Imagine your bathtub was a merry-go-round. No, a turnstile--
H'mm. That's not the place to begin. How does a road cross a canal? A bridge, of course. If it is a low bridge and the canal is actually used for boats, it might be a lift bridge or a swing bridge.
Okay, how does a canal cross a road? An aqueduct, right? Yep.
Fine, almost there. How does a canal cross a canal? Especially if the lower canal is for huge ships and the difference in height won't clear them?
As far as I know, this problem has only come up once, over a hundred years ago. The answer was a swing aqueduct -- the Barton Swing Aqueduct (and companion road bridge) and it's still in use. Follow the link and see it in action!
Simple and easy; you seal off a great long section of canal and gently pivot tonnes and tonnes of water out of the way, with no fuss or muss and very little noise. Why, anyone could do it...if they were clever enough. (Some details).
Living within a short bicycle ride of Indy's very own canal, I'm a bit jealous. Ours is only navigable by tiny boats, thanks to low bridges, and they chase you right off ahead of the system's only (non-moving) aqueduct.
Neat! Added to my list of "wanna see" things and places. Decidedly worth some travel and lodging funds when already on that side of the pond.
ReplyDeleteAh, "water conservation" is the reason why they just didn't build two locks, one to lower barges down to river level and one to raise them back up after crossing.
ReplyDeleteOf course, you still need at least one lock if you want to make a right turn from canal to the river.
Just came across this other bit of technology. It's a bit of a stretch but, then again, stranger contraptions do exist. It is the origin of the pilot's "pucker factor". See http://centercomp.com/dc3/14511.html
ReplyDeleteRelated to canals but not an aquaduct. Not an example of Victorian engineering, but a nifty alternate solution to a series of locks. We were planning to visit this in Scotland last summer while there but didn't have time. My son did stop by there to take some pictures two years ago. We are both engineers and appreciate this kind of stuff.
ReplyDeletehttp://en.wikipedia.org/wiki/Falkirk_Wheel
Fascinating solution.
ReplyDeleteOh, I'm a huge fan of the Falkirk wheel. The Inland Navigation system fascinates me; Indiana went broke trying a similar scheme much later -- so late that the the railroads caught up before it was completed.
ReplyDeleteI wonder what they do in freezing weather and how do they maintain the integrity of the movable acqueduct? I'm sure it gets below 32 degrees F in Manchester...
ReplyDeleteAll The Best,
Frank W. James
Tiny icebreakers?
ReplyDeleteSome of the system shuts down in winter. The Swing Aqueduct does operate restricted hours.
Wow, that is so cool! Oh, I have just found out that Tam does not appreciate proper writing instruments. Let us have no carnage, there, seeing that both of y'all are well armed. Instead, let us hope that Tam will be convinced by sweet reason that the flowing liquid ink from nib of the pen is the best and most perfect way in which to write things.
ReplyDeleteTam's former roomie agrees with us, you know.
--Let me point out that Tam is left--handed; this can tend to prejudice one against fountain pens.
ReplyDeleteGreat stuff. Another example of engineering by necessity is the Peterborough, Ontario lift lock on the Trent-Severn waterway which is a canal-lake system that connects Lake Ontario with Lake Huron.
ReplyDeletehttp://www.youtube.com/watch?v=8rmklGExZwM&feature=related
Been over it I have; so has PDB.
Sum Canadian dude
The C&O canal was drained every winter.
ReplyDeleteOTOH, the canal was able to deliver coal to DC much cheaper than the rail could during it's heyday.
Executed in genius, but surely conceived with drunkenness and roaring laughter!
ReplyDeleteEd, that's a tall tale, right?
Maybe it is, maybe it isn't. Never underestimate the range-finding abilities of ducks,.
ReplyDelete