The following publications support the content in this lesson:
OPNAVINST 5100.19 Navy Occupational Safety and Health (NAVOSH)
NAVEDTRA 14343 Boatswain’s Mate Manual
S9086-TV-STM-010/CH-581, Naval Ships’ Technical Manual, Chapter 581 Anchoring
Anchor windlasses are installed on board for handling the anchor and chain used to anchor the ship and handling chain in preparation for towing.
There are two general types of windlasses installed on Navy ships, the vertical shaft type and the horizontal shaft type. Most Navy ships are equipped with a vertical shaft type windlass.
The wildcat is a special type of drum or sprocket constructed to handle the anchor chain links. It can be secured with a brake and disengaged from the driveshaft, which allows chain to be veered.
The wildcat is rotated by the windlass drive to heave in or pay out the chain
A revolving drum on a vertical axis that is used for controlled deployment and retrieval of lines.
A revolving drum on a horizontal axis that is used for controlled deployment and retrieval of lines. They consist of two declutchable wildcats on the main shaft and one gypsy head on each end of the shaft ends, all driven through suitable speed reduction gearing by the electric motor
Locking Wheel/Bar and Brake
The locking wheel or bar is a device used to engage or disengage the wildcat from the driveshaft. The brake must be set prior to using the locking wheel or bar.
The brake is a flat band/drum brake used to secure and control the wildcat when it is disengaged.
The driveshaft connects the motor and winch drums together
Horizontal and vertical anchor windlasses provide a means of handling both line and anchor chain. Which statements below are correct?
- Horizontal windlasses are provided with gypsy heads.
- Vertical windlasses are provided with capstans.
- Vertical windlasses are provided with gypsy heads.
- Horizontal windlasses are provided with capstans
- - Horizontal windlasses are provided with gypsy heads.
- - Vertical windlasses are provided with capstans.
______ anchors are carried on the bow, usually in hawsepipes with deck and shell bolsters or deck edge bolsters that normally accommodate lightweight type (LWT) anchors
_____ anchors are carried on the stern.
_____ anchors are 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.
The anchors in use in the Navy today can be grouped into one of the three anchor types.
The most common anchors used by the Navy are the:
Commercial stockless anchor
Standard Navy stockless anchor
Mark 2 stockless anchor
The two-fluke, balanced-fluke are used for anchoring some surface ships. It is designed to allow it to hawse flush with the surface of the ship. It can be a bower or a keel anchor.
The flukes of a balanced fluke anchor are always in a vertical position when the anchor is suspended by the anchor chain.
These anchors are used on surface ships in place of bower anchors where the ship’s conventional anchors interfere with the ship’s sonar dome when lowering or in-hauling.
Mushroom anchors are used by some older submarines and for special purposes, such as mooring of navigation buoys and torpedo-testing barges.
They are mushroom-shaped with a shank projecting from the center of the cupped side.
Anchor chains have the following characteristics:
- A 15-fathom length of chain is referred to as a standard shot.
-Chain size is determined by the wire diameter (the diameter taken at the end of the link and slightly up from centerline).
-Each shot of anchor chain has a serial number stamped into each end link.
-Chain shots are painted with black paint, except the detachable links that are painted red, white, or blue depending on the shot number, and links painted white on either side of the detachable link.
-The number of links painted white on either side of the detachable link will correspond to the shot number.
-The anchor chain is secured in the chain locker with a shackle attached to a padeye. The shackle has a breaking strength equal to the weight of 20 shots of the anchor chain it holds. The padeye is 1.75 times stronger than the shackle
- One link on each side of the 15-fathom (90 feet) detachable link white
- Two links on each side of the 30-fathom (180 feet) detachable link white
- Three links on each side of the 45-fathom (270 feet) detachable link white, and so forth
At 15 fathoms (90 feet), red
At 30 fathoms (180 feet), white
At 45 fathoms (270 feet), blue
Repeat the red, white, and blue order every 15 fathoms
Paint all of the links in the next to last shot yellow. This shot is also known as the warning shot.
Paint all of the links in the last shot red. This shot is also known as the danger shot.
On Navy submarines, anchor chain markings are not required
The chain swivel is installed in the _______ swivel shot and serves to eliminate twisting of the chain and prevents chain kinking near the anchor.
End links are special links that connects the swivel shot to the bending shackle. They are similar to the chain common links except that one end is longer and of larger diameter
The bending shackle is used to connect the end link on the outboard swivel shot to the anchor shackle.
