TM 5-820-3/AFM 88-5, Chap. 3
ductile iron. Reinforced concrete grates, with cir-
for load-carrying capacities. Selection of grates and
cular openings, may be designed for box drains.
frames will depend upon capacity, strength, an-
Inlet grating and frame must be designed to with-
choring, or the requirement for single or multiple
stand aircraft wheel loads of the largest aircraft
grates. Suggested design of typical metal grates and
using or expected to use the facility. As design
inlets is shown in figures 3-2 and 3-3.
loads vary, the grates should be carefully checked