Customized Artillery Launcher Truck Cab Underscores Crew Protection.
This wheeled artillery platform, called the high-mobility artillery rocket system (HIMARS), is touted by Army and Marine Corps officials as an ideal weapon system for expeditionary forces who need to deploy on short notice and cannot afford to bring along heavy artillery. HIMARS has been in development for four years, but it is now gaining high-level attention because the Army is emphasizing the use of weapon platforms that are C-130 transportable. The HIMARS is based on a 5-ton truck chassis, which means it can fit on a C-130 medium-lift aircraft.
The HIMARS cab is a modified version of the basic truck steel cab used in the Army's family of medium tactical vehicles (FMTV). Unlike the basic cab, it has special linings and reinforcements, designed to protect HIMARS crews from shrapnel, fumes and other hazards involved in launch operations. This platform fires both rockets and missiles.
The Army is buying eight HIMARS prototypes with the new cab. Two of them will be used by the Marine Corps, which recently joined the program. Four existing prototypes, which do not have the new cab, have been tested during the past two years--three of them at Fort Bragg, with the Army's 18th Airborne Corps. The fourth is used as an engineering test bed by the HIMARS prime contractor, Lockheed Martin Missiles and Fire Control, in Dallas.
Lockheed Martin is using FMTV chassis made by Stewart & Stevenson Tactical Vehicle Systems, in Sealy, Texas. The cab work was subcontracted to O'Gara-Hess & Eisenhardt, in Fairfield, Ohio. The company makes customized military and civilian armored trucks.
At O'Gara, the cab is stripped down to the bare shill and is rebuilt and lined with a lightweight synthetic armor material. The armored lining also replaces some of the windows. A set of louvers is installed over the windshield, for flash protection. The crew must close the louvers before munitions are fired. Otherwise, their eyes would be damaged by the glare, which is comparable to a welder's torch, said Earl Young, program manager for HIMARS at Lockheed Martin. A special poly-carbonate laminated glass is used for the windshield and windows.
The cab must be sealed completely, said Young in an interview. That means every joint, nook and crevice is covered. A central air-filtration unit, installed within the cab, pulls air from the outside and discharges it into the cab with such strength that the air pressure within the cab is higher than the air pressure outside the cab. That is how toxic gases are prevented from entering the cab, Young explained. "As long as sufficient air pressure is kept inside the cab, the crew can fire rockets without having to wear gas masks."
The Army uses similar air filtration systems in the upgraded Bradley infantry vehicles and the tracked MLRS (multiple launch rocket system).
The HIMARS cab also has to be re-arranged inside, to accommodate the communications and computer equipment that is needed to launch weapons. A commander's hatch, additionally, is installed in the roof of the cab. When the launcher is moving or is in a defensive position, that hatch can be opened and the commander can occupy a seat mounted over the vehicle's engine cowling. The basic cab only has two seats. HIMARS crews include a commander, a driver and a gunner.
The rationale for building a new cab, said Young, was to determine whether these customized pieces can be manufactured efficiently, while meeting the Army's requirements. "The emphasis for the new cabs is to come up with processes that are repeatable, so that every cab will be alike and, when fielded, can be expected to last 15-20 years without major repairs."
Obviously, it will be difficult to predict how these cabs will age during a 36-month development program, said Young. But a more important issue, he added, is to determine that the cab can be manufactured and that its weight can be lowered, compared to the existing HIMARS prototypes. "The original prototypes are quite heavy" and were built largely with commercial materials.
The vehicles with the new cabs will be tested for ruggedness and sturdiness, said Young. "We will shake them, strike them with lightning, fire [weapons] from them. We'll have instruments all over the cab to predict load, shock and vibration. We'll make sure toxic gas doesn't get in. Then we can certify the cab is acceptable for a crew."
The protection offered by the HIMARS cab is not ballistic protection, even though many of the materials used are the same as in bullet-proof systems, explained Wayne Robbins, director of the HIMARS program at O'Gara-Hess & Eisenhardt.
Robbins believes that the HIMARS cab program could lead to a much bigger project, in the future, to equip all FMTV trucks with armored cabs that would protect crews from assault rifle rounds and landmines.
Hartwell Champagne, program manager of engineering and sales at Stewart & Stevenson, cited armored cabs as one area that truck manufacturers should emphasize. "You are going to have more peacekeeping missions, where crews will be more isolated in deployments. Trucks are going to be more isolated," he said in an interview. Ideally, he said, trucks should provide protection against rifle grenades, sniper bullets and landmines. "You'll see an attempt to come up with armored cabs that have anti-mine protection. We are working that with several armor makers."
The Army is trying to decide whether it can afford the cost and the weight of adding armor to FMTV trucks. To address the weight problem, Robbins suggested that there are ways that the Army could take advantage of the technology in the HIMARS cab and still keep the weight down. The louvers, for example, could be removed. The weight saved could then be transferred to the windshield glass to make it bullet-proof. The metal flash-protection devices on the doors also could be removed.
Even though the HIMARS cab has a low level of ballistic protection, it contains the same materials O'Gara uses in armored commercial and military vehicles. In the HIMARS program, said Robbins, "weight is a critical factor. We have to watch everything we put in the cab. We use aluminum when we would use steel otherwise." The cab is lined with DuPont's newest form of Kevlar, called Impak.
A stripped-down FMTV cab gains about 1,000 pounds when it's customized for HIMARS. Among the items that add to the weight are fire extinguishers, radio racks and storage compartments, said Robbins. "A lot of that is not just protection, but other equipment as well." More weight would have to be added, in order to turn it into a ballistic cab.
HIMARS lost 350 pounds just by having the spare tire removed, Young noted. The weight was not just the tire, but also the hydraulic lift used to move the tire to the rear of the truck. Lockheed Martin suggested that the HIMARS launcher could get by without a spare tire because it is deployed with two 5-ton resupply trucks, which have spare tires. The truck has a central tire inflation system, so it takes a lot of damage before a spare is needed. "All that considered," Young said, "we thought it would be all right if we didn't have a spare immediately available on the launcher."
The first mock-up of the new HIMARS cab was delivered last June to Lockheed Martin. The next one will be shipped in late February or early March, Robbins said.
Rick Vallario, manager of business development at Lockheed Martin, said the company plans to complete the first HIMARS "maturation" launchers by September. Under the current contract, he said, "we will do eight: six for the Army, two for the Marine Corps. This is for the maturation program only."
It is not certain, however, that the O'Gara cab will be kept beyond the current phase of the program. "There is a possibility that the cabs will change as the program progresses," said Vallario. The current HIMARS program is scheduled to produce 363 systems.
Industry sources speculated, however, that the HIMARS fleet could grow to 1,000 vehicles, given the high-level of interest in the program by the Marine Corps and the Army's top leadership. Two artillery battalions would be fielded by 2005.
The Army also is looking at HIMARS as a possible platform for the new medium brigades, which are rapid-response units currently in development.
HIMARS, like the MLRS, was not conceived as a brigade asset, but as general support corps systems that could be allocated to brigades.
The medium brigades, however, will have towed 155 mm howitzers. But Vallaria does not expect HIMARS to become a substitute for howitzers. The howitzers, he said, are more suited in direct support role for close fires. Most howitzers have a range between 20-30 km. HIMARS, with guided rockets, will have a 60 km range. Equipped with tactical missiles, the range goes up to 150-300 km. "The types of missions are different," he said. "HIMARS is not a replacement, but a complement to cannon artillery fires."
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|Author:||Erwin, Sandra I.|
|Date:||Jan 1, 2001|
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