Tidal Trent current flows

[by'eck]

Having trouble finding any typical current flow data. I would like to know in advance the speed of currents I can expect when travelling upsteam on the tidal Trent at various points between Keadby and Cromwell. I appreciate that these currents will vary with state of tide and whether spring or neap, and also be modified by the amount of fresh water flowing downstream, but some rough mean data at various points would help.

 

So far I have established that the flood lasts about 2.5 hours and that (by chance) it starts at West Stockwith at the same time as high water Hull.

 

When I studied for RYA Yachtmaster we regularly calculated such via commonly available secondary port data that allowed extrapolation/interpolation with that from the associated main port. Such data doesn't seem to exist for anywhere along this stretch of tidal Trent though.

 

I know what speed through the water my boat is capable of on rivers (only a little over 4 mph), but would like to know how well it would cope on the Trent in terms of speed over ground, how far I could get on the flood etc. Even peoples personal experience backed by state of tide would help.

[magnetman]

I have Navionics UK and Holland on my android phone which has flow speed and direction data for the Humber but it doesn't cover the Trent.

 

I don't know the area but are there any sailing clubs about which might collect data?

[nicknorman]

One our recent trip Cromwell to Torksey is all I have experienced. At Cromwell the tidal effect is minimal, there is only a foot or so level change and less during neaps. At Torksey the flood on a moderate spring with summer average fresh water is about 1.25mph. When we went down it was perhaps 1.5mph of ebb at Torksey. So as low as Torksey the tidal flow is not strong, but I'm sure it gets stronger lower down. Due to your relatively low speed I would suggest breaking the journey at Torksey (good and safe pontoon moorings) to maximise your transit on the flood. Also just to mention that there is virtually no slack water, the flow reverses very quickly (as far down as Torksey anyway).

 

We managed to stay with the flood nearly all the way from Torksey to Cromwell, losing it just in the last 30 mins or so. Most of the time we were doing over 6mph ground speed.

Edited July 29, 2015 by nicknorman

[peterboat]

On the right day you will be doing 14 mph through Gainsborough it narrows there and speeds up I have been up and down the Trent a few times and know two journeys have ever taken the same time wind tide fresh everything seems to effect it. Others who use it more frequently can give you a better idea but in September it will take us however long it takes because for me thats the Trent enjoy

 

Peter

 

edited for dicky fingers

Edited July 29, 2015 by peterboat

[Alan de Enfield]

The flow last week, on the NON-TIDAL section of Newark to Cromwell was 0.8 knots (about 1 mph) - this needs to be at least considered along with the tide. The river flow does not just 'stop' at Cromwell weir.

[by'eck]

Thanks Nick and Peter. It was just the speeds that Peter mentions I found a bit scary though. Exhilarating when they take you where you want, but less fun if they don't. Lack of suitable mooring points to break up journey doesn't help of course, especially if flood only lasts 2.5 hours with quick change to ebb.

[Naughty Cal]

Thanks Nick and Peter. It was just the speeds that Peter mentions I found a bit scary though. Exhilarating when they take you where you want, but less fun if they don't. Lack of suitable mooring points to break up journey doesn't help of course, especially if flood only lasts 2.5 hours with quick change to ebb.

If your really want to break up the journey you can stop at Gainsborough, West Stockwith, Torksey or Dunham Bridge.

[Scholar Gypsy]

There's a nice video (can't find it just now on youtube) of a narrowboat moored at Gainsbourgh when the aegir/bore went past.

 

The owner looked a little surprised.

[DHutch]

We broke our trip by drying out on a sandabnk and moving off again at 1am when the next tide came. I am told the sandbanks are fairly static and good charts are available. Its also wise not to get held for am hour for a dreger to pass and miss most of the slack water, but heyho!

[nicknorman]

Thanks Nick and Peter. It was just the speeds that Peter mentions I found a bit scary though. Exhilarating when they take you where you want, but less fun if they don't. Lack of suitable mooring points to break up journey doesn't help of course, especially if flood only lasts 2.5 hours with quick change to ebb.

But it lasts longer than 2.5 hours if you are motoring up stream.

[peterboat]

There's a nice video (can't find it just now on youtube) of a narrowboat moored at Gainsbourgh when the aegir/bore went past.

 

The owner looked a little surprised.

I have had two surprises at Gainsborough you can hear them coming in the dark like a slapping on water noise most certainly made my world move but wouldnt have missed it for the world

 

Peter

If your really want to break up the journey you can stop at Gainsborough, West Stockwith, Torksey or Dunham Bridge.

You are right we are popping into Stockwith this year.

 

Peter

Edited July 29, 2015 by peterboat

[zenataomm]

I can't help with your question, but I'm snatching the opportunity to say Cromwell to Torksey was the fastest I've ever been in a 30 ton narrow boat powered by an HA2. Having been fascinated by the swirling water I looked up and to my astonishment saw the banks were hurtling past.