The clevis pin in the bending shackle is oval-shaped and held in place with two locking pins for shackles that are 1-5/8 inch or larger.
Only one locking pin is required for 3/4 inch to 1-1/2 inch shackles
Anchor shackles are shackles that connect the swivel shot to the anchor.
The anchor shackle is furnished with the anchor and is in accordance with the applicable anchor specification and drawing for the ship.
The anchor shackle pin can be tack welded on both sides to the shackle, to prevent the pin from backing out.
As the anchor chain is paying out, you notice eleven white links clearing the hawsepipe. At this point, numerically, how many fathoms of chain are out?
The anchor buoy is a small float attached to the chafing chain on the anchor with small stuff used to mark its location.
An anchor buoy is made up of a chafing chain or wire rope pendant, anchor buoy line, and the buoy.
It marks the position of the anchor in the event it must be slipped or the chain breaks, allowing salvage teams to retrieve the anchor and chain.
The buoys are painted a distinctive color scheme:
Green – starboard anchor
Red – port anchor
White – stern anchor
All personnel involved must be in the proper uniform. The proper uniform for anchoring requires wearing: pant legs tucked in, hard hats with chin straps, and safety goggles.
Walking out is the method of anchoring accomplished by lowering the anchor with the anchor windlass to several fathoms from the bottom. The wildcat is disengaged and the anchor is lowered the rest of the way by releasing the brake.
This method is the best method for deep water anchorings. Anchorings are considered deep water when water depth is 15 fathoms or greater. It is also a recommended method for ships equipped with a sonar dome.
The brake release method of dropping anchor is accomplished by disengaging the wildcat from the windlass then using the brake to release the anchor.
Stopper release method of dropping anchor is accomplished by disengaging the wildcat and releasing the break. The anchor is released by pulling the stopper pin and striking the bail of the pelican hook with the maul. With this method, the anchor is held by the outboard stopper. Usually the housing stopper is used to hold the chain, but the riding stopper may also be used.
What are the three methods of dropping anchor?
- Walking out method
- Stopper release method
- Brake release method
Making the Anchor Ready
1. Test the windlass and free the anchor from the hawse.
2. If the ship is anchoring in deep water or if the bottom is rocky, walk out the anchor using the windlass. Otherwise, set the windlass break then disengage the wildcat.
3. For a deep sea anchor only, remove all but one stopper and attach the anchor buoy to the pendant.
Your ship will be conducting a deep sea anchoring using the walking out method and the bottom is not rocky. What is the correct sequence of steps for making the anchor ready?
a.Test the windlass and free the anchor from the hawse.
b.Remove all but one stopper and attach the anchor buoy to the pendant.
c.Set the windlass break then disengage the wildcat.
- a.Test the windlass and free the anchor from the hawse.
- c.Set the windlass break then disengage the wildcat.
- b.Remove all but one stopper and attach the anchor buoy to the pendant
Passing the Stoppers
When the desired scope of chain is out, the order to “PASS THE STOPPERS" is given.
To pass the stoppers, carry out the following procedure:
1. Engage the windlass brake.
2. Apply the stoppers to the anchor chain.
3. Even up the stoppers.
4. Disengage the windlass brake to place tension on the stoppers.
5. Slack the chain between the windlass and the stoppers.
6. Set the windlass brake and disengage the wildcat. If the windlass brake fails, damage could occur to the wildcat due to engagement.
7. Before securing the evolution, pick up all gear and stow it away.
When weighing anchor, the following list of equipment is needed:
Chain stopper wrench
Chain cable jack or anchor bar
Detachable link toolbox set
Anchor buoy and line
Making Ready for Weighing Anchor
Mking ready for weighing anchor is essentially ensuring that the anchor windlass is operational and in good working order.
1. Energize the anchor windlass.
2. Engage the wildcat.
3. Release the brake.
4. Test the operation of the windlass by moving it up and down just a little.
5. Set the brake.
6. Cast off the riding stopper and clear it from the chain.
The anchor is again made ready for letting go and kept that way until the anchor detail is told to secure it. This is done once the ship is outside the harbor or channel. To secure the anchor for sea:
1. Engage the windlass brake.
2. Pass the chain stoppers.
3. Even up the chain stoppers (meaning that they take equal strain).
4. Disengage the windlass brake.
5. Slack the chain between the wildcat and the stopper.
6. Set the brake and disengage the wildcat.
The appropriate PPE for an anchoring evolution is: