Title: SEAMANSHIP CH. 9 ANCHORING
1SEAMANSHIP CH. 9 ANCHORING
The study references for this chapter are again
found in Chapmans Piloting, Seamanship and Small
Boat Handling, along with this Power Point
Presentation and the USCG Auxiliary Student
study guide and practice questions.
2QUESTIONS TO CONSIDER
- The process of anchoring is mostly a combination
of a SEAMANS EYE and common sense. - What do you want the anchor to do?
- How big an anchor do you need?
- Where will you be anchoring?
- Where will you keep it on the boat?
- Who will handle the anchor
3WHAT DO YOU WANT THE ANCHOR TO DO?
- You want the anchor to HOLD THE BOAT WHERE YOU
PUT IT. - That implies that the anchor must STAY where you
PUT it. - It must be light enough to comfortably handle and
yet heavy enough to dig in and hold the bottom. - It must be designed for the bottom types you will
encounter the most. - It must hold in all kinds of weather, seas and
current.
4HOW BIG AN ANCHOR DO YOU NEED?
- A mistaken concept is that the effectiveness of
anchor depends upon the weight, for its holding
power. For most Auxiliary vessels ( 16-26 ft.) a
utility type 12-18 lb. type is satisfactory.
Deeper draft vessels may need a little more. - The anchors holding power depends on the design.
- There are anchors designed for every type of
bottom known. Try to choose the anchor for your
vessels weight, handling characteristics, use
and area of operation bottom type. - They are made from aluminum, steel, cast iron and
bronze, depending on the desired use.
5DESIGN
- The primary motivation for the design of an
anchor, is its HOLDING POWER. - Most of the characteristics of the anchor reflect
its ability to DIG IN and continue to hold,
without turning over, flipping, or simply
breaking loose. - Additional considerations are its ability NOT to
foul on anything it may encounter. - Finally, the ease of maintenance feature must be
considered.
6WHERE WILL YOU BE ANCHORING
- Bottom type is probably the greatest item of
consideration for the TYPE of anchor you will
need. Consult your navigation chart in your
operating area. Its printed right on it. - Lightweight anchors such as the Danforth-type by
Danforth or Fortress, the Plow, the Delta, the
Bruce, the Max, the Kedge, the Navy-type and the
Grapnels, Folding types, and the Northill and
Mushroom type are either general purpose or
designed for a limited range of specific uses.
7STORING THE ANCHOR
- It and all other accompanying gear such as the
rode, should be stored in a location FOR
IMMEDIATE USE mode. - It should remain free of all entanglements or any
fouling apparatus. - There should be ample room for the rode to run
free.
8WHO WILL HANDLE THE ANCHOR?
- Do not buy an anchor that cannot be comfortably
handled by your crew. It will not be a satisfying
experience. - Consideration should be given to the physical
capabilities of the crew including their
eyesight, hearing capabilities, their
limitations, training and knowledge of the
functions and importance of ANCHORING.
9ANCHOR TYPES
10MORE ANCHOR TYPES NOMENCLATURE
Flukes
11SAMPLE ANCHOR TYPES
http//www.go2marine.com/category.do?no12417view
item
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13THE KEDGE, NAVY AND GRAPNELS
KEDGE types The Hereshoff, Fisherman and the
Yachtsman. All Excellent on heavy grass or weed
bottoms. Also commonly used to kedge a grounded
boat off the bar. NAVY types Not the best for
small boats. They must weigh far too much before
their holding power becomes efficient. Used on
big ships because they are flukeless so as to be
retrieved into hawse pipes. GRAPNELS Not
recommended for small boats. Good in rocks. Must
use a tripping line to free them otherwise, you
are permanently attached to the bottom!
14TWISTED THREE STRAND NYLON
- All of the gear, collectively, between the anchor
and the boat, is called the ANCHOR RODE,
whether it is of chain, synthetic fiber or a
combination of both. - The most widely used material for the anchor line
is three-strand twisted or double braided nylon.
Chain makes a good rode but the weight is
generally prohibitive. - DOUBLE-BRAIDED NYLON is elastic. The stretch
qualities (15-25) make it ideal for stress
loads in heavy seas while at anchor. Stow it out
of the direct sunlight!
15BRAIDED SYNTHETIC LINE
DOUBLE BRAIDED NYLON Gives exceptional
stability without the twisting characteristic of
the twisted variety. No kinks. Can be easily
faired through fittings and into storage. You
need to fake it down to prevent a set.
