Selection of Turbine for Abrams-Crusader Both Praised and Criticized.

The U.S. Army's decision to install a new turbine engine on both the Abrams tank and the Crusader artillery platform was "a bold step" that will prove beneficial for both vehicles, said Maj. Gen. John S. Caldwell Jr., head of the Tank-Automotive and Armaments Command (TACOM).

The announcement in mid-September that the Army had selected a Honeywell-General Electric turbine system for the Abrams-Crusader common engine program re-ignited a decades-old debate about the merits of turbines versus diesel engines.

"Honeywell got the contract for the new engine for the Abrams and Crusader, because it was the best value for the Army," Caldwell told National Defense during the 2000 Combat Vehicles Conference, at Fort Knox, Ky.

He stressed that he had not been personally involved in the contractor selection process and, thus, felt free to provide his opinion. "The Abrams basically was designed to mount a turbine package," he said. "You can't get that kind of horse power from diesel."

Back in the early days of the Abrams, Caldwell said, the argument of turbine versus diesel "raged for years." Diesel has been "looked at many, many times," he said. "Every time there is a foreign sale [of the Abrams], questions are raised about diesel engines."

The choice of the turbine, he said, "was a bold step." The turbine "buys you a lot of horsepower in a small engine."

The Crusader--which Caldwell noted is not one of his programs--had been designed with a diesel engine originally. Replacing the 12-cylinder diesel engine with a turbine, he ventured "will take a lot of weight off the Crusader."

The Abrams currently has an older turbine, called the AG-1500.

The contract awarded to Honeywell's engine division, in Phoenix, is a two-phase project valued at $212 million over three years. It covers the delivery of 24 engines, called the LV-100, which will be tested on both the Abrams and Crusader systems. In the second phase, Honeywell will produce 2,709 engines for General Dynamics Land Systems to integrate into Abrams ranks between 2004 and 2010. Another 720 engines will be delivered to United Defense to integrate into Crusader vehicles (480 self-propelled howitzers and 240 tracked resupply vehicles) between 2005 and 2012.

Tom Culligan, Honeywell's vice president for defense programs, said people should not be fooled into thinking that the Army's decision to stick with the turbine technology means it is nor achieving improved capabilities.

When comparing the AG-1500 to the LV-100, Culligan said in an interview, "They have to remember that there is a 25-year leap in technology."

Some of the decisive factors that Culligan believes helped sell the LV-100 to the Army are the "operational characteristics and maintenance costs." Specifically, he cited the turbine's low smoke and noise signatures, which make a vehicle more survivable in combat. Another selling point, Culligan said, is the "weight savings" that the turbine can help achieve for Crusader, which is undergoing a redesign to trim the system down from 100 tons (for the howitzer and resupply vehicle combined) to 80 tons.

Honeywell officials also suggested that the turbine would offer the Army more flexibility in the logistics arena because it can run on multiple kinds of fuel.

"Turbines can run on just about anything that will burn--car gasoline, diesel fuel, jet fuel, marine fuel," said Barney Heath, program manager at Honeywell. "That gives logisticians quite a bit of flexibility and interoperability, especially when the commander also operates helicopters, which run on jet fuel, [in addition to operating] tanks and trucks," Heath said. "You can supply one type of fuel to the battlefield and operate all the equipment."

Regarding fuel consumption, the Army was satisfied that the LV-100 will be 35 percent more fuel efficient than that AG-1500, a gas guzzler that runs 3/5 mile per gallon.

This engine is not the same LV-100 that competed originally in the Crusader program, and lost to a Perkins CV-12 diesel engine. The turbine proposed for the Abrams-Crusader award has been changed somewhat, said Heath. "It's the same basic core. We modified the outside to adapt to the commonality requirements the Army established so it could be used for Abrams and Crusader."

The existing Crusader transmission, for example, "would not physically fit because they have shrunk the vehicle. All the competitors had to look for a different transmission." Honeywell chose an Allison transmission. Crusader originally had been designed with a General Dynamics transmission.

"The [timing of the] weight problem in Crusader" worked to Honeywell's advantage, Culligan said. "The stars aligned for us."

The cost of refitting the Abrams with a diesel engine also may have been a significant factor in the Army's decision, suggested Heath. "They probably decided that the cost of retrofitting the Abrams with another turbine would be lower," he said. "We can use the existing transmission. We don't have to move anything within the engine bay." The bottom line, Heath said, is "very little risk [is involved] to incorporate modern technology." The electronics and the gun systems in the Abrams, for example, "have been optimized around a vibration level where a turbine was the baseline."

United Defense LP, the Crusader's prime contractor, did not participate in any way in the engine selection process, said company spokesman E. Jeffrey Van Keuren. "We were kept at arm's length from the competition," he said. "The contractor side of team Crusader had no involvement in the decision or the competition. No information came our way."

The company is now conducting a cost study for the Army to estimate the expense involved in taking out the Perkins diesel engine out of Crusader and integrating the LV-100. For the program, overall, said Van Keuren, there will be "some level of additional cost" to integrate a new engine. An increase in development costs would be "logical," given the nature of the integration work. "We are putting together a proposal to the government, so we won't have definitive numbers for a month or two.

Within United Defense, Van Keuren said, "expectations ran high on both sides of the diesel-turbine debate. Some people are turbine fans. Others are not."

Any of the engines that competed in this program, he said, could have integrated with Crusader. Honeywell's competitors were the CV-12 diesel, made by Perkins Engines, a subsidiary of Caterpillar Inc., and an engine developed by Performance Diesels, a partnership between General Dynamics Land Systems and the German manufacturer MTU.

Asked about the "weight issue," Van Keuren said "it potentially would have been more of a challenge to integrate a diesel engine and meet the weight reduction goals." But he stressed the word "potentially" because United Defense did not see the proposals submitted by either of the diesel competitors:

An industry source familiar with the competition, who was speaking on condition of anonymity, said that "weight was probably the area that diesels got the lowest marks." The Perkins team, however, had included in its proposal some "new technologies for weight reduction that are in practice in the United Kingdom," said the source. Perkins officials were unable to comment by press time.

It appears that the Abrams-Crusader engine decision could have implications for the military engine industrial base, said the industry source. It is not clear yet whether the current diesel engine makers will choose to exit the U.S. military market because there will not be any further engine work on the horizon, at least until the Army fields the next-generation Future Combat System. Performance Diesels formally protested, in early October, the Army's selection of the LV-100, to the General Accounting Office.

"To eliminate diesel entirely is not the right decision," said the source. The Defense Department, he added, could have chosen to fund an "alternate diesel program" to keep the diesel manufacturers from exiting the business.