Does a few inches make a difference?

[sal garfi]

Hello all,

 

I've been looking on the net at some potential GRP boat purchases (I hope to buy something before Christmas). I would want to have the ability to cruise the entire system, and there are many boats with beams of 6'10". But I have seen some at odd beam measurements, like 7'2", or 7'4". So my question is, would 4 or 6 extra inches really matter in the norrowest locks?

 

Sal

[Dave Clinton]

It would be a restriction on the areas where you can go boating. It depends on your intended cruising ground.

[1st ade]

Yes

 

To (Mis)quote Charles Dickens - "Width of Lock 7' 0, width of boat 6' 11, result; Happiness. Width of Lock 7' 0, width of boat 7' 1, result; Misery"

[Alan de Enfield]

The answer to the question is yes.

 

A 7' 2" boat will not fit in a 7' lock.

 

Also bear in mind 'height' (air draft) the roof of our GRP cruiser is 3 metres ( 9' 9") above water level, some bridges are under 8'.

[bizzard]

A 7'4'' beam boat might go in 7' wide locks if you heal it over by about 45 degs. Depends on the hull shape and coach roof width.

[sal garfi]

Thanks, and this is all interesting. The locks are really that tight? One would have thought that there would have to be some leeway. Hhmm..!

[bizzard]

A 7'4'' beam boat might go in 7' wide locks if you heal it over by about 45 degs. Depends on the hull shape and coach roof width.

If it did go in healed the problem would be keeping it healed whilst in the lock. Half a ton of cannon balls moved about might do it.

[RLWP]

Some locks are that tight. Will you be visiting them is another matter

 

Richard

[John V]

sometimes the walls are not completely straight either !!! it might be 7'3" but shaped like a banana

[Rob-M]

I saw a cruiser at Hawkesbury junction a few years ago that somebody had purchased without checking the width, on arriving at the stop lock they found out the hard way that over 7ft wide will not fit through a narrow lock.

[Starcoaster]

Is anyone else frankly amazed that this thread hasn't turned really rude yet?

[Rob-M]

Is anyone else frankly amazed that this thread hasn't turned really rude yet?

Must be your mind

[Woodstock]

Is anyone else frankly amazed that this thread hasn't turned really rude yet?

and there's me thinking of alcohol- It's the difference between a small and a large wineglass

Edited May 29, 2015 by Woodstock

[David Mack]

In practice a 7 ft 2 in boat will go almost anywhere, although 7 ft 4 in is probably pushing it a bit. But apart from a few known pinch points where boats even a fraction over 7 ft get stuck, I doubt anybody can tell you where you will and won't be able to go with a wider boat.

[RLWP]

Wasn't there a court case about selling a new boat over 6' 10" recently?

 

Richard

[Starcoaster]

The HNBC (Historic Narrowboat Owners Club) keeps a list/database of locks that are particularly narrow and boats that have come to grief in them, as well as boats that have traversed them successfully and their respective widths.

This might be worth a look.

[cuthound]

Some locks are banana shaped, so a shorter over-width boat might go through, but not a longer one.

 

To further comp!icate things, last time I went up through Hurleston bottom lock (Llangollen Canal), I was held up by an ex-working boat which couldn't go through forwards but managed to get through backwards!

[Paul C]

Some locks are banana shaped, so a shorter over-width boat might go through, but not a longer one.

 

To further comp!icate things, last time I went up through Hurleston bottom lock (Llangollen Canal), I was held up by an ex-working boat which couldn't go through forwards but managed to get through backwards!

 

Did they manage to turn in an intermediate pound? If not, its a long run to bridge 6's winding hole, which is the next available turning point!

[cuthound]

Did they manage to turn in an intermediate pound? If not, its a long run to bridge 6's winding hole, which is the next available turning point!

Yes, they must have turned in one of the intermediate pounds because the next time I saw them they were moored fa ing Llangollen just after the top lock.

[Paul C]

To answer the OP's question: YES, the few inches does make a difference, and its a risk in more ways than one:

 

1. Obviously, the boat will go no further on that canal. It only takes one lock or other pinch point to halt progress

2. Risk of damage to boat during squeeze in the lock

3. Risk of damage to lock wall during the squeeze

4. Risk of sinking the boat due to getting wedged going up, or more likely part wedged then tilting during going up or down; or being caught then releasing in a way which can create a wave in the lock which subsequently sinks the boat

5. Hold up to other traffic due to blockage in the lock

[X Alan W]

Thanks, and this is all interesting. The locks are really that tight? One would have thought that there would have to be some leeway. Hhmm..!

Some locks of the 7ft width you could have problems with a boat of 7 ft beam, that's why the 6ft 10 inch beam became more or less the norm in pleasure boat beam with modern boats

[Phil Ambrose]

Is anyone else frankly amazed that this thread hasn't turned really rude yet?

Yes, I'm surprised too.

Phil

[sal garfi]

The HNBC (Historic Narrowboat Owners Club) keeps a list/database of locks that are particularly narrow and boats that have come to grief in them, as well as boats that have traversed them successfully and their respective widths.

This might be worth a look.

This seems really helpful - Thanks!

Yes, I'm surprised too.

Phil

Me too, and I started it!

[sal garfi]

To answer the OP's question: YES, the few inches does make a difference, and its a risk in more ways than one:

 

1. Obviously, the boat will go no further on that canal. It only takes one lock or other pinch point to halt progress

2. Risk of damage to boat during squeeze in the lock

3. Risk of damage to lock wall during the squeeze

4. Risk of sinking the boat due to getting wedged going up, or more likely part wedged then tilting during going up or down; or being caught then releasing in a way which can create a wave in the lock which subsequently sinks the boat

5. Hold up to other traffic due to blockage in the lock

What a shame, 'cos there was one boat that I was interested in, but it's 7'2", and I hate to have to curtail a journey just for 4". Such is life...

[Arthur Brown]

Finding out that your boat doesn't fit isn't usually simple as it may hang on the odd brick in the lock wall. If you enter high and hang on a brick then you may tilt alarmingly and possibly sink one end first. If you enter low and rise to a protruding brick then you could hang downwards and still tilt endwards alarmingly and sink.

 

If a boat is over 6ft10ins then assume it's a wide beam and cruise accordingly. If boat and lock are long then a banana shaped boat and a banana shaped lock could be fine one way round but disastrous the other.

 

A boat full of water is worth almost nothing less the cost of the recovery crane.