Total finished build weights?

BillD

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I thought this would be a good informational thread for the "novice" when it comes to building one yourself or having a DE built by a pro.

I've always wondered how a builder, either professional or owner, knows what a certain hull can handle for total weight before the hull is "a bit too heavy"?

Is all weight complied, thought out and tallied before and throughout the build?

I may be off a few lbs. but years ago I recall a 34 Calvin that came in @ 22,500 lbs. The boat was NOT fast with 500 hp.

Brian's (Powderpro) 34 Calvin build came in around 14,500 (maybe 17,500) with a QSC.

I had a good friend who had a custom blue hull sedan/flybridge 40 Young Brothers built by the "Arvin and Alvin" (2005). It was one of the last boats to come out of the YB shop, took more than three years to build. The boat was named the "Maddie B" out of Beverly Ma. From the shop the boat had a list to the port side. The owner had to add a few hundred lbs. of lead to the starboard for ballast.

Beautiful boat, all custom interior wood, heavy as hell, had a 500 Volvo, best it would cruise was 10 knots, WOT maybe 15-18 knots with little fuel and what prop it had @ the time. The finished weight was 39,000 lbs. "as weighted on a travel lift".

I'm curious if total build weights are a "science" or a "guess".
Of concern is shelling out $200K + for a new boat and have it not meet your expectations on "reasonable" speed?

Bill D
 

Blitzen

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Bill,
To a degree some of the stability calculations are done by the designer when designing the boats and its intended purpose, so a basic layout and weights are considered. Some are a given and some are approximate estimations. When you get into CG inspected and passenger carrying vessels these calculations are more in depth and tested by the CG.
I am not sure that all builders have all the detailed information; I would guess that most have a good idea and many finishers get their info from the designers or builders or not at all.
As for finished weights, I think it comes down to money, high tech light weight builds costs a lot more money and take some skill.
Then there is always stuffing 10lbs of chit in a 5lb bag.
 

F/V First Team

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Brian's (Powderpro) 34 Calvin build came in around 14,500 (maybe 17,500) with a QSC.

Bill D
Quite a spread there as far as a weight estimate. Building for lightness and building for speed sometimes are two different things. Hull shapes always help and of course differ from vessel to vessel as well as how everything is laid out. My boat weighs 15,000 before 300 gallons of fuel is added to it and I've topped out around 38 with 410 hp SisuDiesel. Last sport fish boat we did weighed 22,850 and tops out at 36 with a QSM11-670 hp. Pretty impressive speeds for boats that weren't built light.
 

Powderpro

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Bill- I wish I knew exactly what my 34' Calvin weighed at sea trial, but the only thing I have is a guesstimate. I will say one thing that helped keep my weight lower was the fact that the hull was layed up thinner than the other DE boats I have personally seen. I even had Stewart more or less apologize to me (even though I bought my CB 34 before he owned the molds), because he felt the lay up was too thin when Lessard was doing the lay ups. Stewart promised if I bought another Calvin Beal hull, the layup would be thicker and better quality. Two thumbs up to Stewart for his quality of work. But the way I design and build my boat for MY USE, I thought the lay-up for my Calvin was adequate. To Stewarts dismay, I told him if I bought another Calvin hull from him, I would want it thinner like Lessard layed mine up. Stewart probably thinks I'm a knuckle head for wanting such a thin hull, but the thinner hull works beautifully for my use and design. I have so many compartments (fish holds) and bulkheads, my boat is reinforced way more than the average DE boat. When my 34 Calvin was done, it was a very rigid boat, but also very light. I used 1/2" marine plywood for every bulkhead, and 5/8" for my decks. That is less material than what most or all builders use, but because of the way the boat is put together with all it's fish holds, I think it's a rigid boat. As I said earlier, my boat probably weighed around 14,500 pounds at sea trial with no fuel weight added in. But it wasn't completely finished yet, and would have probably weighed another 2,500 - 3,000 pounds after all my gear was put on the boat. At sea trial it did 33 mph with 500 hp QSC. We pumped approx. 7,000 lbs of water into the front 2 fish holds and it slowed down to 31 mph. Then we pumped another 7,000 lbs of water into the rear 2 fish holds, and the boat topped out at around 19 mph? I think...
 

Powderpro

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Another weight saver on my 34 CB was the 1/8" thick diamond plate hatch covers (reinforced on the bottom side) that made up 75% of my back deck. The aluminum weighed much less than if the entire back deck were built with plywood, glass, and gelcoat.

We stick built the entire top and wash rails. It was a bare hull when we picked it up.

Very clean and small wake.

This boat did not have lifting rails, which would probably have added 1 or 2 mph perhaps?? Also, it only had a 26" prop because everyone said that's all that would fit under there. Once I got the hull, I realized I could have put a 28" prop in there, which may have helped with speed, at least at cruise.

DSCN3064.jpg

DSCN3105.jpg
 

GoodChance

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The 35 Duffy weighed 17,500 according to the marina's travel-lift scale while full of 200-gal fuel. But I think this weight was a bit high. I think the actual was closer to 14-15k based upon comparision to other similiar-built 35 Duffy's.

IMG_1077.jpg
 
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BillD

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So far I "guess" the exact science for tracking weight of materials going into a build is not computer based cad/cam science.

More experience based and buying a hull that REALLY has to be overbuilt weight wise to "slow it down" or make the boat unstable.

Brain, I noticed you comments about "component support" when you built the 34 Calvin.

The WESMAC build (I hope to have progress update pics this weekend) is being built as 1 piece integrated puzzle. Like an aircraft wing sort of speak.

Each composite piece fabricated/glassed to build tanks, bulkheads, deck supports etc.etc. serves a structural purpose.
 

Eastporter

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Are the aluminum hatches watertight? They look to have a gap where water would get into the bilge.
 

Powderpro

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Are the aluminum hatches watertight? They look to have a gap where water would get into the bilge.
Hatches are water tight, they have a 1.75" deep lip around the edges, just like the top of a shoe box. Even if water could get in there (it doesn't), the fish holds are separate from the bilge, so no water in the bilge. My bilges are bone dry with the PSS (packless shaft seal).

Here is a pic of my last boat and how the fish holds are layed out. This obviously isn't a Calvin Beal, but same design and layout. Totally and completely different than your lobster fishing boat or lobster yacht.

DSCN6878.jpg
 

Eastporter

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I like the design- thanks for the reply.
 

cb34

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weight

I think most owners would be very surprized at how much their boat weighs if they put it on a scale. My 34 was heavy 22,500.00 totally loaded but still ran 24kts w/500hp. The same hull 5-7000 lbs lighter only runs at best a few kts more and in several cases the same top end. I agree, hull design is the major factor when looking for speed. Depends upon what is important, all hulls as well as all boats are a compromize.
 

Powderpro

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I think most owners would be very surprized at how much their boat weighs if they put it on a scale. My 34 was heavy 22,500.00 totally loaded but still ran 24kts w/500hp. The same hull 5-7000 lbs lighter only runs at best a few kts more and in several cases the same top end. I agree, hull design is the major factor when looking for speed. Depends upon what is important, all hulls as well as all boats are a compromize.
Well said. The Calvin Beals have a huge flat running surface, so they are really good at hauling weight and going through the water efficiently. Here is a pic of my 34' Calvin- lots of bottom for a 34' boat.

DSCN3068.jpg
 

petrel

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My 56' DMR w/ twin 671's and 400 gallons of fuel weighs 40,000 pounds.
 
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