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View Full Version : In case anyone is curious about GRP lobster boats



mmd
11-22-2017, 08:12 AM
This is one of the projects that I am currently working on, a relatively conservative 49' x 25.5' x 9.75' with only 429 hp main engine. Please note that this is not a design of mine; I am just preparing the drawings for the builder:

6279

Paul Pless
11-22-2017, 08:21 AM
fat

mmd
11-22-2017, 08:25 AM
Not really. Fat is 20% beamier.

Paul Pless
11-22-2017, 08:32 AM
husky then

SKIP KILPATRICK
11-22-2017, 08:45 AM
Interesting!

Steve McMahon
11-22-2017, 08:51 AM
One begins to question where the line is drawn between what is a boat, and what is a powered barge.

amish rob
11-22-2017, 09:32 AM
husky then
Haha. You got scarred! :)

Peace,
Highwaters

jackster
11-22-2017, 09:48 AM
That is a LOOOONG shaft!
I'm guessing the engine can't be moved to the stern for stability reasons?

mmd
11-22-2017, 10:26 AM
No, the engine is that far forward to maximize the hold volume. The shaft shown is just shy of 25 feet long and is 4-1/2" diameter. You don't want to know the cost.

TomF
11-22-2017, 10:30 AM
Let me guess. A "fat" lobsterboat has a beam greater than its length?

Keith Wilson
11-22-2017, 10:49 AM
That doesn't seem to be a very big motor for a boat that size. OTOH, are they fairly lightly loaded, traps being bulky but not that heavy? That shaft is one big chunk of steel.

mmd
11-22-2017, 10:51 AM
When I was studying naval architecture in school (back in the dark ages - I studied by candlelight...) the 'normal' length-to-breadth ratio for a displacement powerboat was 3:1. The one in the OP is 1.92:1. The 'fattest' that I have seen to date around here is 1.55:1.

There are a few catamaran lobster boats hereabouts, but are not popular - too radical, I guess. I do not know why they are unpopular. The argument about 2x engines & shafts being 2x expensive is proven to be false; the increase in deck space and fuel efficiency is undeniable, load-carrying is not an issue (the fish hold in a monohull is never ever used to more than about 50% capacity), and manoeuverability is vastly superior. Conservative lot, these fishermen...

Keith, this one is about where it needs to be - my calcs indicate loaded hullspeed requires about 375 hp, plus 50 hp for hydraulics. Many boats of the same size & displacement have 750 - 900 hp. The drivetrain stupidity of late has been prop diameter; I calculated one boat to need a 50" wheel, but the client paid to have the skeg dropped so he could have a 76" one installed. The heaviest load these boats normally carry is on 'dumping day', when they want to carry all of their lobster traps at once, a deck load of around 25 tons. Normal fightin' trim is fifty traps on deck and two live wells flooded, a load of about 10 tons.

Rob Hazard
11-22-2017, 12:42 PM
Any chance we could see a standard lines drawing of this critter?

mmd
11-22-2017, 01:04 PM
No such thing, Rob. Each hull is "sliced & diced" to modify it to suit the owner's desired beam, length, keel drag, sternpost location, etc., and because there is no requirement for stability booklets unless you engage in specific fisheries (e.g., herring) there is no need to measure the hull and produce a lines plan for it. However, I do have a couple of lines plans of the molds used as the 'former' for the sliced & diced hulls. This one is the basis for the drawing in the OP:

6287

CWSmith
11-22-2017, 01:10 PM
"...There was no romance on a cold winter's ocean and the gale sang an awful song."

The days when work boats looked good have passed. I'll be happy with the lobster they bring home and look to Jonesport or some of the small builders up north for something pleasing.

David G
11-22-2017, 01:22 PM
Horses for courses. Looks like it'll have a nice roomy engine room (except may be for headroom?). Always a joy. I hate doing anything mechanical. My hatred grows exponentially as the space tightens.

David W Pratt
11-22-2017, 01:26 PM
Didn't they used to lobster out of 2:1, L:B cat boats?
Does the beam obviate the use of outriggers and birds?

mmd
11-22-2017, 01:56 PM
CW, smaller, older style Cape Island boats are lovely, and there are still molds laying about if anyone wants a glass hull. The Northumberland Strait boats are also very nice, and are still being made.

David G, the boat in the OP has full standing headroom, and then some, in the ER.

David Pratt, some of the beamy lobster boats have removable outriggers, but mostly only those who switch over to scallop dragging or fish trawling in the off-lobster season.

