Guest Post by Willis Eschenbach
Due to good fortune and the WUWT readership, we got the chance to not only see the Falkirk Wheel, but to take a ride on it … what a marvelous piece of Scottish engineering. No wonder the engineer on the Starship Enterprise was “Scotty” … here’s the wheel, on a lovely day of rain and sun, but mostly rain. Or what is known as “un-made whisky”, as I’m told rain is called locally:
The wheel rotates to move boats up and down, in lieu of a system of locks, to overcome the difference in height between two canals above and below. When you’ve been moved up from the bottom to the top, you are looking out along an elevated waterway that you can see below:
We didn’t go far on the canal, just through the tunnel and back. The gorgeous ex-fiancée and I take care of her father, who is 85 and legally blind. We’re always looking for things that he can do, and so we were graciously given a very short ride on a boat that is used to carry disabled people along the canals, so that they can be safely out and moving in the fresh air. It would be perfect for the old man, he loves the water but has trouble on the ocean, so we’ll see if we can find something equivalent back in the States.
The boat is one of ten that is operated by a charity called the “Seagull Trust Cruises”. I have been amazed by the amount and extent of work that is done by various charities in the UK. Many things that are done (poorly) by the government in the US are done, and done well, by the charities in the UK. For example, the Seagull Trust Cruises operates totally on public donations, and is staffed entirely by volunteers … and they’ve given free rides to over a million disabled people to date. What a wonderful gift for someone cooped up in a nursing home, or homebound for some chronic medical problem, to be able to take a canal cruise.
So I put £20 into the charity right there on the spot, and if anyone else is so inclined, their website is here, it’s a good cause. They’re set up to take people on wheelchairs, and every penny of the money goes to the actual operating expenses—no one, from the highest to the lowest, takes any money at all for their time.
The engineering on the Falkirk Wheel is so well-balanced that it only takes about the amount of energy needed to toast three slices of toast to rotate the wheel by a half turn, boats, water and all … it’s all computer controlled, and if the water levels in the two chambers are different by more than 75 mm (3″), the whole thing stops. Here’s a view from the top of the wheel, just prior to starting back down:
And here are the gears that make it all go round …
From there, an old sea-dog who reads WUWT took us on a tour of the “kirk”, or church, for which Falkirk is named. First, though, we stopped at the Antonine wall. It served the same purpose as the better-known Hadrians wall, regulating commerce. Unlike Hadrian’s Wall, however, it was built of turf, and has since disappeared. All that is left are the trench that was excavated to provide the turf for the wall and increase its height, and the heap of earth on the left that is where the wall once stood:
I was irresistibly reminded of Matsuo Basho’s haiku, written on a battlefield that was already ancient in the 1600’s …
Summer grass
Of stalwart warriors’ spendid dreams
The aftermath …
We were then taken on a guided tour of the Falkirk church. “Falkirk” means “spotted church”, because the original church (built in 36,000BC or some such date) was built with stones of different colors. The church feed lunch every day to the homeless, and the cost of that is recovered by selling the same meals to anyone who comes in … so we started out with lunch at the church. Like the Seagull Trust, the restaurant is completely staffed by volunteers.
Inside, the church is very unusual, because it’s rounded. Unlike most churches, it felt well-worn and well-loved. The best part of the tour, though, was we went up into the belfry.
I’ve never been up in an actual belfry before, in the US churches generally have loudspeakers … the old sea-dog said bells were a gift from the Dollar family of San Francisco … “The owners of the Dollar Steamship Lines?” I asked, because that name is very familiar on the West Coast. Yes, I was told, the family came from Falkirk, and they had the bells made in the US and shipped back to the old country after they’d made their fortune.
And wonder of wonders, I was invited to play the bells! Rather than subject the entire city to a novice, I just played a few notes … I’ve never, ever played an acoustic instrument of that power, it was astonishing. The only thing I can compare it to, which some may understand, is driving a D10 Caterpillar dozer … raw unbridled strength at my fingertips.
Parts of the church are made of sandstone … and it is so old that the very stones themselves have been worn away, not by people or by traffic, but by the rain … where I grew up, that only happens to mountains. The folks of Falkirk appear to be harder than their sandstone, however, if this plaque near the church is accurate …
The old sea-dog had graciously invited us to spend the night at his home, and on the way there we stopped at the Carron Iron Works … or more accurately, a monument to the former Carron works, cheaper ironwork from the Japanese drove them out of business. There I learned that a “carronade”, which is a small cannon which I’d read about in many histories of the period, was named after the Carron works. It’s a lethal affair designed to shoot “grape-shot” at infantry, basically a shotgun on steroids.
All that’s left of the works now are a couple of cannons and carronades … the cannon in the background is one of two surviving cannons from the battle of Waterloo, the other is to the left of it just out of the picture.