 

Turning into Torksey was exciting, I'd never had to turn so early and found the sideways approach most worthy of comment. The other slightly disconcerting element of this manoeuvre was the sight of a loaded gravel barge forging its way towards me as I cut across (this was 20 years ago). His bow wave was more impressive than anything I'd ever witnessed.

I panicked as I was sideways on to him whilst aimed at Torksey cut. However I needn't have worried on this occasion as his speed over land was so slow that I was nearly into the lock chamber before his stern end had passed the cut entrance.

 

Some years later I repeated the journey in a wide beam twin screw cruiser throwing 90 hp out the back, in comparison it was quite boring really.

[by'eck]

But it lasts longer than 2.5 hours if you are motoring up stream.

 

Good point. Thanks NC re stopping points. Gainsborough is a no no due to local scum throwing stones at boats I understand. West Stockwith and Torksey sound good, Dunham also although a little far upstream.

 

Coming back to original query it seems its a very fluid (pun?) situation given all the variables. Seems like I would reach West Stockwith in as little as two hours from Keadby, even with my modest hp. Maybe Torksey in one hop wouldn't be so far out of reach.

[matty40s]

Coming up the Trent in March, on a fairly 'in between' tide, I didn't lose the flow until Dunham, and it was static most of the way from there to Cromwell.

On reaching Cromwell, the level had dropped about 2 inches from high tide.

 

Out of Keadby at 06.48

West Stockwith at 08.32

Gainsborough at 09.07

Torksey at 10.37

Dunham pontoon at 11.19

Cromwell at 13.42

Edited July 29, 2015 by matty40s

[nicknorman]

Torksey at 10.37

Dunham pontoon at 12.19

Cromwell at 13.42

Doesn't seem quite right, Torksey to Dunham = not very far, Dunham to Cromwell = a lot further.

[Tony Dunkley]

Having trouble finding any typical current flow data. I would like to know in advance the speed of currents I can expect when travelling upsteam on the tidal Trent at various points between Keadby and Cromwell. I appreciate that these currents will vary with state of tide and whether spring or neap, and also be modified by the amount of fresh water flowing downstream, but some rough mean data at various points would help.

 

So far I have established that the flood lasts about 2.5 hours and that (by chance) it starts at West Stockwith at the same time as high water Hull.

 

When I studied for RYA Yachtmaster we regularly calculated such via commonly available secondary port data that allowed extrapolation/interpolation with that from the associated main port. Such data doesn't seem to exist for anywhere along this stretch of tidal Trent though.

 

I know what speed through the water my boat is capable of on rivers (only a little over 4 mph), but would like to know how well it would cope on the Trent in terms of speed over ground, how far I could get on the flood etc. Even peoples personal experience backed by state of tide would help.

 

If your boat's top speed is really only just over 4mph then, presuming that you'll be returning downriver to Keadby, it's on the return journey that you're going to have to be very careful about the time (state of tide) of your arrival at Keadby.

Going downriver at the the usual times and state of tide that the lock keepers at Stockwith, Torksey and Cromwell send boats on their way, you may well find yourself at Keadby with the ebb running down faster than your boat's top speed, and being carried past there and unable to get into the lock after rounding up.

How soon are you setting off, and are you sure that your boat's as slow as you say?

 

Ps. I've been having a look at your boat website. The hull looks to have to have a good clean run aft to the prop and I would guess draws around 2' 8''.

With a JP2 swinging a 24''(x 22') propeller, even if it's an early 18 bhp @ 1000 rpm rather than the later 21bhp @1200 rpm. you should be getting something around twice the speed you say your're getting, in deep water on a river.

There's something not right, and either the gearbox is slipping, the reduction ratio is wrong or the engine isn't achieving it's rated rpm.

Edited July 29, 2015 by Tony Dunkley

[matty40s]

Doesn't seem quite right, Torksey to Dunham = not very far, Dunham to Cromwell = a lot further.

You are right, Dunham was in a different gallery still set at BST!!! Amended.

[nicknorman]

You are right, Dunham was in a different gallery still set at BST!!! Amended.

OK so sticking it in excel I get:

 

 

What do you reckon your speed through the water was?

[matty40s]

OK so sticking it in excel I get:Speeds.jpgWhat do you reckon your speed through the water was?

No idea, I was enjoying it too much.

 

https://youtu.be/eBZ2LrtHFCk

Edited July 29, 2015 by matty40s

[nicknorman]

No idea, I was enjoying it too much.

 

https://youtu.be/eBZ2LrtHFCk

Oh well, I see it was The Dog House so perhaps its former owner might know?

[Naughty Cal]

 

Good point. Thanks NC re stopping points. Gainsborough is a no no due to local scum throwing stones at boats I understand. West Stockwith and Torksey sound good, Dunham also although a little far upstream.

