National Defense Logo tagline Search Tips

Current Issue
E-mail the Editor



March 2001

Naval Guns: Can They Deliver ‘Affordable’ Precision Strike?

by Sandra I. Erwin

In the U.S. Navy’s plan for fighting wars in the future, combat ships will serve as mobile sea-based artillery, providing fire support from as far away as 100 miles. Advanced naval guns shooting satellite-guided munitions, officials said, will provide the same land-combat firepower that today would require several batteries of howitzers. Further, if the new gun systems work as advertised, they would allow the Navy to hit targets ashore for much less than what it costs to strike with Tomahawk cruise missiles.

“We want an affordable round to do a small hole in a building, right where you want it. [But] we don’t want to spend a million dollars a pop,” said Capt. Tom Bush, program manager for the Navy’s futuristic destroyer, called the DD-21.

But Bush cautioned that long-range naval guns will not replace tactical missiles and are “not here to take away land-strike naval aviation. ... [They are] just a small part, an affordable small part.”

The so-called land-attack mission by the U.S. Navy has become a linchpin of the service’s plan for fighting future wars, and is driving a $25 billion investment in DD-21.

Several more billions, additionally, will be spent on new 5-inch guns and smart munitions for the current Arleigh Burke guided-missile destroyers, the DDGs. The upgraded 5-inch 62-caliber guns—designed for a land-attack role—are expected to launch guided projectiles out to at least 41 nautical miles (nm).

By comparison, the current 5-inch, 54-caliber gun fires out to 13 nm.

Since the Navy did away with the 16-inch gun-equipped battleships, it only has used 5-inch versions. But after conducting several studies, the service decided that the 5-inch size offered limited capability for long-range strikes with smart munitions, so it decided that its new land-attack ships, the DD-21s, would have bigger guns.

The DD-21 Zumwalt-class destroyers will have, unlike any other ship, 155mm guns, two per ship. The Navy decided to go to a 155mm caliber, equivalent to 6 inches, because it wanted both a larger projectile and one that would have some commonality with heavy land-combat ammunition, which also is 155mm.

Going from a 5-inch to a 6-inch gun drastically changes the rules of the game, said naval experts. With a larger gun, more lethality comes not just from bigger projectiles but also from the ability to increase the length of the rocket motor in guided rounds, so they can travel farther.

The 62-caliber gun for DD-21, called the advanced gun system (AGS), will fire 12 rounds a minute and largely will automate the ammo-loading process. This is an important consideration, because DD-21 will sail with two-thirds fewer crew members than the DDGs.

The AGS primarily will be a land-attack weapon, but also could serve in anti-surface warfare missions. It will be able to fire both long-range guided munitions and traditional ballistic ammunition.

“This is the first modern naval gun where the ammunition is part of the naval gun-system development,” said John M. Paul, AGS deputy program manager at United Defense LP, in Minneapolis. The company is designing the gun and also is responsible for the initial development of the long-range guided projectile.

Last August, UDLP awarded two contracts for the guided projectile design: one to Science Applications International Co. (SAIC) and one to the Raytheon Co. The two teams will compete for an award scheduled for December 2002.

Tests of the competing designs were scheduled to begin in late February at the Dugway Proving Ground, in Utah.

The Navy wants each AGS gun to have an automated magazine that can accommodate between 600 and 750 rounds, for up to 1,500 rounds per ship. The DD-21, at 14,000 tons, will be able to store more ammunition than the 9,000-ton DDGs.

Two shipbuilding teams, meanwhile, are competing for a DD-21 contract award scheduled for April. AGS will be the DD-21 gun, no matter which shipyard—Bath Iron Works or Litton Ingalls—is selected to design and build the vessels.

UDLP’s current gun contract ends in March. Assuming that the Navy selects a ship contractor in April, UDLP would submit a proposal to continue with the gun design and prototype testing, said Paul. “Up to six guns could be awarded as options to the contract we hope to get immediately after down-select in late March, early April,” he said in an interview.

“At the time of down-select, our customer will become the chosen [shipyard] contractor,” Paul said. “We submitted the same proposal to each of the two teams.”

Both shipyards integrated the AGS into their designs. Within UDLP, said Paul, there are three separate teams working on this gun. “I represent the core team, which is developing the basic upper gun elements. We also have two other teams ‘firewalled’ from one another, each under contract to one of the DD-21 teams.” Each firewalled team is responsible, for example, for developing the magazine, which is ship-unique.

