineering purpose. The 'well' they rotate in is dry, so there is no need for them to shed drips of water! Jschwa1 17:18, 12 December 2006 (UTC)

[edit] Order of images

I changed the order of the images under "how the wheel rotates" to what I believe is correct. There are two reasons why I think this is the correct order. Firstly, see the discussion "Flange" above. The flanges are, I would presume, for allowing water to drip off, and they can only do this if they are pointing downwards on the cassion which is coming out of the water. Second, there is a boat passing under the boat lift, and unless this boat is reversing (not many boats, to my knowledge, have a rudder at the front), the order I changed it to is correct. Someone has reverted the order back to how it was. What do people think? --Nathan (Talk) 16:00, 19 February 2006 (UTC)

My mistake... the boat isn't moving, it's the camera that's moving. But I still think my speculation about the flanges is good. If you're sure that the photo's are the right way round (ie, you've seen it moving) that's fine. Can someone confirm? --Nathan (Talk) 16:08, 19 February 2006 (UTC)
User:SeanMack who reverted your change was the one that originally took the pictures. I think it is reasonably safe to assume he knows what order the Wheel operates in. Dashbox 02:32, 20 February 2006 (UTC)
I've just had a look at the diagram on the website, and it has arrows confirming that SeanMack is right. --Nathan (Talk) 05:28, 20 February 2006 (UTC)

[edit] Capacity of cassions vs boat weight capacity

Unless I am mistaken, 300 cubic metres of water weighs 300 tonnes. That means that the two cassions combined have 600 tonnes of water in them (when there are no boats inside). To say that the machine is capable of moving 600 tonnes of canal barges would therefore be innaccurate, because the boats will never displace all the water. Unless anyone can find a reference of the actual weight limits applied to the machine, the statement about "600 tonnes of canal barges" should be taken out. --Nathan (Talk) 00:35, 22 February 2006 (UTC)

Hi, you are correct, the machine is designed to carry 300 cubic metre of water in each caisson, and carry less water when barges are loaded, it is imposssible for all the water to be displaced in practice. At that point archimedes principle would no longer apply either.

I found out that the water level in the caissons is dependant on the level of the water in the upper and lower canals and that a small pump is used to top up the caissons so that they balance perfectly when in motion..

Regards, Gregorydavid 08:58, 22 February 2006 (UTC)

[edit] Wondering more about the physics of this

It seems that when one of the caisson is submerged at the bottom, the entire wheel would be top heavy. It also looks like the design is such that when the caissons are in position for loading and unloading, that the top heavyness would tend to make the wheel rotate in one direction and not the other. This unbalanced loading position might help accelerate the wheel when it starts to move and de-accelerate the wheel at the end of it's journey. Am I thinking about this correctly? Is it worth saying something about this in the article? -- Samuel Wantman 02:10, 25 February 2006 (UTC)

The bottom caisson is never submerged, instead it moves in a kind of dry dock which can be seen at Image:Falkirk_wheel.jpg. If the seals between the caisson and the canal are good enough there should only be minimal leaking of water, possibly captured in a sill. In brief the wheel is pretty balanced at all times as long the water levels are matched. -213.219.185.222 16:05, 25 February 2006 (UTC)

Hi, User:SeanMack added links to external sites above which clarify a number of questions. There is no mention of a dry dock at the bottom although this may be possible. I understand from the information given that the caissons have doors that at both ends. This allows water from the canals to rush in or out, depending on the difference in water level. The level of water in the top caisson is determined by the level of water in the canal above and the level of water in the bottom cassison is determined by the level of water in the canal below. Due to rainfall and other reasons it is possible for the level of water in the caissons to difer and thus be out of balance. One of User:SeanMack's references state that a small pump is used to fill the caissons after the doors have been closed, so that they balance perfectly. Regards, Gregorydavid 15:36, 26 February 2006 (UTC)

Thanks for the explanations. So is the shape of the wheel just for decoration? Or do the pointy things serve any other purpose? -- Samuel Wantman 20:39, 26 February 2006 (UTC)

Hi, the weight of the arms is small relative to the weight of the caissons, so I think one can safely say the pointy things are just for show. I think the external links seem to sugggest that one of the architects contributed those.. They have been described as claw-like, celtic axe shaped. I think they remind me of the Ying and Yang. Regards, Gregorydavid 14:30, 27 February 2006 (UTC)

The top picture in [1] clearly shows the dry dock. --Dashbox 15:09, 27 February 2006 (UTC)

[edit] Dry dock

Hi, User:Dashbox Thanks for bringing up the aspect of the dry dock. It made me think more about what I had already read and the missing gaps. I saw the schematic diagram you refered to after changing the description of the photo back to almost what it was. When I changed the description I also discussed it and acknowledged the possibility of the dry dock existing. Later I thought about it more and the lack of evidence on other images of any water drippping from a wet exterior of a caisson convinced me you are right about the dry dock. So there is a canal door both top and bottom, and caisson doors front and back.. It would be nice if we could get a good image of the dry dock.. Regards Gregorydavid 07:10, 28 February 2006 (UTC)

I'll change the photograph caption back to mention the dry dock until there's a better photo. It would be good if someone in the Falkirk area could get a good photo of it for us though. --Nathan (Talk) 13:08, 28 February 2006 (UTC)
I must say I'm not 100% comfortable with the dry area being called a dry dock, as far as I am aware a boat needs to be actually in a dry dock for it to be called such a thing, for example a repair yard, ([2]). Here the boat is never in the non water-filled area outside the gondola...

