As noted in the post “GAO Responds to Fleet Mix Studies, Part 1, The Report,” the Department of Homeland Security “Cutter Study” raised the possibility of an austerely equipped Offshore Patrol Cutter (OPC) possibly deleting some equipment or capabilities of the ship as currently planned including:
- Sensitive Compartmentalized Information Facility (now referred to as the Ship’s Signals Exploitation Space or SSES)
- Air Search and Fire Control Radars
- Electronic Warfare Support Measures
- Berthing space (114 instead of 122)
- Weapons suite (e.g., 25mm gun instead of 57mm)
This got me to thinking. What do these ships really need, both for their peacetime functions and for possible wartime roles? I hope the Department’s suggestion presages a return to CNA (Center for Naval Analysis) to do a more formal evaluation of the effects of these changes. Until then, I’ll venture some comments on these proposed deletions, then go on to talk about how the ships might be equipped first for war, then for peace.
- Ship’s Signals Exploitation Space (SSES): This seems to be mostly for drug enforcement, but with obvious Defense Operations implications. It’s possibly useful for fisheries and SAR as well. While we never used to have a formal SSES, cutters did frequently feel compelled to generate their own. Intel is a great force multiplier, so I would not cast aside the capability casually. Still we are hearing there is already far more intel available for drug enforcement than there are units to act on it, so it’s loss might not be that significant.
- Air Search and Fire Control Radars: While the CG has managed to live without these on the 210s, the air-search and/or fire-control radars seems likely to be needed to exploit the Unmanned Air Systems (UAS) the CG hopes to use, because they can provide a substitute for the eyes in the cockpit required to “see and avoid” other traffic. They may also be necessary to fully exploit the range of the embarked helicopter.
- Electronic Warfare Support Measures: The ships probably could do without the ESM (and associated decoys) in peacetime, unless it is feeding info into the SSES.
- Berthing space (114 instead of 122): I would not expect simply reducing berthing (but not crew size) to save much money, and it would unnecessarily reduce future flexibility. If these ships are used for cadet cruises, they are likely to need all the berthing that might be available.
- Weapons suite (e.g., 25mm gun instead of 57mm): This might be doable, but there is still a concern for the peacetime requirement inherent in the Ports, Waterways, and Coastal Security mission of being able to stop a ship being used for a terrorist act, as illustrated in the Concept of Operations, section 3.3.4 (pdf, accessible here). I’m unconvinced that the 57 mm is much of an improvement over the 25 mm, while other systems with a smaller footprint, might be more effective and, if adopted, might extend this capability to more numerous and more readily available vessels than the few cutters mounting 57 or 76 mm guns.
Designed for Peace or War?:
I’ve always felt Cutters built since World War II have been neither fish nor fowl. They have been much more expensive to build than ships built to commercial standards because they are in many ways warships. In other ways, not a lot of consideration seemed to have been given to their war time roles, which meant that they had only limited potential as warships.
It is probably be counter-productive to equip cutters as fully armed warships. Not only does it significantly raise their operating costs, it would make them less welcome in many areas where cutters are accepted, but US Navy ships are viewed with suspicion.
My own feeling is that the large patrol cutters should be adaptable as warships. Ships take a long time to build. Cutters constitute a naval reserve that can be brought on line much quicker that new ships can be built. But they would need to be upgraded significantly before they would be “battle-worthy” in the more demanding scenarios. That is probably as it should be, but making that transition not only possible, but as quick and effective as possible is a worthwhile objective. Additionally extra weight moment margins mean the ships will also be more adaptable to changes in peacetime Coast Guard missions over the long term.
The Offshore Patrol Cutter Concept of Operations (which can be accessed here) actually seems to agree at least to some degree, but does not include the proposed capabilities of the fully armed version of the cutter other than some non-specific references to upgrades in section 18.104.22.168.
“The WMSM will have the ability to install additional equipment to augment its capabilities if it is required to conduct operations in higher threat environments in support of national security objectives.“–Executive Summary, Concept of Operations.
Later, in defining Defense Operations there is this statement, “The WMSM will operate in a low, multi-threat environment as defined below. The cutter shall be designed for, but not delivered with, the equipment and configuration to allow for operations in higher threat environments.”
(This may mean little more than that the ships are equipped for, but not with Phalanx.)
