The June 2021 edition of the U. S. Naval Institute Proceedings has a short article by Captain Michael Cilenti, USCG, currently CO of USCGC Tampa, in the “Professional Notes” section, pp 78-79, about the service life extension program (SLEP) planned for six of the 270 foot WMECs. It is available on line if you are a USNI member.
Captain Cilenti, confirms what we have suspected, that the 76mm Mk75 gun and Mk92 firecontrol will be replaced by a 25mm Mk38, the same gun currently used on the Webber class WPCs.
The Captain is concerned primarily because the loss of the Mk92 means the loss of the ships’ most capable radar. The Mk92 is a multi-function radar. In addition to providing firecontrol, it is the ships’ only air search, and its most sensitive surface search. It is more effective in detecting the targets such as low profile semi-submersibles.
Capt Cilenti suggests that there is are alternatives already in or planned for Coast Guard use that could be installed to provide these capabilities. He suggest the AN/SPS-75 (TRS-3D), currently installed on the Bertholf class National Security Cutters and the Freedom class LCS, or the AN/SPS-77, planned for the Offshore Patrol Cutters and currently used on the Independence class LCS.
He notes that the addition of a multi-mode radar would allow the 270s to control emergency helicopter low visibility approaches by the embarked helicopter and facilitate UAS operations.
I hope someone is paying attention to the Captain’s plea. Adding a modern multi-mode radar and a UAS system such as V-BAT, could give us WMECs that are more capable than ever, of performing their law enforcement and SAR missions, while requiring few crew members and less extensive training. Deleting the Mk92 firecontrol system without replacement will leave these ships little more capable than the 210s and probably preclude installation of more capable Unmanned Air Systems.
The 270 SLEPs will begin in the near term. A decision to retain and enhance these ships sensor capability is urgent.
Late Addition:
I would suggest that the 25mm Mk38 be mounted up a deck, like the gun of the very similar Irish Naval Service Offshore Patrol Vessel LÉ Eithne pictured below. This would provide a greater degree of protection from green water coming over the bow. (Incidentally that gun is an earlier version of the 57mm being used on the National Security Cutters.)
Chuck Hill's CG Blog 
I read that article as well, very good points brought up by the Captain. It’s things like these that would otherwise go overlooked by the top brass. When these changes are made, the planners and decision-makers need to discuss possible problems and issues which only the crew would intimately understand (something perfectly illustrated here).
@Dave, Yes I commented on this problem in July last year, https://chuckhillscgblog.net/2020/07/08/tidbits-from-the-fy2021-budget/
but hopefully this piece in Proceedings, by an O-6 commanding a 370 will have more impact.
I added a “late addition” to the post concerning the location of the 25mm Mk38.
It seems as though they are doubly handicapping them. Not only is it losing an extremely important sensor but a decent gun as well. While I assume the ships will return to Atlantic, in the Pacific the Chinese have 100mm guns on cruiser sized vessels as well as drones. A 76mm would be a bit more reassuring against both aerial and surface targets when things get rough. The 57mm is already too small for all but the smallest merchant fishing vessels, and the 76mm would be still be marginal for the biggest potential threats.
I am sure part of this is logistics problems. SInce the USN unwisely decided to dump the Mk75 76mm gun, parts of probably hard to get? The double whammy is that the USCG is going to use the Mk38 25mm gun which is NOT being updated by the Navy.
So with two strikes the USN is putting the USCG out of modern naval guns.
A newer radar is also needed. But the CG should be able to configure their cutters as needed?
Lee,
You are correct, the main issue being addressed is sustainability of the MK-75.
I’m a fellow blogger and the new guy in the new division who now owns the MK-75 gun weapon/MK-92 fire control systems, in addition to all Navy Type/Navy Owned (NT/NO) surface, air, and C4I equipment, so please bear that in mind as I offer our perspective as to how we got here. In my mind, down gunning the 270 is the least bad option:
1. The Navy began phasing out these systems in 2015 and, as most of the competent technicians will retire in the next five years, they will not be supportable through the 270’s service life.
2. The cutter resource council did evaluate replacing the MK-92, SLQ-32, and IFF. However, the Navy was not willing to acquire systems for what at the time was a shorter service life and the Coast Guard could not afford the installation costs.
3. The MK-75/MK-92 combo costs 331% more than the MK38 machine gun system to sustain and we currently have a $2.4M Navy reimbursement shortfall across all three domains.
4. Coast Guard anti-air warfare capability will be picked up by the National Security and Offshore Patrol Cutters, with associated updates to the myriad documents that make up DoD maritime superiority planning, e.g. Required Operational Capabilities/Projected Operating Environment, Naval Operational Capabilities, Global Force Management Board, etc.
No one likes losing capability, and as a HITRON alum I’ve seen the MK-92 used firsthand for non-compliant vessel interdictions. The decision was made well before and above me.
Pat
There is an unanswered question here. We have known for some time that the plan was to rearm the six 270s that are being SLEPed, but what about the other seven? Will they retain their Mk92 and Mk75 gun until decommissioned?
Prior to the current building program we had 25 ships armed with 76 mm guns. It appears when completed about 2038 we will have 36 armed with 57mm guns. We are currently at 22 comparable weapon systems, nine 57mm and 13 Mk75 76mm.
Are we going to attempt to maintain something comparable to our previous capability during the transition period?
Chuck,
The decision on 270s #8-13 is still pending, the long pole being the remove/install costs.
That’s an interesting way to compare capability, but I’d have to defer to 721 and 751 to see how the measure.
Pat
As I have said before, if the 76mm are to be removed in favor of the 25mm Mk38, then at least they should get two mounts, one forward, raised a deck above the foc’sle to keep it dry and one on top of the hangar.
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