Tug conversion

[JWellington]

This new mini tug should be an interesting conversion to a livaboard cruiser. IZ 1205 HDPE

 

[JWellington]

I would just extend the roof, have the top loaded with solar cells, and have the galley- saloon, up there, bunks, storage below, hybrid electric. Would be a nice litte boat for many.

 

[guy with a boat]

Seems a little like converting a dump truck into a motorhome. It could be done, but why would you?

 

[OldDan1943]

This new mini tug should be an interesting conversion to a livaboard cruiser. IZ 1205 HDPE

https://izmirshipyard.com/boat-91-IZ_1205_HDPE_T.aspx

Obviously, the house needs to be extended and reworking the interior.
AND I am sure the shipyard would be more than happy to work with you with your needs and desires.
Of course, we have no idea of the price of the basic tug.

 

[JWellington]

Seems a little like converting a dump truck into a motorhome. It could be done, but why would you?

Fair enough, but I think of it more as a van to rv. I like heavy, clunky looking boats. And it does have many attributes anyway. Foe example, with HDPE hulls, not only dont you have tp paint them, you dont even need antifouling.

 

[JWellington]

https://izmirshipyard.com/boat-91-IZ_1205_HDPE_T.aspx

Yes, thats the one.

 

[Simi 60]

Seems a little like converting a dump truck into a motorhome. It could be done, but why would you?

They do get done but the water they push and the HP required ain't exactly efficient

https://yachthub.com/list/boats-for...ing-tug-converted-to-luxury-superyacht/244397

 

[JWellington]

OK, but that one is over 100 feet longer. But certainly a nice conversion.

 

[Simi 60]

OK, but that one is over 100 feet longer. But certainly a nice conversion.

My point being is they have inordinate amounts of hp and push a lot of water for their size.

12m doing 12 knots with 350hp is far from economical

 

[Nomad Willy]

Seems a little like converting a dump truck into a motorhome. It could be done, but why would you?

If you’re into the electro boat fad it makes a good choice.

Why? To carry all those heavy batts.
A guy was looking at Willy (30’ Willard .. 8 tons) and as we talked about it somebody went to Alaska on an extra light boat. But his was a solar panel boat. Can be done. But constantly charging and discharging the batts. Frequent layovers.

With the solar panels you can have a light boat w small batts and go relatively short distances. But accommodation wise not have much of a boat.

But w a heavy boat one has much more flexibility. And most likely a very much more seaworthy craft at the nasty places. And perhaps comfort of boat motion could even be more important.

But either light or heavy has an advantage.

The OP’s “liveaboard cruiser” shows an engine .. not a motor in the ER.

 

[JWellington]

My point being is they have inordinate amounts of hp and push a lot of water for their size.

12m doing 12 knots with 350hp is far from economical

No problem, one could outfit with smaller motors, and move at 4 or 5 kts. Electric motors would save you more. Still, even an unmodified one would be way more economical than the 144' one you submitted. And I already knew it woyld take more fuel than some little 20' one.

 

[Simi 60]

If you’re into the electro boat fad it makes a good choice.

Why? To carry all those heavy batts.
.

You can have a heavy boat that can carry a load yet still maintain some semblance of efficiency.
Water line length and a easily driven hull shape is the key.
Tugs with their house brick hull shape seem to rely on "brute force" to make way.
And, that not "slippery like a fish" hull shape will need more power to push
Don't think that would play nice with electric motors and batteries.

 

[Simi 60]

No problem, one could outfit with smaller motors, and move at 4 or 5 kts.
Electric motors would save you more.
.

Do the numbers on that and report back

Can't imagine being limited to a 4 or 5 knot cruise speed, thems some slooooow miles

Still, even an unmodified one would be way more economical than the 144' one you submitted

.
That was used as an example that tugs do get converted, nothing more.

 

[JWellington]

Nomad Willy. Yes a good choice as a cruiser, or as a tugboat. And why? To carry 2 or 4 people all over the world. This one is 25% bigger than your friends boat, way mor solar capacity, and batteries. And if not to sunny up north, genset , and one could also put on a kite sail. That wont even sjade the solar panels. I think it would be a false good cruising boat. And a lot of benefits to an HDPE hull..

