The crew of Coast Guard Cutter Northland conducts a live firing of the MK 75 76mm weapons system while underway, on September 20, 2020, in the Atlantic Ocean. (Photo: USCG)
As we have discussed, the MK 75 OTO Melera 76/62C Compact gun has been sunset by the U.S. Navy and USCG after a 50-year-run, with the Ordnance Shop at the Coast Guard Yard taking ownership of the remnants of the program, tapped to support the guns on FFG-7 frigates and 378-foot cutters transferred overseas.
The CG Yard Ordnance Repair Facility recently completed a five-month overhaul of an MK75 gun mount for an international partner.
“This effort is part of a larger Foreign Military Sale Program, which prioritizes robust national security partnerships and U.S. global leadership.
The Yard is the only certified MK75 overhaul facility in the U.S. The Ordnance shop manufacturers and repairs critical components from decommissioned Navy donor guns, since these parts are no longer manufactured. After the overhaul, the weapon is boxed and shipped for transit to the international partner.”
Before:
After:
And packed up for return shipment.
Death in a box!
As to why it takes five months to refirb one of these mounts:
It takes that long because the shop has to remove/ship it, pre test, completely tear down, sand blasted all parts, send part for plating, source or get parts made that are no longer in the stock system, repair all corrosion, overhaul all hydraulic components with new gaskets/hardware, paint / repair everything, start assembling have QI come in for major sub component test, finish assembly, start the ISMAT / ISMEP testing, round 100 rounds, package the system, ship it, install it on new cutter/ship then Test it again on the ship and this is completed with up to a 3-4 man team while training new workers. It’s a big team effort, but rewarding the workers in that shop are really top-notch.
Today is the 235th anniversary of the circa 1790 founding of Alexander Hamilton’s old Revenue Cutter Service/Revenue Marine, which became today’s U.S. Coast Guard.
It is also the rough 35th anniversary of the beginning of the USCG’s continuing service in the Arabian and Persian Gulfs, which is about 6,700 miles as the crow flies from the continental U.S.
When Saddam crossed the line into Kuwait on 2 August 1990, the resulting Operation Desert Storm build-up in Saudi Arabia soon saw Coast Guard Marine Safety Offices (MSOs) activate personnel to inspect the nearly 80 Ready Reserve Fleet (RRF) vessels preparing for sea duty.
Soon after, four 10-man USCG LEDETs and a 7-man staff liaison team deployed to the Gulf to work from U.S. and allied vessels to inspect shipping.
USCG LEDET on a Turkish ship during Desert Shield
The first Iraqi ship impounded, Zanoobia, was on 4 September by a LEDET team from USS Goldsborough (DDG 20). Once the shooting started as Desert Shield became Desert Storm, LEDET personnel helped clear Iraqi oil platforms, securing 11 such platforms and aiding in the capture of 23 Iraqi prisoners, with one of the busiest being on the OHP-class frigate USS Nicholas (FFG-47).
Something like 60 percent of the 600 boardings carried out by U.S. forces were either led by or supported with the USCG LEDETs– which shows how busy those 40 guys were!
Further, 950 USCGR personnel were activated to support Desert Storm, with over half of those being in Port Security Units.
As noted by the USCG Historian’s Office:
On September 14th, PSU 303 (Milwaukee, Wisconsin) became the first Port Security Unit deployed overseas when it was assigned to Al Damman, Saudi Arabia.
On September 22nd, PSU 301 (Buffalo, New York) deployed to Al Jubayl, Saudi Arabia, and on November 14th, PSU 302 (Port Clinton, Ohio) deployed to Bahrain.
These PSUs featured the first Coast Guard women to serve in combat roles, including female machine gunners assigned to “Raider” tactical Port Security Unit boats.
The first allied craft into Kuwait’s Mina Ash Shuwaikh Harbor on 21 April 1991 was a Coast Guard Raider tactical port security boat from PSU 301, which gingerly led a procession of multinational vessels into the harbor.
Members of the U.S. Coast Guard Port Security Unit 302 patrol the harbor aboard a Navy harbor patrol boat during Operation Desert Shield.
Finally, to address the ecological nightmare that occurred once Saddam ordered scorched earth on the Kuwait oilfields during the liberation, on 13 February 1991, two USCG HU-25A Falcon jets, equipped with AIREYE side airborne looking radar (SILAR) and oil detection equipment, flew from Air Station Cape Cod to Saudi Arabia, supported by two Coast Guard HC-130 Hercules cargo aircraft from Air Station Clearwater packed with ground crew, spare aviation parts and support packages.
The Falcons were deployed for 84 days and mapped over 40,000 square miles of the Persian Gulf. They logged 427 flight hours in the region and maintained an aircraft readiness rate of over 96 percent. These flights provided daily updates on the size and direction of the spill.
Post Desert Storm, with LEDETs continuing work with the 5th Fleet Maritime Interception Force adjacent to Operation Southern Watch from 1992 onward, in November 2002, the all-USCG Patrol Forces Southwest Asia (PATFORSWA) was stood up with what would eventually become six 110-foot Island class cutters (USCGC Adak, Aquidneck, Baranof, Maui, Monomoy, and Wrangell).
Persian Gulf (April 27, 2005) – Coast Guardsmen aboard U.S Coast Guard Cutter Monomoy (WPB 1326) wave goodbye to the guided missile cruiser USS Antietam (CG 74) after the first underway fuel replenishment (UNREP) between a U.S. Navy cruiser and a U.S. Coast Guard Cutter. Antietam completed fuel replenishment with the Monomoy in about two hours and saved the 110-foot patrol boat a four-hour trip to the nearest refueling station. Antietam and Monomoy are conducting maritime security operations (MSO) in the Persian Gulf as part of Commander, Task Force Five Eight CTF-58). U.S. Navy photo by Journalist Seaman Joseph Ebalo (RELEASED)
7/25/2007. NORTH ARABIAN GULF-Petty Officer 3rd Class William J. Burke performs a security sweep aboard a tanker ship in the North Arabian Gulf. Burke, a machinery technician, is part of Law Enforcement Detachment 106, which is deployed in the NAG to help train Iraqi Navy and Marine personnel in boarding procedures and tactics. U.S. Coast Guard photo by Public Affairs Specialist 2nd Class Nathan Henise.
As it had in Operation Desert Storm, the Coast Guard deployed port security units, law enforcement detachments, and patrol boats to the Middle East to support Operation Iraqi Freedom and the Global War on Terrorism. Adak captured the first Iraqi maritime prisoners of the war, whose patrol boat had been destroyed upstream by an AC-130 gunship.
USCG small boat team conducting operations in the Gulf – 31 August 2022
In OIF, LEDETs deployed on Coast Guard and Navy patrol craft continued to board and inspect vessels in the Northern Arabian Gulf. As a member of one of these LEDETs, DC3 Nathan B. “Nate” Bruckenthal died when boarding an explosives-laden dhow that detonated near USS Firebolt (PC-10).
Today, PATFORSWA is still very much in business with six new 154-foot Fast Response Cutters (USCGC Charles Moulthrope, Robert Goldman, Glen Harris, Emlen Tunnell, John Scheuerman, and Clarence Sutphin Jr) replacing the old 110s in 2021-22.
220822-A-KS490-1182 STRAIT OF HORMUZ (Aug. 22, 2022) From the left, U.S. Coast Guard fast response cutters USCGC Glen Harris (WPC 1144), USCGC John Scheuerman (WPC 1146), USCGC Emlen Tunnell (WPC 1145) and USCGC Clarence Sutphin Jr. (WPC 1147) transit the Strait of Hormuz, Aug. 22. The cutters are forward-deployed to U.S. 5th Fleet to help ensure maritime security and stability across the Middle East. (U.S. Army photo by Spc. Noah Martin)
With some 300 personnel assigned, it is the largest Coast Guard command outside of the U.S.
A vintage deck gun system that was once a staple of the U.S. Navy and Coast Guard has quietly fired its final shots.
Designed by the famed munitions firm of OTO Melara of La Spezia, Italy, and marketed from 1963 onward as the 76/62C Compact, the remote-controlled 76mm (3-inch) gun with its characteristic bubble dome was an immediate hit with NATO and Western fleets, eventually seeing service with 60 nations.
West German Type 148 missile boats show their 76mm OTO guns during a visit to the UK, in 1977
The reason it was so popular was that using aluminum alloys, a water-cooled gun barrel, and an automatic loader with an 80-round magazine, it delivered much better performance than any manned 3-inch gun mount in service at the time while weighing much less. Guided by the ship’s onboard radar and fire control system, it could engage air targets as high as 13,000 feet and surface targets out to 20,000 yards.
