OTO Melara is pitching its 76 mm gun as a longer-range, cost efficient alternative to the legacy 57 mm system that is currently planned to arm the Navy's future frigate.

February 27, 2015 -- OTO Melara is pitching its 76 mm gun as a longer-range, cost efficient alternative to the legacy 57 mm system that is currently planned to arm the Navy's future frigate.

The 76 mm would replace BAE System's Mk110 57 mm, which currently equips both variants of the Littoral Combat Ship and is planned as the main armament of the modified LCS, or future frigate. In addition to the 57 mm, the planned frigate will field an upgraded SeaRAM for close-in engagements, two 25 mm guns to counter threats inside the horizon, an MH-60 Seahawk helicopter armed with Longbow Hellfire torpedoes to fight at the horizon, as well as a to-be-determined over-the-horizon missile. The Navy will also be able to pull on additional weapons systems for the planned surface warfare (SUW) "swing" configuration of the ship.

Despite criticism that the LCS and planned FF do not have the firepower to counter growing threats in the littorals, in particular small fast attack craft, the Navy has so far shown no sign that a switch from the 57 mm gun to the 76 mm is imminent. Sean Stackley, the service's top weapons buyer, said Dec. 11 during a roundtable at the Pentagon that the Navy has concluded that, at least for now, the 57 mm is the right gun for the ship.


BAE officials told Inside the Navy in a recent interview that the Navy has given every indication that officials are happy with the 57 mm gun's performance.


The small surface combatant task force, given the job last year of providing a more lethal, survivable alternative to the current LCS, combed through "hundreds and hundreds" of technologies to find the right configuration for the future frigate, according to Charlie McCullough, BAE director of maritime business development.


"Many different systems have been solicited for, evaluated, and [the Navy's] determination for the main deck gun is the 57 mm system," McCullough said, adding that he does not expect the Navy will solicit proposals for a new gun system to arm the FF.


The Navy originally selected the 57 mm gun system for LCS in the early 2000s due to the weapon's "superior threat engagement" -- the gun's 220 rounds-per-minute rapid fire and intelligent ammunition, according to Tom Dancyzk, BAE Mk110 program manager. LCS is also constrained by weight in order to get the required speed, Dancyzk said, noting that the 57 mm with required ammunition weighed about four tons less than BAE's competitors at the time. Finally, the gun also required significantly less maintenance than other proposed systems, he said.


OTO Melara: Switch to 76mm increases FF range


OTO Melara, a subsidiary of the Italian defense company Finmeccanica, is arguing that a switch to the 76 mm gun as the ship's main armament would significantly increase the lethality of LCS and allay the critics. The 57 mm gun only goes out to five nautical miles -- within the horizon, according to Eric Lindenbaum, vice president for navy and maritime programs for DRS Technologies, which is supporting OTO Melara in the U.S. By contrast, the conventional 76 mm gun system provides a range of nine nautical miles, Lindenbaum said. The gun has a firing rate of 120 rounds per minute.


"The issue of lethality, the problem that the ship has can be encapsulated in the gun," Lindenbaum said during an interview with ITN. "If you are out there on a ship and you are looking at something on the horizon, that is approximately 10 to 11 miles, so you have to have that vessel, that threat, come halfway from the time I've seen it into the ship for me to be able to engage it with the 57 mm."

Fifty-five international navies currently equip their ships with the 76 mm gun, Lindenbaum emphasized.


"So if the LCS as configured today, or the FF [of the future] goes into the littorals where those other 55 navies are, they don't have to come within weapons range of this ship to engage it," he continued. "They can stay there at 10 nautical miles and engage this ship and this ship can't engage them."

The 76 mm would allow the future frigate to be able to perform independent operations in the littorals without fear of being outgunned by a foreign navy, Lindenbaum stressed. For these missions, LCS will not have the protection of a cruiser or destroyer.


If the Navy were to add Finmeccanica's gun system to the future frigate, Lindenbaum claimed the service could re-examine the need for the additional guns provided by the SUW "swing" configuration, or even the hotly-debated vertical launch system (VLS), which would lend the ship ballistic missile defense capability.


"You could re-think the entire [SUW] mission module, even the need for it, with our gun," Lindenbaum said. "You can see the improved lethality and survivability that the ship will have with the 76 over the 57, and that's what it ultimately comes down to."


The 76 mm gun fits onto the LCS hull form, is only marginally heavier than the 57 mm system, and would be simple to backfit onto the ship earlier than 2019, when the first modified LCS is planned for procurement, Lindenbaum argued. BAE's gun must be taken off the ship and sent to the factory for refurbishment every six years, he said. At the six-year point, the Navy could easily install a 76 mm gun in place of the 57 mm, Lindenbaum said. DRS' system only needs to be refurbished once every 16 years, he noted, adding that this reduces life-cycle costs for the system.


Another advantage of the 76 mm over the 57 mm is that when the BAE gun runs out of ammunition, operators need to rotate the barrel so that it sticks straight up into the air in order to reload the weapon down below. At the gun's range of five nautical miles, swarming boat threats would be able to see the 57 mm gun point toward the sky and know that it is out of ammunition, Lindenbaum said.


