boat weight

[nicandanna]

Hiya can any one tell me the aproximate weight of a 50 ft and a 70 ft narrow boat please??? am trying to organise it to be lifted and transported and want to see if it is possible to do it with a hiab truck.

thanks kind regards

Nic

[Gary Peacock]

Hiya can any one tell me the aproximate weight of a 50 ft and a 70 ft narrow boat please??? am trying to organise it to be lifted and transported and want to see if it is possible to do it with a hiab truck.

thanks kind regards

Nic

 

We used to use a hiab truck but it could only lift about a 15 ton bare shell so a fitted boat is going to be fairly unlikely, also the hiab will not have any reach so lifting a boat out of or onto water would be very tricky.

[dave moore]

Hi all

This is a question difficult to answer accurately...how long is a piece of string thing... I helped crane a 65' almost fitted boat last week; the crane driver quoted 20 tons to the owner. My boat is apparently 23 tons or so (60' fully fitted), others I know will have their own experiences to add. Like Gary, I'd have thought a crane rather than a HiAb...sorry!

Cheers

Dave

[bottle]

Weight is one factor, another one is the reach of the crane.

 

A 100 ton crane may only be able to lift 20 ton at a distance.

 

The only safe way is get a specialist.

[Gary Peacock]

We messed up yesterday, the boat was thought to weigh 36 ton so the £3K of 200 ton crane should have played with it but the calculations were way out and the boat actually weighed 46 ton and the lifting rig a further 2 ton, at that the crane could not pick it up at the reach required. We did manage it but this was down to the crane ops being very corporative in working out a solution to do it.

 

Often in these situations the crane ops will simply say sorry you got the weight or lift statement wrong so sorry it's a non starter and here's your bill.

 

Edited January 31, 2009 by Gary Peacock

[nicandanna]

ok thanks all more research to be done then!

[Lady Muck]

Use a specialist boat transporting company - you need to be certain that should it go pear shaped - they have all the relevant insurance. Back of the canal mags there are ads for boat transporting companies. It isn't cheap, but you are paying for the expertise and insurance.

[bottle]

This one was used to move one fully complete narrow boat and my empty shell.

 

[Neil TNC]

Weight is one factor, another one is the reach of the crane.

 

A 100 ton crane may only be able to lift 20 ton at a distance.

 

The only safe way is get a specialist.

 

This is indeed true...and one that knows the launch site and does not want to rip you off.

Once we knew accurately the weight of Earnest (from the gauge on P&S crane - 18.5 tons), the firm we used in Ireland said the quote would be cheaper, because they could use their 20 ton crane, as the jib would be near vertical.

I thought that P&S were good, but these guys made the whole lift quick and effortless.

[Mac49]

My 50ft narrow boat was about 12.5 tonnes pretty much complete. I don't know what size the crane was but it couldn't have reached much further. The lift was done in two stages aswell.

 

Rick

[chris w]

Hiya can any one tell me the aproximate weight of a 50 ft and a 70 ft narrow boat please??? am trying to organise it to be lifted and transported and want to see if it is possible to do it with a hiab truck.

thanks kind regards

Nic

A boat will float at a draft at which the total volume that is floating equals the boat's weight. Draft will vary from boat to boat but if you take a fairly typical 2 feet draft and allowing for the fact that some of the boat's length is not actually floating (like the last few feet of the bow and the swim) then one can make some fairly realistic approximations.

 

Let's assume that 25% of the length is not actually floating and that the draft is 2 feet and we assume they are both (7') narrowboats.....

 

So for the 50' boat the volume would be 38' x 7' x 2' = 532 ft³ which will weigh around 15 tons.

 

Similarly the 70' boat will weigh 53' x 7' x 2' = 742ft³ which will weigh around 21 tons.

 

Chris

[alan_fincher]

A boat will float at a draft at which the total volume that is floating equals the boat's weight. Draft will vary from boat to boat but if you take a fairly typical 2 feet draft and allowing for the fact that some of the boat's length is not actually floating (like the last few feet of the bow and the swim) then one can make some fairly realistic approximations.

 

Let's assume that 25% of the length is not actually floating and that the draft is 2 feet and we assume they are both (7') narrowboats.....

 

So for the 50' boat the volume would be 38' x 7' x 2' = 532 ft³ which will weigh around 15 tons.

 

Similarly the 70' boat will weigh 53' x 7' x 2' = 742ft³ which will weigh around 21 tons.

 

Chris

That's erring well on the side of caution for most modern narrowboats, I'd say.

 

Most are built to 6' 10" at the top of the hull, but with a typical width across the baseplate of 6' 6", few will be over 6' 9" at waterline. So the average width of what's in the water is unlikely to exceed 6' 8".

 

So any estimate based on a 7 ft width is probably going to be of the order of 5% too high, I think, possibly even more, as a 6' 10" width probably includes the rubbing strakes.

 

Alan

[Tam & Di]

That's erring well on the side of caution for most modern narrowboats, I'd say.

 

Most are built to 6' 10" at the top of the hull, but with a typical width across the baseplate of 6' 6", few will be over 6' 9" at waterline. So the average width of what's in the water is unlikely to exceed 6' 8".

 

So any estimate based on a 7 ft width is probably going to be of the order of 5% too high, I think, possibly even more, as a 6' 10" width probably includes the rubbing strakes.

 

Alan

 

If you look at original gauging books for narrowboats you can see that the "standard" 72' x 7' boat is as near as dammit 1" to the ton. I don't know how many people have an accurate idea of their draft, but obviously you can add draft at fore end to that at the stern and divide by 2 to get the average. For a 50' boat you should get a reasonable estimate of the weight by working on it having 72/50 inches of draft for each ton weight. So if you have an average 18" draft this would mean 18 x 72/50; if you have a modern boat built with 2m wide plates on the bottom you would have to make a further adjustment.

[Tree Spirit]

Our boat is 71 ft / 25T fitted out plus weight of fuel and water.

 

But agree with previous posts, it very much depends on how close the lifting crane can get to the boat. SWL is always a factor of weight at reach.

 

My advice dont lift it - if you want to black it dry dock it - if you want to move it thats what the canals are for

 

Steve