After taking much of the 1990s to develop a new cannon, the Army has come up with a mammoth artillery piece that shoots farther, faster and more accurately than any big gun in the world.

It even has a space-age compartment dubbed "the cockpit," crammed with video displays and other computerized gadgetry that allow a three-member crew to load, fire and reload without ever handling any artillery shells or fuel. Called the Crusader, it's the ultimate in howitzer high-tech--and the Army was planning to spend $22 billion to produce 1,138 of these behemoths.

There's just one hitch: The self-propelled cannon and its fully loaded resupply vehicle have a combined weight of 110 tons, too much to lift even on the military's largest transport plane, the C-5B, without waiving flight rules.

For an Army newly bent on becoming leaner and more agile so it can cope with post-Cold War missions, the Crusader suddenly looks out of place. Gen. Eric Shinseki, the new chief of staff, has made production of the weapon conditional on shedding some of its tonnage.

Shinseki's treatment of the Crusader is being watched closely as a measure of the Army's commitment to real change. Although he announced plans last month to begin revamping the Army's divisional structure--disposing of heavy units in favor of lighter, more quickly deployable ones--the four-star general lacks the money to carry out such reforms without trimming or eliminating some prized weapons programs.

But the choice is complicated. The Army's artillery force, which has trudged through four decades using one updated version or another of the M109 howitzer introduced in 1963, argues that a new cannon is long overdue--and essential if artillery units are to keep up on the battlefield with more modern, faster-moving Abrams tanks and Bradley armored vehicles.

They contend that the Crusader's revolutionary firing capabilities more than compensate for its weight. And not incidentally, proponents note, the Crusader requires only about two-thirds as many people to operate as the M109--a manpower savings all the more important in an Army confronting recruiting and retention shortages.

Further, some in Congress have strong parochial interests in preserving the program--especially lawmakers from Oklahoma, site of the gun's final assembly plant and home of the Army's artillery school at Fort Sill. Sen. James M. Inhofe (R-Okla.), who sits on the Armed Services Committee, and Rep. J.C. Watts Jr. (R-Okla.), chairman of the House Republican Conference, have pressed the Army to spare the Crusader.

The Crusader's origins stretch back a decade, when Army planners conceived of a new family of mechanized weapons, including an advanced field artillery system, that would be built on a common chassis. By 1994, when the Crusader was formally launched, it had evolved into a unique system, designed from the ground up solely as an artillery piece.

And it was an ambitious project, aiming to score more than a few technological firsts for U.S. field artillery. Among them: a fully-automated subsystem for loading ammunition, and a cooling subsystem for keeping the rapid-fire cannon barrel from overheating.

Another innovation--an attempted switch to liquid fuel--proved too challenging and costly and was dropped in 1996 in favor of more traditional solid propellant bags. Even so, the General Accounting Office warned in a report two years ago that the Crusader program was trying to accomplish too much in too short a time. The GAO urged the Army to slow development and consider making further improvements in its top-of-the-line M109A6 Paladin or purchasing a European howitzer such as the German PzH 2000.

But the Army forged ahead and even boosted the number of Crusaders it planned to buy. Recently, the program has run into problems writing the 1.8 million lines of computer code required by the complex gun. Such difficulties have delayed development at least 18 months, with delivery now projected for 2007.

"Some folks at the Pentagon have claimed we're just as sophisticated as the F-22," said the program manager for the Crusader, Col. Charles Cartright, referring to the Air Force's new jet fighter without a trace of irony, though the plane has suffered delays, cost overruns and a bruising battle this year in Congress.

Even some artillery enthusiasts now regard the Army's decision to buy a giant, brand-new gun as overreaching. Tom Davis, a retired Army artillery officer who works for Northrop Grumman Corp.'s analysis center in Arlington, said he once supported the Crusader but has since concluded that the Army would be better off trying to mate existing howitzers with newer, precision-guided shells.

"If you could get a lightweight howitzer that could shoot these precision munitions," Davis said, "then you wouldn't have to bring as many bullets to the fight, and you'd get a double savings." Davis, who fought during the 1991 Persian Gulf War, recalled lugging 4,000 shells around the desert with his artillery unit.

Reluctant to cancel the Crusader, Shinseki has asked United Defense LP, the prime contractor, to reduce the weight of the cannon and its resupply vehicle by a total of about 20 tons.

"We've definitely said that at 110 tons, we're not happy with what that presents us as a deployment platform," Shinseki told a group of defense writers earlier this month. "I've registered our description of the future requirements, and it's up to them now to decide whether or not they can help meet them."

The Crusader's managers sound confident they can make the weapon lighter.

"There are a number of things within the art of the possible to bring the weight of Crusader down," said Dave Napoliello, director of Washington operations for United Defense.

He said the options under consideration include installing a smaller engine, which also might permit shortening the vehicle; cutting back on the number of ammunition rounds carried by the howitzer and resupply vehicle; and resorting to kits of armor that can be bolted on when needed rather than built into the cannon. Army authorities also are looking at making do with about half the planned number of Crusaders.

Other weapons under development--less costly and lower profile than Crusader--appear headed for elimination ahead of the controversial howitzer. These could include several short-range missiles, an airborne mapping system and a command vehicle, according to defense officials.

But such savings hardly will be enough to fund Shinseki's long-range plans for a slimmer fighting force. The Army chief said that even if he cut all the Army's modernization programs, including Crusader and the Comanche armed reconnaissance helicopter, he still would be short the many billions of dollars needed to transform combat divisions.

CAPTION: IN DEVELOPMENT: THE CRUSADER (This graphic was not available)