New month new topic discussion..Weight Distribution in a DE !

[BillD]

Hello ALL,

I've been wanting to discuss this topic for a while.
I've talked with builders, owners, "old DE salts" and others about weight distribution in DE hulls.
I've been told, "DEs hull weren't designed to carry weight forward of the helm bulkhead", "these hulls were designed to carry weight in the cockpit. (i.e, working lobster boats) "keep the weight out of the front of the boat and you'll be fine".
An example is the 36 BHM pic posted in another thread with 150 ea. 4 foot traps in the cockpit. Total weight= approx 7500 lbs.

Is this true? Did Calvin Beal, Royal Lowell, Ernest Libby, Spencer Lincoln, Richard Duffy, Bunker & Ellis and all the others lay the lines below the water to carry weight in the back half of the boat? Flat afts to carry weight ??

Let's start the discussion!

FWIW, Bill D

 

[googinhater]

Some boats like it up front some need it some don't but is not much up front but I'm talking a 40+ 10kn boat Bruno's like to have wait up in the bow I have fished on 3 one had 100 gallons of fuel up under the v and was a tank but took an exta 50 HP to make the same speed as not and getting your ass kicked

 

[plowin]

Take a plastic coke bottle and put some sand in the bottom of it and then put it in the water with the cap on then take a pcture of how it floats. Do the same thing again but this time put the weight in the top of the bottle and put it in the water, compare how that floats. Obvious observations and generalizations can be made. Now if you put some sand in both the bottom and the top of the bottle and then put the bottle in the water it will sit better, right? I think that generally speaking boat builders that "know" a person is going to have a lot of weight forward puts an amount of weight aft to offset that weight. Also,being very general, the first and true users of the downeast designs tended to carry all of there weight on the work deck or aft. Conversely when a lobsterman fills the trunk cabin with 5 gallon buckets of oil, boxes of lobster bands,gear or anything of the sort the weight is now in a place that it was not originally designed to be. Most of the"boat show" boats know that the cabin is going to have everything from seasick pills to KY jelly and everything in between in there so the weight is offset before it even happens. I know, not much engineering in my thinking but thats how it was explained to me.

 

[Blitzen]

Balance the weight so the running surfaces are doing what they were designed to do.
Not all boats are going to be fast where others will be, not all boats will be able to carry the weight as well as others. Boat designs are like a moment in time, designed for something specific trying to achieve the needs of a given time with given parameters.

Some will some won't and everything is a trade-off.

 

[BillD]

OK,

How bout we "rate the hulls" based on where they are best at carrying weight.

1. Weight in the forward 50% of the hull?

2. Weight in the back 50% of the hull?

3. Hulls that carry weight best 50/50 front and back ?

 

[googinhater]

Bill most de boats want to carry it aft of house and Ford the rudder

 

[F/V First Team]

KY lubricates a shaft in a pinch

Strange but true

Get your mind out of the gutter

 

[F/V First Team]

Don't forget to take the rocker into consideration in the bottom of the hull.

Chances are, if you're going to be cruising or fishing on extended trips, you'll want the majority of the weight as far aft as you can get it to help offset the weight forward. Usually fuel is set in the stern, but as you know this is usually burnt off during a trip so the other large items, generators, water/holding tanks, etc are pushed as far aft as practical as well. Sometimes aft decks are made with heavier materials as well to help offset things. Some vessels are outfitted with ballast tanks that are filled with water as the fuel burns off to help keep things in trim, but these are somewhat rare in the downeast community.

Fun times trying to get everything to balance out and keep things trimmed on their waterlines.

 

[plowin]

Travis my shaft lube is a trade secret but I will say that in a pinch spit will work.

 

[F/V First Team]

If you assemble your dripless seal with KY and leave it for an extended period of time, you might just find it stuck. Then you need to grab onto it with both hands and twist it hard to get it to loosen up enough to rotate freely.

Not sure how much spit you'd need for that one...

Dawn seems the best for assembly, you can leave it for months and it's ready to go. Plus Apple Blossom smells much better than KY

 

[nickyp]

please correct me if i am wrong, but doesn't an older style hull with a sharp deep entrance have less buoyancy up fwd than a newer design with much less forefoot and less deadrise up forward. so wouldn't the older, sharper designs not tolerate weight up forward as much?

