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Boating On Rivers - Reminder of the Dangers


Alan de Enfield

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I'd second this. Turning into the Erewash, coming downstream on the Trent, with a wind blowing counts as one of my least favourite boating experiences. I'd be tempted to continue into the Cranfleet Cut, find somewhere to turn round and approach it that way if doing it again.

 

You leave me almost lost for words !

 

Turning downriver into the Erewash from the Trent is no different from turning into any other side lock or cut elsewhere.

If there's a lot of fresh in the river you simply round-up in plenty of time, drop down stern first until you're outside the canal entrance, assessing the speed and effect of the current on the boat as you're doing it, and then turn into the canal. The prevailing wind there does blow towards the canal entrance, so if it happens to be blowing strongly at the time, it will be sending you where you want to go anyway.

 

What could be easier?

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You leave me almost lost for words !

 

Turning downriver into the Erewash from the Trent is no different from turning into any other side lock or cut elsewhere.

If there's a lot of fresh in the river you simply round-up in plenty of time, drop down stern first until you're outside the canal entrance, assessing the speed and effect of the current on the boat as you're doing it, and then turn into the canal. The prevailing wind there does blow towards the canal entrance, so if it happens to be blowing strongly at the time, it will be sending you where you want to go anyway.

 

What could be easier?

That did indeed seem to be a very over elaborate way of making that particular turn. Besides the entrance to the Erewash is quite wide meaning you have a better chance of turning into it even if you do misjudge it slightly.

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That did indeed seem to be a very over elaborate way of making that particular turn. Besides the entrance to the Erewash is quite wide meaning you have a better chance of turning into it even if you do misjudge it slightly.

 

Not only over elaborate, but not very practical either.

Cranfleet Cut isn't much wider for it's entire length than the entrance to the Erewash. Unless you had a fairly short boat, you would have to pen down Cranfleet lock, swing in the river below, and then come back up it again.

That's an awful lot of farting about, just to avoid rounding up in a stretch of river that must be around 150' wide, and then quite possibly having to work a lock twice to swing round in a bit wider part of the river below it.

Edited by Tony Dunkley
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Could we not simply agree that it's a lot easier to manoeuvre into the stream or prevailing wind than to make the same manoeuvre when being carried headlong by these highly variable elements? I.e. Turning 90° in a boat can often be better achieved by doing a 270° instead.

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Could we not simply agree that it's a lot easier to manoeuvre into the stream or prevailing wind than to make the same manoeuvre when being carried headlong by these highly variable elements? I.e. Turning 90° in a boat can often be better achieved by doing a 270° instead.

 

Well, obviously I'm going to agree with that in principle, but not entirely with the angular arithmetic. It isn't me you need to convince though, there are a couple of folks a bit further back in the thread who seem to think differently.

Edited by Tony Dunkley
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Rivers Can Be dangerous Places.

 

I am surprised that this has not been reported previously but the details are now starting to emerge.

 

A ‘few times’ hirer of NBs decided to buy one for themselves, a mooring was secured in a Marina.,

After a short time it was decided that the Marina was like a ‘Council estate’ and not what was wanted. So they booked into a Marina on the River Trent.

 

8th Feb 2016

 

Leaving the canals via ‘Meadow Lane Lock’ they joined the Trent ...

 

Hi Alan, is it possible that it was Feb 9th or are we looking at potentially two incidents: http://www.notts-fire.gov.uk/56F0DD1E303641428C6B7D192A77B39A.asp

 

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

 

Thanks for the info as I had heard nothing.

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Well, obviously I'm going to agree with that in principle, but not entirely with the angular arithmetic. It isn't me you need to convince though, there are a couple of folks a bit further back in the thread who seem to think differently.

I was just a bit surprised that you shot Richard F down in flames. I read his entry as meaning he'd had a bad experience due to the elements and not handling the manoeuvre well, but that he'd thought it through afterwards and come up with a better plan for if he needed to do the same thing again. Whilst not as polished as your description, it contained the fundamental point of getting the boat stationary in relation to the bank and proceeding from there.

