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| Repower Articles |
| Widgeon - A Very Special 25 FT. Bertram |
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| It's not often that you run into the opportunity to have someone work with your past experiences and efforts and raise them to a new level. In this repower project, I was lucky enough to find a guy who is very special and had the talent and motivation to do just that. That's what this article is all about - A Very Special 25Ft Bertram. |
| I believe this all started about 20 months
ago on "boatdiesel" w/ a posting by a new user asking about repowering his
25Ft Bertram that currently had twin Volvo gasser outdrives. Yes, this should
be a simple repower, right?? READ ON !! |
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Jim Graham, the owner of
the Bertram, decided he would do some research on his upcoming project and
found, what I think, is the best place around to ask a few questions. The thread
was short and but to the point, but got his attention. He contacted Seaboard
after a few postings and the project went forward from there.
Jim turned out to be one of the most talented persons I have ever had the opportunity
to work with, as his finished work is well above what the pics can do justice
too. As you can see from the pictures, this project went well beyond what a
typical repower would be and, to me, it should be called a "new boat" that
was literally built from the bare hull up.
After Jim and I came to a general understanding of what needed to be done to
accomplish his goals, we proceeded from there. Jim "gutted" the boat all the
way down, close to a bare hull and then started the "resurrection" process. |
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| Transom
showing twin outdrive removal |
Keel
and distance layout based upon some initial layout drawings we sent him |
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| I put together a few drawings
and added a lot of individual attention to some initial construction details
on how to get started. We decided with the engineering of the stringers and
placement of the fuel tanks in relation to the engine/boat. The key here was
to come up with a small boat that would be in close to "perfect trim" regardless
of the variable weights-these, being fuel, bait, & and payload (like a 400
Lb Giant Bluefin or 500 lbs of assorted albacore / tuna. |
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| I
think these two pics say it all about Jim's BIG FISH and "little boats" |
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Smaller vessels are very
weight and trim sensitive and experience has shown me that you NEVER rely on
the variable weight of fuel to balance a boat, although, to this date, many
builders and owners do otherwise or seem to think that is the only way to balance
a vessel... WRONG !!!! I'll say it again so it sinks in, "WRONG !!"
With any smaller vessel, one needs to design the vessel so IT IS IN (reasonable)
TRIM, regardless of whether it is full of fuel, low on fuel, heavy on fish,
or NO fish-a very simplistic engineering accomplishment if you give it a few
minutes of thought (as long as you are not stuck on a couch in the frame of
mind that says "it's been done that way for 40 years, why change"............
). |
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| New
stringer and bulkhead construction-Iso-resins & Micro-Lam make for the "best
of the best" from both the practical and engineering standpoint in this
type of re-construction work. A very rigid "H" section from the fwd engine
room bulkhead all the way to the transom is very important to maintain good
engine to prop shaft alignment under the worse conditions. |
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| The
"Magic Stringer ID Measurement" that allows easy mounting of a "B" Series
Cummins |
Transom
patching & fairing all in AFTER the structural work is very important
if you want a yacht quality appearance. |
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| This was the starting point
on how to figure out "trim" |
The above (modified) line
drawing from the original builder was used to figure out the right placement
of the engine, shaft angles, prop size and gear ratio, and fuel tank placement.
Actually, quite simple when you really understand how vessels of this size
range operate in real world conditions. Put this drawing together with the
owner goals, the weight of the engine and drive train, the variable weights
of the fuel & payload, and with some past experience, the placement of the
equipment is a given for the best overall vessel performance and handling.
When these simple calcs were done, the only feasible and practical powertrain
that would give "commercial ruggedness" to the vessel was a conventional shaft,
prop and rudder, a proven diesel engine and properly installed V-Drive.
From there the choice was simple - A Cummins 330B w/ a custom configured High-mount
turbo, and a ZF63IV w/ a 1.5:1 ratio and propping that would allow the 330B
to easily hit rated ++ RPM at WOT under the worst conditions. This engine trans
combo has proven itself to me for over 15 years as a rugged and simple set-up
that will stand up to the rigors of the marine environment and is simple and
inexpensive to maintain.
My original calcs based on my finished "projected weight" called for 19-20"
of prop diameter, pitch so to get not less than 2900 RPM at WOT, 1.5" shafting,
and the engine V-drive placement to allow less than a 12 degree shaft angle.
The base layout is below and is a general overview of a close-coupled Cummins
High Mount set up we have been using for about 15 years now. We consider this
"base layout" a good starting point for planning purposes and can be easily
adjusted for each individual vessel. |
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| Base Layout Drawing w/ a Cummins 6BTA, High Mount Turbo arrangement and a Close
coupled V-drive |
| Progress on the messy part
(fiberglass reconstruction) went forward over the next few months as planned.
Jim is very fastidious in his work and cuts no corners. With East Coast 2006
winter approaching, I think the goal was to get it all painted and ready for
a winter sleep, and then start up again after the thaw in 2007. |
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| Progress
in the first 4-6 months before winter set-in |
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My past experience with projects
like this says the first Champagne bottle needs to be broken when the fiberglass
work, grinding, sanding, fairing, and painting is done. The Launching is anti-climatic
in comparison.