16CHAIN
- CHAIN is for vessels which would require too
large a diameter of nylon for an efficient anchor
line. It can be used, however, as a personal
choice. - In heavy coral or rock areas, chain is ideal and
in some cases, indispensable to reduce or
eliminate excessively heavy chafing. - BBB, PROOF COIL and HIGH TEST CHAIN( the best )
The three kinds of chain most commonly used as
anchor chain. - CHAIN must be matched to the wildcat used to
hoist and lower it. - IDEAL COMBINATION Nylon ,with 6-8 ft. or longer
length of chain. Chain helps to keep angle of
stock very low to bottom for max dig power of
flukes.
17ANCHORLINE HARDWAREEYESPLICE THIMBLE - SHACKLE
18CLEATS, SAMPSON POSTS, BITTS, CHOCKS, ETC.
ALL FITTINGS Should be through-bolted and backed
up with steel plates, to reduce the possibility
of a strain on the anchor line which has been
secured to this hardware, pulling the bolts back
through the deck or anchoring surface. REMEMBER
It is the objective of the anchoring maneuver, to
keep the boats position stationary. If the
fittings pull out and the anchor runs free or
drags as a result, the failure of the fitting may
jeopardize the vessels safety.
19SCOPE
- DEFINITION The length of the anchor rode in
relation to the height of the bow above the
bottom of the water body ( R Bh ) where R Rode
length and Bh Bow Height of the bow above the
water. - Interpretation and application The length of
the rode. - You know you should have a minimum scope of 5
1 but should have 7 1 in fair weather. You have
80 ft. of rode out in 10 ft. of water which gives
you a scope of 81 (80 10). - However, if your bow is 3 ft. above the water
your actual scope is only (80 13
approximately a little more than 6! - The SCOPE is a MAJOR FACTOR that determines
whether you will DRAG or HOLD!!
20ANCHORING FAVORABLE CONDITIONS
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22PERMANENT MOORING
23SELECTING THE ANCHORAGE
1. ALWAYS USE YOUR CHART to pick your anchorage.
Its your road map to the area, in detail. 2.
Try to pick a bottom that has little or no mud,
loose sand or heavy grass, for better holding
characteristics for the anchor. 3. Try to anchor
with your bow into wind. This will help to keep
your sleeping area free of insects living on the
surrounding land mass. It also will help in
getting underway as you are already heading out
and you do not have to turn around! 4. Try to
pick an orientation which will give you as much
lee as possible, in case of inclement weather.
24APPROACHING THE ANCHORAGE
- Keep in mind, if you use only one anchor, you are
free to rotate 360 degrees on your anchor during
the night or day, possibly over dangerous rocks
below or into other anchored boats in the
anchorage. Keep this in mind in choosing the
spot and when approaching. - Use your GPS or suitable range marks you have
chosen, to navigate to the desired spot to drop
the anchor. - Visualize other vessels already anchored and how
they might swing or set up in any current or
wind, before your final selection of a good spot.
25LETTING GO THE ANCHOR
- THINGS TO CONSIDER
- BOATS MOTION
- LOWERING THE ANCHOR
- SETTING THE ANCHOR
- DRAGGING ANCHOR
- DECK FASTENERS
26LETTING GO THE ANCHOR
- As a good sailor, your anchor and all the
necessary gear is ready.That means it is
properly and adequately attached with secure
fittings, backed, and the deck is cleared for
working. - STOP ALL HEADWAY. Reverse you engine at idle
speed. Just as you begin noticeable sternway,
lower the anchor slowly but positively until it
hits the bottom on the crown. - The goal is to PREVENT fouling.
27SETTING THE ANCHOR
- An anchor MUST be SET to yield its FULL HOLDING
POWER. - This is somewhat trial and error because every
boat is different. - Pay out the rode until you get to your
pre-selected marker. Take a turn or two around a
cleat. Check things out to see if it is holding. - Keep doing this until you are satisfied it is
holding. - When you are satisfied, stop the rode with
whatever system you have. - Pick out at least two ranges, one on each side at
about 45 degree angles to each other and make a
note. Your anchor watch can detect drift by
these sightings later and take corrective action..
28WHEN THE ANCHOR DRAGS
- Check the bearings of the two ranges you chose
when you came into the anchorage. - Be prepared to get underway immediately and to
fend off, if necessary. - If there is no immediate danger of collision and
you have enough room, let out additional scope
and test for holding each time. - On the engine, bring the bow back into the wind
to ease the strain on the rode. - If it is reasonable, raise the anchor to clear
any fouling that might have taken place.