Planning for additional weapons in case of a potential major naval conflict was done in the past, to some degree, with the 210s and 270 WMECs. Space and weight was identified for additional weapons. Fortunately it was never necessary to see if those plans were realistic. I would like to see this concept taken further, beginning by designing a true warship, at least through the preliminary design stage, but then choosing to equip it only with those weapons that either serve a peacetime purpose, or are so complex that they could not be added in a yard period of some reasonable period. This would have the additional advantage of making the design potentially attractive to both the Navy and foreign governments seeking to purchase similar vessels for their navies under foreign military sales. It is likely the shipyard might see this as an advantage as well.
Here I am referring to a full conversion to a dedicated fighting ship. It is unlikely to be necessary unless there is a protracted conventional conflict with a near peer adversary. As unlikely as that may seem, it is the sole justification for much of the Defense Department, where many times the Coast Guard’s entire budget is invested annually. In lower level conflicts it may be sufficient to “come as you are” or make selected upgrades.
In considering the OPC, the exact size has not been decided, but it seems likely it will be 2,500 to 3,500 tons. If so, it should not be asking too much to expect a design capable of carrying a weight of weapons and aircraft at least equal to the weight of weapons carried by the much smaller 255 foot cutters, when they were first built during WWII. This included two twin 5″/38s (85.4 tons), two quad 40mm mounts (20.7 tons), hedgehog (12.8 tons), six K-Guns, depth charges, and racks (approx. 25 tons), and four 20mm guns. All together, roughly 140 to 150 tons. This is intended to be a conservative approach because there are certainly additional weights not included below, but these ships really ought to be able to carry considerably more weapons than the 255s.
How could we equip a cutter with a similar load of modern weapons and aircraft? Here one possibility.
- H-60 11 tons
- UAS (weight unknown, but estimate an estimate probably on the high side)
- Mk 38 mod 2 25 mm guns (x2) (estimate on the high side) 3 tons
- AN/SQR-20 Multi-Function Towed Array (MFTA)(Thales CAPTAS 4) 20.6 tons
- Mk 32 Surface Vessel Torpedo Tubes (SVTT) (two triple and 12 torpedoes) 5.2 tons
- CIWS (2) (Phalanx, SeaRAM, or Mk 49 RAM launcher, probably Mk 49 fwd, SeaRAM aft) 14 tons
- 5″/62 Mk45 33 tons
- Mk 57 or Strike length Mk 41 Guided Missile Vertical Launch Systems (8 cells) 33.6 tons
Total 124.4 tons
The helicopter and UAS are expected already. In wartime the helicopter would probably be a Navy variant. The UAS might also be armed. The ship would need space for storage of weapons and sono-buoys. These spaces could have other uses in peacetime, like locker rooms for boarding parties or meeting/rec rooms.
The Mk38 mod 2 is very versatile and given the right projectile it might be an effective ship stopper.
A submarine threat is reemerging. The multi-function towed array is the essential ASW sensor. It can operate in both active and passive modes. In the passive mode, it is an over the horizon sensor that can be used in full EMCON Alpha against an enemy vessel also exercising EMCON. OPCs equipped with towed arrays and MH-60R helicopters, operated in groups, could be deadly hunter-killers.
The torpedo tubes provide an urgent attack capability against a sub that is unexpectedly detected at close range.
Providing a Mk 49 RAM launcher forward and a SeaRAM aft would provide immediate launch facilities for up to 32 missiles that could engage either air or surface threats and counter a saturation anti-ship cruise missile attack. The Mk 49 would integrate with the ships firecontrol and air-search radars, while the SeaRAM would provide automatic autonomous engagement and cover any gaps in radar coverage of the primary systems.
The 5″ Mk45 matches nicely the Concept of Operations direction that the OPC may be included in Expeditionary Strike Groups. These groups’ reason for existence is amphibious assault both by air and over the beach. The 5″ is still the primary Naval Surface Fire Support (NSFS) weapon and even after the 155mm Advanced Gun System is deployed on the DDG-1000, there will still be a place for the 5″ to take out the probably numerous targets close to the landing area, allowing the very limited number of Zumwalt DDGs (three) to conserve its limited ammunition for more difficult targets. A 5″Mk 45, even without advanced ammunition, positioned 10,000 yard off the beach, can hit targets on the beach (assuming it is a straight line) over a more than 19 mile wide front. That is as large as any of the five beaches at Normandy. Additionally Mk48 Gun Weapons System planned for the OPC already works with the 5″.
