The Navigantry

There are many industrial buildings being constructed these days, says Michael Slater, that cannot support the structure needed for an overhead bridge crane. Slater is president of Motivation Industrial Equipment, a Canadian company based half an hour from Niagara Falls in Stoney Creek, Ontario. Motivation has been making gantry cranes and lifting equipment since 1968.

Designed for those very buildings where a conventional bridge structure cannot be built, or where greater flexibility is required at relatively low cost, Motivation produces a powered steerable gantry crane called the Navigantry. Running on wheels, either with or without tracks, it can traverse from bay to bay in a workshop or factory. As it is not fixed to the structure of the building, it can be driven into and out of the workshop, so long as the surface outside is relatively smooth and hard. It can be supplied in a full range of spans and heights, though standard catalogue models go up to 10 US ton capacity and 30ft (9.1m) span. If required, height and span can be adjustable.

The Navigantry is constructed from cross-braced square tubular steel A-frames angle braced to a self-levelling underslung beam. Almost any type of hoist required, whether electric, air or hand powered, can be fitted to the beam. Power can be supplied via power cord, reel, festoon system or portable generator, depending on the area to be covered.

On each A-frame at the end of each gantry there is a drive wheel and a swivel castor. Semi-steel wheels are standard but urethane wheels are an option, depending on capacity requirements. Each drive wheel can be independently controlled by a forward and reverse button, mounted side by side on the drive wheel control pendant. The control buttons are colour coded to match the drive wheel housings to reduce any confusion over which button does what. To minimise load sway the gantry drive motors have soft start and gradual torque build-up to the recommended travel speed.

They can also been supplied with variable frequency drives to give more precise control over the load.

The Navigantry is built to North American standards, meeting ASME2/ ANSI3/PALD4 (12-1986) shop crane standard and applicable sections of CSA5 S16-1969 and CMAA6 specification No 70-2000 and 74-2000. All cranes are welded in accordance with CSA W47.1-1083 and CWB7 W59-1989. Motivation is also CSA W47.1 certified.

Slater says that Navigantry customers to date include several mines across Canada, power generation companies which use this system for routine maintenance of equipment, and a plastic injection moulding company for loading heavy moulds into the injection moulding machines. Other references include both the Canadian and the US military for vehicle servicing.

Slater believes that the Navigantry's reputation as 'probably the most versatile industrial crane available' has now been established in North America and he is looking to broaden its horizons. "Our objective is to find an active partner who will build this for us in Europe under a licensed agreement," he says.