Heritage Class Offshore Patrol Cutter Argus launched

Discussion in 'Boat Design' started by Stephen Ditmore, Oct 29, 2023.

  1. Stephen Ditmore
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    Stephen Ditmore Senior Member

    Argus, the first Heritage Class Offshore Patrol Cutter, is launched:

    The launch is 56 Minutes into the video.

    Would reworked Littoral Combat Ships make good Coast Guard Cutters?

    https://maritime-executive.com/editorials/op-ed-a-derated-littoral-combat-ship-would-make-an-ideal-uscg-cutter

    More about Littoral Ship repair:
    First Littoral Combat Ship With Fix To Plagued Combining Gear Delivered To Navy https://www.thedrive.com/the-war-zone/43219/first-littoral-combat-ship-with-fix-to-plagued-combining-gear-delivered-to-navy

    Any lessons for boats & yachts?
    Anyone care to make comparisons to vessels built elsewhere, like Saab's composite Visby-class corvette?
     
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  2. bajansailor
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    bajansailor Marine Surveyor

    That is an impressive video of her launch!

    Some more info about Argus -
    Eastern Shipbuilding Launches First Offshore Patrol Cutter https://maritime-executive.com/article/eastern-shipbuilding-launches-first-offshore-patrol-cutter

    She still has almost another year of outfitting (and then sea trials) before delivery in September next year.

    Re the launch, I was intrigued by what appear to be tensioned cables securing the hull to the transverse beams under the keel. I presume these beams are timber? After the launch there is a LOT of bits of timber floating in the vicinity - did many of these beams break up, or are the bits of timber from the individual supports breaking away?
    I guess that a workboat would then go around collecting all the various bits of timber, and the yard crew on the ship would recover all the tensioning cables?

    It is a very different style of launch when compared to how the Dutch typically launch their vessels - here is a launch at Royal Bodewes into a VERY narrow canal -



    Re the link to the Maritime Executive column discussing the use of an LCS as a Coastguard cutter, they are talking about a monohull Freedom class vessel - but surely a trimaran Independence class vessel would also work well (perhaps even better) for the USCG?

    Littoral combat ship - Wikipedia https://en.wikipedia.org/wiki/Littoral_combat_ship
     
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  3. BMcF
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    BMcF Senior Member

    The monohull LCS hull was designed (initially based on the "Destriero") to allow very high (>40 knots) sprint speeds. It is not nearly as well suited for long range operations at much lower speeds...as the OPC hull is optimized for. Waterjet propulsion efficiency is poor at lower speeds as compared to the high-speed operation they are sized and optimized for. Hopefully the retiring LCS vessels can find useful service with another navy, although still requiring the total replacement of the propulsion line, at no small expense.
     
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  4. Stephen Ditmore
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    Stephen Ditmore Senior Member

    With the LCS, seems like problems are with the marine gear that permits switching between drive engines. They've recently begun switching in a different transmission. I wonder if really powerful electric motors wouldn't be a better idea, making the whole system not unlike a diesel-electric locomotive. If gas turbine generation is preferred (with heat scavenging), fine, go with that. Why mix fuels when CODAG can be rendered unnecessary?
     
    Last edited: Oct 31, 2023
  5. Stephen Ditmore
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    Stephen Ditmore Senior Member

    Do any of the vessels we're talking about have anything like

    ...?

    Seems funny they don't at least have flaps, or sterns that mimic them, as flaps have already proven effective on USN ships and USCG cutters. Flaps discussed here.

    Also, many years ago I spoke with FastShip Atlantic designer David Giles who said I was free to copy the lines from his patent, rescale them (differentially, perhaps) and apply them to a yacht or use as I wished so long as my boat didn't exceed the length specified in the patent as the lower limit of what the patent claimed, which is 200 feet. Looked FastShip Atlantic up just now and found David Giles sued the US Navy for violating his patent in the design of the Freedom Class LCS.
    https://ecf.cofc.uscourts.gov/cgi-bin/show_public_doc?2012cv0484-181-0

    I'll add this for it's relevance to the two LCS classes:
     
    Last edited: Oct 31, 2023
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  6. BMcF
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    BMcF Senior Member

    The power required for the LCS to go 40+ knots is quite high...and fuel thirsty. Hence the need for the CODAG solution..the vessels would have no range otherwise, and an all-diesel solution would have been prohibitively heavy.
     
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  7. Stephen Ditmore
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    Stephen Ditmore Senior Member

    But add battery storage of energy and one could go either way on generation and use the stored electric power for sprints.

    In shoreside applications gas turbine generators with heat scavenging do OK on efficiency as long as they're on or off, not operating at sub-optimal speed. One can have several small ones and fire each up as needed. Onboard a ship, if one doesn't want a large bank of heavy batteries this is another option, consistent with hybrid.

    Not that I know much about gas turbine / electric locomotives, but I think they exist.
     
    Last edited: Nov 1, 2023
  8. BMcF
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    BMcF Senior Member

    Currently working on several all-electric and hybrid vessel design projects....the weight of the batteries is stunning and very difficult to manage in any weight sensitive high-performance marine vehicle.
     
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  9. Stephen Ditmore
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    Stephen Ditmore Senior Member

    Oh, BMcF, you're the person who posted something that sounded right to me at Semi-displacement boats don't generate lift? https://www.boatdesign.net/threads/semi-displacement-boats-dont-generate-lift.67859! So you're working in this field; might you help define where the state-of-the-art is concerning semi-displacement hulls?

    Is there someone who has refined CFD enough to model semi-displacement speeds? Is that capability available to civilians at lower cost than model testing? Any chance we could find someone to sponsor a group project where we define what we're trying to achieve, then submit our hulls so different things are modeled & tested?

    I posted about wanting to do something like that on Oct. 24 at Stern taper on semi-displacement hulls https://www.boatdesign.net/threads/stern-taper-on-semi-displacement-hulls.60336/
     
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