Mainship 34 Mk 1-3 Vs. 34T useful load.

Rustybarge · Mar 9, 2015

Hi All,

Looking at the specs of the mainship 34 mk1-3 it seems to tip the scales at about 14,000lbs (6 1/4 tons), and the 2005 34T 375hp at 20,000 (9 tons)...

Does this mean I can haul around an extra 6000 lbs of stuff if I buy the Mk1?

Rustybarge · Mar 9, 2015

Just realised that 6000 pounds equals 3200 ltrs of diesel.

Trans -Atlantic at 6 kts? :popcorn:

DavidM · Mar 9, 2015

Not unless you can somehow make up the almost 2' beam difference between the two boats.

Davd

Rustybarge · Mar 9, 2015

djmarchand said:
Not unless you can somehow make up the almost 2' beam difference between the two boats.

Davd

Aha thanks, all is revealed.

It's amazing that the extra 2' weighs so much; nearly 50% more.
The price I suppose is 375hp instead of 220hp.

It reminds me a bit of cars, they always seem to get heavier and heavier. My son drives an Mx5 mk2 which weighs a lot more than the mk1; I just saw that the latest model just released weighs 100kg less; contrary to past practice.

Just shows that 'weight costs' in a S/D boat.

Mark D. · Mar 10, 2015

I have a 1982 Mainship 34 Mark I and it weighs in at approx. 16,000 lbs (at least that is what I have been told).

Rustybarge · Mar 10, 2015

Mark D. said:
I have a 1982 Mainship 34 Mark I and it weighs in at approx. 16,000 lbs (at least that is what I have been told).

I think the early models are the prettiest; I really like the Mk1 version. I'm beginning to realise that it might be an unique classic light weight design at that displacement.

The modern Swift trawler 34 is around 9-91/2 tons, just like the later 34t. At slow speeds it hardly matters what the weight is, but if you want a boat with 'run for shelter ' ability a 3 ton advantage is going to make a massive fuel saving at 14-15kts.

I'm going to try to track down a mk1 here in Europe.

Rustybarge · Mar 10, 2015

Is it my imagination, or is the later 34t very top heavy looking ?

The Mk1 is better portioned...

Is there more headroom in a later 34t?

Almost perfect.

jleonard · Mar 18, 2015

When I had my 78 Mainship 1 I had it weighed as they were hauling me for winter storage. I wanted good numbers since I was planning a future repower.
With 3/4 fuel and full water, plus all our gear (except the dinghy) we came in at 21,000 lbs.
I used that number in my running gear calc and hit the nail squarely on the head.

Rustybarge · Mar 18, 2015

jleonard said:
When I had my 78 Mainship 1 I had it weighed as they were hauling me for winter storage. I wanted good numbers since I was planning a future repower.
With 3/4 fuel and full water, plus all our gear (except the dinghy) we came in at 21,000 lbs.
I used that number in my running gear calc and hit the nail squarely on the head.

21, 000 lbs....!!! 21,000 lbs!!!

Going on the basis of 50hp per ton for a s/d design you'll need 470 hp.

...or maybe jet power, as in 747.

I'm going to guess the crane weight meter was wrong; it's not possible.

ranger58sb · Mar 18, 2015

Our '87 Mk III was documented as 16 gross tons, 13 net. Realize that's different than weight but...

Adding 300 gallons of diesel (I forget the actual capacity) would be what, another 2000 lbs? Full water tanks (I forget that, too), another thou or more?

Plus "stuff"?

(Something odd about the second pic in your post #7... unless the two pics with red hulls are 400s?)

-Chris

Rustybarge · Mar 18, 2015

ranger42c said:
Our '87 Mk III was documented as 16 gross tons, 13 net. Realize that's different than weight but...

Adding 300 gallons of diesel (I forget the actual capacity) would be what, another 2000 lbs? Full water tanks (I forget that, too), another thou or more?

Plus "stuff"?

(Something odd about the second pic in your post #7... unless the two pics with red hulls are 400s?)

-Chris

16 tons is nearly 36,000 lbs
I think I've been mislead by the advertisements that list the weight of the MK 1 at 14,000lbs, which is why I said I thought it was a lightweight classic in comparison to the later 2005 34t.

PS: the GB 42 weighs 16 tons and has twin 500hp to reach 18kts max.

Thanks for pointing out the error with the pics; I've never actually seen a Mainship as there are very few over here in Europe.

jleonard · Mar 18, 2015

Rustybarge said:
21, 000 lbs....!!! 21,000 lbs!!!

Going on the basis of 50hp per ton for a s/d design you'll need 470 hp.

...or maybe jet power, as in 747.

I'm going to guess the crane weight meter was wrong; it's not possible.

No the weight was pretty accurate. Verified by the prop calculations and resulting performance. Remember the boat got on plane very easily with the 270 HP repower. And yes on plane as the wake was very flat. So perhaps the "rule" you are using does not apply here.

Pic #2 is a Mainship 350/390 1997 thru 2005 maybe? (I forget when they stopped production of that model)

Rustybarge · Mar 18, 2015

ranger42c said:
Our '87 Mk III was documented as 16 gross tons, 13 net. Realize that's different than weight but...

Adding 300 gallons of diesel (I forget the actual capacity) would be what, another 2000 lbs? Full water tanks (I forget that, too), another thou or more?

Plus "stuff"?

(Something odd about the second pic in your post #7... unless the two pics with red hulls are 400s?)

-Chris

Just realised your boat did weigh 16 tons, but at the extended reach of the crane jib. Cranes are normally rated a gross weight at 2mtrs reach, half that amount a 4mtrs reach etc etc.....

