Larger trunnion bearings required because of the additional weight of the motor. Spare parts are less costly. Proven reliability with thousands of drives operating successfully. Present size capabilities to 20,000 Hp without exceeding normal gear design allowables. Equipment serviceable by conventional personnel.
Installation is much simpler and less expensive than a gearless system.
Inching operation is extremely simple to perform and cost effective. Auxiliary equipment required for inching operation. Proper lubrication critical to operation. A detailed cost analysis which includes initial capital, net present value of true projected operating costs, and maintenance costs will be required to prove that the girth gear drive is more cost effective on a case by case basis. We believe that the girth geared drive has cost advantages over the gearless driven systems with the technology that is used at present.