OPC Design Evolving?

Below is a comment on an earlier post, “If They Ditch the LCS, Perhaps the OPC as Frigate,” but for some reason, it did not show up on the list of comments. I think it is interesting enough to warrant its own post.

The Brazilian Navy has an on going project to develop and build the new Tamandaré-class corvettes/light frigates which could resemble the OPC derived frigate on this article. Interestingly Eastern Shipbuilding is one of the companies that answered the Request For Proposals. So they might have a conceptual design for an up-gunned OPC. The general requirements include a 25 kt speed, 3d radar, hull sonar, 76 mm gun, 4 deck-mounted anti-ship missiles, multiple torpedo tubes and VLS for Sea Ceptor/ CAMM AAW missiles (the render seems to point to 24 missiles in 2 x 3-cell ExLS).


Quoting from the link, “The Brazilian Navy’s Naval Projects Center developed the corvette basic design project with assistance from Fincantieri’s VARD.” It appears the preliminary design is already done and that it was done with help from VARD, the designer of the Offshore Patrol Cutter (OPC).

This Naval Today post from Dec. 2017  reports, According to the Brazilian Navy’s Ships Projects Center (CPN), the corvettes should be measuring 103 meters in length and displacing up to 2,790 tons.” that is actually a little smaller than the OPC. Delivery of the first of the class of four is expected 2021/22, about the same time as the first OPC. Brazil would like to build the ships within country, but is seeking to partner with another shipbuilder.

Some information on the British developed “Sea Ceptor” missile system here. This missile is larger than the RAM but smaller than the Evolved Sea Sparrow Missiles (ESSM). Like the ESSM, it can be quad packed (that explains how you get “24 missiles in 2 x 3-cell ExLS“). It is currently deployed on British type 23 frigates. Unlike ESSM, Sea Ceptor uses a cold launch system. As explained in Wikipedia, ” …cold launch, where the missile is expelled by gas produced by a gas generator which is not part of the missile itself, and then the missile ignites. “Cold” means relatively cold compared with rocket engine exhaust. A hot launch system does not require an ejection mechanism, but does require some way of disposing of the missile’s exhaust and heat as it leaves the cell. If the missile ignites in a cell without an ejection mechanism, the cell must withstand the tremendous heat generated without igniting the missiles in the adjacent cells.”

32 thoughts on “OPC Design Evolving?

  1. Just with What Exactly is the Brazilians buy these Frigates WITH. Last I heard Brazil is Cash Strap for Funds and couldn’t come up with the Funds to repair their Aircraft Carrier “Sao Paulo”. Forcing them to Retire the Vessel in 2017, and their Joint Venture with Saab fell apart after Saab learned that Boeing was trying to acquire Embraer Aerospace in December 2017…

  2. That’s some pretty good armament for a smaller ship. I’ve always been surprised (and maybe I shouldn’t be) by the lessening of arms on our cutters. For LE purposes, they are fine but if we were called into a wartime role, they sure woudn’t be much help. With the decommissioning of the FFG’s, there sure seems to be a lack of self supporting ships in the USN/USCG fleet. It’s a shame that so much money is wasted on usless projects, i.e. Littoral Combat ship and Zumwalt class deystroyers. If the USCG had that money could you imagine the return we would get on that? It would certainly result it a lot of capable ships! Or I can at least hope it would……

      • @ Chuck Hill

        Probably Not. The Mk.56 stands @ ~38’09” tall and is a “Cold Launcher”, which requires ~1,000psi of Compress Air to Eject the Missile out of the Launch Container…

      • Depends on Height between Waterline and Weather Deck. The Mk.41 VLS comes in Three Sizes: Self Defense @ ~17’05”, Tactical @ ~22’02” and Strike @ ~25’03”. The only problem being, that the Mk.41 is a “Hot Launcher”, which requires Blast Scuppers to Redirect the Flame and Gases as the Missile is Launched…

      • @Secundius, yep MK56, GMVLS, that is the one. It has been put on some pretty small vessels, like the Danish STANFLEX 300, https://en.wikipedia.org/wiki/Flyvefisken-class_patrol_vessel, that are only a little bigger than the Webber class.

        Apparently the NSCs were designed to accept 12 of these. Now that ESSM is being made with active radar homing, the ship does not even need an illuminator as was required for the previous semi-active homing version.

        The Mk57 on the other hand is only on the DDG1000 and is about twice as heavy per cell as the Mk41.