Even though AGS will fire 155mm ammunition, it will not be ground-combat ammo, Paul said. “There is a likelihood that this gun could fire some of the 155mm land ammo.” But the range requirements—100 nm—demand much longer projectiles with a larger rocket motor. AGS ammunition, therefore, will not be compatible with any land-combat system.

Raytheon’s competitor, SAIC, is working on the projectile’s design and is teamed with Lockheed Martin Missiles and Fire Control, in Orlando, Fla. If SAIC’s design is selected, Lockheed would become the prime contractor for the subsequent phases of the program.

SAIC officials declined to be interviewed, citing concerns about the program’s proprietary information.

Joseph Antoniotti, director of guided projectiles at Lockheed, does not anticipate any significant technological hurdles in this program. “We don’t believe that this is new physics,” he said in an interview. “We demonstrated virtually everything that needs to be done in a high-g guided projectile 20 years ago.” In the early 1980s, Martin Marietta (later acquired by Lockheed) made a 6-inch laser-guided projectile, which the Navy opted not to buy.

“The physics to make a guided projectile operate, we know how to do that,” he said.

Antoniotti expects that the AGS projectile will cost less than $50,000 each, once in production. “If you can kill a $4 million battle tank with a $50,000 projectile, that’s a great trade,” he said.

UDLP officials have not yet determined where the AGS will be built. “We are still looking at potential production facilities,” said Paul. But he expects that some large components would be manufactured at company facilities in Minneapolis. Final assembly and tests would take place in Louisville, Ky., at a former naval ordnance station, where the Mk 45 Mod 4 guns also are assembled.

“We haven’t made final manufacturing decisions this early in the design phase,” said Paul.

Given speculation that the Navy may not have enough shipbuilding dollars to buy the DD-21 vessels, UDLP does not discount the possibility that the gun could be used on other ships, assuming they are large enough to hold the huge guns.

“The United Kingdom currently is looking at a derivative of AGS on their Type 45 destroyer program,” said Paul. “In theory,” he added, AGS could have “potential applications on other platforms.”

Extended Range Munition
The Raytheon unit that is competing for the AGS ammunition award also is developing a smart projectile for the Navy’s 5-inch 62-caliber gun designed for land-attack missions, called the Mk 45 Mod 4. The rocket-assisted projectile is the extended-range guided munition (ERGM).

The gun is made by UDLP, but the development of ERGM is managed directly by the Navy.

The ERGM and the AGS efforts at Raytheon have separate staffs, but are “co-located and operating as a product line,” said Brian O’Cain, the company’s program manager for ERGM.

ERGM, using GPS coordinates, will deliver 72 submunitions out to at least 41 nm. A conventional 5-inch round is 3 feet tall and weighs 70 pounds. The 5-inch ERGM round is 5 feet tall and weighs 110 pounds.

The Navy had planned on introducing ERGM to the fleet by 2001, but the program is several years behind schedule, mostly because Raytheon moved its operations from Texas to Tucson, Ariz. According to the new program schedule, the round could be available by 2004.

The newest Arleigh Burke destroyer, the USS Winston S. Churchill (DDG-81), to be commissioned in March, will be the first ship to have the Mk 45 Mod 4. Every new destroyer between DDG-81 and DDG-108 also will have the gun installed. Tests on the DDG-82 (USS Lassen) are scheduled for February 2002.

Earlier versions of the Mk 45 remain in use in the fleet today. The Mod 4 upgrade program began in 1993. The goal was to produce a gun with extended range that could handle much larger recoil forces. The ERGM round will exit the 62-caliber gun barrel at 13,000 g’s (gravity forces), which equates to about 27,000 feet per second. By comparison, the 5-inch conventional round exits the 54-caliber gun barrel at 8,000 g’s.

The Navy plans to buy 72 guns for both destroyers and cruisers, said Capt. Brian G. Schires, director of naval land attack warfare. Each DDG has one gun. Cruisers will be equipped with two.

Officials are looking at potentially including the Mod 4 gun as part of a cruiser-conversion program to upgrade 27 ships. That decision has yet to be made and no funding has been allocated. “We are doing some work with the cruiser conversion program, ... trying to make some smart, balanced decisions,” said Schires.

There are six Mod 4 guns being tested at sea today, he said. About 80 percent of the parts are common between the 54-caliber and the 62-caliber guns.

During the USS Churchill sea trials, the Mod 4 gun fired simulated ERGM shapes, in order to demonstrate that the gun can handle the additional loads.

