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).
http://www.janes.com/article/70498/brazil-attracts-multiple-firms-interest-for-ambitious-corvette-project
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.”
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