too big a diesel(never at full power) and "glazing"?

Discussion in 'Diesel Engines' started by Squidly-Diddly, May 14, 2010.

  1. Guest62110524

    Guest62110524 Previous Member

    wartsila crossheads at that shp? OR 4 CYCLE?
  2. powerabout
    Joined: Nov 2007
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    powerabout Senior Member

    2 to 7k horsepower medium speed 4 stroke, basically just like a high speed engine
    some are 12V32's

    PS 16,000 hrs at 60mph = 1,000,000 miles or just under 2 years non stop
    Std spec for a high speed diesel in a truck.
    Wartsila spec is all pistons out at 10,000hrs.
    I can see why many smaller vessels are going high speed diesel electric
    just swap out the engine with a recon so very little time off hire and they have a longer service life...who would ever have though that!
  3. apex1

    apex1 Guest

    There is another reason for that. Many of these vessels rarely operate near the max power. Tugs for example see full power only between 3 and 6% of their service life, but at 80% of the time they operate below 25%. That makes a D /E installation sensible.
    Other advantage is that the spare genset (there is commonly one set more than needed for max output) can be serviced while underway, no losses.

    I can hardly buy these 10.000hrs. for a rebuilt (which "all pistons out" would mean) on a Wärtsilä 6/32 or 12/32

  4. Guest62110524

    Guest62110524 Previous Member

    Maersk Dover if I remember correctly has these
    Does not seem very long 10000 hrs especially when she runs non stop, ie no cold starts,
    what do they do then , new liners and rings?
  5. powerabout
    Joined: Nov 2007
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    powerabout Senior Member

    ahhh no

    Maersk Dover has 4 × MAN 8L48/ 60B diesels for a combined combined 38400 kW ( according to wkipedia)
    our 80m boats have 11000kw combined

    Yes , let me confirm the 10,000 hrs as thats the same as a 3500 cat
    I do know 2 that have done more than wartsila state but last class inspection they didnt look at the hours...doh?
    If I'm wrong it will only be as high as 12000 hours and they badly need rebuilding when you look at blowby and oil consumption and contamination
    PS they do have anti polishing rings on the pistons to help prevent bore glazing
  6. Guest62110524

    Guest62110524 Previous Member

    lazy me, I have been on this ship many times, should have googled, the engines sound heavy, but going astern the vibration is something else, the rails shake like mad, I dunno how they dont fracture something
    Well thats poor from Warsila is'nt it Dover is rreally slow for such a big shp. probably cos of her stubby length
  7. apex1

    apex1 Guest

    Well, yeah, thats really poor.:p

    I would not call a ship of that size slow, doing 25kn. And I would not blame Wärtsilä for the installed MAN engines............:D
  8. powerabout
    Joined: Nov 2007
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    powerabout Senior Member

    well said Apex!

    Nobody spends more than 1 dollar more on a water bus than absolutely neccassary.....
    Its just a design that met a price and the parts assembled by a shipyard that quoted low enough and classed by the lowest bidder.
    No matter how much you spend you only get 1 year warrantee. That says it all about the commercial shipping world as far I understand it.
    Thanks to classification societes most commercial shipping is designed to be scrapped in less than 10 years these days.
    I know one AHTS owner who has budgeted/projected 5 years life from his (asian)vessels and believe me they will be lucky to last that long...
    You cannot put a cup of tea on a table in the bridge when pulling anchors otherwise it will all spill in forward or reverse and PC's sometimes crash as the hard drives dont like it.
    Norwegians have anchor handlers that are 30 years old...

    (PS ) I worked on a dutch built megayacht that the yard did warratee work after 5 years for the second owner without question. The quality megayacht builders rarely build down to class

  9. Guest62110524

    Guest62110524 Previous Member

    with so much shp, the dover is not the dunkirk, but she does 22 the wl is not so long, a much longer ship with that shp would be faster, just a simple observation Powerabout thats all Maybe top is 25 but everytime I have been on them , even when running behind, they do 22 max, that is with my Magellan handheld, at slack water
    you take the Emma 170000 grt, 400mlong, 25 knots, she is 5 times the weight of the Dover but nowhere near 5 times the shp,
    Anyways powerabout thanks for input
    where are you now
    and yes nobody who wants to stay in Business builds down to a price. Best not to have any orders
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