The Falkirk Wheel

[Graham.]

[Graham.]

There must be parallels to what is happening here.

[fred]

I can't tell, I don't follow blind links ;-)

[Bob Eager]

It's a picture of a tinfoil hat! .-)

[GB]

I had a look at the Barton swing aqueduct (online). It's an awful lot of engineering to solve a problem that could instead have been solved by building a lock on either side of the main channel to bring the canal down to that level.

[John Williamson]

Which would have meant supplying many thousands of gallons of water more from the canal reservoirs per boat than the current solution. The average water use per boat per lock on the canal system is about 56,000 gallons. If I travel from London to Tring Summit or vice versa on the Grand Union, about 100,000 gallons of water is drawn from the resrvoir at the summit, as the locks are wide ones. This amount is independent of the size of the boat.

[polygonum]

I don't know how the Bridgewater canal is fed with water, but if you put a pair of locks there, you would automatically require each section to have its own feed of water. Rather than, possibly, allowing one feed to supply the whole canal.

[GB]

Thanks, guys. I hadn't thought of that issue at all. Quite frankly, I have no idea how significant 100,000 gallons of water looks like in terms of the capacity of typical canal reservoirs and rainfall? It

*sounds* like a lot, but for a reservoir that draws its water from a large hillside it may actually be bugger all for all I know.

[polygonum]

Do an image search for "marsworth reservoir" - will find at least dozens of photos of the reservoirs which supply the canal at Tring. Not exactly mountainous round there! Those reservoirs drop very significantly through dry periods.

[SteveW]

The Bridgewater canal was carefully designed and routed so as to have no locks at all. The Barton aquaduct was originally a stone aquaduct to cross the river Irwell. Later that part of the Irwell was dug out to form the Manchester Ship Canal and the only options were to use a swing aquaduct or two flights of locks (four locks). This would have meant queues of boats, heavy water usage and the need to supply that water to the other side of the canal. Using a swing aquaduct meant no locks, no delays and the canal could continue to be fed with water from one end (from the mine drainage - hence the orangey-brown colour).

SteveW

[SteveW]

Actually I've just thought again and decided that it was the water useage and delays that must have been problematic, not the requirement for a second feed - that could simply have been arranged by a pipe or pipes dropping from the bottom of one section of the Bridgewater canal, crossing under the Manchester Ship Canal and then popping up into the bottom of the other half of the Bridgewater canal.

SteveW

[Chris J Dixon]

Except for during a Royal visit when AIUI they tipped in some chemicals, flocculators (or whatever) to turn it a more photogenic colour.

Chris

[Halmyre]

You have got to be joking!

[Chris J Dixon]

I only remembered it as a tale I had once heard, but this seems to be the story:

Bridgewater Canal Masterplan Brochure (Adobe PDF format, 7.3mb)

"In 1851 Queen Victoria and Prince Albert, accompanied by the Duke of Wellington visited the canal and were given a trip on state barges that had been built specially for the occasion. Even the canal water was dyed royal blue for the day."

Chris

[Adam Aglionby]

Dyeing water for occasions not unknown today

[Scion]

Bob Eager put finger to keyboard:

*My* tinfoil hat?!