It might be assumed that the guided missile vertical launch system tubes are out of place here, but they have become the Swiss army knife of naval weapons, being useful for anti-submarine, anti-surface, and land attack missions as well as air defense. Four Evolved Sea Sparrow Missiles (RIM-162 ESSM) can be launched from each tube so that eight tubes can launch up to 32 missiles. Strike length VLS like the Mk 41 (and here) and Mk 57 can also launch Vertical Launch ASROC, Harpoon, and Tomahawk. If equipped for cooperative engagement, missiles launched from a cutter could be controlled by Aegis equipped ships. The Mk41 VLS would normally be mounted between the gun and the bridge, but the Mk 57 launchers can be added to the side of superstructure or the hangar in groups of four. There are also lighter VLS systems such as the Mk48 and Mk 56 (lots of pictures here) that are US made but not currently in US service.
For its actual construction the ship will need much less. It might have only the following:
- Mk 38mod2 25 mm guns
The type of guns the ship is equipped with in peacetime is still an open question. The Ports, Waterways, and Coastal Security (PWCS) scenario, 22.214.171.124, requires the OPC to protect a “Maritime Critical Infrastructure/Key Resources (MCI/KR)” by “neutralizing” a ship. The size of the ship is not clear, nor is what constitutes effectively neutralizing it, but we know it may not be easy to stop or sink a vessel. If the 25 mm can be proven to effectively stop a ship, the service may choose to risk limiting weapons to these heavy machine guns. But if they do so, the cutter will have to come inside the range of likely improvise armaments that might equip such a terrorist ship, with attendant risk that the cutter’s weapons might be knocked out and the cutter might be still be unable to stop the ship. The 57 mm offers greater range, but may still lack the power to stop a larger vessel. All gun options present the problem of collateral damage from shots that miss or pass through the target. Light weight torpedoes modified to hit a surface ship’s propellers might be an option. There are also missile options that might be considered, that are lighter and less maintenance intensive that a medium caliber gun and its associated supporting equipment.
Really this mission should not depend on the presence of a WMSL or WMSM, that is unlikely to be available when the need arises. These ships are usually either far from the port or in “Charlie” status. We need another way of addressing this mission.
Phalanx might still have a place in the peacetime outfit, if it is found to be an effective ship stopper. (Oct. 27, 2010) Rounds from a Mk-15 Phalanx Close-in Weapon System (CIWS) from the guided-missile destroyer USS Mitscher (DDG 57) impact the ex-USNS Saturn during a sinking exercise. Mitscher and other ships assigned to the George H.W. Bush Carrier Strike Group fired live ammunition at Saturn. (U.S. Navy photo by Mass Communication Specialist Seaman Leonard Adams/Released) More photos here. (It took quite a bit to sink this ship.)
Trade-offs, Options, and Alternatives:
In choosing equipment for the cutters, it might be desirable to include selective upgrades for limited number of ships, rather than building them all the same–AN/SQR-20 Multi-Function Towed Array (MFTA)(Thales CAPTAS 4)–Ships expected to do drug enforcement, looking for self propelled semi-submersibles, might have towed array sonars for drug enforcement while those expected to do fisheries in the Pacific might not.
In the paper exercise of designing both a warship and a peacetime cutter, there are some tradeoffs available that might make it easier.
- Berthing–In designing the fully armed version, it should be acceptable that wartime berthing will be more crowded than the peacetime standard. During WWII crew complements sometimes doubled compared to those planned in peacetime. The crews will be willing to make sacrifices.
- AMIO–The current OPC specs call for the ability to shelter and feed 500 additional people on the weather decks. That is about 40 tons of addition topside weight. The fully armed version would likely have to trade this capability for the weapons outlined above.
- Range/Endurance–The minimum range requirement for the OPC is 7,500 nautical miles. Up to 9,500 is desired. As long as the ship retained a range of about 4,500 miles–typical for American surface warships–trading some fuel space for magazine space on the fully armed version might be an option.
There is also the possibility of including plans for alternative combinations of systems on the fully armed cutter, so that when a need arises the decision maker can pick and choose from a portfolio of possibilities to match the need. Additional missile launch tubes might replace the gun. Littoral Combat Ship mission modules or Mk141 Harpoon launchers might replace the VLS.