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TM 55-3930-660-14
APPENDIX B
LOADING RESTRAINT FACTORS
The loading restraint factors (LRFs) used for surface and air modes are the "G" (acceleration of gravity)
loading factors that can be expected in military transport. The tiedown arrangements shown in the 6K
VRRTFL TGTM are based on the following:
—restraint factors are applied independently in each direction.
—restraint load (GVW times the LRF) was resolved into resultant lashing loads, allowing for tiedown
angle.
–lashing loads are less than safe working load (SWL) of the restraint (that is, wire rope).
Highway:
The Transportation Engineering Agency highway LRFs are:
0.7 in the forward direction (relative to the transporter).
0.3 in the aft and vertical directions.
0.1 in the lateral direction.
Rail:
The Association of American Railroads recommended rail LRFs are:
3.0 in the longitudinal direction (relative to the railcar).
2.0 in the lateral and vertical directions.
Marine:
The Military Sealift Command (MSC) design LRFs are:
1.2 in the lateral direction (relative to the ship).
0.7 in the longitudinal direction.
0.2 in the vertical direction.
MSC LRFs are for severe conditions.
Actual marine LRFs vary. Marine tiedown restraint depends on the size of ship (decreasing on larger
vessels), the expected sea state to be encountered, and the stow location on a given ship. Generally, the
restraint required will increase for locations high and forward (or aft) in the ship. The most severe
conditions occur on exposed “weather decks,” where strong wind and wet conditions add to the problem. A
ship’s crew may require additional lashing on exposed decks. Below-deck locations that are closer to the
vessel’s centers of gravity and rotation will experience less severe motion. The blocking and tiedown
procedures presented (fig 4–1) will allow for severe, below-deck conditions.
Air:
The USAF aircraft LRFs are:
3.0 in the forward direction (relative to the aircraft).
2.0 in the vertical direction.
1.5 in the aft and lateral directions.
B-1
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