The Carron Iron Works was also the company that made the first steam boiler for James Watt, a part of which is mounted in the wall of the monument:
“Stalwart warriors’ splendid dreams” indeed …
We had a lovely evening with the old sea-dog and his good lady, listening to stories of life at sea as recounted by he and his wife, who had accompanied him around the world, and tales of battles in Falkirk won and lost. I can’t thank them enough for their hospitality and the insights into Scotland and life in the north.
The next day we rolled on to Edinburgh, where we are now … but that’s a story for another day, we’re off to see Mary King’s Close.
My best to all, more to come,
w.
For what it’s worth the Falkirk wheel was designed and constructed by Butterly engineering in Derby, England. I did lots of work with them over the years. It is a marvelous execution of the ship lift in engineering terms explained in most enjoyable discussions with staff of Butterly. And I’m Irish. Rgds
Some more technical info on the carronade: Developed specifically for ships. In an era when long-range fire was innacurate, weight of broadside was vital. The distinctive characteristics of the carronade is that the chamber is smaller than the bore, and the barrel is shorter than a similar long-gun, so a carronade for a particular size ball could be as little as a third the weight of a comparative long-gun. The muzzle velocity was also much slower, resulting in more damage. Ships mounted with carronades could therefore:
A) be mounted with bigger or more guns (for heavier broadside)
B) be built more heavily (for better protection)
C) neither of the above (making them faster)
Although it could be (and was often) used as a giant shotgun, this was not its only or intended purpose. Guns of this type were especially useful for merchantmen trying to fight off privateers. (or privateers trying to board a warship mounted only with long-guns). A carronade used at Waterloo would have been as an emergency measure, probably jury-rigged onto a caisson for use in the campaign. It would no doubt have been returned to its intended use (and mount) later.
My mistake – you did not say the carronade was used at Waterloo. (Artillery trivia: The earliest carronades had trunions, but evolved into pintle-mounted guns. A later variety, called a gunnade, was then invented using trunions so merchantmen could mount carronades on standard naval carriages.)
kadaka (KD Knoebel) says:
September 15, 2013 at 10:28 am
I really hate to detract from Willis’ wonderful essay by extending this detour, but this is not the reason the water level drops. Whether the coins/cannonballs are in the floating cereal bowl/canoe or entirely submerged in the water they are still displacing water. While an object floats, it displaces a volume of water equal to its weight. Once submerged an object displaces water equal to its volume, and weighs (presses upon the bottom) less by the weight of the displaced water. Since objects which sink by definition displace more water by weight than by volume, the volume displaced decreases when weights are tossed off a floating platform and sink into the supporting water.
I glossed over Willis’ detail about 75mm of water difference being the maximum the wheel can tolerate, but that just makes my original point. The weight of the volume of water calculated by the area of the gondola times 75mm is the maximum the rotation motor can overcome. So if the wheel is properly sited, and the levels in the upper and lower watercourses are the same relative to the gondolas at the top/bottom of travel, then the bucket weights will be equal, regardless of the weight of the boats in each gondola.
The word “exactly” means different things to mathematicians and and engineers. Nothing is ever exact in engineering, so rather than say the weights are “exactly equal”, I will say instead they are equal within design tolerance of the system. And if they are not equal, due to water levels slightly off the norm, it still has nothing to do with the weight of the boats — the same inequality would apply if both gondolas were empty.
The wheel is an elegant piece of engineering and a delight to behold. And it works by a natural principle first formalized (as far as we know) by Archimedes of Syracuse almost 2300 years ago.
Been away from the web for a few days so I’m late to this.
Perhaps someone will correct me, but my understanding is that the wheel needs a three inch difference between the upper and lower vessels.
My understanding of how the wheel works is that the buoyancy of the part submerged arm gives some upwards impetus, whilst the upper arm gives some downwards impetus.
Once the slightly heavier upper vessel is past TDC, its weight alone is enough to transport the two vessels.
The reason for the tapered arms is to give progressive assistance to braking as the wheel reaches its new parked position.
If someone has already given a similar explanation or otherwise managed to prove me wrong, sorry, not read the whole thread, just Willis’ posts to see if anyone else had posted a similar explanation.
Anywho, 3 inches water effective flow is minuscule compared with the series of locks required for that drop.
You may already have got past Newcastle Willis. Hope you didn’t miss Parsons Turbinia on the way.
A few funicular railways on the way down the east coast too.
Can’t offhand remember some of the other thing I suggested apart from Beamish open air museum. Not sure if you can still go down their drift mine but I’m sure you’ve seen a few of them.
DaveE.
Oh. As I commented in my text Willis, it’s almost worth going to Beamish to see the signpost to No Place.
DaveE.
