Liftcrane attachment, Basic Boom: the liftcrane is equipped with 70' No. 22EL basic boom consisting of 30' butt and 40' No. 22L top with seven 30” diameter sheaves (eighth sheave optional). Includes rope guides, boom-hoist wire rope, boom-angle indicator, and hook and weight ball. Boom inserts available in 10’,20’,and 40’ lengths, powered boom-hinge pins are standard.