Unconventional Contender for the Offshore Patrol Cutter

Vigor Offshore Patrol Craft 01

The first conceptual design for the Offshore Patrol Cutter (OPC) by an American shipbuilder since the demise of the Deepwater program has surfaced, and it is unconventional. Vigor Industrial proposes using the Ulstein X-bow. gCaptain brings us the story.

The proposal is 328 foot long and has a 54 foot beam. More info here.

The information available does not include maximum speed or the configuration of the propulsion systems. On the video it is clear that it has a drop down trainable thruster under the bow, and it appears it may have a single conventional shaft.

It is also unclear if the ship can hangar an H-60.

I like the boat hangar idea, in that it provides some of the flexibility of a reconfigurable space that might be able to use some of the systems being created for the LCS.

27 thoughts on “Unconventional Contender for the Offshore Patrol Cutter

  1. saw this yesterday, while the company promo was pretty interesting, as a snipe i’d like to know about the propulsion equipment and spaces, and she ain’t the prettiest raft i’ve ever seen.

  2. If they can hangar an H-65 with rotors extended, perhaps they can hangar two with blades folded?
    It may also mean hangar is too short for the H-60.

    This looks like they are aiming to be the low bidder by doing no more than meeting the threshold requirements–surprise, surprise.

  3. She’s going to displace ~4,000t, given those dimensions (100 x 16.4 x 5m draft – you can read the draft in the HD video).

    That’s a pretty big baby to replace the WMECs. Not sure they’re aiming to be the low bidder!

    The propulsion setup is interesting. Looks like 2 big diesel generators forward, and one smaller diesel aft. Given its location, that’s the one that is probably mechanically connected to the single shaft… Which in turn implies mechanical propulsion for slow cruise speeds (~8-12kts), with the big diesel generators kicking in above that. Interesting choice (assuming I’m guessing correctly), because usually it’s the opposite (electric for slow speeds, mechanical for sprints).

  4. Technical diagram in video is from an offshore construction ship still, not the OPC proposal, which I am pretty sure has twin diesels (7MW range?) with mechanical transmission to twin screws and diesel-electric (4 generators total it seems) for loiter. And that swing up thruster for combined bow thruster/get-home emergency functionality. OPC RfP requirement was to operate both H-60 and H-65, no? So expect hangar to take either plus a small rotary wing UAV.
    Pretty bespoke compared to the off-the-shelf offshore industry ships, so cost likely to be up there with other offers.

    • Question, if the OPC RfP requirement says that an OPC is to operate both H-60,H-65 and a Small UAV. Wouldn’t a Light Frigate and a Corvette satisfy the requirements for an OPC?

      • You are only looking at one aspect of the specs. So far I have not seen any light frigate or corvette that meets all the specs without some modification. Certainly with modification, some of those designs might work.

        This particular design took to heart the idea that seakeeping is the most important requirement after affordability. So it came out relatively large, beamy, and with the X-bow.

        I expect we will be seeing several proposed designs in the near future.

    • The Contract requirements are generally in two steps, threshold and objective. It meet the specs if it only meets the threshold and hangaring the H-60s is an objective, but hangaring the H-65 (and UAS) is the threshold, just as 25 knots was the objective, but 22 knots was the threshold.

  5. Over at ThinkDefense, the mostly British readers are having a lively discussion about this design: http://www.thinkdefence.co.uk/2012/09/the-vigor-offshore-patrol-craft/

    One of their concerns is that the bridge and much of the crew accommodations are well forward where ship’s motion in pitch would be exaggerated. The question being, would the apparently reduced pitching of an X-bow design compensate for the forward placement of the bridge?

    (I do recall getting rather seasick, eating crackerjacks in the forward berthing area in the bow of a 311 as a cadet.)

    • Other areas we might want to look at closely are how the design deals with the anchors and line handling forward and the position of the flight deck.

      Because the anchors have to exit the hull below the start of the tumble-home, they are mounted very low (seen below the hull numbers in the illustration) and the machinery for anchor handling is also mounted low in the hull instead of on the fo’c’sle. In all probability water will enter this compartment though the hawsepipes in any kind of heavy seas. There might be an attempt to make this compartment water tight by sealing the hawsepipes, but this will probably not work. The other alternative is to make the compartment free flooding so that it will drain freely. In either case it is likely the the compartment will have to be closed off to traffic in heavy seas and the anchor handling gear will be subject to higher than normal exposure to salt water which may cause maintenance problems. The Freedom class LCS have had a problem because their hawsepipes lead to an enclosed space below the foc’sle, but it is still higher than that shown for the proposed OPC.

      Similarly, It appears there would be line handling stations low in the bow (seen on either side of the hull number on the illustration) for lines forward, that would also take on water as the ship pitches. It appears these may be in the same compartment as the anchor handling gear.

      The extreme aft location of the flight deck might also be a reason for concern in that whatever pitch the ship does experience, will be exaggerated toward the extreme ends of the ship. Will the claimed lower pitch amplitude of the X-bow keep the pitch within acceptable limits?

  6. Well, well, well…

    Add the ice capability, and this was my suggestion for an Arctic Patrol Cutter a couple years ago here, remember? I hereby release all claim to my conceptualization services, in exchange for a ride on the completed Cutter! 🙂

  7. Pingback: Offshore Patrol Cutter Concepts | Chuck Hill's CG Blog

  8. Just got a press release that Vigor has renamed a couple of their divisions, “PORTLAND (Oct. 8, 2013) –Vigor Industrial announced today that it has renamed two of the company’s subsidiaries. US Fab, Vigor’s fabrication and shipbuilding subsidiary, is now Vigor Fab. Alaska Ship and Drydock, which operates the Ketchikan shipyard in Alaska, is now Vigor Alaska.”

  9. Pingback: Offshore Patrol Cutters (OPC), the other LCS - CIMSECCenter for International Maritime Security

  10. Pingback: Offshore Patrol Cutters (OPC), the Other LCS | Chuck Hill's CG Blog

  11. Pingback: Offshore Patrol Cutters (OPC), the other LCS - CIMSEC

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