Patent ID: 8702014

Claim:
A method of crossing a drainage ditch at least 8 feet in width with a drive tower for a self-propelled irrigation system, said drive tower comprising a support frame including a base beam with a pair of outer drive wheels disposed on opposing end portions of the base beam and a pair of inner drive wheels disposed between the outer drive wheels, said method comprising: moving the drive tower in a forward direction; while moving the drive tower forward, cantilevering the outer drive wheel on a leading end of the drive tower over the ditch; while moving the drive tower forward, contacting the ground on a far side of the ditch with the outer drive wheel on the leading end of the drive tower while the inner drive wheel nearest the leading end of the drive tower remains in contact with the ground on a near side of the ditch; while moving the drive tower forward, contacting the ground on the far side of the ditch with the inner drive wheel nearest a trailing end of the drive tower while the outer drive wheel on the trailing end of the drive tower remains in contact with the ground on the near side of the ditch; while moving the drive tower forward, cantilevering the outer drive wheel on the trailing end of the drive tower over the ditch; and continuing to move the drive tower forward until both outer drive wheels have made contact with the ground on the far side of the ditch.