 

I often see steerers trying to leave a mooring by going ahead with their tiller bar pointed at the bank. The fact that the stern can't climb the bank to allow the boat to pivot and free the fore end seems not to occur to them. They're treating the tiller like a car's steering wheel.

 

This "aiming straight for where I want to go" approach often being a bad plan is what I was trying to get across. The entry to the Erewash when approaching from Sawley is tight and blind, so I wouldn't support MJG's "go for it, it's a big target" approach. Going past the entrance, controlling the boat and having a look at what's happening below the lock seeming pretty sensible to me.

 

As far as the arithmetic, yup, I was using it illustratively, not literally.

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Hi Alan, is it possible that it was Feb 9th or are we looking at potentially two incidents: http://www.notts-fire.gov.uk/56F0DD1E303641428C6B7D192A77B39A.asp

 

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

 

Thanks for the info as I had heard nothing.

 

Yes - sorry - mistakenly put in the 8th instead of the 9th.

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This "aiming straight for where I want to go" approach often being a bad plan is what I was trying to get across. The entry to the Erewash when approaching from Sawley is tight and blind, so I wouldn't support MJG's "go for it, it's a big target".

Which of course is not actually what I said at all.

 

I was querying the need to go into Cranfleet cut as necessary to ensure a safe entry to the Erewash. The fact it is quite wide means it is more forgiving than some other river exits if you do get it slightly wrong.

 

 

 

Edit to resolve an over enthusiastic autocorrect.

 

..

Edited by MJG
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I often see steerers trying to leave a mooring by going ahead with their tiller bar pointed at the bank. The fact that the stern can't climb the bank to allow the boat to pivot and free the fore end seems not to occur to them. They're treating the tiller like a car's steering wheel.

 

I've never really thought about it before but I suppose tend to treat the tiller as "this points where I want the back end of the boat to go"

 

Boat experience certainly came in handy when I had to jump on a forklift with 16 foot forks (and 20 foot long loads) with no experience (I started by practicing outdoors in wide open spaces), I picked up how to manoeuvre it straight away. When asked afterwards how I did it I said I just treated it like a boat

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I was just a bit surprised that you shot Richard F down in flames. I read his entry as meaning he'd had a bad experience due to the elements and not handling the manoeuvre well, but that he'd thought it through afterwards and come up with a better plan for if he needed to do the same thing again. Whilst not as polished as your description, it contained the fundamental point of getting the boat stationary in relation to the bank and proceeding from there.

 

Yep.

 

It's as much about familiarity with the location as anything else. Turning from a wide river, proceeding downstream, into a canal entrance isn't something that spooks me in principle - we moor at Diglis, after all. Needless to say, I ignore CRT's warning sign that tells people to continue down to the river lock, turn there, then approach from downstream. I'm familiar enough with the Severn, and with that turn, to turn in the main channel and come alongside to the pontoon in one manoeuvre.

 

But the Erewash entrance I wasn't familiar with, and certainly wasn't expecting the strong wind to push us quite so close to the wall. No-one's fault but my own, of course; but given that we do have a short boat, and it's not a location I visit regularly, I'd choose to err on the side of caution next time if the wind's up.

 

(Mind you, I'm not anticipating going up the Erewash again until either the Cromford or Derby is restored, so it's probably a bit academic...!)

Edited by Richard Fairhurst
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I often see steerers trying to leave a mooring by going ahead with their tiller bar pointed at the bank. The fact that the stern can't climb the bank to allow the boat to pivot and free the fore end seems not to occur to them. They're treating the tiller like a car's steering wheel.

 

 

I've never really thought about it before but I suppose tend to treat the tiller as "this points where I want the back end of the boat to go"

 

Boat experience certainly came in handy when I had to jump on a forklift with 16 foot forks (and 20 foot long loads) with no experience (I started by practicing outdoors in wide open spaces), I picked up how to manoeuvre it straight away. When asked afterwards how I did it I said I just treated it like a boat

 

In general, when changing direction, any boat will pivot about a point approximately one third of the waterline length back from the stem.

