Figure 64a shows a transfer plaform with a surface height 11 to 18 inches (280 to 455 mm) above the ground. Figure 64b shows in plan view a transfer platform 14 inches (335 mm) deep minimum and 24 inches (610 mm) wide, minimum; clear floor space that is 48 inches (1220 mm) long minimum is centered on this dimension parallel to the 24 in (610 mm) minimum long unobstructed side of the transfer platform.