January 2013
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ELEVATOR WORLD
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69
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
