At 270 feet and weighing in at 1,646 tons, Coast Guard Cutter Thetis is equipped with the necessary equipment to perform law enforcement, search and rescue, homeland security and national defense missions. To stay mission ready, the ship’s equipment requires routine maintenance usually handled by the crew, but occasionally more attention is needed. Cue the Coast Guard Yard in Baltimore, Md.
One of the many specialized groups working at the yard is the ordnance shop’s MK75 planned depot maintenance team. Often considered an unsung hero of the yard, these men and women work diligently on the overhaul maintenance of the MK75 gun systems on board the medium endurance cutter fleet.
The MK75 is a fully automated remotely controlled gun mount that stows, aims and fires 76 mm, 62-caliber ammunition. The gun interfaces with a fire control system and while it is primarily a defensive weapon against airborne targets it can be effectively used against surface and shore targets.
“The MK75 is invaluable to accomplishing Thetis’ primary missions of counter-drug and alien and migrant interdiction operations,” said Ensign J. Matthew Hurtt, the weapons and electronics materials officer aboard Thetis. “Its prominent barrel and rotating mount, clearly visible on Thetis’ bow, makes it an intimidating piece of weaponry that encourages vessels violating U.S. law to become compliant. In addition, it actively provides for the safety and security of U.S. and foreign flagged vessels in U.S. waters and on the high seas.”
Recently, the MK75 planned depot maintenance team found themselves deep in the Florida Keys to work on the Thetis’ gun change out.
A refurbished gun and ancillary equipment were loaded at the yard onto trailers destined for Florida. The maintenance team – consisting of the ordnance shop foreman, four ordnance mechanics, one rigger and a crane operator – arrived a day early to prepare themselves for the delivery of the gun and the work that ultimately lay ahead.
The team prepared the ship for removal of its current MK75 by disconnecting its cables, revolving magazine, foundation bolts and gun control panel. They offloaded the new gun and ancillary equipment from trucks and removed the control panel and current gun from the cutter. The ship’s crew and the yard’s maintenance team worked closely together to prepare the ship’s foundation for the installation and within two days bolted the new gun and control panel into place.
Cmdr. John Driscoll, Thetis’ commanding officer, quickly discovered when the bar was set high for system repairs and cutter longevity maintenance, the team not only met the task but exceeded all expectations.
“This was by far the best organized, supervised and choreographed operation I’ve seen,” said Driscoll. “The team of gun technicians and riggers worked so smoothly together that hardly a minute was wasted. They…were outstanding representatives of the Coast Guard Yard.”
Initial light-off procedures began the following day after installation of the control panel, revolving magazine and cables. This complex process was verified through a multitude of tests. Once deemed satisfactory, the gun was connected with the fire control system.
Throughout the rest of the week, the ordnance team stayed behind to run a series of tests and procedures that gave assurance the entire gun system was fully operational and ready to serve its mission. Depot maintenance team members – John J. Driscoll, Dale Strucko, James Young, Dennis Fore, Gregory Pulley, William Tyson and Theodore Brown – were able to leave Thetis knowing they had met the demands – all 5,600 labor hours at both the yard and on site – of such an intricate task.
“The Coast Guard’s ability to protect the United States is dependent on maintained proficiency and effective equipment. The installation of a new MK75 makes Thetis even more capable of answering the threats of tomorrow through increased training and continued proficiency,” said Hurtt.
In the end, the depot maintenance team demonstrated the hard work performed by yard members day in and day out. Thetis was once again able to ply the ocean waters of the Caribbean basin, keeping our nation safe and secure.
