E-One, a leading manufacturer of fire-fighting equipment selected Bushman Equipment, Inc. to design and build a high capacity tilt table to test their new breed of fire trucks.
E-One, established in 1974 and employing more than 1,300 people, manufactures virtually every type of fire and rescue vehicle required by fire departments, rescue/EMS squads and airports.
One of the requirements in producing their Aircraft Rescue and Fire Fighting (ARFF) trucks is to test them in accordance with SAE J2180. This specification establishes the procedure for measuring the Static Rollover Threshold for heavy trucks. Very simply, it determines the angle at which the trucks could tip over.
Bushman designed one large, high capacity table as opposed to the two smaller independent tables that were previously used. Based on projected loads, the tilt table was built with a drive-on platform, 11 feet wide and 40 feet long, and with enough capacity to tilt loads weighing up to 150,000 pounds.
The table had to be mounted outside and above grade, due to local flooding concerns in Florida. In its folded down position, the table is over three feet tall. E-One added the concrete ramps leading onto and off the table.
Tilting is accomplished by five, 7-inch diameter dual acting hydraulic cylinders, operating at a system pressure of 2,000 psi from a 25 hp remote mounted hydraulic power unit. A steel curb was incorporated into the table top, and safety tie down bars were built to secure the trucks.
During a test, the truck is driven onto the table, and its axles are secured with chains. The truck is then tilted to the point when the tires begin to lift off the table. This position determines the rollover threshold that is recorded.
Since the table is used outdoors, all controls are housed in NEMA 4X stainless steel cabinets. The fully functional operator’s console is equipped with operating switches and a position readout. Once energized, the table tilts at 0.25 degrees/second. An inclinometer is incorporated into the table. Digital readouts are located on the operator’s console and on a separate six-inch, free standing scoreboard visible to everyone in the test area.
According to E-One’s manufacturing engineer in charge of the project, the table has expanded E-One’s capabilities. “The stability of any vehicle is determined by a low center of gravity. This tilt table not only allows us to test ARFF vehicles, but also a host of other trucks.” Visit www.e-one.com.