Each anchor has anchor flukes. Those are the parts that dig into the ground. If an anchor fluke comes under a rock or cable, it would be impossible to raise the anchor again. A tripping line offers a solution. That is a line on the ring at the bottom of the anchor to which the anchor can be raised in all cases. Often a yellow buoy is attached to the tripping line, so that other ships can also see where the anchor is.
First, we check the anchor ground and the depth or look for it in the sea chart. We check that the anchor, the chain and the anchor line are fixed so that we do not lose the anchor when we drop it. When we drop the anchor, we take into account the tidat streams and wind (always with the bow against the tidal stream and wind). The anchor ground and the depth are usually also shown on the sea chart. Then we sail in the direction of the wind / tidal stream and shout: Prepare anchor! That means that the anchor must be prepared to drop it. Then the skipper calls Let Go!, which means that the anchor can drop. The skipper sails backwards, because otherwise anchor chain might fall on the anchor and the whole thing becomes entangled. Do not sail backwards too fast, because then the chain will come under tension too soon, causing people to fall on board. We drop at least 3 to 5 times the water depth of the anchor chain, otherwise the flukes cannot dig into the ground properly. When we are at anchor we hoist a black anchor ball.
If we are anchored, the ship can start yawing. That means that it will swing behind its anchor because every time a different freeboard catches wind. In that case we could release a second anchor in a V-shape. The ship will then lie neatly in the middle behind the 2 anchors.
What can also happen is that the anchor will drag over the ground and does not dig itself in the ground, for example if the surface is hard, it may take a while before the anchor digs in.
Sometimes the chain is wrapped around an anchor and makes it impossible to dig into the ground.
If we anchor on tidal currents, the steam will change in direction every 6 hours. In that case it may well be that the anchor break out of the ground. If the crew is asleep and the anchor does not dig in again, dangerous situations may arise. That is why 2 anchors can be uses in line with each other on tidal water. If the current turns 180 degrees, the ship will immediately lie behind the second anchor.
Check the anchor
How can we check whether the anchor is dropped correctly? We can do that by setting the anchor alarm on the GPS. If the ship is further than for example 50m from the set position, the GPS gives an alarm because the anchor is not holding properly. We can also determine whether we stay at the same point with the help of a cross-bearing. Something that always works is a line with a piece of lead with which the depth can be measured. You lower that to the bottom with some slack (= some extra space) in the line. If the line becomes tight after a while, the anchor apparently does not hold properly.
We sail with the engine above the anchor and bring in the anchor chain at the same time. So don't sail too fast, because then the chain could hit the bow. And also do not sail too slowly, because then the anchor windlass will have to work too hard when you bring it in. Good communication between the captain and crew is therefore essential. It is useful to place an extra person in the middle of the yacht to pass on the commands between the skipper and crew.
If the anchor is stuck in the ground, you can flip the anchor by sailing over it. Be careful that the chain does not damage the hull. On a sailing ship you could attach a line to the anchor chain and place it on a winch, so that you can use it to lift the anchor out of the ground.
In order to get access to the PowerPoints Slides you need to login first.
Questions & explanations
Question 1: A tripline is a line:
a: between the chain and the ship
b: attached to the ring at the bottom of the anchor
c: between the anchor and the chain
Question 2: We always prefer to anchor:
a: against the wind direction
b: with the wind on the side of the boat
c: sailing slowly in the same direction as the wind
Question 3: What is the fluke?
a: the stem of the anchor in which direction is pulled
b: the ring at the bottom
c: the part that digs into the sand
Question 4: How can we determine if our anchor is digged into the ground well enough?
a: by looking at the speed log
b: by looking at the water
c: by making various cross bearings over time
Question 5: What is the function of a tripline?
a: raising the anchor when the fluke is stuck under for example a heavy rock
b: to release the force on the windlass
c: to use in case the anchor chain is too short