In addition, the 76 mm gun is water-cooled, as opposed to the air-cooled 57 mm, Lindenbaum noted. This avoids a "hot-gun situation," the term used for a gun that must cool down for a period of time after firing a certain number of rounds. The 76 mm can fire continuously until it runs out of ammunition, Lindenbaum said.


In terms of acquisition cost, both systems carry a price tag of approximately $5 million, Lindenbaum said. However, using the 76 mm gun would allow the Navy to take advantage of increased commonality with foreign navies, he said.


"The Navy has the advantage here or the capability to not only improve the lethality, but to be in accordance with Better Buying Power 3.0, because again this is the most common gun out there," Lindenbaum said "The Navy didn't have to pay for its development, this gun is in production worldwide, you are already getting economies of scale by buying into the production line."


BAE: Sticking with 57 mm lends FF faster firing rate


Meanwhile, BAE maintains that its 57 mm gun is still the best option to meet the mission of LCS and the future frigate. The gun uses a Mk 295 pre-fragmented, programmable, proximity-fuzed (called "3P") round that is ideally suited to counter swarm attacks, Dancyzk said. This lends the weapon the ability to fire 220 rounds per minute -- a rate that is much faster than other guns at this caliber, he stressed.


The 3P ammunition also allows an operator to program the gun in six different "modes," Dancyzk said. For example, the most commonly used mode is called "conventional proximity mode," while operators could also program an armor-piercing mode called an "impact mode," he explained.


The "maximum range" of the weapon is 10.5 nautical miles, he said. However, that is not the same as the gun's "effective range," he noted. The gun's effective range is about one-third of it's maximum range -- or approximately 3.5 miles.


BAE also noted the benefits associated with an air-cooled system like the 57 mm as opposed to a water-cooled weapon such as the 76 mm. The air-cooled aspect simplifies the design of the gun and avoids corrosion issues that can occur when water is introduced into a system, McCullough said.


"Water and metal really don't agree with each other too much, that causes some corrosion issues and some maintenance issues," McCullough said. "So it really was a simplified design [to] make it so you can continuously fire at that rate without needing liquid cooling."


McCullough acknowledged that when the gun needs to be reloaded operators must elevate the barrel. However, he argued that in the typical 20-round engagement normally associated with swarm attacks, reloading would not be necessary. The gun has 120 rounds in its upper gun mount, he said.


In addition, BAE is arguing that sticking with the 57 mm gun increases commonality across the fleet. Both variants of LCS currently have the 57 mm gun, and the system was also selected to equip the new DDG-1000 Zumwalt destroyers.


"Commonality across the fleet -- [it's a] great thing for our fleet to have only one intermediate-caliber gun instead of multiple different kinds of guns they have to maintain, train, equip, spare, everything," McCullough said. "So it's a very good buy for the American taxpayer to only have to support that one configuration."


McCullough did acknowledge, however, that the Navy last year replaced the two 57mm guns planned for the Zumwalt with a smaller pair of 30mm guns. This decision was made in order to save weight and costs, according to reports.


Still, the Navy has been pleased with the performance of the 57 mm on LCS, particularly the accuracy of the weapon, according to representatives from Lockheed Martin, which builds the LCS Freedom-variant.


"I think if we were having this conversation maybe 10 years ago and the 57 mm hadn't been able to demonstrate its accuracy and its range, those questions might still arise," Jeanine Matthews, Lockheed director of business development for the modified LCS, said Feb. 18 during a company media day. "I will tell you, in discussions with the Navy, they seem pretty firm behind the 57 mm."


Both companies will modernize their ammunition


Looking to the future, both OTO Melara and BAE are modernizing the ammunition fired by their respective gun systems.


Since the Oliver Hazard Perry-class frigates (FFGs) fielded the 76 mm gun, the Navy has tens of thousands of the current 3-inch rounds in existence that are available for "re-use", Lindenbaum said. The Navy could modernize the fuse on these rounds by changing out the fuse mechanism, he stressed. OTO Melara is also producing a "drivable" -- or re-targetable -- munition called DART, which is currently being sold to three foreign navies. DART is "truly a smart munition," Lindenbaum said.


OTO Melara is also working on a GPS-guided ballistic munition, the VULCANO, which extends the gun's range out to 22 nautical miles, or 10 miles over the horizon, Lindenbaum stressed. Low-rate initial production of the VULCANO is projected sometime in 2015.


However, it should be noted that since the Navy is decommissioning the last of the FFGs later this year, the service is no longer buying the ammunition for the 76 mm gun.


BAE is also working on a guided round, which would lend the 57 mm gun the ability to defeat one target per round, McCullough said. This munition is not yet a program of record, but there are available research and development funds in the Navy's fiscal year 2015 and FY-16 budgets that the service could put toward the project, McCullough said.


Although the Pentagon has faced criticism that the Navy's future frigate does not significantly "upgun" the current LCS, BAE maintains that its planned upgrades to the 57 mm will meet the mission set.


"The term 'upgunned' . . . you hear that word thrown out there, but it doesn't matter how big your gun is," McCullough said. "It's what your gun does for the warfighter, right? A combination of the gun itself, the ammunition and fire control and the sensors, so if you have those elements all correct, you can both upgun without making a bigger round." -- Lara Seligman