29INCREASING THE HOLDING POWER
30GETTING UNDERWAY
- ALWAYS have your mainsail up and set or your
engine on and in gear, for positive control,
before breaking the loose from the bottom. - Setting in a current, near shore, grass and other
like debris will entangle in the anchor rode. - Whipping the line up and down in a snapping
motion will help clear most all of it. - Do not store the anchor line with any of this
debris as it will hasten its breakdown and
carries this moisture down below decks where it
is most undesirable. - KEEP THE ANCHOR OFF OF THE HULL!
31USING TWO ANCHORS
- Use of two anchors, a working anchor and a
storm anchor, will help to correct for
deficiencies with only one anchor, when in heavy
weather. The STORM anchor can be run out and set
without moving the working anchor at all. - Deep draft sailboats will lie head into the wind
naturally. Power boats and small skiffs tend to
put their sterns into the wind, if left alone. It
may become necessary to use two anchors with
these vessels to keep them out of trouble. - http//www.uspowerboating.com/anchoring_gifs/two_a
nchors.gif
32ANCHORING AT NIGHT
- Dont forget your ANCHOR LIGHT to meet your
boats requirements of the Rules. - In addition, during the day, if you are required
to meet the rule, your SINGLE BLACK BALL dayshape
should be flying from your crows nest.
33REVIEW QUESTIONS NO. 1
- The most widely used material for the anchor line
is_________ - a. polypropylene
- b. polystyrene
- c. nylon
- d. rayon
34REVIEW QUESTIONS
- The most widely used material for the anchor line
is__________ - c. nylon
35REVIEW QUESTIONS NO. 2
2. All gear, taken collectively, that lies
between the boat and its anchor is called the
_________. a. line b. mooring c. rode d. cast
36REVIEW QUESTIONS
2. All the gear, taken collectively, that lies
between the boat its anchor is called the
____________ c. rode
37REVIEW QUESTIONS N O. 3
3. The lightweight type anchor is excellent on
______ and sand bottoms. a. rock b.hard c.
gravel d. mud
38REVIEW QUESTIONS
3. The lightweight anchor is excellent in _____
and sand bottoms. d. mud
39REVIEW QUESTIONS NO. 4
4. Chain is designated by the __________ of the
material in the links. a. length b. weight c.
metal d. diameter
40REVIEW QUESTIONS
4. Chain is designated by the _______ of the
material in the links. d. diameter
41REVIEW QUESTIONS NO. 5
5. The ideal rode for most average conditions is
a combination of _________ and a short length,
less than 1 fathom of chain. a. cable b.
nylon c. rayon d. polypropylene
42REVIEW QUESTIONS
5. The ideal rode for most average conditions is
a combination of ____ and a short length, less
than 1 fathom of chain. b. nylon
43REVIEW QUESTIONS NO. 6
6. When anchoring under favorable weather and sea
conditions and using nylon line, a scope of
________ might be considered a minimum. a. 5
3 b. 4 8 c. 5 1 d. 5 1
44REVIEW QUESTIONS
6. When anchoring under favorable weather and sea
conditions and using nylon line, a scope of
_________ might be considered a minimum. d. 5
1
45REVIEW QUESTIONS NO. 7
7. When anchoring, the anchor should _____ be
lowered when the boat has any way on. a.
always b. never c. probably d. must
46REVIEW QUESTIONS
7. When anchoring, the anchor should____ be
lowered when the boat has any way on. b.
never
47REVIEW QUESTIONS NO. 8
8. If an anchor drags, the first step in trying
to get it to hold is to_______. a. pay out more
scope b. take in scope c. change anchor
size d. try another spot
48REVIEW QUESTIONS
8. If an anchor drags, the first step in trying
to get it to hold is to_____. a. pay out more
scope
49REVIEW QUESTIONS NO. 9
9. When chocks, cleats and other fittings are
used on deck, they must be _________ and
reinforced with a strong backing plate. a.
heavily screwed b. through-bolted c.
screwed d. stopped
50REVIEW QUESTIONS
9. When chocks, cleats and other fittings are
used on deck, they must be _________ and
reinforced with a strong backing plate. b.
through-bolted
51REVIEW QUESTIONS NO. 10
10. The type of anchor traditionally used for
permanent moorings is the _______. a. pan b.
mushroom c. folding d. navy
52REVIEW QUESTIONS
10. The type of anchor traditionally used for
permanent moorings is the ________ b.
mushroom
53END CHAPTER 9