pmarx,
According to the 2003 Edition of ANSI/ICC A117.1, Section 308.2.2 = Obstructed High Reach.
Where a high forward reach is over an obstruction, the clear floor space shall extend beneath the
element for a distance not less than the required reach depth over the obstruction. The high
forward reach shall be 48 inches (1220 mm) maximum where the reach depth is 20 inches
(510 mm) maximum. Where the reach depth exceeds 20 inches (510 mm), the high forward
reach shall be 44 inches (1120 mm) maximum, and the reach depth shall be 25 inches (635 mm)
maximum.
You can exceed the 20 in. (depth) reach range, up to 25 in. max, if you lower the (height)
reach dimension to 44 in.
.