 

[JWellington]

Simi, sure, for guys who want speed boats no good. Same as a guy who wants a sports car wont buy a van.For many 4 or 5kts is plenty. It still gets you around the world. And the benefits of the HDPE hull. It was an example of yet another tg boat conersion, and a good one for those who like clunky boats.

 

[JWellington]

You can have a heavy boat that can carry a load yet still maintain some semblance of efficiency.
Water line length and a easily driven hull shape is the key.
Tugs with their house brick hull shape seem to rely on "brute force" to make way.
And, that not "slippery like a fish" hull shape will need more power to push
Don't think that would play nice with electric motors and batteries.

Efficiency was never touted in the OP. A full disp.hull dpesnt need too much brute force to glide slowly, but planning hul ls do, to get speed to plane on top. 4-5 kts, not much force. Its not clear why you think this boat would be any harder on electronics than any other one. Please explain.

 

[Simi 60]

Simi, sure, for guys who want speed boats no good. Same as a guy who wants a sports car wont buy a van.For many 4 or 5kts is plenty. It still gets you around the world..

Have you ever been out in the wobbly stuff?
Unstabilised boats can and do roll terribly at low speed in a slop and often, going a bit faster smooths things out considerably

And I ain't talking speed boat here, still talking full displacement and under 10 knots.

 

[Simi 60]

Efficiency was never touted in the OP. A full disp.hull dpesnt need too much brute force to glide slowly, but planning hul ls do, to get speed to plane on top. 4-5 kts, not much force. Its not clear why you think this boat would be any harder on electronics than any other one. Please explain.

I never mentioned electronics or planing hulls.

I mentioned electric motors (propulsion)

Why do you think all the electric car and boat guys build from composite and make slippery designs?

 

[JWellington]

Have you ever been out in the wobbly stuff?
Unstabilised boats can and do roll terribly at low speed in a slop and often, going a bit faster smooths things out considerably

And I ain't talking speed boat here, still talking full displacement and under 10 knots.

Yes, just two days ago.....and we got all the eay up to 3.8knots. Unstabilised? You must have heard that thete are al sorts of effective stabilizer systems out there. Some powered like Seakeeper,..others passive.

 

[Simi 60]

Yes, just two days ago.....and we got all the eay up to 3.8knots. Unstabilised? You must have heard that thete are al sorts of effective stabilizer systems out there. Some powered like Seakeeper,..others passive.

If you can afford seakeeper surely you can afford something better than 40ft of 4 knot Tupperware?

Maybe a decent powercat, no stabilisers required and better suited for electric drive given their efficient hull shapes.

 

[JWellington]

I never mentioned electronics or planing hulls.

I mentioned electric motors (propulsion)

Why do you think all the electric car and boat guys build from composite and make slippery designs?

You mentioned brute force, and I rebutted you above. Electric or hybrid boats can be, and are already of various hull forms. Some of tne big europan commercial boat builders say they can make all their boats hybrid. This small tugboat could be too. But you like speed, so dont ever get a slow boat or car.

 

[JWellington]

Ok, you know that there exist stabilizers, so thats resolved. Speed resolved because some like slow speed. Electric propulsion...resolved. Costs...never even mentioned in the OP. What else is left ?

 

[Simi 60]

It's not a matter of what's left
It's a matter of what is sane, sensible and financially viable.

Electric hybrid boats make little sense at this stage imho
Take silent yachts as a prime example
Oooh, it's electric, but still connected to 2 X 220hp diesels to make the electricity all so it can tool along at 6 knot cruise.

How do you think it would go with props on the end of those diesels instead?
And all for a lot less coin.

https://www.mby.com/reviews/flybridges/silent-yachts-55-liveaboard-test-electric-catamaran

And that's with an efficient hull shape.

And if cost is not part of the equation you are talking fantasy, so I need not waste any more time.
Happy to talk reality.

 

[psneeld]

Based on the pics, I can't imagine a worse liveaboard based on size unless solo and have a spartan idea of comfort.

I might see it as a seasonal cruiser/ workboat to make some income as a tug...but not much else based on compact interior spaces.

 

[Sailor of Fortune]

This new mini tug should be an interesting conversion to a livaboard cruiser. IZ 1205 HDPE

Tugs make horrible conversions to yachts (real tugs like this small tug). Relatively deep draft, no interior room and fuel thirsty. Over sized fuel tanks, big deep gear ratio gearboxes etc.
Fishboats make better conversion candidates IMHO.

