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Flash locks

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gerontius grumpus
205414.  Thu Aug 30, 2007 7:34 pm Reply with quote

How did boats get from one level to another in river navigations before pound locks were built?

They had to go through flash locks, also known as staunches, navigation weirs, or watergates.
These consited of various methods of opening part of a weir so that boats going downstream could ride down on the flash and boats going upstream had to be winched up against the current.

Some flash locks survived on the Thames until the 1920s when they were replaced by pound locks and a derelict one on the Warwickshire avon was demolished in the 1960s when the navigation was restored.

gerontius grumpus
206025.  Sun Sep 02, 2007 6:02 pm Reply with quote

I find it hard to believe that none of the 50 people who have viewed this staggeringly interesting thread have found anything to add to it.

gerontius grumpus
207261.  Wed Sep 05, 2007 5:18 pm Reply with quote

On the Thames the flash locks were similar to some of the weirs that are still in use. They were composed of paddles and rimers.

there was a timber cill on the bed of the river and a moveable beam above water level, the rimers werte vertical timbers that extended from the beam down to the cill and the paddles were flat boards fitting between the rimers to hold back the water.
When a boat needed to go through the flash, the paddles would be levered up with crowbars, then the rimers were lifted and the beam swung round to allow passage trough the weir.
Flash locks were highly unpopular with millers because each passage of a boat would lose the head of watwer needed to drive the millwheel.

221667.  Thu Oct 18, 2007 3:17 pm Reply with quote

gerontius grumpus wrote:
I find it hard to believe that none of the 50 people who have viewed this staggeringly interesting thread have found anything to add to it.

I have nothing to add either, and I am viewer number 237

222524.  Mon Oct 22, 2007 9:18 am Reply with quote

Okay one question in my mind, as a non boaty type, when do they start putting in weirs and the like on the navagable sections of big rivers and creating different levels rather than letting the river find it's own level and rowing harder, is it to control water coming down or tides coming up (Isn't the last tidal water meadow on the Thames at Sion House)?

222549.  Mon Oct 22, 2007 10:18 am Reply with quote

I fear I can add nothing about flash locks, but did anyone see Michael Palin's show about Poland last night, and see the rather unusual locks on the Kanał Elbląski?

In case you didn't, what happens is that the canal boat is driven into a kind of shoe. The shoe with boat in is then hauled up railroad tracks by means of winding gear, and deposited into a continuation of the canal at the top of the hill. There are only a handful of these so called inclined plane locks in the world, and one of the others is in Canada.

That one is commonly known as the Big Chute, but officially it's Lock 44 of the Trent-Severn Waterway which connects Lake Huron with Lake Ontario. And it owes its continued existence to lampreys!

In the 1960s, the Canadian government planned to close the Big Chute and replace it with a series of conventional locks, since the Big Chute's machinery was worn out and large queues were developing there.

That was before a marine biologist found a population of lampreys to the "downhill" side. Lampreys like eating, and their presence is bad news for commercial fish stocks, so the fishing lobby was extremely keen that they should not get "uphill".

No one could come up with a way to prevent them getting into the proposed locks, whereas they were unable to negotiate the Big Chute. As a result, the locks plan was ditched and a new and improved Big Chute was opened in 1978 - quite possibly the last inclined plane lock that will ever be built.

gerontius grumpus
222637.  Mon Oct 22, 2007 5:12 pm Reply with quote

Thanks for that Suze, two of my favourite subjects, fis and waterways.
I too saw the Michael Palin programme, very good.
The inclined plane was very interesting,. sadly no inclined planes are now operational on the British canal systems but they once formed an important part of the tub boat canals of the Westcountry.
The British inclined planes for larger boats mostly carried the boats in water filled caissons, unlike the Polish one.
Some of the tub boat inclined planes used cradles though.

There is a scheme to restore the inclined plane at foxton on the Leicester arm of the Grand Union Canal.

222681.  Tue Oct 23, 2007 4:42 am Reply with quote

Not really a lock but it does connect canals at different levels to each other.

gerontius grumpus
223871.  Thu Oct 25, 2007 7:02 pm Reply with quote

I had been thinking of starting a thread about the Falkirk Wheel, it's truly a new wonder of the waterways.

Alfred E Neuman
223973.  Fri Oct 26, 2007 6:20 am Reply with quote

I looked at the Falkirk Wheel link. If ever I get around to Scotland, I'm planning a visit. Perhaps in 2010...


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