David A. Evans says:
September 15, 2013 at 4:32 pm
The wheel will tolerate up to a three inch difference in the water levels of the two gondolas; it does not need one.
If the wheel is balanced, which it will be water levels of the upper and lower gondolas are the same, then there is no need for breaking — to the contrary force is required to overcome friction and inertia. The wheel turns slowly enough that breaking is not required. If the water levels are not equal then additional force is required either to lift the heavier gondola if it is on the bottom, or to retard the fall of the heavier gondola if it is at the top.
See my comment immediately preceding yours. If this does does not make it clear, then I must confess my writing skills are inadequate to my intent.
I later read your comment, Sorry but in my view, braking can be achieved with regenerative braking, but only if the upper gondola is heavier than the lower one. The tapered tips will provide additional proportional braking because their buoyancy is applied proportionately. The mass of this wheel is enormous. It must need brakes to stop it at the end of its travel.
The arms provide both assistance in overcoming inertial to start the wheel and also in stopping it.
DaveE.
George V: “Can anyone comment on the points that protrude on the “leading” side of the wheel? Something functional, for better balance or more for aesthetics?”. I wondered exactly that as we went up and there is absolutely no indication of any function to the protrusions so they are clearly aesthetic.
But then the whole wheel is purely aesthetic because there used to be a sequence of something like 10? locks before they were removed. The wheel and tunnel are a modern replacement for the earlier engineering which required NO ENERGY to work (or more accurately all came from the movement of water and a few hefty pushes on the lock gate).
David Evans: see above, the tapered tips do not go in the water, the whole gondola dips into a dry sump – only the ends of the gondolas get wet.
Remakable that you know Basho.
I live in Oishida.
From Alan Watt, Climate Denialist Level 7 on September 15, 2013 at 4:04 pm:
I was wondering if an and what sort of asinine pedant would jump at my attempt at simplified writing. At least you’re one of those who means well.
As I carefully and succinctly worded: “Water does not have to be displaced to support its weight, thus the level has dropped.” That the physical volume of the coins on the bottom would be displaced was so obvious it was cluttering up the originally planned wording so I dropped it.
The difference between displacing enough water to support the weight, to incidentally displacing water by having physical volume, yields the water level drop.
BTW, your original canoe in a swimming pool example, likely wouldn’t have worked as planned. Any swimming pool large enough to not look completely ridiculous with a canoe in it, most likely has automatic level control, as with an outdoor pool that removes excess water during rainfall, to any pool that corrects for evaporation. Thus the water level drop should not have materialized except perhaps as one or more brief pulses, unless the change was so small it didn’t trip the fill mechanism.
Sloppy wording, units don’t match.
Thus when the mixing bowl rests on a scale, does the scale measure less weight when the coins are in the cereal bowl or when they rest on the bottom?
The apparent weight of an object may change when submerged, but the force of gravity has not, well not significantly unless the object when sinking drops a significant distance.
That first part is just confusing. When they sink the displacing is due to the volume of the object, not their weight (their mass?). A floating object must necessarily displace more volume than a sinking object.
The second part you got correct.
Amerinds never even invented the wheel [I am certain that I am stepping on plenty of toes here — but now we are all Westerners, so we’re on the same team].
Partially true. Central American cultures had them on toys, but never, apparently, anything larger.
OK, here’s my 2¢ worth.
The Falkirk Wheel absolutely depends on the Archimedes principle. Indeed, one of the boats that regularly carries tourists is called the “Archimedes”.
In a perfect world, because of Archimedes principle, no matter the weight of the boat, it displaces the exact amount of water equal to its weight. As a result, the two chambers, whether or not one or the other contains a boat, weigh exactly the same.
The problem arises when the doors are closed to seal off the chamber and allow the wheel to rotate. Because they are physical doors, when they close it can change the water level slightly, so that one chamber will weigh slightly more than the other. This difference will, of course, be reflected in a difference in the water height in the two chambers.
The driving motor and the entire system can accommodate a slight imbalance in the weight. The limit has been set at a difference of 75mm (3″) of difference between the two. This is monitored by computer. If the level exceeds that, the wheel won’t turn. If this is the case, a bit of water is pumped out of the heavier chamber and back into its canal. Once it is balanced, the wheel can turn.
Finally, the amount of energy used to spin the wheel is about enough to toast three slices of toast. This is expended in overcoming friction. There is no brake. Instead, less and less power is put into turning it as the wheel approaches the final location, and friction brings it to a halt. At that point, a pin is pushed hydraulically into a socket on the wheel to lock it into place, the doors are opened as necessary, and the boat(s) leave the wheel.
As a side note, as the wheel is turning passengers absolutely can’t step off the boat and stand on the side walkways … or the water level may drop because of the change in weight of the boat, and if it goes more than 3″ the computer will bring the wheel to a halt until the passengers re-board the boat.
w.