Anchorage of Floating Bridges

BRIDGE ANCHORAGE (cont) - TM-5-5420-278-10_298

TM-5-5420-278-10 M85 Tank Chassis Transporting: for Bridge Armored-Vehicle-Launched Scissoring Type Class 80 Manual
Page Navigation
259

TM 5-5420-278-10 0035 00 0035 00-5 BRIDGE ANCHORAGE (Contd) INTRODUCTION (Contd) d. Anchorage of Floating Bridges All military bridges must be held in position by some system of anchorage. Anchorage systems can be classified as short-term or long-term. Short-term anchorage generally refers to a method of holding a bridge in position for a limited period of time. Assault bridges, such as the ribbon bridge, are normally anchored using only short-term means. This work package describes the method of anchoring such bridges using BEBs. Lines of communications bridges, such as M4T6 and Class 60 bridges, remain in position for longer periods of time. For these bridges, long-term anchorage systems are necessary. Anchorage of Floating Bridges describes the design and construction of these long-term anchorage systems. DESIGN OF LONG-TERM ANCHORAGE SYSTEMS: BASIC CONSIDERATIONS The design of any system of anchorage is influenced by several factors, including: • Width of the river • Velocity of the river’s current • River depth • River bottom conditions • Height and slope of riverbanks • Soil conditions • Depth of the groundwater table • Available equipment Each of these factors must be considered when deciding upon the type of anchorage system to be installed. Generally, the velocity of the river and the river bottom conditions will have the greatest impact upon the type of long-term anchorage system that will be selected for a given site. BASIC DESIGN The three basic components of all long-term anchorage systems include approach guys, an upstream anchorage system, and a downstream anchorage system. APPROACH GUYS Approach guys are cables which prevent the bridge from being pushed away from the shore as a result of the impact of vehicles driving onto the ramps of the bridge. One end of each approach guy is attached to each side (upstream and downstream) of the first bay of bridge on both ends of the bridge. The other end of each approach guy is secured on the shore, normally using chain picket holdfasts. Place approach guys at approximately a 45-degree angle with the bridge centerline. (Refer to figure 6.) A minimum of 1/2-in. (12.7-mm) IPS cable should be used for each.

Privacy Statement
Press Release
Contact