How to calculate a boats displacement weight to tonnage

[Alan&sue]

Hi all

It's me again impatient Annie

 

This might seem like a silly question to some but here goes:)

The boats displacement weight is listed as 4. 686kg (10,333 Ibs) ) so how do we convert this to tons for transportation?

 

Mmm must admit I'm not much good at metric

Thanks

Sue x

[Paul C]

Its the same thing, isn't it? Whether the displacement weight is the "empty" boat, and you have additional items in the boat which will also need to be added to the weight, I don't know - though I suspect you'd have to add it in. Things like freestanding furniture, cutlery/crockery, electrical equipment, clothes, personal belongings, bedding, windlasses, ropes, water/fuel/oil, spares, tools, etc etc could add up to quite a significant amount.

Edited June 1, 2014 by Paul C

[bizzard]

1 metric ton=1,000 kg.

[NickF]

you put 4.686kg, I guess you mean 4,686kg in which case it weighs just over 4.5 tons (4.686 to be precise) , I take it it is not a full size steel narrowboat then!

[Alan de Enfield]

Four Tonnes is not a lot.

We had a 30ft x 12 ft fibregalss boat that weighed over 7 tonnes.

Apparently our 45 foot narrow boat weighs 13 tonnes.

[bizzard]

A simple but a bit of a long winded method to calculate your boats gross weight is to wait until your due in dry dock. Actually there are two ways of doin it. (Going in or coming out). When you've finished painting and all and are coming out.= You can get the dock operator to halt filling the dock immediately the water level reaches your base plate and from then on you carry on filling the dock with cups of water of a known weight, (keeping a tally of em all in case you lose count and have to begin all over again), until the moment arrives when you boat just begins to float and STOP!!! Add up the weight of all your cupfuls of water it took to float your boat and you have your displacement weight. This simple procedure can also be executed the other way round when emptying the dock, by emptying it with the trusty cup. The moment your boat touches the the bottom and ceases to float anymore, STOP! and finish off with the cup until the base plate is exposed and count up all the cupfuls again.

If a sunny day add a few cupfuls to your tally to account for evaporation.

Hope this helps.

[Alan&sue]

Hi all

It's me again impatient Annie

This might seem like a silly question to some but here goes:)

The boats displacement weight is listed as 4. 686kg (10,333 Ibs) ) so how do we convert this to tons for transportation?

Mmm must admit I'm not much good at metric

Thanks

Sue x

Mmmm maybe that dot should be a comma 4,686kg and the boat is 30ft x 8.6ft widebeam

 

Sue x

[John Williamson 1955]

So about 9 metres by 2.75 metres, which is probably no more than 22 square metres, allowing for the swim at each end. (Being generous to allow for crane tolerances)

 

Do you know what the draft is? Each metre of draft is 22 ton(nes), roughly, for the size of boat you give, so if your boat draws 18 inches, then the weight for lifting will be about 11 tonnes, so you'd need a crane capable of lifting at least 15 tonnes at whatever distance the lift is happening. If she draws a metre (Or 3 feet,near enough), then she'll weigh about 22 ton(nes). I've assumed a flat bottom, a V bottom will decrease the weight by between a bit and a lot, depending on how deep the V is.

 

If you want an accurate answer, you need to work out the exact area she occupies on the water, and the exact draft and profile of the hull, below water then use the volume below the waterline to work out the actual weight.

 

If she's a seagoing boat, then the registered weight is not the same as the actual weight, as it's worked out by the volume of the hull and (part of the) upper works, then making an assumption which is the same for all boats/ ships.

[jelunga]

Mmmm maybe that dot should be a comma 4,686kg and the boat is 30ft x 8.6ft widebeam

 

Sue x

Very very rough calc gives you 18tonnes displacement at least

[bottle]

I think there may be a one missing form the 4684 it should probably be about 14686 Kg or 14.686 Metric tonnes.

 

I did start to work it out but others posted whilst trying to get my brain into gear so I won't bore you with it.

 

Any decent transport company will have some idea of what it should weigh.

 

As mentioned although the boat may weigh circa 15 tonnes, the crane will have to able to lift a lot more, especially if it has to reach a long way.

 

Could be a 50 tonne or even a 100 tonne lift crane and the ground it stands on will have to be 'solid'.

