# Some big MAN motors...



## Ray C (May 29, 2014)

Been doing some work at the marina again and thought you might get a kick out of these motors...  This particular vessel is powered with two, V-12 quad turbo MAN diesel motors. You can see two turbos in-line and there are two more just like it feeding the six cylinders on the other side of the motor.   Each produces 1245 horsepower (934 kW).  The vessel is a custom power cruiser -aptly named given 2490 (1.87 MW) horsepower is about the power of a locomotive.  These motors make the 55' vessel go 50 knots consuming about 50 gallons per hour per motor (100 g/hour) ...  Onboard fuel tanks are 700 gallons.  Upon getting on board this vessel, it took 20 minutes of looking at the control console to figure-out how to spin-up the motors.  There are no mechanical connections from the helm to the motor room -everything is controlled by servos and/or various electronic or hydraulic actuators.

Here's yours truly trying to figure-out what's wrong with the troll gear on the starboard transmission.  -And just to give you some perspective, while laying on one motor, I laid my leg on the other.   They are surprisingly smooth and not all that loud although ear protection down there is worn while the motors are turning.  This is by far one of the nicer engine compartments I've worked in lately.  You can actually stand up whereas most are crawl-spaces just barely big enough to get your shoulders through.  I've managed to get wedged pretty good more than a few times...






Ray


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## Marco Bernardini (May 29, 2014)

Nice puppies!
The gas station owner must be happy to see a boat like that one approaching!


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## Ray C (May 29, 2014)

Marco Bernardini said:


> Nice puppies!
> The gas station owner must be happy to see a boat like that one approaching!



The shores are lined with thousands of boats like that -and many of them with much higher fuel capacity.  We have about 100 in dry dock at any given moment.  A boat like that will get filled-up several times per season and it's "sparsely" taken out since it's privately owned.  The boats used for regular excursions will need refueling every few weeks.  The maintenance that goes into these vessels is off-the-charts.  The resistance on the hull of watercraft is very high and constant.  These motors work much harder that an equivalent road-use motor and need to be rebuilt every few years.  Costs are astronomical.  

Here's a smaller one, just pulled out of water and dry-docked.  This vessel is about 33 tons (66,000 lbs).  This is a medium sized boat lift with a 75 ton capacity.  There are much larger ones at this marina...  It cost about $1000 to pull a boat and set it on blocks and jacks.





Most of the weight is on the keel (the rib down the bottom center of the hull). The timber on the bottom is 16" wide.  That bottom plank sitting cross-wise is 2" thick and you know it's a heavy load when it compresses and bends like that.  





I was installing a new depth sonar along with new electronics.  The replacement sonar fin comes flat and the angle and contour to the hull must be measured and the block then cut and fit with precision.   This is very different than my usual metalworking but, it's OK I guess.   Many yacht repair places won't handle things like this due to liability concerns.  ... Don't worry guys, I'm not leaving the metalwork trade.  I'm helping a friend who is so busy, he might end-up killing himself trying to do all the work himself.  






...

The other day, we had a vessel with a stuck anchor because the windlass went belly-up.  Very difficult job and it took a very long time to analyze the electronics and diagnose the problem.  Ultimately, the windlass controller had to come out and I came dangerously close to dislocating my shoulder lifting it out with one arm, outreached to the max while working through a hole about 10" in diameter.  I'll do high liability stuff all day long but, the grunt work is for the birds... getting too old for this.

Ray


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## CluelessNewB (May 29, 2014)

That engine room is palatial compared to the space on my sailboat!  The up side is I burn less fuel for the whole season than one of those engines burns in an hour!


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## xalky (May 29, 2014)

Ray C said:


> I was installing a new depth sonar along with new electronics.  The replacement sonar fin comes flat and the angle and contour to the hull must be measured and the block then cut and fit with precision.   This is very different than my usual metalworking but, it's OK I guess.   Many yacht repair places won't handle things like this due to liability concerns.  ... Don't worry guys, I'm not leaving the metalwork trade.  I'm helping a friend who is so busy, he might end-up killing himself trying to do all the work himself.
> 
> ..
> 
> ...



You gotta do what pays the bills ...Ay!  

Maybe if you get a little bit busier you can get a a kid with a good head on his shoulders and some mechanical aptitude to help you with all the heavy lifting and teach him some stuff along the way. For a kid with some basic mechanical aptitude, a job with you beats working at the local McDonalds and you can start him off with a slightly better wage too. It's a win/win. When they're young and eager, they suck it up like a sponge.

Marcel


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## Ray C (May 29, 2014)

xalky said:


> You gotta do what pays the bills ...Ay!
> 
> Maybe if you get a little bit busier you can get a a kid with a good head on his shoulders and some mechanical aptitude to help you with all the heavy lifting and teach him some stuff along the way. For a kid with some basic mechanical aptitude, a job with you beats working at the local McDonalds and you can start him off with a slightly better wage too. It's a win/win. When they're young and eager, they suck it up like a sponge.
> 
> Marcel



For all practical considerations, I am "the kid" but, am working as a contractor for my friend's company.  I don't have great knowledge about boats and I often rely on my friend to point me in the right direction.  I'm in no position to teach this to anyone as, there are so many specific types of valve systems, control systems , navigation systems etc...  A good boat tech knows all about them, inside and out... I'm just fairly good at figuring things out, not screwing things up, and not requiring anyone to double-check my work.  They issue me a fully stocked repair truck and we work independently most of the time but all the guys I work with realize I'm a "craftsman of a different type".  They tolerate me ...


Ray


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## Ray C (Jun 3, 2014)

FYI:  Here's follow-up on the big MAN engines...   The boat was moved to dry-dock the other day and the props were pulled off in preparation for some transmission work.  I wasn't on board when it was piloted to the dock but, a friend of mine was.  At idle, it moves 9 knots (about 15 miles/hour).  One of the transmissions is stuck in high gear because of an actuator gone bad.  -You don't want to own one of these boats...  The actuator alone (about 12" long and weighing about 8 lbs) cost $3500.00.  

Not easy getting the props off...  They're made of bronze, 3' diameter and over 300lbs each.  Those prop shafts you see me standing next to are stainless steel.   They are large scale versions of the ones I frequently work on.




Needless to say, I've been inducted back to the yard for some work but I'm pulling in some good shop jobs which I hope to post about in the upcoming weeks. 


FYI:  Here's a dyno test on that same version of engine shown in the first post.   Standing next to them when they're just idling is pretty nifty.  http://www.youtube.com/watch?v=MjnGqvK5pmQ

Here's an interesting video:  http://www.youtube.com/watch?v=dR2BRx0ZE5c  Note the big drum used for cooling water.  That engine will make 55 gallons of water boil in a very, very short time.  They're cooled with filtered sea water.  I don't recall the pump volume rate but, it's off the charts...


Ray

PS:  Sorry for not looking my best in the photo...  It was the end of the day and I endured quite a struggle working solo on a different vessel when my friend called for help to get those props off.


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