The 76/62 designation comes from the bore (76mm) and barrel length (62 caliber), the latter figure denoting a 4,724mm long barrel, which translates to 15.5 feet.
The 76/62C Compact, seen in its components from a 1980 U.S. Navy training publication:
Note the gun control panel which was mounted in the ammunition handling room below deck under the mount. The mount captain fired the gun from the panel while two ammunition loaders stood by to reload the magazine.
A look under the hood so to speak, showing off the details of the gun itself and its magazine.
The mag used two concentric rings of shells, each holding 35 rounds, with a hydraulic motor rotating the screw feeder– which held another six rounds not unlike that of a common “six-shooter” revolver. Together with the four rounds held in the loader drum, the gun held 80 shells, which could be expended in just under one minute.
A view of the magazine rings of the MK-75 gun aboard USCGC Mohawk (WMEC 913) while underway in the Atlantic Ocean, Sept. 1, 2022. (U.S. Coast Guard photo by Petty Officer 3rd Class Jessica Fontenette)
The types of “war shot” rounds in U.S. service included High Explosive Point Detonating (HE-PD), High Explosive Infrared (HE-IR), Variable Time Non-fragmenting (VT-NF), High Explosive Variable Time (HE-VT), and High Explosive Radio Frequency proximity (HE-RF).
Exercise and training shells included the Blind-Loaded and Plugged (BL&P) round with a live round that had an inert projectile while wholly inert rammable and non-rammable dummy and gauging rounds were also available.
Crew load 76mm rounds into the magazine of the MK-75 gun aboard USCGC Mohawk (WMEC 913) while underway in the Atlantic Ocean, Sept. 1, 2022. HE-PD rounds can be seen in the outer ring and blue-colored BLP target rounds are peeking out of the inner ring. (U.S. Coast Guard photo by Petty Officer 3rd Class Jessica Fontenette)
The gun control panel below-deck under the mount, complete with its view of the magazine rings. Seen on the USCGC Midgett (WHEC 721) in June 1999. USCG photo by PA2 Alice Sennott
Shells were brought on and off the packed in grey shipping containers, loaded old-school via chain gangs.
Sailors aboard the Oliver Hazard Perry-class guided-missile frigate USS Rodney M. Davis (FFG 60) move 76mm rounds during an ammunition onload. Rodney M. Davis, based out of Everett, Wash., is on patrol in the 7th Fleet area of responsibility supporting security and stability in the Indo-Asia-Pacific region. (U.S. Navy photo by Mass Communication Specialist 3rd Class Derek A. Harkins/Released)
For a great look at the inner guts of the 76/62C Compact, check out this short video from the German Navy, which has used the gun since 1965. Don’t worry if your German is rusty, the video speaks for itself.
With the U.S. Navy opting to mount a smaller 3-inch gun on its planned Oliver Hazard Perry-class frigates in the 1970s– a big change from the manned 5-inch guns mounted on the Knox-class frigates that preceded them– the Pentagon went with the Italian “robot gun” design.
A destroyer escort, USS Talbot (DEG-4), in late 1974 had an Italian-produced 76/62C Compact installed on her bow forward of the superstructure in place of the ship’s original 5-inch manned mount which used a design that dated to World War II.
USS Talbot seen circa 1974-75 with an OTO Melara 76/62C Compact installed. (Photos: U.S. Navy History and Heritage Command)
The Naval Systems Division of the FMC Corporation in 1975 won the U.S. contract to build the 76/62C Compact in Pennsylvania under license from OTO Melara and delivered the first American-built model in August 1978. The Navy, which designated the gun the MK 75, went on to install them in 51 Oliver Hazard Perry-class frigates built between 1975 and 1989, along with six Pegasus-class hydrofoil fast attack craft and on the Coast Guard’s 13 new Bear-class cutters that were constructed in the same era.
Likewise, when the Coast Guard’s 12 Vietnam-era Hamilton-class cutters were modernized starting in 1987, they received the MK 75 to replace their outdated 5-inch mounts. The guns were also installed on a series of warships built in the U.S. for overseas customers (Israel, Egypt, Australia, et.al).
The frigates carried the MK 75 atop their superstructure as the bow, the traditional location, was occupied by a missile launcher and its below-deck magazine.
