Our Friend at Navy Recognition was good enough to provide a copy of an artist’s concept of the BIW proposal he had found. We talked about the other two contenders for the OPC contract here.
The proposal is a variation of the the Navantia BAM (Buque de Acción Marítima) (more here).
The BAM has provision for carrying up to six containers. Hopefully this feature has been retained. It looks like all of the proposals may have this feature to some degree.
Presumably the ship will include the BAM’s hybrid propulsion system, with electric motors (two motors of approximately 1,000 HP) run off the ship’s service generators for slow to moderate cruising. The BAM’s main propulsion engines (12,240 HP total providing 21 knots) would probably need to be upgraded to meet the Coast Guard’s speed requirement (22 to 25 knots), but that should be fairly easy. Using the same diesels that are used in the Bertholf Class National Security Cutters (19,310 HP total) would supply the necessary power and simplify training and logistics. Alternately a four engine power plant similar to that used in the closely related Navantia built Venezuelan Guaiqueri class (approx 24,000 HP for 24 knots) would provide the necessary additional power and additional flexibility and redundancy.
In some respects the Bath proposal looks more like the Guaiqueri class with its larger central funnel, although the Bath proposal has a smaller funnel and a small additional stack presumably for the main generators to starboard.
The BAM’s length, beam, and draft are 93.9×14.2×4.2 meters (308×46.6×13.8 feet) their displacement is 2,900 tons, the Venezuelan Guaiqueri class are 98.9×13.6×3.75 (324.4×44.6×12.3 feet) and just over 2,400 tons.
It may only be that the conceptual drawing is slightly distorted, but I am a little concerned that it appears the hangar may not be long enough to take an H-60 sized helicopter. Even if we don’t need that now, we may in the future. The ship is as beamy as an FFG, so it could certainly accommodate a large double hangar.
Like the Eastern design, it looks like the Mk38mod2 on the top of the hangar is going to have a limited field of fire on one side. It does look like there is room for a second mount on top of the bridge. The 57mm, on the other hand, is up out of the green water that will inevitably washs over the bow, and has excellent fields of fire, including the ability to engage contacts close aboard, even when the ship rolls away from the target.
Both the BAM and Guaiqueri class have fewer accommodations than are expected to be provided in the OPC. So some changes were necessary there.
It appears the step-down from the flight deck to the fantail is less than a full deck. If so, then the ship is almost flush decked. e.g. the foc’sle is on the main deck. If that is the case, then the bridge would be on the O-3 deck just as it is on the 210s, 270s, 378s, and NSCs and the ship is really not as tall as it appears in the illustration. On the other hand if the step-down is a full deck (and it is on the BAM), the ship is going to feel unusually tall (but it will give a greater visible horizon).