Why the displacement difference between the old '60 41 footers and the follow on 38'?

[celt]

I am a bit puzzeled. The 1966-71 41' Twin Cabin is listed at 24,500# and 1968 41' Convertable is listed as 23,000# (much lighter - 19, 500K w/gas engines and empty tanks according to a lift weight scale). Yet the 1968-74 38' convertible is listed as 29,000 lbs. That is a delta of 6,000lbs for a 3' shorter and a few inches less beam boat. The other later Hatteras' also seem on the heavy side as well. Did Hatteras start out with lighter layups and increase them as they gained more experience?

celt

 

[REBrueckner]

Why the displacement difference between the old '60 41 footers and the follow on

My 1972 Hatteras brochure shows different figures, dry weight:

38ft double cabin 25,500 lbs
38ft Convertible 22,000 lbs
42ft Convertible 26,500 lbs

From past discussions, I'm not at all sure these weights are realistic/accurate.

 

[Reelin]

My 1965 41 sportfish is 24500.

 

[Boatsb]

ARE YOU GUYS ON HELIUM?

My 1966 41C weighs in at 32,500 dry. Not just per the old paperwork but actual weight on the scales in the slings.

 

[67hat34c]

In the 60's the weight was only an estimate. They did not weigh each boat as it was made and their work on each boat did vary. For instance when the pulled a hull from the mold and it flexed, they dropped it back in and laid up more glass. Hulls from the 60's have very inconsistant hull thicknesses and weights.

Our 1967 34c with gas engines full gasoline 230g and water 70g with no equipment on board tipped the scale on the travel lift at 20k.

She is comming out next weekend so we will have a chance to weigh again, will be full fuel and water and no equipment.

 

[Reelin]

ARE YOU GUYS ON HELIUM?

My 1966 41C weighs in at 32,500 dry. Not just per the old paperwork but actual weight on the scales in the slings.

Interesting, I was pretty sure my boat weighted the same, then the yard I was at doing a repower, explained the difference in weight to me.

It seems not many people understand how the load cells on the travel lifts work. They only measure the true weight when the slings are nearly straight, such as just after the boat clears the water as it is being lifted. As the boat is lifted the angle on the slings and load cell change thus the load cell becomes less accurate the higher the boat is lifted.

 

[shark 1007]

my 1968 41 with 3126 cats, 600 full fuel and tower weighed 35K on the slings 2 days ago

 

[celt]

I reread the surveyors report and he indicates the published weight to be 19,500 (what he referenced is not quoted) and the strain guage weight at the slings to be 22000 lbs - close to the 23,000 lbs quoted in the Powerboat Guide. That's a gas boat with 75 gal of fuel, empty water tanks and nothing else on board of any significance. A Detroit deisel powered boat with full fuel and water tanks would weigh considerably more. Based on the above inputs I guess we write it off to a historical mystery. I once owned a Willard Vega trawler that was built in 1963 and it was supposed to be heavily built as well but turned out not to be the case. The boats Willard built for the Navy at the time were heavy but were built to milspec.

Thanks for your input, Celt