GSA Courthouse Management Group
Mechanical Lift Analysis
Some manufacturers have converted industrial lift designs, used for moving materials
from level to level in a warehouse environment into versions being marketed for use by
the physically disabled.
DESIGN ISSUES:
There are three basic lift and enclosure planning configurations which allow access to
both the witness box and the judge's bench in a typical courtroom.
Lift Platform (Entire Witness Box Floor)
The platform remains at an elevated position except when in operation to accommodate a
physically disabled person.
If this elevated position is maintained by hydraulic pressure the possibility of the lift
sinking over time is predictable. (The manufacturers of this type of unit have tried to
correct the problem by replacing valves within the hydraulic system.)
An alternative to constant dependence on hydraulic pressure to maintain the height could
be a set of retractable struts at each of the four corners of the lift platform. (When the
struts are set in position, by a switch on the lift control panel, they form four legs
supporting the platform. This allows the hydraulic pressure to be released.)
In the opinion of Lerch, Bates & Associates, Inc., it currently could be cost prohibitive
for manufacturers to invest in the development of a four-cornered strut system.
Lift Platform (Partial Section Of Witness Box Floor)
This configuration results in the most complex lift system design, particularly when it
services both the witness box and judge's bench at two independent elevated levels.
Mechanically operated wheel stop components, located at the lift edge facing the witness
box and the fixed floor edge of the witness box, are required for operating the system in
this configuration. (Refer to photographs of these conditions in Section Five.) The lift
platform wheel stop extends when the platform moves up past the witness box level. The
wheel stop at the witness box extends only when the lift platform is at the lower
courtroom well floor level elevation. The finish conditions at the wheel stops were not
well executed at the installations reviewed during the site visits.
Section 3-5
HDR Architecture, Inc.