K&A Summit Closed (again)

[Dave123]

Summit pumps have failed again (doesn't say if it is those at Wootton Rivers or Crofton). Does anyone know why they fail so often? Don't remember the last time I saw a notification about Napton or Calcutt or any other back pumps failing, but the K&A Summit ones fail several times each summer it seems?

[magpie patrick]

The Wootton Rivers ones are slightly too small and thus overworked (so I'm told) - it's certainly true that demand is greater than was anticipated in 1995 when they were installed

[BEngo]

57 minutes ago, magpie patrick said:

The Wootton Rivers ones are slightly too small and thus overworked (so I'm told) - it's certainly true that demand is greater than was anticipated in 1995 when they were installed

How does one overwork a pump?  It will pump at the rate it was designed to deliver, that rate depending on the various pipe losses, the head anda or lift and the motor  power.

 

I can see that too small a set up might cause the pump to have to run for longer spells than planned, ààin order to deliver the needed volumes of water, but that is hardly over working the pump.

 

Na

[magpie patrick]

5 minutes ago, BEngo said:

How does one overwork a pump?  It will pump at the rate it was designed to deliver, that rate depending on the various pipe losses, the head anda or lift and the motor  power.

 

I can see that too small a set up might cause the pump to have to run for longer spells than planned, ààin order to deliver the needed volumes of water, but that is hardly over working the pump.

 

Na

Yes, work for longer hours than originally specified, also with a smaller redundancy factor - that is you can't last as long without it/it takes longer to recover from any downtime. 

 

We were moored at Wooton Rivers when they closed the summit for a day or two (we were there two nights) - the engineer fixing it was explaining his frequent visits. The smaller pumps and smaller bore pipes were among his gripes - smaller compared to all the other k&a ones that is. 

[ditchcrawler]

Maybe CRT will buy another lorry load of coal for the steam boys

[BEngo]

I would expect they will be making hot fog next weekend anyway, since its is a bank holiday.  I think they will be starting warming up about now.

N

[GUMPY]

Didn't  BW pay for a whole summer of running when the pumps failed before, somehow cant see cart doing that.

[magpie patrick]

Running more at Crofton doesn't really solve the problem as they attempt to balance the extraction from either side of the summit - you can't (or at least shouldn't) resolve a failure at Wootton Rivers by simply pumping more at Crofton. 

 

 

[BEngo]

I don't know what BW actually coughed up, but Crofton kept pumping for about a week.  That was about as long as they could find sufficient drivers and firemen for.  Driving is not too much like hard work, though concentration is needed, but firing definitely is.

 

The Wootton Rivers pumps electric bill is a saving to CART, but how the cost of the pumps  compares with the cost of coal for Crofton I dont know.

 

I also dont know if the Crofton steam pumps can run at the same time as the electric ones.

 

N

[magpie patrick]

The whole set up has a complicated history - the original proposed feed for the Kennet & Avon was from Wilton Water to the canal, but Wilton Water is six locks down the Crofton Flight - originally the summit was planned from Devizes to Wilton Water with a four mile tunnel where the summit now is, the promotors decided against and the current short summit was proposed, but it had no water supply, hence the pump at Crofton. The Wooton Locks are about 8 feet drop each, the six locks above the pump at Crofton fall exactly the same amount. They are shallower as the primary purpose of the pump was to feed the western side - the eastern side downstream of Wilton Water was (and is) gravity fed. The Wooton Locks are about the same fall per lock as Devizes, but the Crofton ones are shallower to minimise water running back in the direction of the pump.  

 

During (and I think before) the restoration of the canal the steam pumps operated, which allowed Wooton Rivers locks to reopen so for quite a while before any other locks. Upon restoration it was apparent that demand would outstrip supply so back pumping all the way from the Avon in Bath was agreed - however this supply was only for the western side. At some point (I know not when) modern pumps were put in at Crofton too, so the idea is the Wooton Rivers pump replaces water lost at Wooton Rivers, and Crofton replaces water lost down Crofton locks. 

1 hour ago, BEngo said:

I also dont know if the Crofton steam pumps can run at the same time as the electric ones.

 The electric pumps at Crofton have to be turned off if the beam engine is running, the leat can't cope with them both operating! The capacity of the beam engine is quite a bit more than the electric pumps. It's typical for the electric pumps at both ends to be working when in normal operation, I'm not sure if Wooton also get turned off when the beam engine is working. The leat won't be an issue, but they could still end up with too much water at the top. 

Edited August 23, 2022 by magpie patrick

[BEngo]

I thought the leat at Crofton could cope with both steam aengines pumping. (A rare and short term event these days given the steam demand.)   Perhaps not,  in light of your info, though given the volumes, and the intermittent flow you might be able to sequence the two steam pumps so that only one is flowing into the leat at any time.  

 

I can see why a continuous flow from the electric pump, on top of several tons of water from the beam engines in one lump  would be too much for the leat.

 

N

[magpie patrick]

1 hour ago, BEngo said:

I thought the leat at Crofton could cope with both steam engines pumping. (A rare and short term event these days given the steam demand.)   

 I'm guessing they might be alright so long as they're not in synch, as you observe the beam engines lead to a wave going down the leat, and it would be best is the waves didn't coincide.

 

If you stand at the bottom end, below lock 60, you can also see the level dip as the pump sucks water in.

 

As an aside I once went to the pumping engine at Westonzoyland, different purpose but once again the old pump has been replaced by modern electric ones. The old pump there had a very large impeller, and as they weren't pumping anything they ran the pump almost dry with the lid off so visitors could see the impeller going round. One of the volunteers said that in the early days, out of curiosity, they filled the pump chamber with water and ran it, no outlet, lid off. Apparently it made quite a mess