F/V Venom

F/V First Team

Admiral
Joined
Jan 10, 2012
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Narnia
Website
www.otisenterprisesmarine.com
Boat Make
Northern Bay 36 - Modified
Wait, what? A 2 speed tranny? Whats that about? Whats the speed on that bad ass little rig?

She has a two speed gear box, goes from 2:1 to 1.5:1 with the flick of a switch

Boat needs trim tabs the size of barn doors to keep that nose down

We got rid of those double rails and that brought her down to a more manageable angle of attack. Originally she had an Isotta Fraschini in her, huge V8 pumping out 1000+
 

captchuck

Lieutenant Commander
Joined
Dec 4, 2011
Posts
186
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12
Location
Long Island
Boat Make
26' Seaway
She has a two speed gear box, goes from 2:1 to 1.5:1 with the flick of a switch



We got rid of those double rails and that brought her down to a more manageable angle of attack. Originally she had an Isotta Fraschini in her, huge V8 pumping out 1000+

Travis can you expand on the two speed tranny? We're there any real benefits to it etc or was it a one time thing? Never heard of one before in a Downeast style hull.
 

Keelboater

Admiral
Joined
Oct 3, 2013
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4,816
Location
Clinton Harbor
Boat Make
35' Bruno & Stillman
Back in the early '60's they were using powerglides in Chris Craft Sea Skiffs. But I think this must be a bit more refined and high tech than those days.
 

F/V First Team

Admiral
Joined
Jan 10, 2012
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Narnia
Website
www.otisenterprisesmarine.com
Boat Make
Northern Bay 36 - Modified
The whole idea behind a two-speed gearbox is to get large vessels up onto plane quicker and easier on the engine, then once on plane you can shift to your other gear so you can bring the engine rpm down and keep your vessel up on plane. So how would this work in a downeast boat? Well let's take a lobster boat configuration into consideration, when you're loaded down and freighted with traps and gear you would be in your work load ratio (2:1 for example) so your engine wouldn't have to work as hard to move that load. Then once you have everything off you shift into your running mode (1.5:1 for example) and off you go.

There are 3 boats that I can readily name that have 2 speeds, most people don't consider them. They are fantastic off the line. Brutal, just brutal.

0 to 40 in under six seconds.

Fact.
 

Splinters

Lieutenant Commander
Joined
Jan 9, 2014
Posts
153
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32
Location
Allen,Md.
Boat Make
Egg Harbor
So from a fuel economy stand point this sounds promising. Is this possible with ZF transmissions or is it Twin Disc?
 

WoundUpMarine

Admiral
Lite User
Joined
Jan 1, 2012
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4,981
Location
Boothbay, Me
First Name
John
Boat Make
26' Duffy, 23' Seaway, 14' Holland

F/V First Team

Admiral
Joined
Jan 10, 2012
Posts
6,146
Likes
2,482
Location
Narnia
Website
www.otisenterprisesmarine.com
Boat Make
Northern Bay 36 - Modified
You prop the boat for your least amount of reduction, in this case 1.5:1

Comes out of the hole screaming in 2:1 since there's no load on the engine, flip the switch past the peak of the torque and keep it going now what the turbo is up to speed and can supply the engine.

Handles it real good, didn't like it so much when the 22x35 was on it, seemed to bog down a little at 1.5:1 :rolleyes:
 

Toro

Commander
Joined
Dec 21, 2011
Posts
267
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39
Location
CT
Boat Make
19 Pointer
Travis, If you were doing another tuna boat like Emme, would you do Tricel honeycomb for the cockpit? Or 3/4" medium density PVC ?
I used that in my skiff and seems hard to imagine anything stronger, lighter, more durable. Is that question a wash, 50/50?
 
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