Nstm Ch-581, Anchoring

Front 1

Bower anchors.

Back 1

Carried on the bow, usually in hawse pipes with deck and shell bolsters or deck edge bolsters
that normally accommodate lightweight type (LWT) anchors.

Front 2

Stern anchors.

Back 2

Carried on the stern.

Front 3

Keel anchors.

Back 3

Housed within the hull of the ship or submarine, near the keel, in shell type housing pockets.
A ball guide fitting above the anchor shank is equipped with projections that orient the anchor, by cam
action, into the anchor housing pocket in the hull as the anchor is housed.

Front 4

Anchor size.

Back 4

Anchor size is expressed in terms of the weight of the anchor in pounds. The
anchor holding power ratio is the ratio of the anchor holding power, in pounds, to the anchor weight, in pounds,
and varies between anchor types.

Front 5

Anchor shackle.

Back 5

The anchor shackle is furnished with the anchor in accordance with the
applicable anchor specification and drawing. The anchor shackle pin can be tack welded, both sides to the
shackle, to prevent the pin from backing out.

Front 6

Standard Navy Stockless Anchor.

Back 6

Standard Navy stockless anchors have longer flukes than the commercial stockless anchor and, for the same size of
anchor, more holding power. Typically the anchor holding power for standard Navy stockless anchors is 7.1 times
the anchor weight.
i.e. 9,000 lb. x 7 = 63,000 lbs. of holding power.

Front 7

Anchor markings.

Back 7

Anchors are marked with the type, weight of the anchor in pounds, year of fabrication, serial number
(supplied by the manufacturer) and the letters U.S.N. These markings normally appear on the crown surfaces.
The anchor may also be marked with the name of the manufacturer or commercial name of the anchor.

Front 8

Shot length.

Back 8

Chain for Navy use is procured in shot lengths of 15 fathoms (90 feet). There must always be an odd number of links in a shot of chain so that all detachable links are placed in the same position on the wildcat. The shot length consists of all common links.

Front 9

How are chain links painted?

Back 9

1. One link on each side of the 15-fathom(90 ft) detachable link white.
2. Two links on each side of the 30-fathom (180 ft) detachable link white.
3. Three links on each side of the 45-fathom (270 ft) detachable link white, and so forth.

Front 10

How are detachable links painted?

Back 10

1. At 15 fathoms(90 ft), red.
2. At 30 fathoms(180 ft), white.
3. At 45 fathoms(270ft),blue. and so forth, using red, white and blue, in order.

Front 11

How are the next to last and last shots on the anchor chain painted?

Back 11

Paint all of the links in the next to last shot yellow.
Paint all of the links in the last shot red.

Front 12

How are turns of wire used to mark each shot of anchor chain?

Back 12

1. Place one turn of wire around the stud on the first link at each side of the 15-fathom (90 ft) detachable
link.
2. Place two turns of wire around the stud on the second link at each side of the 30-fathom (180 ft) detachable
link.
3. Place three turns of wire around the stud on the third link at each side of the 45-fathom (270 ft) detachable
link, and so forth.

Front 13

T/F Anchor chain markings are not required on submarines.

Back 13

True.

Front 14

Anchor chain serial numbers.

Back 14

Each shot of flash-butt-welded chain will bear the manufacturer’s
serial number that is stamped, cut or cast on the inner side of the end links of each shot at the time of manufacture.
If one or both of these links are removed for any reason, the shot serial number and the reasons for their
absence should be inserted in the ship’s anchor log. The studs of all die-lock and FBW common links have
U.S.N. in raised letters on one side and the chain size of the links on the reverse side.

Front 15

Match marks.

Back 15

The C-shaped link and coupling plates are provided with random match marks by
the manufacturer. (typically numbers)

Front 16

End links.

Back 16

Similar to the chain common links except that one end is longer and of
larger diameter.

Front 17

Bending shackle.

Back 17

Used to connect the end link on the outboard swivel
shot to the anchor shackle.

Front 18

Mooring shackle.

Back 18

Used for attaching the anchor chain to mooring
buoys. The opening between the jaws of the shackle is seven inches wide for all shackle sizes. Mooring shackles for chain sizes 1-inch up to and including 2-1/8 inches, have a bar installed to
support the sides of the shackle. Mooring shackles for chain sizes 2-1/4 inches and larger do not have a bar
installed between the sides of the shackle.

Front 19

Bitter end shackles.

Back 19

Used to attach the anchor chain to the chain locker padeye. The padeye in the chain locker is designed so that it is 1.75 times the strength of the bitter end shackle.

Front 20

Swivels.

Back 20

Installed in the outboard swivel shot and serve to eliminate twisting of the chain. The swivel allows continuous rotation in both directions. The swivel allows the anchor to turn as it is housed in the hawse pipe, otherwise the twist in the chain could cause the chain to slip or jump the wildcat.

Front 21

Outboard swivel shots.

Back 21

Commonly called a bending shot and attaches the first shot of anchor chain to the anchor.

Front 22

Chain stoppers.

Back 22

Used for securing the anchor in the hawse pipe, for riding to an anchor, for holding the anchor when the chain is disconnected for any reason or for securing the anchor chain when the chain is used for towing purposes.

Front 23

Chain stoppers used for towing.

Back 23

Chain stoppers used for towing shall be equipped with two locking plates, modified eyebolts and cotter pins.

Front 24

Mooring swivel.

Back 24

Mooring swivels, with two detachable links attached at each end, are used
when anchoring with two anchors by the ordinary or flying moor method. This allows the ship to swing without
twisting the two anchor chains around each other.