October 2002. USS Sides (FFG 14) fires her 76mm dual-purpose gun at ex-USS Towers (DDG 9) during a SINKEX near San Diego. (Photo: U.S. Navy)
May 2011. The Oliver Hazard Perry-class guided-missile frigate USS Thach (FFG 43) fires its MK-75 76mm mounted gun while underway off the coast of Brazil. (Photo: U.S. Navy)
August 2014. The Oliver Hazard Perry-class guided-missile frigate USS Rodney M. Davis (FFG 60) conducts a live-fire exercise of its MK 75 76mm/62 caliber gun. (Photo: U.S. Navy)
One of the frigates, USS Simpson (FFG-56), part of Surface Action Group Charlie, had the first combat use of the MK 75 in U.S. service when, in April 1988, used the gun to destroy Iranian naval and intelligence facilities on the Sirri oil platform during Operation Praying Mantis.
Another frigate, USS Nicholas (FFG-47)used her MK 75 during Desert Storm in January 1991 to clear Iraqi troops placed on nine oil platforms in the northern Persian Gulf off of occupied Kuwait. As reported at the time, the frigate “fired three shots at each platform to set the range, followed by about 20 rounds of high-explosive shells, ‘for effect.’ The effect was to demolish quickly all the remaining bunkers.”
The speedy hydrofoils, meanwhile, wore their MK 75 as a hood ornament.
As did the Coast Guard cutters.
Coast Guard Cutter Harriet Lane firing a commemorative shot on 30 May 2019 to honor the 158th anniversary of its namesake’s action near Fort Sumter, South Carolina. (Photo: USCG)
The water-cooled barrel, using salt water during the firing process and a freshwater flush from the ship’s onboard supply after the firing ceased, led to often extreme muzzle shots with the intersection of steam and propellant.
The crew of Coast Guard Cutter Northland conducts a live firing of the MK 75 76mm weapons system while underway, on September 20, 2020, in the Atlantic Ocean. (Photo: USCG)
March 2000. The Coast Guard Cutter Tampa’s 76mm gun blasts a projectile at a moving target during live-fire exercises. Participants took turns firing at “robo-ski,” a small, remote-controlled jet ski. Tampa gunners hit the target every time. USCG Photo by ET3 Shane Taylor.
The gun uses a saltwater cooling system and a freshwater cleaning run after firing concludes, seen here on USCGC Escanaba in 2028.
All things come to an end
However, there has been a slow-motion end to this story that started with the retirement of the hydrofoils in 1993, and the frigates losing their MK 75s by 2015 in a series of refits. This left the Navy, who “owns” the installed weapons on Coast Guard cutters, still on the hook for logistics contracts with BAE systems and OTO Melara (now Leonardo) for parts and support.
Those days are gone as the 76/62C is out of production both in the U.S. and Italy, with Leonardo replacing the system in its catalog with the faster-firing (though still with only an 80-round ready magazine) and more stealthy 76/62 Super Rapid (SR) Gun Mount.
Eventually, the Ordnance Shop at the Coast Guard yard took ownership of the MK 75 program and was even tapped to support the guns on frigates and cutters transferred overseas.
Since then, the Hamilton class has all retired and has been transferred overseas and now the Bear class cutters are in the process of being stripped of their MK 75s during refits, and replaced by smaller (albeit currently produced) MK 38 25mm guns. Overseas allies are similarly phasing out the gun.
This brings us to the coda of the Bear-class USCGC Mohawk (WMEC 913) firing her MK 75 for the last time this summer, an event that was held during a gunnery exercise in the Florida Straits. The service said in a press release this week that it was a “significant historical event” as Mohawk was “the last in its class to fire the onboard Mk 75 gun weapon system.”
Coast Guard Cutter Mohawk’s (WMEC 613) Mk 75 weapon system fires, Aug. 16, 2024, during a gunnery exercise in the Florida Straits. Mohawk was the last Famous-class medium endurance cutter to fire the onboard Mk 75 mm gun weapon system as large caliber weapon systems onboard these cutters are being modernized for the service life extension program. (U.S. Coast Guard photo by Ensign Brian Morel)
Perhaps once the mount is phased out for good, the USS Aries Museum, the only preserved U.S. Navy hydrofoil, can pick up one of the old MK 75s to help complete her Cold War profile.