It was now getting time for the engine trans package. We put all together per
spec, tested the pkg at the shop to be sure all was 100%, and shipped it to
Jim in Spring of 06.
Before the final painting was done (boot stripe, etc), Jim wanted to be absolutely
sure of the vessel's static trim. So, it was to the harbor and a trial setting
of the engine. You can't really blame Jim, as he was relying on our calcs and
he had already received a different repower weight distribution scenario from
the builder that said that this would not be kosher. The pictures below put
all to rest as the boat sat exactly as planned with or without the variable
weight of the fuel. |
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| Custom
6BTA 330 with Hi-mount turbo-ZF V-drive package |
Before the engine set in-"High a Dry",
but with good trim |
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| Precious Cargo - Jim's 6BTA engine package |
The proof is in the puddin' - Engine in place and 100 gallons of water to simulate
a the fuel tanks. |
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Jim now felt much better,
he marked the boot stripe, and it was back to the paint booth...
By Nov 06 the vessel was ready for a winter lay-up indoors for final painting
and the most fun part of the project-Outfitting the engine package and all
of the goodies to complete the vessel.
By the start of the spring thaw (Feb 07), Jim's new puppy emerged with a totally
new look... Now all of his patience and work was coming together. |
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| Nov 06-Primed, faired and ready for a winter lay-up w/ $5K LP paint job next.
Notice the custom center console. |
She's lookin' sharp and is getting really close. |
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| Between Feb 07 and the upcoming
summer, and with the time Jim had to devote to the project, the vessel was
95% finished with completion of the power train, steering system, electrical
system, fuel system, misc engine sub-systems, electronics and all of that extra
gingerbread that you need to catch one of those Giant Bluefin Tuna. |
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| Piece by piece, system by system, she was coming together |
Custom
center console |
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| Clean
install... Nice work! |
Can't skimp here-A commercial quality Multi-Stage Fuel filter system. |
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| By mid-summer 2007, Jim was
finally near enough that he could start getting some pay-back. |
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| In the water in June 07 with some testing
to be sure all is right before he starts chasing those tuna... The vessel sat
perfectly and could easily handle all of the additional weight forward including
anchor gear, a 150 gallon bait tank, and all the creature comforts that were
still missing. With the exhaust exit under water, and with the inherent safety
of the high-mount turbo and mixer about 18" above the waterline, no muffler
was needed. |
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| By Sept, the vessel was up to about 99%
outfitted and it was time for some fun. |
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| Yum
Yum is all I can say when they are this fresh - Cooking not even needed!! |
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Although Jim has a list of things to do
this coming winter ( find me a vessel with this much attention to detail that
is ever finished and I'll show you an owner who'd rather play golf than fish
on the weekends), he has the next few months to play.
Per Jim's own words and how this project went forward, and why WIDGEON will
occupy much of Jim's time this winter... |
"Most people would put me in the "pain
in the ass" category instead of talented. If you were to watch this whole
thing progress, it's the measure twice cut once adage that fit here. Only
I measured 6-7 times, making sure all options were exhausted before making
a final decision. Also very stubborn.
As with any project it's never done. As I mentioned earlier, there is quite
a list of things to do this winter, but as you also mentioned, paying close
attention to trim. It is the paramount concern in having a good boat. Trim
wet or dry. There is a 150 gal bait well forward if the engine. This is
plumbed not only with a pump in and out, but holes in the boat bottom with
plugs and scoops to fill and empty. This allows me to keep bait overnight
without pumping. All this weight does not affect trim either full or empty.
It's nice to have that ballast in a head sea. Also no need for trim tabs.
Nice clean transom. Need to figure out the right covers for the scuppers,
backing down gets a bit tense.
Bought a case of WD-40 and keep everything wet. So much so there are drippings
in my clean bilge. Aargh!
As the winter approaches there will be lots more questions.
The performance is plenty good for me. Not sure of accurate fuel consumption
yet, the shape of the tanks renders a fuel gauge useless. Need to get a
Floscan system this winter.
I am still topping out at 2800 on the dot. That's with 135 gals of fuel
on board.
The manual says at 2200 the burn is about 8.4/hr.
Prop is 20 X23 four blade with a slight cup.
At 2200 GPS says 22.5 kts depending on sea conditions
2300 almost 24 kts
2800-30kts
Couldn't be happier with this setup. Especially the industrial strength
Cummins." |
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My Current Thoughts:
Now that most of the dust has finally settled, I am recommending to Jim that
he buy a new prop as I am sure the 4 blade is dragging him down with unneeded
blade area as WIDGEON is lighter that I thought it would be. I'd go with a
"ZF Faster" or "Michigan DJX" Nibral prop, class 1 or better, 19 x 24 - 3 blade
with a #4 cup. I would expect Jim to make 32+ knots and allow the engine to
reach an extra 50-75 RPM. Fuel consumption should rise to about 2.8~3 KPG at
22-23 knots......
My hat is off to Jim and his "pain in the ass" attitude as I just don't think it could get much better, although our motto at the shop is that "there is always room for improvement". Jim didn't leave any in my opinion......
Tony |
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Widgeon - A Very Special 25 Ft Bertram |
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