Red boards at Beeston lock

[Alway Swilby]

We came up from Beeston to Cranfleet on the Trent today. Above Beeston lock the guage board was showing red (but we carried on anyway). At the other end of the same pound (or is it a reach on a river?) the guage below Cranfleet lock was showing green. I presume it's the Beeston board that isn't placed correctly.

[Tony Dunkley]

We came up from Beeston to Cranfleet on the Trent today. Above Beeston lock the guage board was showing red (but we carried on anyway). At the other end of the same pound (or is it a reach on a river?) the guage below Cranfleet lock was showing green. I presume it's the Beeston board that isn't placed correctly.

 

You would be nearer the mark if you said they were probably both wrong, and the same would apply to most of these river level boards all along the Trent.

I posted the below reply [my post #120] to this post on the "Boating On Rivers - Reminder of the Dangers" topic yesterday:~

 

Rob@BSSOffice, on 23 Feb 2016 - 11:07 PM, said:

Hi Alan, is it possible that it was Feb 9th or are we looking at potentially two incidents: http://www.notts-fir...D192A77B39A.asp

I suspect it one, but I thought I'd better check.

Thanks for the info as I had heard nothing.

__________________________________

My reply:~

If the Boat Safety Scheme includes navigational hazards and safety in it's remit, then there are locations on the Trent requiring your attention where there are useless or misleading river level indicator boards which can lead boaters into believing that flooding and rates of flow are much less severe than they actually are.

Edited February 26, 2016 by Tony Dunkley

[bassplayer]

When we did that bit 2 years ago we couldn't find the red board at Beeston. When we crawled to Cranfleet the board there showed we were 4-5ft into the red!

 

Another boater we met there had done exactly the same.

 

There's a bottle neck in the river just before Cranfleet lock where the current was very strong. We thought about turning back when we realised we were nearlly flat out and moving about half a knot. The lockie said we did the right thing struggling on because we would have ended up flying back down the river sideways.

 

Moral of the story, if you cant see the red board there might be a reason for it...

[Tony Dunkley]

When we did that bit 2 years ago we couldn't find the red board at Beeston. When we crawled to Cranfleet the board there showed we were 4-5ft into the red!

 

Another boater we met there had done exactly the same.

 

There's a bottle neck in the river just before Cranfleet lock where the current was very strong. We thought about turning back when we realised we were nearlly flat out and moving about half a knot. The lockie said we did the right thing struggling on because we would have ended up flying back down the river sideways.

 

Moral of the story, if you cant see the red board there might be a reason for it...

 

I know where you mean, it's called Thrumpton Nip, and the current does whistle through it a bit sharpish if there's a lot of fresh in the river.

If there was 4'-5' on lowside at Cranfleet, the river would be about half that amount above normal at Beeston Lock.

[bassplayer]

 

 

If there was 4'-5' on lowside at Cranfleet, the river would be about half that amount above normal at Beeston Lock.

That's interesting Tony. So is that just the river surge causing the difference? Or is there a problem with the board accuracy?

[Tony Dunkley]

That's interesting Tony. So is that just the river surge causing the difference? Or is there a problem with the board accuracy?

 

It's just the normal pattern of water levels and movement on flooded rivers.

Whenever a river is above normal levels, the rise in water level below a weir is approximately twice the rise in water level above it.

That's not to say there isn't a problem with the boards though, . . . both the ones for indicating river level, and the one masquerading as a navigation authority.

[Mrs Trackman]

Some suggest the nip is the reason for the difference in the boards. The lockie at Beeston has told me the board is wrong even when Beeston is on red-would be interesting to know the view the insurance companies would take if your boat sank. There is a depth gauge at beeston if you know where to look for it-its not at the lock-but the bottom of that is broken off and in any case there is no indication as to which level is correct.

[Keeping Up]

 

It's just the normal pattern of water levels and movement on flooded rivers.

Whenever a river is above normal levels, the rise in water level below a weir is approximately twice the rise in water level above it.

That's not to say there isn't a problem with the boards though, . . . both the ones for indicating river level, and the one masquerading as a navigation authority.

Surely that's the point here. At Beeston the marker ABOVE the lock had risen into the red, but BELOW Cranfleet it was still in the green. Even the rise that is caused by the Nip had not elevated the water at Cranfleet significantly so how could the board at Cranfleet be correct?

[Tony Dunkley]

Some suggest the nip is the reason for the difference in the boards. The lockie at Beeston has told me the board is wrong even when Beeston is on red-would be interesting to know the view the insurance companies would take if your boat sank. There is a depth gauge at beeston if you know where to look for it-its not at the lock-but the bottom of that is broken off and in any case there is no indication as to which level is correct.

 

It isn't Thrumpton Nip that's the cause, it's the significant variation in river level and flow due to the varying demands of the Hydro-Electric plant in Beeston weir, and the weir cill being raised to provide a better head of water for the Hydro plant.

Surely that's the point here. At Beeston the marker ABOVE the lock had risen into the red, but BELOW Cranfleet it was still in the green. Even the rise that is caused by the Nip had not elevated the water at Cranfleet significantly so how could the board at Cranfleet be correct?

 

Yes, as I've already said, the indicator boards along the Trent are all to cock.

[Alway Swilby]

Yes, we did have to up the revs a bit coming round the bend at Thrumpton.

I also noticed the unmarked posts near there sticking up just to port of the centre. Ok for us going upstream but I did think that going downstream you might not see these with time to manoeuvre away from them.

[Tony Dunkley]

Yes, we did have to up the revs a bit coming round the bend at Thrumpton.

I also noticed the unmarked posts near there sticking up just to port of the centre. Ok for us going upstream but I did think that going downstream you might not see these with time to manoeuvre away from them.

 

With the river at normal levels, or even with just a couple of feet or so on, it's not just the two posts you need to avoid.

The posts are two lengths of Larssen pile set in a stoneheap on Thrumpton shoal and in normal, or near normal level conditions you would either ground on the shoal or hit the stones before you got anywhere near the piles.

The deepest water there is about one third of the river's width out from the western bank, and much closer still past Thrumpton Ferry to about a quarter of a mile below Cranfleet Lock.