[Neil2]

Either that boat is made of seriously thin plate, aluminium, or the number's way out. A 23 foot Springer Waterbug with an outboard and 3mm plating still weighs three tons,

 

I also think there's a figure 1 missing it must weigh at least 12 tons.

 

But, Sue, why do you want to move it by road? It's going to cost a fortune and if the boat is already in the North, which I believe it is, it's a pretty straightforward journey up and over the Leeds Liverpool, A&C and the Selby canal to the Ouse.

[Alan&sue]

A simple but a bit of a long winded method to calculate your boats gross weight is to wait until your due in dry dock. Actually there are two ways of doin it. (Going in or coming out). When you've finished painting and all and are coming out.= You can get the dock operator to halt filling the dock immediately the water level reaches your base plate and from then on you carry on filling the dock with cups of water of a known weight, (keeping a tally of em all in case you lose count and have to begin all over again), until the moment arrives when you boat just begins to float and STOP!!! Add up the weight of all your cupfuls of water it took to float your boat and you have your displacement weight. This simple procedure can also be executed the other way round when emptying the dock, by emptying it with the trusty cup. The moment your boat touches the the bottom and ceases to float anymore, STOP! and finish off with the cup until the base plate is exposed and count up all the cupfuls again.

If a sunny day add a few cupfuls to your tally to account for evaporation.

Hope this helps.

Mmmm this sounds like s really good idea can I use a mug cos I haven't got any proper cups & saucer only mugs, very nice mugs I might add.

 

oh I forgot I have got some posh coffee cups & saucers only use them for special occasions, but this is a special occasion.

 

 

Sue x

[Alan&sue]

Either that boat is made of seriously thin plate, aluminium, or the number's way out. A 23 foot Springer Waterbug with an outboard and 3mm plating still weighs three tons,

 

I also think there's a figure 1 missing it must weigh at least 12 tons.

 

But, Sue, why do you want to move it by road? It's going to cost a fortune and if the boat is already in the North, which I believe it is, it's a pretty straightforward journey up and over the Leeds Liverpool, A&C and the Selby canal to the Ouse.

 

Hi

We did think about it but It would take us about 14 days according to canal planner. As we haven't had a narrowboat ( 8.6 ) oops widebeam & have no experience we thought the best option would be to transport by road to York & from there we will sail her to ripon were she will be moored.

 

Sue x

[Machpoint005]

You don't have to do the whole run in one go -- do it in bite-size long weekends, if your time is at a premium.

Regarding your lack of experience, you are not going to gain any at all if the boat goes by road!

 

The repatriation of our boat (narrow) bought dahn sarf took three long weekends, more or less 150 miles and 200 locks. A brilliant experience all round.

[Alan&sue]

You don't have to do the whole run in one go -- do it in bite-size long weekends, if your time is at a premium.

Regarding your lack of experience, you are not going to gain any at all if the boat goes by road!

 

The repatriation of our boat (narrow) bought dahn sarf took three long weekends, more or less 150 miles and 200 locks. A brilliant experience all round.

Hi

We would loved to do this but unfortunately we both work me shifts & other half works days so we don't get every week end off together.

Roll on retirement

[RLWP]

You could ask for some help here, you'll probably get someone to help you crew

 

Richard

[Alan&sue]

You could ask for some help here, you'll probably get someone to help you crew

Richard

Mmm

Seriousness thinking if someone can just move the ribble link for us lol

[RLWP]

Are you saying your boat is not capable of doing the Ribble link?

 

Richard

[luctor et emergo]

Norty Unkle Richard.

[Neil2]

Ah, so the boat's on the Lancaster canal?

[RLWP]

I'm trying to understand what the issues are here. Taking the boat by water is going to be far cheaper and lots more fun than using a lorry

 

Richard

[Alan&sue]

Are you saying your boat is not capable of doing the Ribble link?

Richard[/quote

Oops no she is more than capable, it's my sense of humour

I'm trying to understand what the issues are here. Taking the boat by water is going to be far cheaper and lots more fun than using a lorry

Richard

Totally agree it would defiantly be more fun on the water & a whole lot cheaper.

However it is a time issue, by transporting via lorry to York (naburn) we can then enjoy a couple of days on the water taking her to ripon motor boat club.

Edited June 3, 2014 by Alan&sue