For those who don't know, the Falkirk Wheel is a canal boat lift. (google it!) Anyway, approaching it from above in a boat is quite scary - you're high in the air and looking like you're about to fly off the end of the canal into space. I've taken most visiting family there, but until yesterday never when the weather was bright and calm enough to show such a terrific reflection.
(http://cameracraniums.com/gallery/albums/userpics/10222/normal_KS2_2933Rs_Falkirk_Wheel.jpg) (http://cameracraniums.com/gallery/displayimage.php?pid=18048&fullsize=1)
The Falkirk Wheel
I did Google it and yes, I can see it must be scary!
Went on the wheel a few years ago and yes - we had rain! Looks much nicer in the sun. I`ll have to try and find my photos now you`ve reminded me of it.
Ive seen pictures of it before from other angles, and I've always wondered why they would go to so much engineering and construction, then have to go through a conventional lock below it anyway. I am sure there is a good reason, I've just never seen any explanation.
In interesting thought. My guess is that firstly the wheel would have had to be a further ten metres or so radius, and secondly the layout of the land and existing roads and railways would have made construction of the mooring basin and surrounding parkland much more difficult. There is also one lock above it, to drop the canal low enough to tunnel underneath the old Antoinine Roman wall and the railway. But the wheel replaces 11 locks which used to take all day for a boat to cross, and can carry two in each direction all in just a few minutes.
My guess is that it had to do with either emptying the container that the bottom of the wheel sits in, or they needed to isolate the water of the canal from the river for environmental concerns. Or maybe to isolate from the variable height of the river.
The container at the bottom needs to be empty because otherwise as the wheel dropped into it, the buoyancy of the thing (gondola?) holding the boat would unbalance the wheel. (I read that somewhere) So before the gondola can be lifted or dropped into the space below it, that space needs to be empty, and if they could just dump that water into the river below, it would save from having to pump it... just open a valve. Then refill it from the canal above. Without that lock there wouldn't be enough drop to flow water.
But of course I am just speculating, and I've never even been there, so what do I know.
Sorry Willy, but it's really not like that. Firstly there is no river involved, just two canals meeting. Also, the wheel itself runs dry, it doesn't enter the water. And unlike a lock it does not loose water downstream during operation. Each gondola carries water with or without boats, up as well as down, and the level of the water in each can be slightly adjusted so that they are equal weight so the whole thing needs almost no power to turn.
(The normal lock just upstream does of course loose water with each operation, and as the water level immediately above the wheel mustn't change, there's an overflow (just like in your house bath or sink) taking the excess around to join the other canal further down).
Ok, other than what I thought was a river downstream being a canal, I think I was pretty close. There has to be a well at the bottom for the gondola to go down into, so the water inside the gondola is at the same height as the pool around it. So since that is open to rain and whatever it has to be emptied somehow. My point on the buoyancy was about the weight and balance of the gondola as it enters this well. If the well was filled up with water, the gondola, having some buoyancy, would weigh less.
But my question is why is the pool higher than the downstream canal, necessitating the downstream lock you can see in the pics? Would making it even with the canal make the wheel too large to be practical, or are there other issues?