 

[Mako]

Too bad Mal Low isn't around anymore selling his small tug plans. Nice stuff

 

[Comodave]

Fair enough, but I think of it more as a van to rv. I like heavy, clunky looking boats. And it does have many attributes anyway. Foe example, with HDPE hulls, not only dont you have tp paint them, you dont even need antifouling.

I have owned 2 HDPE boats. Stuff will grow on them if you leave them in the water. I didn’t leave them in the water but if I were going to I would have painted them. You have to flame the area to be painted in order to get the paint to stick to it.

 

[Nomad Willy]

S of F how true,
But heavy boats can carry a lot of fuel or batts.
But every pound you add increases the wetted surface and shape drag or as some say cross sectional shape drag. Basically the form that pushes the water aside and by something akin to suction pulled it back to roughly where it was. Some of this form drag pushes the water up a bit ahead of the stem of the bow.

My favorite way to consider power to move a displacement vessel is stating the requirement of how much power does it require to push at a reasonable speed. My W30 Weighed 8 tons and had 40hp.. just a little overpowered. 33hp would have been fine. With 40hp I cruised her at about 6.2 knots w a full speed of about 7 knots. Seven knots is her hull speed and there's no reason to ever go 7 knots (except for systems check) but w a FD boat of 27.5' WLL one can consider their boat to be properly powered if it can reach 7 knots. I was running at 2300rpm cruising on a 3000rpm engine. As far as I could tell the 40hp engine was at very close to 50% power output .. at 2300rpm cruise.

But the interesting and applicable number here is how many hp is required to give her a reasonable cruising speed. In this W30 case it's 5hp per ton of displacement. To have 5 hp per ton on a 38' boat w a WLL of 35' we'd be looking at a hull w more disp. The displacement to have the 5hp per ton requirement on the 38' boat I don't know. I don't know as I'd need to calculate the hull volume below the WL for both boats ..?? But such a boat will not be likely as it would be very wide. But it would still have 5hp per ton to function as the W30 does. The numbers I gave re my old W30 dictates 4-5hp per ton is a well powered boat.

3hp per ton would produce a boat that would require a bit more power and thus perhaps 100rpm more to achieve. Three hp per ton would be for a boat on the large size for a trawler like Simi's boat. He would do well w 3hp per ton. I think 4hp per ton would be a very good starting point when considering the desirable amount of power for a FD typical of a rec-trawler.

I once saw a boat about 65' on Passagemaker Mag w 2hp per ton. I think you could consider that a low to extremely low amount of power. It was a canoe stern boat. I think it had an 8cyl. Gardner engine.

HP per ton of displacement gives us a starting point. I used it mostly observing other boats and finding out the size of their engine. 7 to 9 or 10 is probably a good ballpark range of typical SD rec-trawler boats on the slow power/speed side. Faster boats like the Camano would have a higher number. But since there's such a wide range of SD hull forms and weights using a number per ton of dips. is probably is less applicable than the number applied to FD boats.

 

[JWellington]

It's not a matter of what's left
It's a matter of what is sane, sensible and financially viable.

Electric hybrid boats make little sense at this stage imho
Take silent yachts as a prime example
Oooh, it's electric, but still connected to 2 X 220hp diesels to make the electricity all so it can tool along at 6 knot cruise.

How do you think it would go with props on the end of those diesels instead?
And all for a lot less coin.

https://www.mby.com/reviews/flybridges/silent-yachts-55-liveaboard-test-electric-catamaran

And that's with an efficient hull shape.

And if cost is not part of the equation you are talking fantasy, so I need not waste any more time.
Happy to talk reality.

Wrong on the Silent yacts. They have two electric motors and one genset, and at least 10kw of solar panels. But if you want to call all those who actually have bought hybrid electric boats as fantasists, thats your problem.

 

[JWellington]

Based on the pics, I can't imagine a worse liveaboard based on size unless solo and have a spartan idea of comfort.

I might see it as a seasonal cruiser/ workboat to make some income as a tug...but not much else based on compact interior spaces.

That comment might hurt the feelings of everybody out there with boats 40' or less. Re interior space, I had mentioned extending the roof...solar panels on top and galley/ salon inside...bunks below. Ive seen many living comfortably with such space. But certainly , for those who need 60 footers or whatever, then this size is no good.