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

[Rustybarge]

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]

Just realised that 6000 pounds equals 3200 ltrs of diesel.

Trans -Atlantic at 6 kts?

[DavidM]

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

Davd

[Rustybarge]

Originally Posted by djmarchand

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.]

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]

Originally Posted by Mark D.

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]

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]

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]

Originally Posted by jleonard

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]

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]

Originally Posted by ranger42c

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]

Originally Posted by Rustybarge

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]

Originally Posted by ranger42c

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]

Originally Posted by jleonard

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]

Originally Posted by Rustybarge

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]

Originally Posted by ranger42c

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]

[QUOTE=ranger42c;317804
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[/QUOTE]

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]

Originally Posted by Rustybarge

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]

Originally Posted by jleonard

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]

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