Sinking a narrowboat

[jonk]

My other post was asking about how far a narrowboat could tilt before either capsizing or taking on water. It occurs to me that this is an unlikely event unless at sea or caught on the side of a lock or perhaps a centre rope too tight on a rising boat, BUT a more likely problem is the fore and aft tipping of a boat - probably because of being caught on a cill in a lock?

The new question is this then: At what angle can the boat survive before water enters? Assuming the bow is down does water first come through the bow doors? If so what about if the boat does not have bow doors, would it then be windows? If the stern is down I suppose the engine room floods first and then water enters through the rear hatch doorway?

Can anyone think of a quickly deployed method of saving such a boat from sinking?

 

John

[muddywaters]

My other post was asking about how far a narrowboat could tilt before either capsizing or taking on water. It occurs to me that this is an unlikely event unless at sea or caught on the side of a lock or perhaps a centre rope too tight on a rising boat, BUT a more likely problem is the fore and aft tipping of a boat - probably because of being caught on a cill in a lock?

The new question is this then: At what angle can the boat survive before water enters? Assuming the bow is down does water first come through the bow doors? If so what about if the boat does not have bow doors, would it then be windows? If the stern is down I suppose the engine room floods first and then water enters through the rear hatch doorway?

Can anyone think of a quickly deployed method of saving such a boat from sinking?

 

John

Bow doors, I've got this image of someone driving a car on and off a narrow boat now lol.

Seriously though I would imagine it would be down to design and possibly length of the boat, sure someone will tell me I'm wrong though lol

[tony collins]

With the possible exception of an air-cooled engine which ordinarily has a low air intake, I think you will be surprised how far a narrow boat will tilt before going over. It all depends on freeboard of course, but I think this picture illustrates my point.

Having said that once the water has started to enter the boat, I think, unless it hits the bottom, you are unlikely to be able to get the water out quicker than it is coming in. Every cumec* that enters makes the situation worse quicker than anyone can act. Witness the tragedy of the Spirit of Free Enterprise, it was the water inside the ship that caused it to capsize, not any great wave or other natural force.

 

*cumec = Cubic metre per second

 

Tony.

[mykaskin]

My other post was asking about how far a narrowboat could tilt before either capsizing or taking on water. It occurs to me that this is an unlikely event unless at sea or caught on the side of a lock or perhaps a centre rope too tight on a rising boat, BUT a more likely problem is the fore and aft tipping of a boat - probably because of being caught on a cill in a lock?

The new question is this then: At what angle can the boat survive before water enters? Assuming the bow is down does water first come through the bow doors? If so what about if the boat does not have bow doors, would it then be windows? If the stern is down I suppose the engine room floods first and then water enters through the rear hatch doorway?

Can anyone think of a quickly deployed method of saving such a boat from sinking?

 

John

 

About this far:

 

[Chris Pink]

 

 

 

To my mind that tilt is not very far at all, 15deg at most, probably nearer 10 and I don't think, intuitively, it could go much further

[bottle]

At what angle can the boat survive before water enters?

 

It will be different on every boat, it all comes down to where the first hole is that will let water on board.

[the grinch]

we used to haul the boats up with a steel chain at clubline to repaint the hull, tied onto the opposite handrail and then under the boat, we could get at least a foot of the hull out of the water this way.

[jonk]

About this far:

 

 

I see that it is moored from the centreline!

That is quite an angle.

John

 

Other posters - thanks but I was asking about tipping fore and aft as being caught on a lock cill, the other topic was on sideways tilting

 

John

Edited August 27, 2011 by jonk