322 machine. The traction winch is designed for use with 3 1/2-inch to 14-inch circumference fiber line. The
traction winch has an automatic payout capability, with a set range of 15,000 to 110,000 pounds. There is no
automatic reclaim capability. Maximum heave is 110,000 pounds at 20 FPM; maximum line speed is 90 FPM
Both machines are totally enclosed within the ship's deck house. Normal operation is from an enclosed
operating station in the after portion of the space, which is equipped with all controls and instrumentation. Much
of the instrumentation is repeated in the pilot house Emergency shutdown controls are located in the towing
machine compartment. The ARS 50 towing machinery has no auxiliary drum incorporated into the design
K-4.5 STOTHERT & PITT TOWING MACHINE (ATS 1 CLASS). This machine was built in the U.K to AAJ
specifications. It has two side-by-side main drums, each capable of spooling 3,000 feet of 2 1/4-inch wire. The
level wind apparatus is adjustable for use with 1 5/8-inch, 2-inch and 2 1/2-inch wire as well. Two 75 HP DC
motors can drive the main drums in any combination. With both motors engaged to one drum, line pull varies
from 30,000 pounds at 120 FPM to 200,000 pounds at 20 FPM. Both main drums are outfitted with automatic
payout and reclaim features with maximum and minimum scope limits Automatic tension can be set at any
desired level from 15,000 to 96,000 pounds.
The Stothert & Pitt Towing Machine has an auxiliary drum, located on centerline forward of the main drums,
capable of spooling 5,000 feet of 1-inch wire. The level wind is adjustable for 5/8-inch, 1-inch and 1 5/8-inch
wire. Power is derived from one or both of the main motors at a maximum pull of 30,000 pounds at 250 FPM
Slack line speed is 400 FPM on the auxiliary drum.
All drums are equipped with tension and cable scope readouts, but they are calibrated for only 2 1/4-inch and 1-
inch wires, respectively, on the main and auxiliary drums.
The ATS 1 has no traction winch.
K-4.6 SMATCO TYPE 1 TOWING WINCH AND LAKE SHORE TRACTION WINCH (T-ATF 166 CLASS). The
SMATCO winch, see Figure 3-30, is a single-drum machine capable of spooling 2,500 feet of 2 /4 -inch wire A
level wind is provided. There is no automatic payout or reclaim capacity. Wire tension measurement is
provided by strain gauges in the winch foundation. There is a remote tension readout, but no scope-of-wire-out
instrumentation. Maximum hawser heave-in is 179,000 pounds at 14 FPM; maximum hawser speed is 280
FPM at 18,000 pounds tension on the first wrap. At the top wrap (twelfth layer) maximum line speed is 775
FPM at 6,000 pounds tension. Maximum pull on the twelfth layer is 64,000 pounds at 38 FPM.
A major difference between the SMATCO towing winch and those found on other Navy towing ships is that the
SMATCO is diesel-driven through an air operated clutch, a torque converter and a gear train. For various
reasons, towing is frequently accomplished with the drum locked on the "dog," rather than riding the brake In
order to increase hawser scope, or even let it run free in an emergency, the engine must be started, engaged
and the load taken off the dog before the dog can be released. Managing the hawser with this system is more
difficult than with the other U S Navy towing machines.
The T-ATF 166 Class has a separate Lake Shore traction winch suitable for fiber hawsers up to 15inch
circumference. See Figure 3-31. The hawser is stored in a below-deck storage room with appropriate fairleads
to the winch. The winch has no automatic functions. The Lake Shore Traction Machine is electric motor-driven,
with infinite speed adjustment available. Maximum line pull is 175,000 pounds at 12 FPM. No-load maximum
line speed is 370 FPM in payout, 134 FPM heaving in. The unit can be declutched to permit the lines to run
free in emergencies. There is a manual brake to control disconnected payout. The winch will hold and
structurally withstand the breaking strength of a 15-inch-circumference double-braided nylon hawser.