6-9. LOCATION AND DESCRIPTION OF MAJOR COMPONENTS (CONT).
c. Twist Locks and ISO Corner Castings. The lower ISO corner castings (4) and twist locks (5), allow three
empty folded flatracks to be stacked and locked together. The lower ISO corner castings allow the flatrack to be
interchangeable between the truck, trailer, M871 semitrailer, M872 semitrailer, container chassis, containerized ships
and ISO transportation system. The upper ISO corner castings (6) allow up to nine loaded flatracks to be stacked in
the cargo cell of a containership.
d. Stowage Boxes. Two stowage boxes (7) are sized to allow storage of Basic Issue Items (BII) and other items.
The stowage boxes are hinged and have provisions for locking.
e. Rear Wall and Rollers. The rear wall (8) folds forward to prepare unloaded flatrack for stacking.
Removable rollers (9) are used for loading/unloading flatrack onto the trailer or docks. The rollers can be detached
from the deck and stowed on the upper front wall stowage points (10).
f. Tiedown Rings. Six 25,000 lb (11,350 kg), capacity tiedown rings (11) and twenty-two 10,000 lb (4,540 kg),
capacity tiedown rings (12) and twenty-two straps are provided to secure payloads or to secure flatrack for modes of
shipping when flatrack is not on truck or trailer.
g. Pin Assemblies. Pin assemblies (13) at the front and rear of the flatrack allow front and rear walls to be