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 TB 55-1900-232-10
b. Change course if necessary to avoid or ride out the storm. It is far better to depart from the projected track, ride out the
storm and then set a course for the original destination than to endanger the ship and tow by remaining on a dangerous
course and speed.
CAUTION
Under more strenuous sea conditions, dynamic hawser tensions, when towing down wind, can be significantly
higher than when heading into wind and seas at the same speed and power. Turning into the wind and seas,
and slowing to maintain steerageway, are appropriate under such conditions.
c. Estimate the size and direction of the waves. Review the applicable data in Appendix N to establish average hawser
tension limits for the different wave heights and directions. Determine whether extreme tension predictions can be eased
by slight changes in course away from towing directly into the wind.
d. Recognize that the tug and tow likely will make negative speed over the ground Sail for a position that will minimize
navigational hazards of a down-wind track.
e Rig the fantail for heavy weather. Stern rollers and Norman pins should be down and other obstructions to the towline
cleared.
f. Increase hawser scope, if possible.
g. Set the towing machine on automatic if it has an automatic feature. Otherwise, tow on the brake, rather than on the
dog, in order to ensure a capability of rapid reaction to changing circumstances.
h Arrange for quick-disconnect of the towline by free-spooling the towing machine drum or other appropriate means.
NOTE
Water depth permitting, an increased towline scope and the automatic feature of the towing machine should be
used in heavy weather. This enhances shock load reduction for the towline system. Every vessel rides
differently in severe storms and the tug Captain should use good seamanship to determine how his tug and tow
ride best. He should use the best combination of towline scope, speed and heading. Generally, better control
of the tow results from heading into the weather.
3-5.6 PASSING THE TOW AT SEA (TUG-TO-TUG). Casualty, operational orders, weather or other requirements may
necessitate transfer of the tow to another tug. Preparation for transfer and an understanding of the evolution between the
tugs are necessary to ensure success and to minimize difficulty.
The following sequence may be used for disconnecting the towline and passing the tow. Refer to Figure 3-11.
a. Set a course into the seas and reduce speed.
b. Heave in until the pendant and connecting jewelry to the towing hawser are on deck.
c. Signal the receiving tug to come close aboard on the designated side on a parallel course.
d Secure the tow bridle or pendant on deck with a chain stopper; allow sufficient length to lay on deck to facilitate
disconnecting from the hawser.
e. Break the tow hawser from the pendant.
f The receiving tug passes a messenger connected to the bitter end of its hawser, or to a messenger strong enough to
control the tow.
g Bring the receiving tug's hawser or heavy messenger on deck and bend it onto the tow pendant.
3-27
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