Design Weight vs. Actual Weight..

[paul77]

Not sure if this is the right forum, but wasn't sure Sailboat design was right either. Mods please move as appropriate.

So we just unloaded our 1997 Hylas 46 from the truck this morning after completing the voyage across the country. I just used the rough design number on the bill of lading since I didn't know the real weight, so rounded it to 28,000.

The trucker commented that the boat had definitely felt heavier than 28,000lbs on the way, and based on his scales readings seemed 10k higher. He weighed his empty truck on his way out of seattle, and compared the two. He called me back to tell me the actual weight was 38,000lbs!

I emptied the water tanks before shipping.. I'm not sure how much diesel was in there. The boat had all the owners old gear on it, but I would really not say it was loaded for cruising. Is this difference typical? The surveyor had commented the boat had a lot of bottom paint, maybe that's helping?

[Giulietta]

Paul, in its life a boat can "soak" up to 20% its weight in water...(this number I heard once was up to 25%...so don't quote me on that.

Second the design weight is normally dry weight without sails, a real heavy thing, and empty tanks.

Also not accounted is the wight of dishes, cushions etc.

But a 10.000lb extra is too much...and even 30 paint jobs wouldn't weigh that much.

Granted the boat will get heavier, but could be that the trucks sacle is off by a few 1000's???

Alos, some manufacturers weights are empty without any ropes on and no sails on, no biminis, no anchor, no dodger...just hull and mast. No electronics either.

I remove around 1200 lbs of stuff of my boat every year.

[max-on]

Originally Posted by Giulietta

Paul, in its life a boat can "soak" up to 20% its weight in water...(this number I heard once was up to 25%...so don't quote me on that.

Really??? WOW!! Giu, is that the fiberglass soaking-up water?? If a boat is out of the water 6 mo of the year, does it evaporate out??


I cannot resist, Giu, during its life, do American designed boats gain more weight than European designed boats??

[Faster]

Ten thousand pounds does seem excessive vs a design of 28,000. What is a bit troublesome is that I would think that highway truck scales are required to be fairly accurate, certainly better than 30%(!)...

It seems that anytime someone "weighs" a cruising boat it comes out heavy - e.g. travel lift numbers never seem to match expectations.

[blt2ski]

I go across several different scales here rather frequently in the Seattle area, rarely am I off more than 200 lbs one way or the other, most likely cause is 30-50 gal swing in diesel in the two trucks I drive across the scales.

So I doubt the scales are that far off. Along with most truckers, myself included, generally know who much there truck/truck and trailer weigh with in a small variance as mine are.

I think Alex hit the majority of the reasons you are if true, 10K lbs over. Then again, look in the bilge, maybe some rain water or equal got in there along with way, a lot of fuel...........major number of ropes hidden in a storage area you did not remove............

marty

[Giulietta]

Originally Posted by max-on

Really??? WOW!! Giu, is that the fiberglass soaking-up water?? If a boat is out of the water 6 mo of the year, does it evaporate out??


I cannot resist, Giu, during its life, do American designed boats gain more weight than European designed boats??

I have a friend that is the editos for a magazine here, and one of the articles he had was on blisters...

I will contact hin, to find out the exact number, but I am sure Acrdiacpaul can confirm the number.

Alex

[donradclife]

Klondike (Beneteau First 456) is loaded for cruising, but the weight on the load cells on various travelifts has been 33,000 to 36,000 pounds versus a design weight of 26,000.

A few hundred pounds here and there for sails, anchors, chain, fuel, tools, books, paint, beer, dinghy, outboards, lines, food, clothes, souvenirs, absorbed water...it really adds up fast.

[sailingdog]

The displacement often neglects the equipment and gear necessary for cruising. As donradclife points out, there's a lot on a fully fitted out cruising boat that will boost the numbers quite a bit.

[GeorgeB]

It wouldn’t be the first time a builder used a stripped down boat to determine their weight measurement. No builder wants their vessel to appear as a “lead sled” in the specs no matter how true it really is. My last two boats both came in at a couple thousand pounds over their design weight. A fellow sailor who owned the same 28’ knew the true weight of the boat and was able to successfully appeal his PHRF rating (his was the first of it’s class to get rated here in Nor Cal). I believe that the C30’s also have a more accurate weight in their PHRF measurement which gives them their (sandbagged) rating of 180 here in San Francisco.

[Giulietta]

Originally Posted by max-on

I cannot resist, Giu, during its life, do American designed boats gain more weight than European designed boats??

Hey you edited it, so I missed it..

Actually since we don't haul our boats in winter (except the Nordics), our boats spend more time in the water, absorbing more.

Also, judging by the time some members are here, their boats might be pretty dry...