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 TB 55-1900-232-10
FIGURE 2-13. Towing Rigs.
equal to the beam of the towed vessel. The fitting at the apex usually is a flounder plate with the two bridle legs
connected at its base and the apex usually connected to the lead chain and/or towing pendant, which in turn is connected
to the tow hawser The bridle rig places more and heavier rigging outboard of the towed vessel than does the pendant rig.
This can lead to rigging problems on the deck of the tow. Furthermore, the bridle rig, by definition, uses two off-
centerline fairleads. As a consequence, if the tow does not track the tug directly astern, there may be an off-center
dynamic load This load, while tending to be self-correcting, unbalances the loads on each bridle leg. Therefore, each
bridle leg must be of full towline strength. Finally, a critical problem of the bridle rig occurs when turning, or when the tow
sheers off to the side of the tug's track, and the bridle leg on the far side can ride against the cutwater of the tow, causing
damage to Itself as well as to the tow In many cases, the foredeck arrangement, hydrodynamic characteristics or need to
tow the vessel backwards does not permit the use of a bridle rig. For example, aircraft carriers and LSTs have forecastle
arrangements that require using a pendant rig. Ships with large bulbous bows or sonar domes tow more favorably on a
pendant rig, and a damaged ship may require towing it stern first. Bridle rigs are commonly used on ships with blunt
bows, such as barges.
c. Towing Alongside. Towing alongside or "towing on the hip" is illustrated in Figure 2-15. In congested waters, towing
alongside offers excellent control, however, it is not recommended for the open ocean because of motion between the
tug and tow in a seaway. When complex maneuvering is required, consider having harbor tugs to do the job or assist
during difficult phases of the maneuvers.
2-21
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