Combat lessons drive design changes in Paladin howitzer

Feb. 1, 2004
U.S. troops used an array of high-technology tools to achieve a swift victory in the fighting phase of the Persian Gulf War of 2003 (Gulf War II).

By Ben Ames

SAN DIEGO — U.S. troops used an array of high-technology tools to achieve a swift victory in the fighting phase of the Persian Gulf War of 2003 (Gulf War II). But one of the soldiers' most valuable weapons was designed in the 1950s.

The Paladin howitzer rolled over challenges such as sand storms and extreme heat, and fired the first shot of the war, taking out an Iraqi observation tower on the Kuwait border, says Ken Hurban, project manager in the U.S. Army Paladin howitzer program office at Picatinny Arsenal.

Eventually, Paladin crews fired nearly 14,000 rounds in 26 days, as U.S. and coalition forces traveled more than 2,000 cumulative miles across the Iraqi desert. Troops valued Paladins the most when weather conditions like sandstorms grounded aircraft and confounded smart bombs, he says.

The late-model U.S. Army Paladin self-propelled howitzer, pictured above, saw heavy action during Gulf War II, and was particularly effective because of its digital fire-control system.
Click here to enlarge image

This performance did not come easily, however. The war was the first major test of the latest model, the M109A6 Paladin Self-Propelled Howitzer.

Those four weeks of combat use during Gulf War II put as much wear on the systems as five years of peacetime training, he explains. Across the Army, troops saw equipment failures due to sand in keyboards, power-supply faults in extreme heat, and vibration from driving 25 to 30 miles per hour in tracked vehicles.

Vehicle electronics designers learned lessons from every day of the Paladins' combat experience, Hurban told a crowd at the Military & Aerospace Electronics West/COTSCON show in San Diego in December.

That is particularly important because the Army's reliance on commercial off-the-shelf (COTS) components has accelerated the pace of design change in recent years. Army designers fielded the first-generation M109 in 1963, followed by the A1 in 1973, A2/A3 in 1978, A5 in 1992, and A6 in 1993.

The 975 vehicles in the Paladin A6 generation were the first ground-combat vehicles to use a fully electronic fire-control system, Hurban said. The history of its design reveals the military's progress in learning to design with COTS components.

In the mid-1980s, Paladin engineers built the first automatic fire-control system (AFCS) with 16-bit digital military electronics. It ran on 1970s technology such as Intel 8086 chips, so it became quickly outdated, he said.

Experts upgraded the design in 1993 to take advantage of 32-bit military computing. Running slow 25-MHz microprocessors, however, the system was obsolete before it was produced, Hurban said.

Finally, in 1998 they fielded the first automatic fire-control system to use COTS parts such as the Intel Pentium 133-MHz processor, Windows NT operating system, and open architecture.

Army engineers are still tweaking the design. With the COTS adoption behind them, and with the U.S. Department of Defense's C4ISR initiative in front of them, planners must apply new rules to keep up with the speed of modern design.

Planning for obsolescence

One lesson they have learned is to plan for obsolescence, Hurban said. Paladin designers now begin a program to replace each system while they are still procuring parts for it.

Another lesson is that configuration-management processes are crucial for making timely replacements of hardware, software, and firmware.

A third lesson is the necessity of following the industry model of replacing industrial electronics every three to five years, and always to plan on making software upgrades with any hardware change.

Those design rules will enable Army engineers to keep pace with the Pentagon's C4ISR plan (command, control, communications, computer, intelligence, surveillance and reconnaissance), Hurban said.

In the near term, Paladin designers plan to ensure the new digital fire-control system remains compatible with the latest battlefield command systems and with the Force Battle Command Brigade and Below (FBCB2) systems. In the long term (beyond two years), designers are planning a migration path to the Joint Tactical Radio System (JTRS) and Warfighter Information Network-Tactical (WIN-T).

Also, they will run fire control over the tactical Internet, and replace scrolling menus and text-based screens with a graphical user interface. That will ensure the Paladin can interoperate with the Army's Future Combat System, using software version 7 of the Army Battle Command System.

In the very long range, they are taking a close look at the software operating system. Designers have had some trouble with Windows NT because it is not deterministic; they cannot reproduce errors in the lab, he said. Yet designers cannot choose a proprietary real-time operating system (RTOS), since they must preserve the open architecture. So they plan to migrate to Linux within four years.

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