Diesel Electric Conversions - Are Systems Available

Discussion in 'Hybrid' started by Barron, Sep 25, 2009.

  1. fcfc
    Joined: Feb 2005
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    fcfc Senior Member


    Diesel electric does not store any electric energy. You just replace gearbox + some mechanical linkage with alternators and electric engine. + control electronic. It can also ease multi engine coupling. (several propulsion engine drive the same shaft : several gensets that power the same electric engine)

    Hybrid does need to store electric energy somewhere.
  2. CDK
    Joined: Aug 2007
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    CDK retired engineer

    Thanks for explaining that to me.
  3. apex1

    apex1 Guest

    And me too! :D
  4. kistinie
    Joined: Aug 2007
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    kistinie Hybrid corsair

  5. powerabout
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    powerabout Senior Member

  6. Barron
    Joined: Mar 2009
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    Barron Junior Member

    I guess I missed all that............

  7. Cypherus
    Joined: Jun 2017
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    Location: United Kingdom

    Cypherus New Member

    Hi all, new to the forum and fell into it after an extensive search in relation to a project very similar to that described by the OP.
    To place this in context the ship we are looking at is a 24 meter TSDY some 26 years old, it current prop system includes twin 1300hp MTU's which frankly are approaching the end of their service life and as part of a more general replacement study we have chosen to look at 'All', available options open to us in what will be a major refit of the ships interior spaces.

    My own background is in Rail so Deisel Electric propulsion is something I understand and recent developments in AC motor tech and power provision lend themselves towards marine applications providing not only lighter installations but also very flexible design options in the area of component placement, in short everything does not have to be in one place but can be distributed around the vessel in locations chosen more for interior layout design than the normal engine room layout would allow.

    Looking over the OP's spec's brief as they are this points directly to what in the Rail industry has come to be known as the 'Genset Principle' which is based on the idea of how much power do I really need to move this lump from one place to another, running light a 150 tonne locomotive can easily get around even at mainline speeds with a single 560hp generator pack, hang 3000 tonnes on the hook and things scale up quickly so additional packs are started and cut in and out as required, specs of course vary but on average four or five units are slotted in and bussed to provide traction power on tap up to the rated maximum.

    So how does this apply to Cruiser design, in this case, the OP indicates he requires a suitable DE alternative to his current installation and one possible solution would be to install a single equivalent AC traction unit of around 800hp supplied by four generator sets meaning that he would have many options on how much power he could apply again up to rated maximum, this option would not only provide a far lighter installation but avoids major surgery to the ships hull using as it does the original shaft drive, unless he wants to go for pod drives or azipods.

    As for where he might go for such a system, well the components are available as we have found out, however, a ready to install off the shelf set up is not an option for him and he needs to employ a design team to draw up the system in full, again this is the option we have to take for our preferred setup, a four Genset supplied twin AC motor direct drive (Ungeared), system. Initial discussions indicate a 40% incurred weight saving and approx 60% space saving for the installation as two of the Gensets are utilising what was wasted space in the Bow section and on the upper deck.

    There are of course penalties to all of this, of course, there are, installation being the main issue, but as part of a major interior refit they are not game breakers, As for the OP's insistence on a maximum of 16knots well how often would such a ship be punching it's way about the seas, probably not very often, more like a steady 8/10 knots unless he's towing one of the Gulf states behind him to fuel it in which case he would more likely be only running two or maybe even one of the Gensets at its optimum output which is where these systems come into their own and provide significant economies.

    We came into this not knowing what to expect so we had no hard and fast theories to work against, all options were open to us, what we quickly learned is never to NOT look at all of them.
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