FYI, [3], "The undersides of the gondolas are always dry," notes Project Manager Paul Hudson of Butterley Engineering, the structural engineering firm responsible for design and construction of the Falkirk Wheel. SeanMack 13:28, 28 February 2006 (UTC)

I know what you mean. If you think of a better name, change it. --Nathan (Talk) 00:13, 3 March 2006 (UTC)

Hi, yes, it is actually a type of hybrid dry dock. I shall write something about it in the article in due course. For operational and safety reasons one would want to restrict boats from getting in the way of the wheel. Also one would not want the wheel to be wet like a water mill with tourists being showered at every turn.. Regards, Gregorydavid 07:12, 3 March 2006 (UTC)

[edit] Google map

There is a Google Map of the subject, alas, the zoom doesn't show any part of the structure. -- ke4roh 10:53, 2 March 2006 (UTC)

[edit] Tons/tonnes

The article listed a caisson capacity of 80,000 gallons, and 320 tons. This second figure was probably derived from a water weight of 8 pounds per gallon, and a 2000 pound (US) "short" ton. But water is more accurately 8.34 pounds per gallon, and the ton commonly used in the UK is either the imperial "long" ton of 2240 pounds or the metric tonne of 2205 pounds. So 80,000 x 8.34 / 2205 = 302 (metric) tons (or 298 imperial tons). --Blainster 10:22, 29 June 2006 (UTC)

[edit] This is a Good Article

After review, I've determined this article to meet the qualifications for Good Article status. It is well written, and a facinating topic. What a cool machine!

Continued improvements include internationalizing measurements (is the confusion between tons/tonnes dealt with properly?), and adding references as necessary. Personally, I'd love a little animation of the wheel actually turning, if a free license one could be created.

Keep up the good work, folks. Don't hesitate to message me on my talk page if you have any questions about my rationale. Phidauex 21:22, 11 July 2006 (UTC)

Sorry if this is not the correct way to do this, but the "talk" mentioned about videos of the structure rotating, there are small videos that can be linked to from my site on the wheel http://www.gentles.info/link/Webcam/Animations.html that show time-lapse of the structure moving. There is also a stop frame of the construction. http://www.gentles.info/link/Webcam/Fixed/020316-1530.html (near the end of construction) http://www.gentles.info/link/Webcam/Fixed/010305.html (near the start of construction)

[edit] GA Dispute

The Good Article dispute entry on this page has been archived, after a 4 to zero decision, this article has been delisted, primarily for a general lack of references and for lack of broadness on certain sections. The actual review is archived here: Wikipedia:Good articles/Disputes/Archive 6 Homestarmy 01:02, 5 October 2006 (UTC)

[edit] Map

One of the first things I went looking for when I read the article just now was a map! Some kind of map containing the two canals and highlighting the location of the Falkirk Wheel would be really helpful, if somebody has the time to find one. Just throwing the idea out there. Great work on the article guys! —Lantoka ( talk | contrib) 10:28, 5 December 2006 (UTC)

[edit] How the caissons are kept level

I tried to visualise in my mind how the gears work to keep the caissons level, but ran into difficulties trying to animate it! This section calls out for a diagram of the workings so that the less engineering-literate, like myself, can understand it better. Is there a public domain picture of this, or can someone with suitable knowledge and skills produce one? That aside, I concur with the general view that this is a very informative and interesting article. --King Hildebrand 15:12, 18 January 2007 (UTC)

I have created a detailed explanation at User:RealGrouchy/FalkirkGearing, using Lego technic gears to demonstrate the principle used on the Falkirk Wheel. I hope you enjoy it! --RealGrouchy 03:31, 19 January 2007 (UTC)

[edit] Grammar edit war - that/which

How the hell does this make sense: "...the amount of water leaving the caisson has exactly the same as the boat." The same what? (weight).

This uncommented edit introduced this error (although it wasn't clear in the previous version, either), and also replaced "that" with "which" in two places that went against the definitions/preferred uses in Wiktionary's entries for that and which.

I reversed the that/which error (which User:Rocinante9x changed in a number of articles), and clarified the "exactly the same" sentence, only for User:Calton to "revert" my "misguided" edits back to the improper and unclear version by User:Rocinante9x! If my understanding of the English language is incorrect, I would encourage someone to reference a source that says so! --RealGrouchy 19:36, 12 February 2007 (UTC)

[edit] Add html comment for story/storey?

Since it seems to come up somewhat frequently, how about putting an html comment in the code after the word "storey", such as...

to an eight storey <!-- this is the correct spelling, per WP:MOS#National_varieties_of_English --> building

...or perhaps just...

to an eight storey <!-- sic --> building

Actually, maybe just linking to "storey" would work... I know it's making a mountain out of a molehill, but still it bugs me. --RealGrouchy 04:21, 21 March 2007 (UTC)

Good idea. I like the first version, though putting a wikilink into the comment won't work as a link from the edit window. —Stormraven 13:18, 21 March 2007 (UTC)
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