47MarineTrader-Are twin Volvo 255 enough power?

[John Sarasota]

I'm looking for at a 1985 47 Tradewinds Marine Trader.

We plan on traveling at least the east coast if not the entire loop. We live in Florida, family in NY.

I worry that this won't be enough power and I may get tired of 8 kts, which is what the present owner claims is pretty close to top cruise.
Claims 4 gal/ hr at that rate so fuel economy is great but not my primary concern.

Any opinions on this particular boar or general thoughts on this class of boats
and the pro/cons of powering them would be appreciated.

Just retiring and looking for a few year adventure.
thanks in advance.
John

 

[BruceK]

2x 255hp sounds heaps to me. 8-9 knots is what it`s meant to do. Trying to run faster will consume lots of fuel and produce large amounts of wake for a marginal speed increase.

Have you checked parts availability for the Volvos?

 

[READY]

I have a 48 Hatteras LRC. Probably heavier and it has 2 120 HP engines. I rarely run them hard because I could get 1.5 to 2 extra knots at about double the fuel burn. That Marine Trader has plenty of power for the intended purpose. If you want to cruise at higher speeds suggest you look at a planning hull.

 

[Delta Riverat]

Yeah, my 44 foot gypsy has Volvo 235's which will do 8 knots at minimum recommended rpm (1400) and do 13 knots pegged (2500)

Boat weighed in at 42000 lbs last haul.

 

[mvweebles]

500hp combined is plenty for displacement speeds. We happen to really like life at jogging speed, but it's a decision you have to make for yourself. It's a lifestyle decision.

POs fuel burn sounds a bit optimistic. I'd guess around 5 gph at 7.5 kts. She should push to at least 10-kts and burn 11-12 gph would be my guess.

To be brutally frank, if you're worried about getting bored at 8-kts, you really should charter something similar before you purchase. Would be an expensive unforced error of displacement speeds are not for you.

Good luck with whatever you decide.

Peter

 

[John Sarasota]

Thanks for the feedback. Everything seems to be some sort of compromise.
Glad to know that this is a common configuration.
Decisions, decisions. Thanks again.

 

[Hookmeup]

Volvo parts check

Really need to look at parts availability on the Volvo I looked at a Volvo powdered 40 footer and parts concern killed the deal. I even checked with friends in Sweden.
If you want higher speeds look at a cat.

 

[Delta Riverat]

I was trying to reduce travel time of the "re-homing" cruise, 85 miles from Alameda to Stockton, so I goosed the motors to 1600-1650 and made 9 to 10 knots depending on wind & current and we were 9 hours dock to dock.

So good to know everything checks out pretty well. The motors do hull speed at or around their minimum recommended, the screws are correct and the max advertised speed (by the broker) was also correct.

But yeah, these boats are made for the slow ride, around 8 knots. Sure you can go faster, but not much and you burn a lot more fuel.

 

[Comodave]

There is plenty of power for up to about 10 knots. But it will cost a lot more fuel at that soeed. Check availability for parts for Volvos. Very expensive and can be very hard to get depending on what you need.

 

[koliver]

I looked seriously at a MT 47 with Volvo TAMD40s, don't recall the hp, but not more than what you report. Are those the TAMD40s? That seemed to me to be lots of hp for the size and purpose of that boat.
My own is a 44000 lb C&L44, does 8 happily.
If you think you need to go 12 or faster, this won't be the boat for you.

 

[BruceK]

Possibly TAMD60Cs ?

 

[Delta Riverat]

Sounds right. Mine are TAMD 60B

 

[ranger58sb]

I worry that this won't be enough power and I may get tired of 8 kts, which is what the present owner claims is pretty close to top cruise.

That's probably a critical factor for your boat type selection.

Even if the boat in question can "speed up to" 10 kts or so (above hull speed?) that won't seem like much difference compared to 8 kts -- except maybe for the additional noise.

IOW, if you might not be happy with an 8-kt boat, another knot or two won't solve that.

Maybe decide first how much speed you want... then shop for boats that will do that.

-Chris

 

[Flatswing]

I'm looking for at a 1985 47 Tradewinds Marine Trader.

We plan on traveling at least the east coast if not the entire loop. We live in Florida, family in NY.

I worry that this won't be enough power and I may get tired of 8 kts, which is what the present owner claims is pretty close to top cruise.
Claims 4 gal/ hr at that rate so fuel economy is great but not my primary concern.

Any opinions on this particular boar or general thoughts on this class of boats
and the pro/cons of powering them would be appreciated.