Differing conditions of trim [the difference in draught fore and aft] will move the position of the pivotting point. For instance, with an empty barge or [working] narrowboat ballasted down aft but drawing virtually nothing up forard the pivotting point will move aft a considerable distance, up to around almost half the waterline length from the stem.

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In general, when changing direction, any boat will pivot about a point approximately one third of the waterline length back from the stem.

Differing conditions of trim [the difference in draught fore and aft] will move the position of the pivotting point. For instance, with an empty barge or [working] narrowboat ballasted down aft but drawing virtually nothing up forard the pivotting point will move aft a considerable distance, up to around almost half the waterline length from the stem.

Do you mean forward?

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Do you mean forward?

I suspect you may have misread steM as steRN (with some fonts it can happen)

 

Stem : The curved vertical post at the foremost part of the bow of a narrowboat or canal boat into which the hull sides are welded.

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I suspect you may have misread steM as steRN (with some fonts it can happen)

 

Stem : The curved vertical post at the foremost part of the bow of a narrowboat or canal boat into which the hull sides are welded.

That's it. Small phone text.

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It's as much about familiarity with the location as anything else. Turning from a wide river, proceeding downstream, into a canal entrance isn't something that spooks me in principle - we moor at Diglis, after all. Needless to say, I ignore CRT's warning sign that tells people to continue down to the river lock, turn there, then approach from downstream. I'm familiar enough with the Severn, and with that turn, to turn in the main channel and come alongside to the pontoon in one manoeuvre.

 

But the Erewash entrance I wasn't familiar with, and certainly wasn't expecting the strong wind to push us quite so close to the wall. No-one's fault but my own, of course; but given that we do have a short boat, and it's not a location I visit regularly, I'd choose to err on the side of caution next time if the wind's up.

 

 

I was just a bit surprised that you shot Richard F down in flames. I read his entry as meaning he'd had a bad experience due to the elements and not handling the manoeuvre well, but that he'd thought it through afterwards and come up with a better plan for if he needed to do the same thing again. Whilst not as polished as your description, it contained the fundamental point of getting the boat stationary in relation to the bank and proceeding from there.

 

 

It wasn't my intention to do that, and it is apparent from his later post [above] that his usual and preferred way of entering a side lock off a river is to round up early and come to a standstill where he's going to turn in.

 

All in all, this is by far the best way of getting into any side lock that you've come downriver to, even more so if there's a downriver wind blowing and adding to the effect of the current or tide.

 

From what I've seen on video clips and from posts on this Forum, the majority of pleasure boats entering side locks like Stockwith and Keadby on the Trent, and Selby on the Ouse go flying past the lock entrance on the ebb, then round up, usually in the wrong direction by turning towards the faster current/tide side of the river instead of the slacker side, then stem the current back up to the lock before finally entering it with far too much way on and from much to far out in the river. This not the best way to go about it.

 

By sticking to that approach, folks who may already have been fairly apprehensive over what they're about to do, are just giving themselves even more of a hard time, which, can be avoided with the different approach of rounding up much sooner and dropping down stern first to the lock tail. By doing this and then bringing the boat to a standstill on the edge of the slack in the lock tail you've got the chance, and the time, to assess the effect of both current/tide and wind on the boat, and to see just what the water in the lock tail is doing, so you'll then know how it's going to affect the boat as you enter the lock, which is done with full rudder and short bursts of full power without allowing the boat to gather very much way.

 

There's always a circulating eddy round the slack in the tail of a side lock off a river, and if you get close enough to the down current/tide wall with the boat stationary and the bows level with the lock chamber, the circulation round the slack will help you to turn in by first giving the bows a considerable push into the lock and then when you're part way in, pushing the boat sideways towards the up current/tide wall. Shortish boats, up to, say, around 50' will get in cleanly without any assistance from a head spring on the down current tide wall in most conditions, but with a longer boat and/or a very strong tide or current, running against a [lengthening, or payed-out] head spring as you turn in makes a doddle of the whole manoeuvre.

Edited by Tony Dunkley
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Well put, Tony - all very helpful stuff I think.

