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 TB 55-1900-232-10
should keep its speed low to minimize strain and surging and yet maintain steerage.
2-2.3
MANNED VS. UNMANNED TOWS. Approval to man a tow must come from the Fleet Commanders-
in-Chief (CINCs).
The Navy command requesting the tow should make the manned/ unmanned
recommendation with the following considerations. The first consideration is the lives of the personnel; second
is the value of the tow. The value of the tow can be either its replacement cost, value of its safe and timely
delivery or cost of the consequences of loss from a tactical, strategic or public-relations standpoint. Safety
considerations in making the manned/unmanned decision must be made on the basis of the crew's influence on
the tow's safety rather than the tow's influence on crew convenience.
2-2.3.1 Manned Tows. Rescue tows should be manned if possible in order to have personnel on board to
make the tow connection and to respond to changes in the tow's material condition or to respond to fires,
flooding, chafing of the hawser or bridle, loss of the towline or other such emergencies. The presence of the
riding crew can add immeasurably to the general safety of the tow. When a tow is manned, it must be
adequately supplied and equipped to sup- port the riding crew.
2-2.3.2 Unmanned Tows. Barges, floating derricks, ocean dredges, pontoons, crane barges, pile drivers,
dry-docks, caissons and yard and service craft can be towed without a riding crew. Under normal conditions,
after carefully securing for sea, many point-to- point tows are undertaken without a riding crew.
CAUTION
River and harbor dredges generally have little or no compartmentation and machinery occupies
most of the below deck space throughout. Additionally, they tend to have a very low freeboard.
Whether towed with or without a riding crew, dredges should be given extra attention from
departure to destination and should be towed with extreme caution (Page-2-3).
To be considered seaworthy, a towed vessel must have adequate watertight integrity, structural soundness and
intact stability Officers-m-charge must consider the impact on stability of the free-surface effects of cargo or
liquid ballast
The tow's hull design may require taking numerous steps in preparing to tow. Examples include cranes, pile
drivers, dredges, dump scows or other equipment designed for operation in sheltered waters. These measures
may include removing high weights, securing booms, dredge ladders and other deck structures, adding or
removing ballast or adjusting trim; stiffening the hull and performing other functions. Wherever possible,
heavy, welded brackets should be used to secure heavy movable objects and a tow should always be secured
for the worst sea conditions. Expect large angles of roll and pitch and secure all heavy objects accordingly.
2-2.4
REQUIREMENTS PLACED ON THE TUG. The primary requirement placed on the tug is to provide
a power plant that the tow does not have available, due either to its construction or to a casualty or other failure
of its own main power plant. Secondary requirements include such functions as steering for maneuverability,
navigation and communications, security, damage control and fire protection. In addition, the tug may have to
supply all the rigging for the towing system. The degree of service required from the tug will depend upon the
circumstances.
2-3
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