Just retiring and looking for a few year adventure.
thanks in advance.
John

More than sufficient power - but from your stated concerns the MT (or any other Asian, displacement trawler) won’t meet your needs. As an example: my DeFever 49 RPH weighs 67,000 lbs. loaded. Twin 225 HP JD 6068’s cruise at 7-8 knots. WOT: barely 10 knots. Most 49 RPH came with twin 135HP FL’s or Perkins - same cruise speed & WOT but less bow wave @WOT.
Perhaps you should consider a planing hull, or semi displacement design that can deliver similar fuel economy at 8 knots. But plane at 16-20+ knots with sufficient HP (& vastly higher fuel burn) for when time is an issue.

 

[John Sarasota]

This is all great feedback. I'm new to the forum and not great at posting. Don't want anyone to think I'm rude for not replying.
I've sailed and chartered slow canal boats in Europe. I have experienced life at 8 kts in short time frames. Very relaxing but this is a little different. Glad to know about the parts issue. I'm not sure how to check on that but I'll start asking some questions.
I am guessing that no wake zones keep you under hull speeds anyway for a good part of the trip. After 40 years working, I need to practice slowing down.
Thanks again to everyone for the feedback.

 

[ranger58sb]

I am guessing that no wake zones keep you under hull speeds anyway for a good part of the trip. After 40 years working, I need to practice slowing down.

No wake zones depend on where you are and where you're going. Lots of area where those aren't in play...

I didn't mean to imply you need to change. Just suggesting you buy a boat that matches who you are/who you want to be.

-Chris

 

[Comodave]

Only you can decide what cruising speed you want. That should be your first decision because everything else hinges on that. What type of boat you want/need is the first question. And we don’t discriminate against faster boats here, I have an express cruiser. Then you can look at individual boats and see what you like.

As to the Volvo engines. I don’t even look any further at a particular boat when I see it has Volvos. I have had them in the past and don’t desire to go there again. Others may feel differently. We bought a brand new boat with twin Volvos in it. I used to sell boats part time for the dealer so he would take parts off the new boats to keep mine running. And those were current engines. Now go to engines that are 30+ years old and what support is there?

 

[DavidM]

That boat as never meant to go 15 kts. Maybe 12 kts at 75% of max power is all you can expect. It was designed for 8 kts which should be easy on those engines.

David

 

[jbloyd]

Educate yourself about the basics

You really should decide what type of cruising you will do. Then, you will need to know what hull configuration can achieve that. One of the issues that make that difficult is, almost all non-planing hulls have engines that are too large. This is especially true of semi-displacement hulls. But, even boats with a displacement hull will often have engines above a HP rating that is more than double the HP necessary to achieve and maintain hull speed. For instance, my Defever 44 OC has twin 120HP LH engines. There are many methods to calculate the HP but, I think it would be safe to say my boat would only need less than 70% of one engine to maintain about 8 kts. If you are cruising in areas that have higher rates of tidal flow (my area, the PNW) that could have a greater effect on speed than trying to use engine power. My actual SOG can easily vary from 4kts to 10kts while maintaining a fairly optimum engine rpm of 1750. Geek out and have fun learning all this stuff while you decide what you really want to do. It's a lot better than just spending a bunch of money on something you only think you want based on ignorance.

 

[JRO]

Single engine diesel? Sure love the low fuel consumption.
The owner may have told you what his “sweet spot” top speed is but the boat may be designed to go faster within its operating capacity.
8-9 Knots is trolling speed so “fish on”. And it’s a comfortable speed to socialize, make cocktails and eat sandwiches. Once you get over 15 knots you need to concentrate and be far more careful of where you’re going and what your wake is doing to others. I’d bet the boat is designed to have a higher top speed but you need to research to know such.

 

[Flatswing]

Single engine diesel? Sure love the low fuel consumption.
The owner may have told you what his “sweet spot” top speed is but the boat may be designed to go faster within its operating capacity.
8-9 Knots is trolling speed so “fish on”. And it’s a comfortable speed to socialize, make cocktails and eat sandwiches. Once you get over 15 knots you need to concentrate and be far more careful of where you’re going and what your wake is doing to others. I’d bet the boat is designed to have a higher top speed but you need to research to know such.

I very much doubt that a 47 MT will go much faster than 10 knots with the twin Volvos and that the fuel burn will justify running close to WOT except for short jaunts (to make a bridge opening etc.) in a basically displacement trawler.