small tug engine sugestions

[yowiepower]

G’day all from the land down under. Could some one please give me an idea on the sort of engine I should be looking for I am currently in the planning stage of my boat project which is a 21 foot mal low pelikan tug design, I am going to build in steel. What I would like to know is what make/model engine should I look for in the 120-150 hp range? What gearbox would be recommended? My first post so please forgive stupid questions.

[Frosty]

Small tug? Make one,- don't waste money on some thing like crap Yanmar.

I would use a Hino E700 180 HP and bolt up a Borg warner.

Keel cool it with fresh water system and big ole chinese heat exchanger with dry exhaust.

[marshmat]

Hi yowiepower, welcome aboard :)

Frosty's a little bitter about Yanmar these days (he has a couple of troublesome ones). In any case, most of the Yanmar line seem to be intended either for sailboat auxiliaries or for fast craft that need light, high-revving motors.

What it really comes down to, yowie, is what you can readily get repaired in your area. Everything breaks, eventually. If you buy a Cummins and the nearest Cummins service centre is 1200 miles away, shame on you. On the other hand, if you have a Cummins dealer in the next town over, and he has good mechanics, that could be a big factor in favour of that brand.

For a tug-like boat, you're probably more interested in something that can run quietly and smoothly at 75% throttle for hours on end, than in something that can give you short blasts of insanely high power.

The way to figure out your gearbox needs (and, to some extent, your engine needs) is to start with the propeller calculations. Do the Bp-delta calculation for your hull, with a few different propeller styles, and you'll know how much torque you need at what RPM on the shaft. From there, you can start matching engines to gearboxes.

[apex1]

Welcome here yowie,

the 120 to 150 range is a bit a difficult one because thats exactly the upper end of the 4cyl. and the lower of the six cyl. engines at a heavy duty power rating. (M1 or M2)
The "Vetus Deutz" DT 66 is a six cyl. of about 160 horses shaft rating at 6.6ltr. displacemet, the "JohnDeere 6068" 6 cyl. of 6.8 ltr. displacement is another example in that ballpark. The "John Deere 4045" 4 cyl. of 4.5 ltr. comes at the lower end of your power requirement.
Cummins is worth a closer look too.
Gearboxes to fit these high torque engines are commonly ZF, PRM or Twin Disk . When really heavy duty "Reintjes" is the gear.

If you are out for extended use, or do´nt like to buy a second and third prop due to failed Prop calc.s (a common mistake), you should choose a Controllable Pitch Propeller (no gearbox). That makes your engines happy, economic, and last ´til eternity. (due to the better "load" characteristics achieved by prop setting, which is´nt possible with a fixed prop/gearbox)
Main names in that field are "Sabb", "Hundested", "Helseth", "Westmekan" to name the most common and proven. The complete Scandinavian fishing fleet uses one or the other of the brands named.

Choose the largest wheel you can turn at the lowest rpm and match that with the highest torque engine you can find.
Take care to have a min. tip clearance of 15% (prop dia.) between prop and hull, 20% is better.

Regards
Richard

[CTMD]

Yowiepower where in SW Victoria are you? Port Fairy, Warrnambool? I might have a local contact for you for second hand engines. Would you be interested?

[Frosty]

A variable pitch prop and shaft arrangement will I think be more that the entire boat will cost.

[apex1]

A variable pitch prop and shaft arrangement will I think be more that the entire boat will cost.

Well Frosty, that is a very common belief, nevertheless it is´nt true. If compared with a high quality conventional installation, the price is about the same! When you have to replace a prop due to wrong calc.s or so, you are way above the cost of a CPP system. And I have seen many owners replacing the original prop (some even more than once) pretty soon.

[Frosty]

A freind of mine bought a 90 foot Russian trawler, it was on the beach. I went to see him and found my way down to the engine room where he was fixing a starter motor to start the generator to start the compressor to pump up enough air to start the main and see if the variable pitch prop worked.

He said that if the prop dont work the boat is scrap.

A conventional installation is a shaft and prop with some shaft bearing supports. A variable needs a hollow shaft to operate the prop which by the way only changes pitch. If the shaft is only slightly bent it wont work the prop pitch mechanism.

A good idea for ocean going deepwater tugs with constant RPM engines but for economical coastal DIY ?

[hartley]

g;day yowiepower,south west victoria eh ,warrnambool my old home town
born in hamilton,a looong time ago.where are you going to use the 21 footer
pretty rough coast along there ,portland maybe.good advice from CTMD ,get a good second hand diesel ,a machine shop will be able to bolt up a borg warner gear,plenty of those about ,and easy to bolt up ,keel cooling and dry
exhaust and there you have it ,maybe CTMD could help you along the way
naval architecs KNOW what they are talking about ......cheers hartley

[yowiepower]

Thanks for the ideas guys and the warm welcome,
I am about 60 k’s north of portland CTMD (seems so logical that I would want to build a boat so far from the coast doesn’t it) and we have a holiday house down at pt fairy so any contacts you have would be great. this variable pitch prop sounds very complex also sounds like it costs a small fortune but spot on in many different conditions.

