2-4. NOSE BOX
a. The nose box has the connections for the air lines and electrical cables from
the towing vehicle to the semitrailer.
b. Service gladhand (1, fig. 2-4) and emergency gladhand (2) couplings provide
the connection between the semitrailer brake system and the towing vehicle air
c. Electrical connectors (3) provide the connections between the semitrailer
lights and the towing vehicle electrical system. Both connectors use spring loaded
covers to keep foreign matter out when the cables are disconnected. The left
(roadside) connector is for 12 volt and the right (curbside) is for 24 volt.
d. TWO dummy couplings (4) are fitted to the SERVICE and EMERGENCY air hose
couplings when brake air hose couplings are not connected to the towing vehicle.
Dummy couplings (4) are used to prevent dirt and moisture from entering the brake
Figure 2-4. Nose Box
2-5. SIDE PANELS
a. The side panels (1, fig. 2-5) are used to contain bulk cargo such as bags of
grain or sand.
Side panels (1) are installed in sill holes between the side stakes (2).
c. Side stakes (2) are installed into the sill holes. They hold side panels (1)
Spreader chains (3) aid in supporting side panels (1) to contain bulk cargo.
e. The side stakes (2) and side panels (1) are stowed against the forward
bulkhead (4) when not in use.
f. Side panel stowage retainer straps (M871) (5) or chains (M871A1) are used to
retain side panels (1) in stowage.