single vs twin

looking at mainship 34 pilot, like the twin engine because of its shallow draft,but told it does not have enough room for working on engines and they will charge considerably more to work on engines because of this, any experiences and comments would be appreciated thanks mark

Hello. Having owned both types - an Ocean Alexander 38 with twin Lehmans, and now an AT-34 with a single Cummins, I am a strong believer in the single engine scenario.
- one half the maintenance cost
- easier access to both sides of a single engine
There is a reason that most commercial fishing vessels are singles.

BUT ... you better get your maintenance right. Good luck.

David

When I was looking for our Pilot 34 some years ago, I had the opportunity to take a hard look at one with twin Yanmar 4LHs. I do all of my own diesel engine maintenance and maybe I was spoiled by the spacious engine room of our prior single engine Mainship 34T.

The 34T has a beam of 14' which is abnormally wide for that length. But it is the only boat that I would be comfortable working on the twin engine version.

So when I looked at the Pilot 34 twin with its 12' beam, I said no way am I going to be able to crawl over and around those engines to get to the outboard stuff. The Pilot 34 has a very large engine hatch where the entire floor of the aft cabin swings up to provide access. But there is all of the beam port and starboard underneath the settees that is still covered. You have to lay on the twin and reach down to work on anything outboard, which since engines aren't made in left and right hand versions is everything. Only the stuff in the front of the engine- the belts and the coolant pump is fairly easy to reach because you can crawl up the middle to get to it.

But if you just open your checkbook for engine maintenance, then go for it.

David

If I could have a single QSM11 at 660hp instead of my 2 6BTAs at 330 per....I would take that single in a heartbeat....

Baker said:

If I could have a single QSM11 at 660hp instead of my 2 6BTAs at 330 per....I would take that single in a heartbeat....

Click to expand...

Baker
What would estimate the cost of normally planing vessel with a single in the 40 foot range? That would be a real nice vessel like an MJM; except for specialty builds few others come to mind.

As far as double the maintenance cost, nope. Two engines at say 220 HP vs one at 400? Been there done that. But all prejudices aside, it really comes down to what boat do you want. ATs, NTs or smaller Nordhavns don't come with twins and Flemings, SeaRays, Carvers or Outer Reefs don't come with singles.

We have an acquaintance who owns an N60 with twins. He has smaller twins vs a normally installed larger single with a get home. And - gasp - he has wet exhaust!

Different strokes.

HAHAHA!!!!! I was being somewhat facetious. But my purely theoretical first choice in boat configurations would be a single with a bow thruster. Handling it is simple. And maintaining it is simpler....regardless of cost.

On a single, just make sure it has at least a bow thruster. I have a single and wouldn't be able to dock it in the wind without my thruster.

I hate not having the option of twins....

But, this year doing the dampner plate replacement, head gasket and then engine alignment....

Whew, not sure I would have had the patience and energy to do 2 at a time. Sure stagger them, but then there is economy of effort with doing 2 at once...but mine was easy due to room....maybe with twins the lack of room would have killed me. Especially with all the other maintenance.

So, depending on engine room access and the amount of maintenance you do or have to pay for could be a factor.

My personal opinion is that a bow thruster on a single Mainship 34 is nice but not needed in all but the most inclement weather.

Sure I have to do a go around every once in awhile but i'm nothing special, fight river current, back in, single hand the boat most of the time, etc. Gets easier every time.

I will say that when the wind is whipping i'll stay at the dock but I would either way.

David Rive wrote;
“There is a reason that most commercial fishing vessels are singles.”

And do they have a lot more knowledge and experience than we do? Is this what you don’t say but imply?

They also use oil stoves and anchors most of us wouldn’t consider buying. I’ve never seen a modern anchor on a fish boat. They put tar on their decks, run their engines hard and have hydraulic reel anchor winches. And those single engined fish boats run in groups of several to many other fishermen as they do need a tow at times.
They do lots of things we yachties almost never do. So emulating them may not a good idea .. or desirable.

Nomad Willy said:

David Rive wrote;
“There is a reason that most commercial fishing vessels are singles.”

And do they have a lot more knowledge and experience than we do? Is this what you don’t say but imply?

They also use oil stoves and anchors most of us wouldn’t consider buying. I’ve never seen a modern anchor on a fish boat. They put tar on their decks, run their engines hard and have hydraulic reel anchor winches. And those single engined fish boats run in groups of several to many other fishermen as they do need a tow at times.
They do lots of things we yachties almost never do. So emulating them may not a good idea .. or desirable.

Click to expand...

You nailed it Eric.

Thanks sunchaser,
The fishermen have other agendas and operate in different environments.
Our yachts are owned and piloted by individuals many of whom are motivated to have the very best. Many threads here are started in search of the best of this or that. Or the best methods but industry is only interested in getting the job done .. most of the time. A fisherman is OK with dragging anchor at times as long as they almost never drag into the beach. Fishermen get buy w tried and proven equipment and methods that have worked over time. Just good enough to get by. They don’t experiment or research gear they just observe what the older fishermen are doing or using. The Forfjord anchor is a good example. Been around for a long time and lots of old fishermen have them. And young fishermen lust for them but they are a very low performance anchor.
Fishermen are motivated to catch fish. Becoming a skilled boater in the process is not a high priority. Catching fish is. When fishermen come down to the harbor to work on their boat they do work .. and diligently so but most often the work in on the fishing gear, not the boat itself. Trolling gerties, hydraulic systems that control fishing gear, nets ect ect. They do work on boats when they have to. When it effects their bottom line.
I’m not enough of a fisherman to elaborate on most of fishermens activitys but a twin screw boat is obvious not very ideal as nets and trolling lines are much less likely to be fouled in a deep centrally located propeller. I could attempt to go on w the cost of propulsion ect but I’m not a fisherman. There are probably many reasons for fish boats and other commercial boats to have a single screw.
But IMO we should be asking why have twins as twins cost considerably more money. Twins must be better. Many people are paying for it.

Edit;
Why isn’t this thread under Power Systems?

Yup,single or twin. they are the best! Glad I chose wisely...

sunchaser said:

You nailed it Eric.

Click to expand...

Boat is to fisherman as tractor is to farmer.

Not sure I agree with a lot of Erics observations. Bering sea crab boats went from all single screw to predominantly twin screw. Bristol bay boats went from single screw to twin jet powered rigs. To say they don't experiment and research is not what Ive seen.Regional conditions,competition drive trends.

Undoubtedly true, Eric and Tom, but the commercial operators are telling us something. Their object is to make $, and they can`t do that if the boat is not operable, so depending on tolerating acceptable limits on operation, what ever they do gets their boats working, presumably economically.
We have different needs and aims,I favour the maneuverability of twins over sheer $, and would not put up with the boat looking like a worksite. It`s a bit like learning from motor sport car developments, their are things to pick up, but plenty that is no practical use.
If I can get, and maintain and manage twins, I would. I`ve owned a single, it had no thrusters,and I managed. But I definitely enjoyed the transition to twins. Maybe a single with thrusters both ends would change my mind, I probably need to take a ride on one, preferably not with the man trying to sell it to me.

Hi,


Twins or single?


I need one for me and I'm fine if you like twins ...




NBs