So maybe your boat puts 16tons weight on the crane at 4mtrs and a bit reach....

Rustybarge · Mar 18, 2015

jleonard said:
No the weight was pretty accurate. Verified by the prop calculations and resulting performance. Remember the boat got on plane very easily with the 270 HP repower. And yes on plane as the wake was very flat. So perhaps the "rule" you are using does not apply here.

Pic #2 is a Mainship 350/390 1997 thru 2005 maybe? (I forget when they stopped production of that model)

Ah ok, that makes sense.

I think the later 2005 34' t has a totally different hull shape, but it needs 370 hp to max out at 17kts according to several owners on the forum.

Maybe a deeper vee needs more power?

ranger58sb · Mar 18, 2015

Rustybarge said:
16 tons is nearly 36,000 lbs
I think I've been mislead by the advertisements that list the weight of the MK 1 at 14,000lbs, which is why I said I thought it was a lightweight classic in comparison to the later 2005 34t.

PS: the GB 42 weighs 16 tons and has twin 500hp to reach 18kts max.

Thanks for pointing out the error with the pics; I've never actually seen a Mainship as there are very few over here in Europe.

Ummm.... well, no, gross tonnage is a volume measurement, not exactly equitable to weight. Just meant to point out that sometimes you may be seeing apples and oranges in ad specs. (But then I rambled off into weight things, likely confusing...)

The second pic looks to me like a 350/390, but I thought those models had a swim platform that was more or less integral with the hull, not bolted on as in that pic.

-Chris

Rustybarge · Mar 18, 2015

ranger42c said:
Ummm.... well, no, gross tonnage is a volume measurement, not exactly equitable to weight. Just meant to point out that sometimes you may be seeing apples and oranges in ad specs. (But then I rambled off into weight things, likely confusing...)

The second pic looks to me like a 350/390, but I thought those models had a swim platform that was more or less integral with the hull, not bolted on as in that pic.

-Chris

I've heard of this before; it's a way of measuring how much a commercial freight ship can carry at the different plimsole lines, and of course allows the customs impose tariffs on ships in an equitable way.

I believe there was yet another system used on the Thames in London at the turn of the century, to measure volume/load carrying capacity.

jleonard · Mar 19, 2015

ranger42c;317804 The second pic looks to me like a 350/390 said:
They do have an integral platform...however that was not the initial design so perhaps this is a very early one.
OR since the integral platform leaked so badly maybe this was a permanent fix.

jleonard · Mar 19, 2015

Rustybarge said:
Ah ok, that makes sense.

I think the later 2005 34' t has a totally different hull shape, but it needs 370 hp to max out at 17kts according to several owners on the forum.

Maybe a deeper vee needs more power?

That could be. I know I could get to 18.5 knots in mine but after 16 it got squirrely because there was not much left in the water.

ranger58sb · Mar 19, 2015

jleonard said:
They do have an integral platform...however that was not the initial design so perhaps this is a very early one.
OR since the integral platform leaked so badly maybe this was a permanent fix.

Ah. Yep, could be either. best I could say is it looks like a 350/390 with an odd-looking swim platform.

We shopped pretty hard on those back in the late '90s. At the time, the leaky swim platform wasn't known (or at least publicized much, yet) but in any case we really liked the boat. Turned out we went a different direction, though, partly because the 350s were so new at the time we couldn't afford one. (And then since then, we've gone a third direction, anyway...)

-Chris

johnma · Mar 19, 2015

photo #1 is a 400; photo #2 is a 34T. The 400 and 34T look a little top heavy because of the overhang on the side decks. The 390 did not have that and they look more like the older 34 I-II-III

john
2003 MS390

ranger58sb · Mar 20, 2015

johnma said:
photo #1 is a 400; photo #2 is a 34T. The 400 and 34T look a little top heavy because of the overhang on the side decks. The 390 did not have that and they look more like the older 34 I-II-III

john
2003 MS390

So photo #1 is a 400, #2 is a new-ish 34T, #3 is an early one (34 Mk I or II?), #4 is a 400, and #5 is another early one (34 Mk I or II?) ?

I've only ever seen on new-ish 34T in person...

-Chris

Rustybarge · Mar 20, 2015

johnma said:
photo #1 is a 400; photo #2 is a 34T. The 400 and 34T look a little top heavy because of the overhang on the side decks. The 390 did not have that and they look more like the older 34 I-II-III

john
2003 MS390

Your model the 390, and the mk1 and mk3 from the 1980's are the prettiest IMO.

tumblehome · Mar 24, 2015

older vs newer

I have to agree that the newer ones look top heavy; and I prefer the design of the MK1,2 & 3. That has a lot to do with why I bought one.

DavidM · Mar 24, 2015

Although the 34T does look top heavy vis a vis the original 34, there is a world of functional difference.

You could hold a nice party (respecting the weight limit of course) on the fly bridge of a 34T. Or have lots of room on the boat deck for a tender or solar panels.

In the main cabin the extra beam makes the salon look huge compared to the older 34.

The negative to this is weight and the horsepower required to push it to the same speed. The old 34 weighs about 16,000 lbs dry and the 34T weighs 20,000 lbs.

David

jleonard · Mar 24, 2015

djmarchand said:
You could hold a nice party (respecting the weight limit of course) on the fly bridge of a 34T. Or have lots of room on the boat deck for a tender or solar panels.

David

I had 17 guests aboard my old 34 when we went on a sea trial/cocktail cruise to break in the new Cummins. :dance:

Of course they were not ALL on the bridge deck. (The cooler was in the cockpit).

Mainship 34 Mk 1-3 Vs. 34T useful load.

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