BCN Challenge 2018

[Rob-M]

The Explorer cruise ends at the Pumphouse on the Friday as well so there could be plenty of boats there over the weekend.

[RLWP]

I think I'll bring along a couple of buckets of water for the locks

Richard

[matty40s]

I have just decided not to bring Old Friends for the weeks accommodation as I may never leave.

The New mainline is only 'possibly' opening on the 25th May, and by what I saw two weekends ago needs a massive amount of work to be re-bricked.

Just hoping they are not using the same mortar as at Penkridge and Braunston.

 

[Captain Pegg]

I believe Oldbury locks have a back pumping system which is why putting 40+ boats through them in about 8 hours on the Sunday of last year's Challenge worked fine. It should be able to cope with the arrivals for the rally on the Friday and be ready for the Sunday of the Challenge.

JP

[nicknorman]

9 minutes ago, Captain Pegg said:

I believe Oldbury locks have a back pumping system which is why putting 40+ boats through them in about 8 hours on the Sunday of last year's Challenge worked fine. It should be able to cope with the arrivals for the rally on the Friday and be ready for the Sunday of the Challenge.

JP

I very much doubt it. The summit is fed from rotten park reservoir as well as titford pools. Apart from anything else, if you consider the amount of traffic normal,y traversing those locks (virtually nothing) it wouldn’t make economic sense to spend a fortune installing back pumping.

[David Mack]

11 minutes ago, nicknorman said:

I very much doubt it. The summit is fed from rotten park reservoir as well as titford pools. Apart from anything else, if you consider the amount of traffic normal,y traversing those locks (virtually nothing) it wouldn’t make economic sense to spend a fortune installing back pumping.

We'll the building at the top is "The Pumphouse"!

[nicknorman]

1 minute ago, David Mack said:

We'll the building at the top is "The Pumphouse"!

True. But pumps are really bad at sucking, much better at blowing. So it would be sensible to place one at the bottom, if the intention was to back-pump. I’m posting all this bravely, without checking my facts, so I’ll now go away and do my research!

[nicknorman]

Oh well, looks like I was wrong as usual! Of course it’s complicated because originally it was a feeder for the smethwick summit level (ie the level above the old main line, long since defunct), then diverted to the reservoir. And yes, the beam engine has been replaced by electric pumps which apparently can still be activated. Off to dunce’s corner for me!

[RLWP]

9 hours ago, nicknorman said:

has been replaced by electric pumps 

More than once. You'll remember that one of the original electric pumps sits alongside the pound below the top lock. A big, black cast iron thing about six foot tall

Richard

[Dave_P]

It's with some disappointment that I can say that I won't be entering this year.  On the saturday I will be completing the last leg of a 100 mile hike across the Scottish Highlands - Glasgow to Fort William.  I'll be sure to raise a dram to you all.

Would anyone be willing to take on the management of the BCNChallenge twitter account this year?  I don't mind having it back next year if nobody wants the permanent responsibility.  Otherwise I'll try to do what I can in terms of re-tweeting each boat's progress but I may have signal issues when down in the glens.

[dmr]

27 minutes ago, Dave_P said:

It's with some disappointment that I can say that I won't be entering this year.  On the saturday I will be completing the last leg of a 100 mile hike across the Scottish Highlands - Glasgow to Fort William.  I'll be sure to raise a dram to you all.

Would anyone be willing to take on the management of the BCNChallenge twitter account this year?  I don't mind having it back next year if nobody wants the permanent responsibility.  Otherwise I'll try to do what I can in terms of re-tweeting each boat's progress but I may have signal issues when down in the glens.

BCN Challenge is a good event but I reckon the West Highland way beats it easily. I am envious.

About 10 years ago we seriously thought about doing it but then I had some work on Loch Lomond and watched lots of bedraggled and badly equipped walkers in the torrential rain having a very bad time so we changed our plans. I have this image of a few Glaswegians going for a few beers on a Saturday lunch time then one says "what shall we do next this afternoon" and another says "I've got an idea......"