      • @ Chuck Hill

        I’m not following, unless were not talking about the Same Thing! The “Wikipedia” site you Posted talks about the Dimensions of the Missile, Not the Launcher. Mine “AlternateWars” talks about the Dimensions of the Mk.56 GMVLS Launcher, Not the Missile. The Question Posed by “You” states Launcher Size, Not Missile. Or did I misinterpret the question asked…

      • @Secundius, What we were talking about was Lyle’s question if a Mk41 VLS could be installed on the OPC. I said they might fit with an stretch, an extension of the hull, but Mk56 VLS might fit with no significant change. In the next two notes you expressed doubts, in one you mistakenly quoted specs for the Mk57 as specs for the Mk56, ” Mk.56 stands @ ~38’09” tall and is a “Cold Launcher”, which requires ~1,000psi of Compress Air to Eject the Missile out of the Launch Container…” in the other you stated, “Depends on Height between Waterline and Weather Deck. The Mk.41 VLS comes in Three Sizes: Self Defense @ ~17’05”, Tactical @ ~22’02” and Strike @ ~25’03”. The only problem being, that the Mk.41 is a “Hot Launcher”, which requires Blast Scuppers to Redirect the Flame and Gases as the Missile is Launched…” but as I pointed out the means to handle the gases and flames is incorporated in the Mk41 launcher and that height is not necessarily limited by the main deck height. The Wikipedia site I referenced with regard to ESSM also provides the dimensions and weights of the associated launchers. https://en.wikipedia.org/wiki/RIM-162_ESSM#MK_56

        Hope that helps.

  3. Mr. Hill thank you for featuring my comment. The latest news about this program say that the Brazilian Navy could accept some proven designs other than their conceptual corvette (designed with the aid of VARD as you said). So no hard requirements on displacement or length which opens the door to frigate designs like the MEKO A-200 [also offered by TKMS for the U.S. Navy FFG(X) Frigate Program] or modifications of existing designs (like a lengthened OPC).

    • ROM of firepower of some examples of naval cannon based on the rule of thumb, caliber/shell dia. to power of 3 (cubed/volume) times rate of fire, using the Mk 46 ATK Mk 44 Bushmaster II 30mm as base.

      GD Mk 46 Mod 0 with ATK Mk 44 Bushmaster II 30mm @ ~ 200 rpm 1.0
      BAE Bofors 40Mk4, 40mm @ ~ 300 rpm 3.6
      Raytheon Phalanx with M61 Vulcan 20mm @ ~4,500 rpm 6.7
      Oerlikon Contraves Millennium 35mm @ ~1000 rpm 7.9
      Thales Goalkeeper with GE GAU-8/A Avenger 30mm @ ~4,000 rpm 20.0

      The Mk 46 30mm is more of a sniper type cannon, the others are machine gun types, the 40mm is a major step up in firepower from the Mk 46. As firepower capability increases so usually does weight and volume.

      • Bushmaster Barrel of the Mk.46 Gun Mount is surrounded by a “Waterjacket” for Longer-Firing Time of Sustained Rates of Fire. So instead of 5-Second Burst with a Cooling Cycle required after the Burst. A FULL 220-round is now possible. Also Magazine of Mk.46 can be “Hot-Swap” while gun is still engaged with Threat Target. So No Down Time between Reloads…

      • @ Chuck Hill

        Magazine capacity is ~200-rounds. Minimum Range is ~330-meters. Effective Range is ~2,200-meters. And Maximum Range is ~4,400-meters. Cyclic Rate of Fire was Increased to ~250rpm…

      • @ Secundius, I was addressing that to Nick, but thanks. Actually I am kind of hoping the new icebreakers will have provision for mounting a pair of LCS Mk46 modules, but also a pair of SeaRAM.

  4. @secundis

    Thanks for the update on the Mk 46 with Bushmaster water cooled cannon, re-worked the firepower figures

    GD Mk 46 Mod 0 with its 30mm @ 250 rpm FP = 1
    BAE Bofors 40Mk 4 @ 300 rpm FP = 2.8

    The 40 mm increased firepower factor drops from 3.6 to 2.8X to that of the Mk 46 30mm, the Bofors 40 advantage lies in the larger volume of the shell and slightly higher rate of fire.

    • I like the 40mm/70 mk4 and would like to see it on the FRC, but it has only 100 rounds on the mount. The Mk46 has 400, but the 40mm is a much better AAW gun and potentially, using the right projectile, much greater penetrating power. Unfortunately the 40mm is not in the USN system, so its not going to be in the USCG system either.

      • What about the Rheinmetall GmbH/Oerlikon Contraves AG 35x338mm/117.5-caliber Millennium” Impulse Revolver Autocannon. Approximately 252-ready rounds @ 1,000rpm, with a maximum effective range of ~4,000-meters. And a Elevation from -15 to +85 degress…

  5. @ Chuck Hill.

    My Bad! I thought “Raytheon’s” website stated in INCHES, Not Centimeters.

    Thank you for telling ME that I’ve been Banned from the Website! I had to use a Friends Computer to Write Statement. I WON’T bother You or You’re Website Anymore…

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