Anchoring - Shiphandling Facts and Rules

Question 1

Anchoring - Four Steps

Answer 1

• approach
• placement
• laying out
• fetching up

Question 2

Anchoring - deep water

Answer 2

walk out the anchor until near the bottom in depths greater than 100 feet

Question 3

Anchoring - wind/current perpendicular (MacElrevey)

Answer 3

use running moor (MacElrevey pg 186)

Question 4

Anchoring - in-line with current (MacElrevey)

Answer 4

use standing moor (MacElverey pg 186)

Question 5

Anchoring - bow movement while dredging (MacElrevey vs. Rowe)

Answer 5

• the bow of a ship with head way is not pulled in any particular direction, but steadied (MacElverey pg 151)
• OR bow is pulled in the direction of the dredged anchor (Rowe pg 54)

Question 6

Anchoring - large turn

Answer 6

-if a large turn is initiated then using the anchor on the inside of the turn will reduce the turning diameter

Question 7

Anchoring - dredging anchor selection

Answer 7

use offshore anchor for dredging

Question 8

Anchoring - dredging chain length (MacElrevey vs. Hooyer vs. Rowe)

Answer 8

• use anchor chain equal to twice the depth of water for dredging (MacElrevey pg 194)
• OR about 1.5x the depth (Hooyer pg 171)
• OR do not exceed 1.5x the depth (Rowe pg 54)

Question 9

Anchor - windlass speed

Answer 9

design speed = 3 minutes per shot of chain (0.3 knots)

Question 10

Anchoring - brake power

Answer 10

static brake power 3 times that when brake is running

Question 11

Anchoring - minimum lifting capacity

Answer 11

minimum lifting capacity = anchor + 4 shots of chain

Question 12

Anchoring - anchor holding power (Hooyer)

Answer 12

• shank flat to bottom = 4x weight of anchor (without the weight of the chain)
• shank raised 5º = 25% loss of holding power
• shank raised 15º = 50% loss of holding power (Hooyer pg 70)

Question 13

Anchoring - heaving stern anchors (Hooyer)

Answer 13

if not deployed, good idea to drop bow anchor before heaving stern anchor (Hooyer pg 83)

Question 14

Anchoring - power swing in current - loaded ship
(Hooyer)

Answer 14

• do not power swing on anchor in current, dangerous when on beam (Hooyer pg 130)

Question 15

Anchoring - swing with a strong beam wind (Hooyer)

Answer 15

in strong beam wind, we may apply full power to start swing if slack is out of chain (Hooyer pg 131)

Question 16

Anchoring - dredging UKC (Rowe)

Answer 16

• at least 20% max draft
• to avoid damage to hull

Question 17

Anchoring - dredging recommended speed (Rowe)

Answer 17

0.3 kts (some companies use 0.5 kts)