.............Dave

[Dave_P]

52 minutes ago, dmr said:

BCN Challenge is a good event but I reckon the West Highland way beats it easily. I am envious.

About 10 years ago we seriously thought about doing it but then I had some work on Loch Lomond and watched lots of bedraggled and badly equipped walkers in the torrential rain having a very bad time so we changed our plans. I have this image of a few Glaswegians going for a few beers on a Saturday lunch time then one says "what shall we do next this afternoon" and another says "I've got an idea......"

.............Dave

I'll be praying to the weather gods.  Camping all the way, so a soggy week would put a real dampener on the proceedings.

[Captain Pegg]

16 hours ago, nicknorman said:

True. But pumps are really bad at sucking, much better at blowing. So it would be sensible to place one at the bottom, if the intention was to back-pump. I’m posting all this bravely, without checking my facts, so I’ll now go away and do my research!

This has got me thinking. The water level at the top of Oldbury locks is 38' higher than the bottom so if you had a pumping station at the bottom you would need an aqueduct that starts 38' in the air to then transport the water along the length of the locks to the upper pound. Does this explain why the pumping station would be built at the top as it is easier to provide a culvert at the lower level to a sump beneath the pumping station?

[nicknorman]

2 minutes ago, Captain Pegg said:

This has got me thinking. The water level at the top of Oldbury locks is 38' higher than the bottom so if you had a pumping station at the bottom you would need an aqueduct that starts 38' in the air to then transport the water along the length of the locks to the upper pound. Does this explain why the pumping station would be built at the top as it is easier to provide a culvert at the lower level to a sump beneath the pumping station?

For electric pumps at least, you would just have an up-sloping pipe running under the towpath. But perhaps the original steam pump WAS better at sucking than blowing, just delivering water not at elevated pressure. Must have been quite difficult to ensure an airtight seal all the way down to below the bottom lock though.

Even with a perfect seal, you can only suck water up so far. Then, if you need to suck harder, you just pull a vacuum. According to a brief search on Google this happens at about 34' which is a bit less than the rise you mention. Not sure how they got around that, perhaps the pump inlet is less than 33' above the wolverhampton level  and the output pumps up a bit further, but even so, it would surely be a struggle. Or was there some sort of intermediate pump?

[john6767]

6 minutes ago, Captain Pegg said:

This has got me thinking. The water level at the top of Oldbury locks is 38' higher than the bottom so if you had a pumping station at the bottom you would need an aqueduct that starts 38' in the air to then transport the water along the length of the locks to the upper pound. Does this explain why the pumping station would be built at the top as it is easier to provide a culvert at the lower level to a sump beneath the pumping station?

Normally pumps push the water up a pipe in the ground, as pushing rather than sucking avoids any possibility of cavitation.  I doubt that there is a culvert level with the bottom of the locks and then a vertical pipe to the pump.

2 minutes ago, nicknorman said:

For electric pumps at least, you would just have an up-sloping pipe running under the towpath. But perhaps the original steam pump WAS better at sucking than blowing, just delivering water not at elevated pressure. Must have been quite difficult to ensure an airtight seal all the way down to below the bottom lock though.

Even with a perfect seal, you can only suck water up so far. Then, if you need to suck harder, you just pull a vacuum. According to a brief search on Google this happens at about 34' which is a bit less than the rise you mention. Not sure how they got around that, perhaps the pump inlet is less than 33' above the wolverhampton level  and the output pumps up a bit further, but even so, it would surely be a struggle. Or was there some sort of intermediate pump?

The pump I think is below the top lock, so that would just do it, but it does seem a strange arrangement when you think about it.

[Captain Pegg]

1 minute ago, john6767 said:

Normally pumps push the water up a pipe in the ground, as pushing rather than sucking avoids any possibility of cavitation.  I doubt that there is a culvert level with the bottom of the locks and then a vertical pipe to the pump.

I am thinking about the technology of the 1800s though not how it might be done today. The pump house is at the top and it would have had a beam engine. It appears it didn't push water up a pipe longitudinally.