[apex1]

To make that clear again (we had this senseless discussion more than twenty times now), a CPP does NOT cost more than a good quality conventional installation! And all the suppliers named above produce extremely reliable and top quality CPP installations only. There will nothing bend or fail.
And Frosty, no Scandinavian fishboat has a constant speed engine, but ALL have a CPP! And I know for sure that fishermen do´nt have money to waste either. The opposite is reality, they save a lot of money, due to far better economy on their engines. Fuel savings of about 30% are not the maximum achievable. And lifetime easily doubles.
Of course if second hand equipment is the competition, there is no race to win for a CPP.
To conclude: A CPP is not complex, not more expensive than a gearbox/shaft and has at least the same reliability. When it comes to lifetime cost the CPP is far cheaper than the conventional. When economy is a must, the gearbox arrangement is out of race! And when the boat (as I mentioned above) is really in use, the engine lifetime cost will be worlds above in a conventional arrangement.

So, why do´nt we see more of those CPP´s? Thats due to the stupidly and stubbornly repeated nonsense that such installation costs a fortune. Even some boatbuilders and designers are stupid enough to say so. Fact is that nobody who ever did install it comes to the same conclusion. Quite the opposite!

I install far more conventional systems than CPP´s only for one reason, 90% of my boats are fast powerboats, there a CPP has no advantage, the speed optimized fixed prop is the better choice. In my displacement boats you find Sabb and Hundested only!

Regards
Richard

[Frosty]

Wow Apex your soooo good , how could I be so foolish. Im sorry for annoying you and having said something in your presence.

You tell him what to do, I wont say anything anymore.

I cant be bothered to argue with you, Im sure your right.

[apex1]

Dunno why you take that personal Frosty.

It´s just a fact that when you leave the Baltic and North sea region nealrly nobody knows a bit about CPP installations, but almost all believe they are complicated and expensive.

And it was your friend who made a foolish statement. When the shaft is bent (no matter fixed or variable prop) your propulsion is shot! But when a CPP has a damaged blade it is less than half the cost to fix that as it was to fix a similar damage on a fixed prop (if possible).


But lets hear what a well established US designer has to say about his experience with CPP versus fixed prop:

http://www.kastenmarine.com/CPprops.htm

Regards
Richard

[yowiepower]

cheers guys by the sounds of it a CPP will save u money by not having to keep replacing you prop and like everything if you buy quality you will get a good run out of it. also sorry apex1 for opening up that old wound about the cost of a CPP great articale you gave us

[apex1]

Welcome mate. I do´nt mind to inform a amateur or novice, none of us knows everything. But it is annoying to repeat the same prayer to the same audience everytime again. And having everytime the same stupid and non valid "arguments". If they are too lazy to read a article, they should stay quiet. Nobody can be blamed for ignorance, but combined with a know all attitude it´s a plague.

If you can afford a higher than average (of course they are), investment in your propulsion and if the vessel in question is used more than the average 100hrs per annum go for a CPP system. You otherwise may find out soon: the poor man pays twice.

Regards
Richard

[Frosty]

It´s just a fact that when you leave the Baltic and North sea region nealrly nobody knows a bit about CPP installations, but almost all believe they are complicated and expensive.

And it was your friend who made a foolish statement. When the shaft is bent (no matter fixed or variable prop) your propulsion is shot! But when a CPP has a damaged blade it is less than half the cost to fix that as it was to fix a similar damage on a fixed prop (if possible).



Don't make me into a liar Apex, the boat was 90 feet bought on the beach of Singapore off Changi . A Russian trawler seized by the Sherrif of Singapore and finally sold to Cyril a friend of mine who sold me his 60 footer so he could get money to buy it,--he is a ship builder.

The rest I have already told you.

But your probably right, I must have dreamed it sir.


I cant find any prices for a CPP system suitable fort a 17 meter boat but Im sure you can ,--enlighten us.

[hartley]

g'day yowie ...funny old place this isn't it ,now to get on to a lighter subject please tell me if you can still get the worlds best fish and chips at that shed on the wharf at port fairy , a plate of those with a dash of vinegar and a little sauce on the side is heaven on earth ,and just in case some folk think i am talking about some exotic fish, i am talking about southern ocean SHARK known as flake to us .I now live on the sunshine coast in QLD and they wouldn't know a decent feed of fish and chips if it hit them in the face ,all they do is rip off the tourists,oh and by the way the so called flake they try and sell here is GREY totally revolting ,ah well such is life ,one last thing don't listen to armchair experts tread your own path......cheers hartley

[yowiepower]

copy that hartley and you will be pleased to know that they still sell the best fish and chips on the wharf at pt fairy a trip there without a feed of them is just not complete.

[Frosty]

You guys can afford fish and chips?

Do they do spam and chips?

[hartley]

we're in orstraia frosty we don't eat no spam ,nothing but the best for us ha ha ha .but the way we are going in qld under that corrupt despot capt'n bligh, god knows what we will be eating .....cheers hartley

[Frosty]

No? maybe --but you are guilty of eating the most disgusting spread on this planet Vegimite, Oh that is just --- it needs pushing back up the dogs arse where it came from.