 

Coming back to original query it seems its a very fluid (pun?) situation given all the variables. Seems like I would reach West Stockwith in as little as two hours from Keadby, even with my modest hp. Maybe Torksey in one hop wouldn't be so far out of reach.

We have never had a problem when we have stayed there. We have found it to be a really quite quiet spot and only a short walk to the town centre to the shops and pubs.

[David Mack]

 

 

Going downriver at the the usual times and state of tide that the lock keepers at Stockwith, Torksey and Cromwell send boats on their way, you may well find yourself at Keadby with the ebb running down faster than your boat's top speed, and being carried past there and unable to get into the lock after rounding up.

 

When we did the trip in Fulbourne a few years back we rang the lockie at Stockwith who said the lock would be open for us, but when we got there the gates were closed, the lock was full with a boat coming down. So we had to go on past and turn. Our National DM2 (18hp @ 1000 rpm) struggled to make much headway against the ebb and we had to keep close in to the bank in the slacker water to make progress. By the time we got back to the lock entrance the departing boat was away, the lockie was indicating that we should head straight towards the upstream wingwall brickwork, but when I made the turn at the last minute we shot into the lock without touching!

[Tony Dunkley]

 

When we did the trip in Fulbourne a few years back we rang the lockie at Stockwith who said the lock would be open for us, but when we got there the gates were closed, the lock was full with a boat coming down. So we had to go on past and turn. Our National DM2 (18hp @ 1000 rpm) struggled to make much headway against the ebb and we had to keep close in to the bank in the slacker water to make progress. By the time we got back to the lock entrance the departing boat was away, the lockie was indicating that we should head straight towards the upstream wingwall brickwork, but when I made the turn at the last minute we shot into the lock without touching!

 

If that's the ex GUCCCo 'Fulbourne' then, I think, the last time I saw it was sometime in the late 1960's when I was showing the then owner how to get it back out of gear when the 'stern clutch kept jamming in . If I remember right it was converted and ballasted down to a bit under what would be equivalent to about half loaded.

Even if about half loaded, with a good National and a decent blade (prop) a big Woolwich is no slouch, and the fact that you had to work it hard to get back to the lock after rounding up illustrates well the difficulties that By'Eck may find himself in, going downriver on the Trent with what he says is a much slower boat, despite having at least as much engine power, and a propeller close to the same diameter. The standard diameter for Nationals to swing in a narrowboat was around 27'' but with a lighter pitch than the 22'' that he's got, so By'Eck's boat with similar propulsive power and displacement to 'Fulbourne' should do much better than the just over 4 mph that it is doing.

Edited July 29, 2015 by Tony Dunkley

[by'eck]

 

If your boat's top speed is really only just over 4mph then, presuming that you'll be returning downriver to Keadby, it's on the return journey that you're going to have to be very careful about the time (state of tide) of your arrival at Keadby.

Going downriver at the the usual times and state of tide that the lock keepers at Stockwith, Torksey and Cromwell send boats on their way, you may well find yourself at Keadby with the ebb running down faster than your boat's top speed, and being carried past there and unable to get into the lock after rounding up.

How soon are you setting off, and are you sure that your boat's as slow as you say?

 

Ps. I've been having a look at your boat website. The hull looks to have to have a good clean run aft to the prop and I would guess draws around 2' 8''.

With a JP2 swinging a 24''(x 22') propeller, even if it's an early 18 bhp @ 1000 rpm rather than the later 21bhp @1200 rpm. you should be getting something around twice the speed you say your're getting, in deep water on a river.

There's something not right, and either the gearbox is slipping, the reduction ratio is wrong or the engine isn't achieving it's rated rpm.

 

Hi Tony - my boats draught is a good 33 inches despite builders more modest claims, and probably down to the 15mm base plate. The JP2M powers a couple of large alternators as well, so unless batteries are near fully charged it would struggle to achieve max power revs, especially as its a 1200 rpm marine version. Maybe I'm being over cautious but given the relatively large prop I doubt it would achieve much more than 900 rpm with its 2:1 reduction even without alt load. Close to this I have achieved over 5 mph with a slight downstream flow. On the tidal Thames well over 6 mph on the flood to Teddington. I was deliberately under estimating speed through water to give myself a cushion should an extreeme situation arise. Maybe 4 mph was a tad pessimistic though.

 

Many thanks to Matty for the timings and to Nick for interpretation of same - they help me a great deal.

 

ETA: I won't be heading back downstream to Keadby (this year at least) so hopefully there won't be the issues you allude to. This considered journey is to avoid the Calder & Hebble/Rochdale part of the northern ring I hoped to complete. A scare in a triple staircase lock shortly before Leeds, despite five C&RT lockies being present, has increased my caution. Add in 60 feet length, 33" draught, shallow pounds etc.!

Edited July 29, 2015 by by'eck

[Scholar Gypsy]

This chart (dating from the 1970s) deludes me into thinking I understand what is going on...