 

[F/V First Team]

An empty hull? Sure. One that's properly loaded? That's another matter. I think the soda bottle full of sand was a pretty good analogy.

Just remember, when you fill the bottle to the top with sand it sinks.

 

[48lobster]

Weight aft is the way to go in a DE hull. When I take up gear(traps) I start aft and work forward....the pitch and roll slows drastically.The boat we are building now will have approx 400 gallon water tank in the stern to be used as ballast to hopefully tame those 4-6 footers that usually send people home.

 

[F/V First Team]

Will you be using a diaphragm pump to flood/empty the tank?

 

[48lobster]

They will be used in the summer(better weather) as freshwater to rinse tuna gear,probably only fill as needed.They will have a regular fill pipe fitting with hatch in deck. Will have jabsco type pump running forward to some sort of hose.
In the fall will fill with saltwater once upon destination then drain for steam home.
Thats the plan anyway.....

 

[BillD]

OK, let's discuss say a "typical" working lobster boat.
Let's use a 33 Crowley Beal commercial lobster boat as an example. Please try and limit the discussions to "weight distribution" in this particular boat.

Assume the boat was built as a working lobster boat for the owner. Open deck space was the requirement.

A John Deere (2200 lbs. fixed)is about 12"-18" into the forward cabin and there is a single 225 gal fuel tank (1600 lbs swing weight ) that is placed just behind the shaft log that extends back to about 18" forward of the rudder post. I'm pretty sure the shaft log (where the shaft comes through the hull) is 12 feet from the transom.

I assume this boat runs pretty good and carries as many traps as the owner can load up on her.

Assume the owner wanted to get the "noise" out of the helm area and didn't want an engine box to deal with in the helm area.
Essentially swapping the two weights. Fixed engine weight in the back, variable fuel weight under the helm area.

OK, make your best guess on how this boat would "run"/"handle" as a fishing/cruising boat ?

 

[48lobster]

It would run/handle better is my guess

 

[traditions]

Bill,take a look at the picture of the ManOWar,38 Holland ,that was posted on here a while back.That boat has a v drive.The bow is high and half the boat is out of water.I don't know if he has trim tabs.That boat doesn't go as good as one would think.If you think about a downeast with twin screws,the motors are further aft then they would be with a shaft log.I do know that to much weight aft and the boat wont perform as well as a well balanced boat.

 

[VPC]

very familiar with the boat hada a jim beal ok here's a couple of suggestions take it for what it's worth not gospell if the boats primary use is pleasure/moderate fishing scratch that engine go yanmar 800lbs less lower profile probbaly no engine box or very litlle, that engine could be put behind the bulkhead which now enables you to have more room down below and also allows a center entry in lieu of the fact that the boat has curved sides and stepping downs a hassle if not from the center. plus from my experiences the jim beals like the weigh toward the stern it allows the prop i guess to dig in better now the cabin being finished head, bunks galley exct should offset and "balance" to a degree the weight back. that hull pushes easy and my 31 jim beal flies with a 3116 you'll get an honest upper teens to 20 knots with maybe a 1.75 /1 gear and yes the 33 is a better or should i say improved 31 no belly midship like the 31 and a prettier rig imo

 

[mainely boats]

very familiar with the boat hada a jim beal ok here's a couple of suggestions take it for what it's worth not gospell if the boats primary use is pleasure/moderate fishing scratch that engine go yanmar 800lbs less lower profile probbaly no engine box or very litlle, that engine could be put behind the bulkhead which now enables you to have more room down below and also allows a center entry in lieu of the fact that the boat has curved sides and stepping downs a hassle if not from the center. plus from my experiences the jim beals like the weigh toward the stern it allows the prop i guess to dig in better now the cabin being finished head, bunks galley exct should offset and "balance" to a degree the weight back. that hull pushes easy and my 31 jim beal flies with a 3116 you'll get an honest upper teens to 20 knots with maybe a 1.75 /1 gear and yes the 33 is a better or should i say improved 31 no belly midship like the 31 and a prettier rig imo

The 33' was a smaller 36' not a larger 31'