ARMY TM 5-5420-212-10-1
MARINE CORPS TM 08676A-10/1-1
Section II. EQUIPMENT DESCRIPTION
EQUIPMENT CHARACTERISTICS, CAPABILITIES AND FEATURES
The Medium Girder Bridge (MGB) is a two girder deck bridge. The wide upper surfaces of the girders, and
the deck units laid between them form a roadway 13 ft 2 in (4.0 m) wide. The girders can be constructed in two forms: a
shallow single story construction as shown in Figure 1-2, or a deeper double story construction as shown in Figure 1-1.
The double story can be reinforced by adding components of the Link Reinforcement Set (LRS) as shown in Figure 1-4;
this permits longer Military Load Class (MLC) 70 bridges to be constructed.
The maximum load capabilities of single story, double story and link reinforced MGB are given in Table 1-1. The Military
Load Class (MLC) for each length of bridge is shown in Table 3-6.
Figure 1-2. Single story MGB.
The two grinders are constructed from a number of panels pinned together, and are separated by two
bankseat beams, one pinned to each of the girders. The roadway is formed by hanging deck units between the girders and
connecting ramps to each end. Curbs and guide markers are placed at the outside edges of the girders to mark the edge
of the bridge. The single story bridge is used for light loads, for example it will carry MLC 70 (tracked) up to 32ft (9.8m)
decreasing to MLC16 at 74ft (22.6m).
Figure 1-3. Double story MGB
The U.S. junction panel is slightly longer than standard, therefore the bridge lengths quoted below
for double story and link reinforced bridges are nominal lengths.
A double story bridge (DSB) uses all of the parts of a single story bridge (SSB) which are pinned on top of
triangular bottom panels, with junction panels and end taper panels at each end. These parts make the