Quality Wins Project of the Year

parted for the ground floor. In the event of the landing entrance failing to retract during the lift’s down trip, electrical interlocks prevent the lift from leaving the ground floor. The lift’s drive is hydraulic. Three direct-acting hydraulic pistons set at 120° to each other are mounted within and supported by a cen- tral steel frame. This frame also holds the guide-rail systems. Control of the lift is fully automatic and operates much as that of a traditional lift. Beneath the platform lift, housed within a 6.5-m-deep pit, exists an intricate arrangement of mechanical mechanisms, hydraulic systems and electronics: guide rails and support system, cylinders, rigid and flexible pipe work, rupture flow valve; traveling-cable follower de- vices, stabilizers, counterbalances, dampers, wiring, well switchgear and floor positioning sensors. A standard hydraulic tank, pump and valve assembly, along with the control cabinet with customized con- trols, are located adjacent to the pit in a motor room. Considering the palace was an existing building and located on land reclaimed from the Arabian Gulf some 30 years ago, excavating a suitable pit to the required depth in the center of the palace was challenging. A high water table complicated matters, and the actual depth fell short of the requirement of the first design. By utilizing a telescopic drum section fitted below the main drum of the platform lift that extends automatically as the lift ascends, then retracts during descent stage as it approaches the ground floor, it became possible to accept a reduced pit depth. The telescopic drum, when extended, pro- vides the platform lift with adequate stability during travel and when stationary at the first floor. A shorter pit affected other aspects of the installation. There was not enough space to hang a traveling cable in the traditional manner,

Central support tower at the factory during testing

Continued

January 2013 | ELEVATOR WORLD | 69