Here's a little timelapse video showing this at Wisbech - arriving on the flood tide, turning early and then dropping back. Actually this is the only way to do it - the river is largely occupied by pontoons (see photo below), so if you turn too late you are going to hit some rather expensive plastic.

 

post-13477-0-08467400-1456379027_thumb.jpg


One place where it's tricky to follow this approach is Limehouse on the tidal Thames, arriving on the ebb. The lock is on the outside of a right hand bend, and visibility around the corner is not really good enough at the ideal turning point, given there might be a riverbus coming the other way at 25kts ....

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Well put, Tony - all very helpful stuff I think.

 

Here's a little timelapse video showing this at Wisbech - arriving on the flood tide, turning early and then dropping back. Actually this is the only way to do it - the river is largely occupied by pontoons (see photo below), so if you turn too late you are going to hit some rather expensive plastic.

 

 

attachicon.gifw08_1M.jpg

.

 

The carrying company I got my first job with after leaving school used to load timber where all those mooring pontoons are now, either from the wharf or overside from ship into narrowboats for Leicester.

Because the river is so narrow there and they had nowhere to swing except the old Wisbech Canal entrance a bit further back downriver, the coasters bringing the timber in would time their arrival for no earlier than a few minutes after HW, when the ebb was just starting to run down, and run ahead almost up to the bridge to tie up.

Leaving there, they would drop down stern first, on the first of the ebb, and put their stern into the slack in the old canal entrance, letting the ebb swing the head round.

Edited by Tony Dunkley
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Hi Alan, is it possible that it was Feb 9th or are we looking at potentially two incidents: http://www.notts-fire.gov.uk/56F0DD1E303641428C6B7D192A77B39A.asp

 

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

 

Thanks for the info as I had heard nothing.

 

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.

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The carrying company I got my first job with after leaving school used to load timber where all those mooring pontoons are now, either from the wharf or overside from ship into narrowboats for Leicester.

Because the river is so narrow there and they had nowhere to swing except the old Wisbech Canal entrance a bit further back downriver, the coasters bringing the timber in would time their arrival for no earlier than a few minutes after HW, when the ebb was just starting to run down, and run ahead almost up to the bridge to tie up.

Leaving there, they would drop down stern first, on the first of the ebb, and put their stern into the slack in the old canal entrance, letting the ebb swing the head round.

 

Here's the current place where ships turn - I imagine that's where you are talking about...

 

dscf6248.jpg

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In general, when changing direction, any boat will pivot about a point approximately one third of the waterline length back from the stem.

Differing conditions of trim [the difference in draught fore and aft] will move the position of the pivotting point. For instance, with an empty barge or [working] narrowboat ballasted down aft but drawing virtually nothing up forard the pivotting point will move aft a considerable distance, up to around almost half the waterline length from the stem.

 

One of the main factors in the position of a boat's pivot point will be its speed in forward or astern.

 

http://principlesofshiphandling.blogspot.com.es/p/pivot-point.html

 

I'm not sure why the article uses the term CG in the first diagram?

Edited by blackrose
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One of the main factors in the position of a boat's pivot point will be its speed in forward or astern.

 

http://principlesofshiphandling.blogspot.com.es/p/pivot-point.html

 

I'm not sure why the article uses the term CG in the first diagram?

 

Yes, at ship speeds there is more effect on the longitudinal position of the pivot point than at the sort of speeds achieved by canalboats and river barges.

I don't understand why they've shown an arbitrary position for C of G in isolation in only one diagram either, an estimated position for the centre of transverse lateral resistance, which is closely related to trim and the longitudinal position of the C of G would have made more sense.

Edited by Tony Dunkley
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Here's the current place where ships turn - I imagine that's where you are talking about...

 

dscf6248.jpg

 

Yes, that's going to be the old canal entrance, Simon, . . . it's port side inbound, the best part of a mile from the town bridge.

It's been strengthened and tidied up a lot since those days though. I'm pretty sure the banks were held up with big timber piles and some timber revetting behind them, similar to the waters edge of the side-slip at Cochranes at Selby, but quite a bit higher.

Edited by Tony Dunkley
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