[hartley]

I rather like it frosty,especially when i am feeling crook (too much rum)
but then thats just me......cheers

[yowiepower]

bundy from mundy to sundy, vegimite is good stuff u can live on it, even better is trying to convince foreign tourists (terrorists) that it is heavy duty australian sun sreen

[apex1]

Don't make me into a liar Apex,

Where have you seen such attempt? Do you refer to my contradiction on your opinions about CPP´s? That does´nt make you a liar, just your statements are wrong.

--he is a ship builder.
The rest I have already told you.

Ok, what does that tell us? He is a shipbuilder with ZERO experience in CPP systems, nothing else.

I cant find any prices for a CPP system suitable fort a 17 meter boat but Im sure you can ,--enlighten us.

Of course you can´t. No manufacturer gives you a direct quotation, but sure I can have one.
What is a 17 meter boat? A new Olympic class?


Regards
Richard

[Frosty]

17 meter is the length of the boat being built!!

A man with your contacts would be able to get a rough price if the word quotation worries you.

I would be very interested as would others.

I dont think my freind was wrong ,if the CPP prop system did not work the ship would have been scrap which is the price he paid for it anyway and its worth.

A 48 inch CPP 3 blader prop would be, Oh,--- say how much?

How much do you think?

[apex1]

Thats beginning to be a bit annoying mate! What is a 17 meter boat? 5 tonnes carbon composite sailing cat or 45 tonnes steel coaster? 25hp single cyl. or 2x 1550 hp MAN 12 cyl?

You are kidding

To your friend, where was the difference between a shot CPP and a shot conventional prop? If the boat was´nt worth the difference it was worth nothing.

And I´m surely not willing to guess or estimate prices for your entertainment. I recommend to have a rest and have some thoughts about your behaviour.

[Frosty]

How can you not know? its the question to the original thread that you have been replying to.

I can see you just want the CPPP thing to go away now.

[apex1]

Frosty which "original thread" please? Where did I reply on something like a 17m boat?

And why are you guessing what I want? You will not force me to play childish games with my suppliers. Read the article I posted so many times , improve your knowledge, its never a loss.

[Jimbo1490]

No? maybe --but you are guilty of eating the most disgusting spread on this planet Vegimite, Oh that is just --- it needs pushing back up the dogs arse where it came from.

I've (unintentionally) had paint remover in my mouth many times while spraying stripper. I've eaten vegemite once. I can say truly and honestly that paint remover tastes better than vegemite; as god is my witness!

Jimbo

[apex1]

paint remover tastes better than vegemite; as god is my witness!

Jimbo

Should this case come to court, you can rely on me as a witness too.:D

Richard

[Frosty]

It Aussie food, thier beer is similar were cheapness is more important than quality.

Probably something to do with Kangaroo excrement.

Paint stripper is a bit more tangy.

Kiley Minouge is not a true representative of Australian women.

Dame Edna Everage is, understandably massive quantities of cheap beer needs consuming before copulation can be even thought of. And that would be if there was no attractive roos around.

Ive been there 3 times.

[yowiepower]

just a bit harsh frosty got to remmember that it is hot and dry here and as u sweat u have to keep replacing your fluids it is very important to keep hydrated

[Frosty]

Do you think its hotter than where I live?

[yowiepower]

no way been to far nother qld and indoneasia and thiland, bangkok dont rember much was pretty pissed but you have heat + humidity in central australia where i have jacarooed during the dry season in 45 degree heat. we get dry heat and wrestling cattle in that heat leaves you with a hard earned thirst.

[dskira]

To conclude: A CPP is not complex, not more expensive than a gearbox/shaft and has at least the same reliability. When it comes to lifetime cost the CPP is far cheaper than the conventional. When economy is a must, the gearbox arrangement is out of race! And when the boat (as I mentioned above) is really in use, the engine lifetime cost will be worlds above in a conventional arrangement.

So, why do´nt we see more of those CPP´s? Thats due to the stupidly and stubbornly repeated nonsense that such installation costs a fortune. Even some boatbuilders and designers are stupid enough to say so. Fact is that nobody who ever did install it comes to the same conclusion. Quite the opposite!


Regards
Richard

I agree completly. It is sad we don't see them more often. But for some reason glosy magazines and uninformed journalist (an oximoron) do not even know them, or never tryed them, and designer very often do not mention them to customers.
As for engines while in my boatyard in Spain we installed Kelvin in fishing vessel and pleasure vessel. What a beautiful engines, extremely reliable, easy to maintain, and I think, a superbe design. That was long time ago, I hope they still in business. I installed also some Gardner, quite a treat, but I don't think they are in business anymore.
By the way a customer of mine just find an old Sabb 30hp 2JHVP with CPP brand new, in box, original, to be used for his schooner which still in design stage.
Daniel

[powerabout]

Didnt/ dont DS Jongerts have manual Hunterstads or was it an option?