A U.S. District Court jury in Baltimore has ordered International Harvester Co. to pay $400,000 in damages to a former federal government groundskeeper who was left severely disabled after he was crushed beneath an International Harvester tractor four years ago.

The six-member jury on Friday ordered the firm to award the money to Robert H. Johnson, Jr., 65, of Olney, who was run over by the tractor in October 1977 after he slipped from the tractor seat and fell onto the gear shift, causing the vehicle to move forward in first gear.

Johnson's attorney, Silver Spring lawyer Allan Sosslau, had contended that the tractor, a model 2400, was unsafe because the gear shift protruded into the path of an operator mounting the tractor seat.

In addition, Sosslau said, the gear shift did not lock, so a driver stepping to the seat could easily shift the tractor into first gear by accident. He said there were no warnings on the tractor or in the operator's manual.

"I don't think people realize the hazards in this type of machine," Sosslau said. "This whole thing could have been prevented with a $2 modification," such as a locking mechanism over the gear shift, he added.

Sosslau said another another tractor operator in Chicago is suing International Harvester for a similar accident.

A spokesman for International Harvester, which has suffered from financial troubles in recent years, had no comment on the jury's ruling or on the company's plans in regard to that particular tractor model.

About 200,000 model 2400 tractors were manufactured between 1970 and 1977, until that line was discontinued and the tractor modernized. The side gear shift, however, is still used on some International Harvester models.

Johnson, an employe of the General Services Administration for 30 years, was filling the tractor with antifreeze at the time of the accident. He climbed onto the seat, started the engine, then slipped while climbing off.

The 7,000-pound tractor crushed his left foot, fractured his right hip, crushed his chest and fractured about 20 ribs, Sosslau said. Johnson was hospitalized for two months and forced to retire at age 63 when he was declared 60 percent disabled.