Guessing a boats weight..

[DownWest]

So, have been slightly involved with an old Breton fishing boat. Dates from the 50's? and plank on frame. Had a step for a mast, but was fitted with an early Volvo Penta MD2.
We need to work out the weight to get a road legal trailer. He reckons over 1.5 Tons. Me, rather less.

So, on friday I looked in at the yard were it is currently parked and took off some girth measurments. With a length of 5 mt. That gave me 16 squ mt of planking. 16mm? Call it 20mm. Some type of pine, so used an average density and it worked out at 200kg . Framing and keel + other bits I guessed at double that, So 600kg. Engine is 220kg Stern gear, rudder, other bits?? Likely still under a ton?
Any comments?
DW

 

[waynes world]

I reckon over a ton, easy, for a trailer get a 1500kg then your covered for extra bit when needed.

 

[DownWest]

I reckon over a ton, easy, for a trailer get a 1500kg then your covered for extra bit when needed.

Hi. Yes, but trailers here are not exactly cheap. One for 1500 will be a LOT more than 1000kg.
No DIY here, and trailers over 500kg gross, have to be registered with their own number and log book. Get expensive. Regular MOT too.

 

[waynes world]

Hi. Yes, but trailers here are not exactly cheap. One for 1500 will be a LOT more than 1000kg.
No DIY here, and trailers over 500kg gross, have to be registered with their own number and log book. Get expensive. Regular MOT too.

will it be just for a one off or permanent use. If permanent then i would go for a trailer over 1000kg as once loaded with gear it will be i reckon over 1000kg easy And yes braked road trailers are mad/ money.

I cant see it be over 1500kg but still over 1000kg.

 

[penfold]

Get it weighed, no point in mucking about when legality and a large amount of cost is involved. If the yard has a crane hire or buy a load cell, if not then borrow or hire a trailer, weigh it on a weighbridge then again with the boat on. I'd be surprised if a working boat had planking less than an inch and pine from the 50s isn't like the matchwood we buy today.

 

[AntarcticPilot]

Remember that the wood will have absorbed water so the dry weight will be a significant underestimate.

 

[srm]

How often will the road trailer be used? Would it be more economic to hire a flat bed truck with a Hiab crane to move it when needed?

 

[DownWest]

Remember that the wood will have absorbed water so the dry weight will be a significant underestimate.

Yes, just trying to get a start point. It has been out of the water for a couple of years, so pretty dry.
The trailer will be just for local seasonal to and fro-ing, but needs to be legal. It is a simple boat and used on the river. No 'additional kit' allowance needed for towing. I did built a yard trailer for a boat they also had at 4.5 tonne and that travelled a km or two on public roads. Not keen on that now.

How often will the road trailer be used? Would it be more economic to hire a flat bed truck with a Hiab crane to move it when needed?

It will live on the trailer out of season, as previously it was causing headaches when left in the water all year. I built a 'yard' trailer for it, but they moved and no longer can store it by the slip. Has to go by road. Flatbeds and hiabs, not convenient at either the slip or the new storage.
Looks like I might be able to borrow a trailer and weigh her at my local steel supplier.