[nicknorman]

5 minutes ago, john6767 said:

Normally pumps push the water up a pipe in the ground, as pushing rather than sucking avoids any possibility of cavitation.  I doubt that there is a culvert level with the bottom of the locks and then a vertical pipe to the pump.

The pump I think is below the top lock, so that would just do it, but it does seem a strange arrangement when you think about it.

I wonder if its a pressure thing - ability of the pipe to contain pressurised water. With sucking, the absolute maximum pressure differential between inside and outside is 1 bar. With blowing, although you only need 1 bar to overcome the same height, with the stopping and starting of the water flow the pressure peaks will be more than that. Probably not by a huge amount though.

[TheBiscuits]

I have often wondered why the canal builders did not use either wind or water powered pumps.

Using the water itself to do the back-pumping with a ram pump would seem to make sense, or a wind-pump at the top of a flight.

For that matter I wonder why CRT don't fit some themselves!

[john6767]

7 minutes ago, TheBiscuits said:

I have often wondered why the canal builders did not use either wind or water powered pumps.

Using the water itself to do the back-pumping with a ram pump would seem to make sense, or a wind-pump at the top of a flight.

For that matter I wonder why CRT don't fit some themselves!

You mean like perpetual motion   I think you need to patent that idea

[john6767]

15 minutes ago, nicknorman said:

I wonder if its a pressure thing - ability of the pipe to contain pressurised water. With sucking, the absolute maximum pressure differential between inside and outside is 1 bar. With blowing, although you only need 1 bar to overcome the same height, with the stopping and starting of the water flow the pressure peaks will be more than that. Probably not by a huge amount though.

If you have a pump that is sucking you have to think about how it gets primed as well.

[TheBiscuits]

22 minutes ago, TheBiscuits said:

I have often wondered why the canal builders did not use either wind or water powered pumps.

Using the water itself to do the back-pumping with a ram pump would seem to make sense, or a wind-pump at the top of a flight.

For that matter I wonder why CRT don't fit some themselves!

 

13 minutes ago, john6767 said:

You mean like perpetual motion   I think you need to patent that idea

No, I did specify a ram pump.  They use the energy in the flow of moving water to pump some of the water higher. 

It's not magic or perpetual motion - they can only pump about 20% of the flow through them.

 

[RLWP]

Without actually doing some research, the beam engine probably used to have a pressure pump at the bottom of a deep well shaft

I suspect you couldn't suck the water to the top. one atmosphere is only 33 foot of water

Richard

[Victor Vectis]

19 hours ago, Captain Pegg said:

I believe Oldbury locks have a back pumping system which is why putting 40+ boats through them in about 8 hours on the Sunday of last year's Challenge worked fine. It should be able to cope with the arrivals for the rally on the Friday and be ready for the Sunday of the Challenge.

JP

The pumps were running on the Sunday when we arrived but not on the Monday when a lot boats were leavng.

We moored up by the railway bridge. Fine on Sunday but by the time we pushed off on the Monday we were bumping the botton. I was a bit concerned that there would be enough water to get to the winding 'ole and back without getting stuck.

9 hours ago, Dave_P said:

Would anyone be willing to take on the management of the BCNChallenge twitter account this year?  I don't mind having it back next year if nobody wants the permanent responsibility.  Otherwise I'll try to do what I can in terms of re-tweeting each boat's progress but I may have signal issues when down in the glens.

What is this 'Twitter' of which you speak?

[Captain Pegg]

55 minutes ago, RLWP said:

Without actually doing some research, the beam engine probably used to have a pressure pump at the bottom of a deep well shaft

Richard

Those were my thoughts in terms of the construction but I take it you mean it was groundwater being pumped to replenish the upper level? Obviously the shaft would still be several hundred metres away from the lower pound hence my suggestion of a low level connection. I think your explanation is more likely.

I was thinking of how the Severn and Mersey rail tunnels are pumped vertically from the bottom of deep shafts into which water is collected via independent drainage culverts. Different scenario there though as the source of the water being pumped very much matters.

JP

[matty40s]

Car parking at Titford, how much available, is it free, safe??