What is the weight of a Marstrom 20 hull? Any one know?

THanks

Sorry no definate answer here.

But when looking at the all up weight of the M20 of 120 kg (108 kg in the prototype versions) I would wager that the hull weight is close somewhere between 25 kg - 30 kg a piece. Otherwise I really can't understand that the whole platform comes out at 120 kg.

If it helps I give the weight distribution of another lightweight boat.

Hull 25 kg
beams (alu + stainless strap) 12 kg (M20 all carbon but also wider and if you run the numbers than 12 kg for M20 seems about right)
Mast + fittings (alu) 15.5 kg (I expect the M20 mast to be about 16-18 kg in carbon on what I know about carbon masts)
Mainsail 7.5 kg (will be about 10 kg for the M20)
Jib 1.5 kg
Spi gear + snuffer 5 kg
Boards 4 kg (M20 may be slightly lighter but not much as the boards are much longer as well)
rudders/stocks/tiller/extension 4.5 kg (These are carbon)
Extra like blocks lines etc about 7kg - 10 kg.

This boat comes out at 107 kg fully rigged with normal stainless steel rigging etc. In order for the M20 to come out at 120 kg (Texel rating measurements) it need to gain weight somewhere. As all fittings like stays etc are carbon or lightweigght spectra/dyneema line it must be found somewhere in the mast, hull, beams and boards. If we use the prototype min weight of 108 kg than the M20 must have 25 kg hulls, If we use the 120 kg as a reference the hull weight comes close to 30 kg.

That is the best I can do. And I replied because I don't think anybody but Marstrom himself can tell you the real hull weight.

I hope this helps you in any way

Wouter

why not ask the man himself

marstrom Contacts web page

M20's hull weight is advertised at 26 Kg on the Marstrom web site. However I suppose it is somewhat higher (close to 29 Kg).
See:
http://www.marstrom.com/administration/Boats/M20/index.asp

My 5.7 hulls weigh 35kgs each

Beams are alloy (10ft) and total 15kgs including jib track.

total boat weight (carbon mast, sails etc) is 122kgs

Macca,

Can you tell us where you saved the weight ?

135 kg - 122 kg = savings of 13 kg's. That is too much savings for the mast alone, I estimate.

Apart from that it doesn't seem from your post that you replace much other stuff with carbon (like beams)

Thanks

Wouter

Beams are alloy but are actually the same weight as the original 8ft beams.

Pole is carbon and is just over 2kgs total and Boom is carbon and weight is less than 2kgs. has some mainsheet included (internal)

So Platform is 90kgs with tramp and fittings

Rig is 13kgs

Rudders are 6kgs (both)

Boards are 5kgs (both)

Boom and Pole 5kgs (including some fittings)

Plus sails

So 122kgs is all good

Macca,

If I add up your weights I get

90 + 13 + 6 + 5 + 5 = 119

I believe 90 kg for the platform is about right ; 2 * 35 + 15 + some = 85 kg + some , with some being trampoline, selftacker or jib blocks etc.

13 kg voor de whole 9.5 mtr rig is a bit low. I believe this only to be the carbon mast and fittings but not the stays and sails.

Actually my F16 mainsail weights in at 7.5 kg and the jib comes out at just over 1 kg. Together they are therefor about 10 kg's. Noticing that your sails are larger I don't expect them to be lighter than 10 kg combined. This is excluding 1.2 kg for the spi sail. You didn't include these weights in your 122 kg total so we are now at about 132 kg.

Your rudders are 5 kg together. That is where I expected them to be knowing my boards are 2.096 kg.

Rudder setup 6 kg. I trust you have the alu stocks. I expected them to be close to 5 kg but better err on the conservative side ehhh ?

Boom + pole = 5 kg sounds good.

However I'm missing the spi gear. If you have a snuffer than that will add about 1.5 kg to the total and again some 1 to 1.5 kg for the blocks and sheets. spi kit + spi sail typically come out at 4 - 5.5 kg's. Lets take 4 kg in your case as I trust you have everything in carbon.

So we have 122 kg and than we have to add about 10 kg's in mainsail and jib and 4 kg for the spi kit. All rounded down ==> total 136 kg. or about 135 kg give or take a bit

This sounds about right to me if widening the platform didn't add weight and the weight savings on the mast are lost again on the spi kit.

I estimate that you didn't loose more than 5 or 6 kg on the mast by going carbon. The spi kit would have taken up at least 4 kg of that.

Does that sound right to you ?

Main point is that mainsail and jib together weight more than 122 kg - 119 kg = 3 kg. So 122 kg is to low an estimate.

Regards,

Wouter

Snuffer is carbon hoop and soft sock so less than 1kg

rudders including stock are 6kgs for both(Same as a Tornado)

Mainsail is D4 Carbon and Battens are Marstrom hollow, total weight is less than 5kgs

Jib is the same 1kg or so

kite gear is included in the platform weight, there is only 4 blocks total for the kite (two ratchet and two turning blocks)

Mast is 13kgs including downhaul, diamonds, wires etc. basically a strengthened A class mast.