K-4 U.S. NAVY TOWING MACHINERY
This section provides a more detailed description of specific towing machinery installations on U.S. Navy
towing ships. This is not intended to substitute for, or supplement, technical manuals for the specific machines.
Towing machinery installed in mine warfare ships and in ice breakers is not addressed. In the following
sections, "AAJ" refers to Almon A. Johnson, Inc., a major designer and builder of towing machines.
K-4.1 AAJ "222 SPECIAL" AUTOMATIC TOWING MACHINE (ATF 76/110 CLASSES). This towing machine
has a main towing drum and two auxiliary drums The main drum can spool 2,100 feet of 2-inch diameter wire
rope. It operates in an automatic range of up to 80,000 pounds line pull and a manual range of up to 100,000
pounds line pull, on the second layer of the drum. Tension settings are adjusted by manually setting the desired
maximum tension level on the Direct-Acting Tension Controller mounted on the towing machine. The machine
is powered by a 75 HP DC electric motor The main towing drum is equipped with an automatic spooling device
(level wind) and a cable indicator, which shows the length of cable remaining on the drum This indicator has an
electric interlock which will shut down the machine if too much wire is paid out.
The two auxiliary drums may be operated singly or simultaneously, either with or without the main drum, but
are not under automatic tension control The starboard side auxiliary drum has capacity to spool 5,000 feet of 1-
inch diameter wire in 15 layers. It has an automatic spooling device to spool the wire tightly onto the drum This
drum has a maximum line pull heave-m of 26,000 pounds at 80 feet per minute on the eighth layer The port
side auxiliary drum is designed to spool 1,800 feet of 1 1/8-inch diameter wire rope in 13 layers It does not
have a level wind.
The towing machine system includes a 93.6 HP/62 8 KW DC/DC electric motor-generator set with a DC motor
starter, variable voltage control panel and a set of armature loop resistors. These items are located inside the
ship, since they are not waterproof. The towing machine is driven by a 75 HP DC motor and is operated from a
control stand located next to the machine on the main deck.
K-4.2 AAJ "260 SPECIAL" AUTOMATIC TOWING MACHINE (ASR 9 CLASS). This machine is identical to
the AAJ "222 Special" model installed in the ATF 76 Class except, that the two auxiliary drums are designed to
spool 750 feet of 9-inch circumference nylon line or 4,500 feet of 1 1/8-inch wire rope.
K-4.3 AAJ "250 SPECIAL" AUTOMATIC TOWING MACHINE (ARS 6/38 CLASS). This machine is similar to
the 222 and 260 AAJ machines. Its main drum has the same capacity of 2,100 feet of 2-inch wire and the same
automatic setting up to 80,000 pounds and a maximum pull under manual control of 100,000 pounds. An
upgrade of an earlier version, the "250 Special" uses a smaller motor with different gearing to provide the same
hawser tensions, but at a slightly lower line speed Some of these machines also have a single auxiliary drum,
with a level wind, capable of spooling 5,000 feet of 1-inch wire.
K-4.4 AAJ SERIES 322 AUTOMATIC TOWING MACHINE (ARS 50 CLASS). See Figure 2-29 for a drawing of
this towing machine. It is equipped with two side-by-side main drums, each capable of spooling 3,000 feet of 2
1/4-inch wire. Level winds are provided which can be adjusted to spool 2 1/2 -inch wire as well. Power is
provided by two 125 HP DC electric motors which can be connected singly or together to either drum. Each
drum can heave a maximum 110,000 pounds at 37 FPM. Maximum line speed is 100 FPM Each drum can be
set for automatic operation within the range of 25,000 to 115,000 pounds Automatic operation includes payout
and reclaim, with limits on maximum and minimum hawser scope.
The ARS 50 has a Series 400 traction machine located adjacent to, and forward of, the Series