Stern Anchor
Stern
Anchor Winches, Cables, & Anchors:
Electric-powered stern anchor winches on the LSTs resemble towing winches on fleet tugs, but they are specifically designed for the job they do. The winches were supplied by Sandy Hill Iron & Brass Works, Hudson Falls, New York & Joy Manufacturing Co, Franklin, Pennsylvania with designs by Almon A Johnson Inc, New York, New York.
They can be set to pay out at three different speeds and heave in at four
speeds. While
they are not constant-tension winches, they can be set to automatically keep a
strain on the anchor cable to prevent the stern of the LST from swinging around
while beached.
The
cables are 900 feet of high-grade plow steel wire 1-5/8 inches in diameter.
The first 15 to 20 feet of the outboard end of the cable is painted
yellow to make it easier to estimate when the anchor will break out.
Every hundred feet the cable is marked with yellow bands--one band
9-inches long for each hundred feet.
That is, at 100 feet, l band; at 200 feet, 2 bands; at 300 feet, 3 bands,
and so on up to 700 feet.
Halfway between the 100-foot markers there is one 12-inch white band.
That is, there is only one 12-inch white band at 50 feet, 150 feet, 250
feet, etc. Between
700 and 800 feet, the entire cable is painted yellow.
The last 100 feet (800 to 900) are painted red.
The Stern anchor winch on board LST 325. (click for larger
picture)
The stern anchor winch aboard former US LST in Philippenes.
The
anchor was a 3000-pound Danforth type.
A stern anchor is secured on a catting frame at the stern by a wire strap
stopper extending from the main deck down under lugs on the shank of the anchor
and back up to the main deck.
A turnbuckle at one end of the strap facilitates tightening, and a
pelican hook at the other provides a quick release.
Two views of the Danforth type anchor. The stern anchor of LST 325 was
removed and placed on the main deck to facilitate her recent dry docking.
Operation
of the Stern Anchor Winch During Beaching:
1.
Rig the anchor buoy.
2.
Release the stopper.
3.
Push setup button to energize controls.
4.
Move controller 1 point left to DRIFT and back to OFF to make sure motor
brake operates.
5.
Release “dog” on cable drum and secure with “pedal latch”.
6.
See that spiral jaw low-speed clutch is open.
7.
On the order, “Standby”, partially release clutch brake (high-speed
compressor) 5 turns.
(Not enough to allow cable to run out)
8. On the order to let go the anchor, release clutch brake 20 turns or more.
9. When the anchor digs in (sets), move the controller back to OFF position.
CAUTION:
Failure to release clutch brake will damage motor and motor brake!
Normally,
the anchor is dropped between 700 and 500 feet from the spot where it is
expected the midships portion of the LST will ground. Occasionally, however, the entire 900 feet of cable will be
run out and lost overside. In order
to expedite recovery of the cable and anchor, an emergency buoy is rigged so
that it can be quickly and easily attached to the end of the cable as the cable
pays out. The buoy is triced to the
lifelines or at some other convenient place.
The buoy line is led to the anchor cable fairleader and a clove hitch
loosely looped around the cable and hung on the fairleader.
In an emergency, the clove hitch can be quickly drawn tight around the
cable and the buoy either tossed overside or pulled free from its lashings by
the weight of the cable.
After
the anchor has been dropped during the beaching run, the man in charge must keep
the conn informed of the amount of cable out, the tension (strain) on the cable,
and the angle (direction the cable is tending) of the cable.
Tension is reported in the same manner as for a bow anchor; angle is
reported by the clock method.
After
beaching, heave in all slack in the anchor cable by moving controller to SLOW or
to NORMAL heave. Then set up on the
clutch brake. If the wind or tide
tend to swing the stern, maintain strain on cable by setting controller in
AUTOMATIC. Set tension adjustment
at 15,000-pounds or higher, if necessary.
This
picture shows the stern anchor winch controller and the clutch brake control.
Operation
of Stern Anchor Winch During Retracting:
1. Move controller to OFF position.
2.
Release clutch brake compressor.
3.
Move controller to SLOW heave.
4.
When cable drum stops turning, step down on the mechanical latch pedal
and engage low- speed spiral jaw clutch. Make sure you push hard enough to engage fully.
5. Move controller to NORMAL
heave and attempt to retract vessel.
If the anchor drags, move controller to OFF.
6. If motor stalls because it can’t start vessel, move controller to OFF for a short interval.
7.
Repeat the heaving operation until vessel moves astern.
CAUTION:
Never leave controller on heave unless the motor is turning.
8.
As the ship begins to move, the motor will speed up.
When the speed indicator (tachometer) shows 500 rpm, move controller to
MEDIUM heave; when the motor reaches 800 rpm, move controller to HIGH.
NOTE:
If it is necessary to slack off the stern anchor cable while the winch is
in low gear, push the bypass pushbutton below the low-speed clutch and move the
controller to SLOW stick-out. When
sufficient cable has been payed out, release the button and winch will stop.
High
speed heaving:
When
the motor speed reaches about 1300 rpm or when low speed clutch opens
automatically:
1.
Set up on clutch brake compressor to shift into high speed.
2.
Set controller on automatic heave with tension adjuster setting between
15,000 and 20,000 pounds.
3.
The winch is now under automatic control and should heave in cable fast
enough to keep out
NOTE:
If necessary, put the winch back into low gear to get the anchor to break
ground.