The development of the gun largely is complete and has not been hampered by the delays in the ERGM program, said John Smalkoski, director of gun systems at UDLP. “We are waiting for some design information to be completed at Raytheon, so we can finish the design of the gun,” he said in an interview. The only unfinished part, he explained, is the gun’s fuze setter, which has to be programmed to communicate with the ERGM internal electronics.

ERGM presented “tough technical problems,” said Smalkoski, because no other round of that caliber has ever been able to reach 41 nm. “This was new ground,” he said. “You are taking components and electronics typically used in missiles.”

Missiles, however, experience “soft launches,” where the g-forces aren’t as high as those coming out of a gun barrel. “The hard part is getting all the components to survive the gun launch,” said Smalkoski.

During the next several years, until ERGM is fully developed, the Navy will use conventional, ballistic ammunition developed by the Crane Division of the Navy Surface Warfare Center, in Indiana.

Because the 62-caliber gun can handle greater g forces—in order to launch guided munitions—the Navy is buying a new type of ballistic ammunition, called cargo projectile, that is effective for distances up to 21 nm, explained Larry Massa, program manager for naval 5-inch ammunition at Crane.

The cargo projectile contains dual-purpose submunitions that are dispensed in the air and fall to the ground exploding on impact. It is the same size as the 54-caliber gun round.

Congress mandated that the Navy buy 14,000 of the cargo projectiles. Each costs between $1,600 to $2,200.

The service still has about 50,000 of the older rounds in its inventory, and there are no plans to produce any more of those. “The requirements for 5-inch 54-caliber ammunition dropped so drastically that we are just using what is in the inventory and probably will do so for the next five to six years,” Massa said in an interview.

Crane’s new projectile can be used in any gun, but is “most effective in the 62-caliber gun,” he said. There are provisions to increase the production of the cargo projectiles and propelling charges if ERGM is delayed further. The propellant charges are built at the McAllister ammunition plant, in Oklahoma.

Massa believes that the cargo projectiles could be turned into guided munitions, if the Navy chose to do so. “That work is not funded currently, but if it were funded, it could be done in two to three years,” he said. There were studies done at Crane that showed that the range of the cargo projectile could potentially be extended to 40 nm. It would not be GPS-precision guidance, but a less-accurate form of guided ballistic projectile, Massa said. It probably would cost $5,000 to $6,000 each.

The Navy, however, wants a round with a range of at least 41 nm but, preferably, of 63 nm, in order to meet the Marine Corps’ standard for long-range fires. Massa predicted that ERGM may achieve the 63 nautical-mile range within a couple of years.

ERGM program officials said that it is too early to put a price tag on ERGM rounds, since the program still is in development. But industry sources said the expectation is that it will cost anywhere between $35,000 to $60,000 each.

When it comes to cost, ERGM is no different than any other guided munitions program, said Don Kennedy, a warhead designer who worked on the ERGM project during the early stages of the program, when it was managed by Texas Instruments.

“Every program I’ve ever worked on starts out as ‘low-cost ammunition,’ and then it turns out to cost 10 times as much,” he said. But he predicted that ERGM “will survive and will work.”

Raytheon officials currently are trying to validate “pricing data,” said O’Cain, the company’s program manager. “There are a lot of numbers out there,” he said. “Our biggest effort for the coming year is to validate what the real numbers are.”

The high-cost components in ERGM are the guidance system, the rocket motor, the airframe components and the control system, O’Cain explained. These components have been tested in various gun-launch events, “proving that they survive the gun launch and function afterwards,” he said.

Last month, ERGM performed its first flight test at White Sands missile range, in New Mexico. Tests will continue throughout the year, O’Cain said. Later this year, he expects that ERGM will be ready for its first guided-flight test, “where we actually close the loop with the GPS guidance system and guide to a specific target point.”

The survival of the GPS guidance unit, payload and electronics in high g-forces has been demonstrated, he said. “Now, we are tying all those systems together in a real flight round, all integrated.”

Even though Raytheon has confidence in the technology, O’Cain said, “the gun launch is always going to be an issue. ... I don’t think we ever get past the point when it’s not a concern that we always think about.

“Our focus is on the manufacturing techniques and processes that will provide a round that will survive.”

O’Cain is certain that ERGM will meet and exceed the 41 nm range, but it is not clear whether it will reach 63 nm. “Right now, we are not achieving the full 63 nm, but we have a plan in front of the Navy for how to raise the range and get close or beyond the objective range.”

Currently, he added, “we do not believe that we will achieve the objective range of 63 nm, but we won’t be far off.” But if the Navy decided to fund an upgrade program to boost the range, “we have a thought process to get there.”

Back To Top