David G
11-22-2017, 01:59 PM
CW, smaller, older style Cape Island boats are lovely, and there are still molds laying about if anyone wants a glass hull. The Northumberland Strait boats are also very nice, and are still being made.

David G, the boat in the OP has full standing headroom, and then some, in the ER.

David Pratt, some of the beamy lobster boats have removable outriggers, but mostly only those who switch over to scallop dragging or fish trawling in the off-lobster season.

Hurray!!!

Peerie Maa
11-22-2017, 02:47 PM
No such thing, Rob. Each hull is "sliced & diced" to modify it to suit the owner's desired beam, length, keel drag, sternpost location, etc., and because there is no requirement for stability booklets unless you engage in specific fisheries (e.g., herring) there is no need to measure the hull and produce a lines plan for it. However, I do have a couple of lines plans of the molds used as the 'former' for the sliced & diced hulls. This one is the basis for the drawing in the OP:

6287

Thought as much. I have seen better looking more fit for purpose tea trays.

CWSmith
11-22-2017, 03:01 PM
CW, smaller, older style Cape Island boats are lovely, and there are still molds laying about if anyone wants a glass hull. The Northumberland Strait boats are also very nice, and are still being made.


I was trying to remember the name "Cape Island boats". Isn't that ironic given the quote I used? I have seen them and they are lovely! I'm not familiar with Northumberland Strait boats, but I'll look them up.

johnw
11-22-2017, 03:06 PM
Not really. Fat is 20% beamier.
Okay, zaftig.

Steve McMahon
11-22-2017, 03:11 PM
I was trying to remember the name "Cape Island boats". Isn't that ironic given the quote I used? I have seen them and they are lovely! I'm not familiar with Northumberland Strait boats, but I'll look them up.

You might have better luck by searching google images for PEI Lobster Boat. They are very nice - I love the flare of the bow.

http://www.provincialboat.com/database/gallery/169.jpg

johnw
11-22-2017, 03:20 PM
When I was growing up in Maine, lobster boats looked like this:

http://penobscotmarinemuseum.org/pbho-1/sites/default/files/collection/Lobster%20Boat%20Genevieve-2.jpg

mmd
11-22-2017, 03:27 PM
Provincial Boats' hulls are hard-chine; many are round-bilged. This hull is by Hutt Brothers Ltd.:

http://www.huttboat.ca/index_files/image534.jpg


johnw, when I was growing up, Cape Islanders looked like this:

https://caperfrasers.files.wordpress.com/2010/07/28127_1383633683860_1622542190_887201_943538_n2.jp g

Modernization has not improved the looks much, IMHO...

David G
11-22-2017, 03:27 PM
Okay, zaftig.

No. No. No.

I know and love zaftig. But zaftig implies beautiful, sensuous curves. Not bricklike blockiness... <G>

Phil Y
11-22-2017, 04:11 PM
No, the engine is that far forward to maximize the hold volume. The shaft shown is just shy of 25 feet long and is 4-1/2" diameter. You don't want to know the cost.
Did anyone do a comparison with hydraulics?

Phil Y
11-22-2017, 04:16 PM
All that beam, she'd make a great houseboat one day.

Stiletto
11-22-2017, 04:32 PM
Is there much difference in behaviour on the water between Chined and round bilged lobster boats?

Garret
11-22-2017, 04:44 PM
Did anyone do a comparison with hydraulics?

I wondered about that too. Actually, I wonder about that on a lot of boats? Too expensive? Inefficient?

mmd
11-22-2017, 04:50 PM
Phil Y - not that I know of. If someone did, it probably wouldn't have any takers. First, it isn't what the fishermen are used to, so they won't like it; second, too much power loss; third, see reason No. 1. Conservative bunch, those fishermen. As for a houseboat, by the time these boats are ready to stop fishing, there isn't much good left in them. They live a hard, hard life.

Stiletto, yes. Chined boats are usually faster, but their roll characteristics are different and usually not for the better. Chine boats tend to slap and hesitate when the chine enters the water surface during a roll, and this is uncomfortable when you are trying to dance around on deck slinging a 50-kilo trap around. Also, a chine is an obstacle to hauling the trap on-board; the edges of the traps catch on the chines, beating the hell out of both the trap and the chine, and both are expensive.

Dumah
11-22-2017, 08:30 PM
Mike, do you tend to use a "conventional" stuffing box or are babbit shaft tubes starting to be installed?

Dumah

mmd
11-22-2017, 09:30 PM
It is the client's or builder's choice. It seems to be about evenly split between conventional tallow packing in bronze stuffing boxes and the newer dripless ones.