The world's largest cargo ship full load displacement can reach 800,000 tons, equivalent to 8 times the aircraft carrier, even ordinary cargo ships can reach about 100,000 tons, the waves on the sea surface are undulating, if you encounter unloading or other situations that need to stay, how can these ships be firmly stable on the sea surface without drifting with the wind?
First of all, the ship itself weighs a lot, so it is relatively stable on the sea surface, the general wind and waves can not help it, and the speed of the cargo ship is not very fast, it is not difficult to stop, the key is to let them stay on the sea smoothly, which depends on the anchor.
Anchors are roughly divided into four types of rod anchors, rodless anchors, large grip anchors and special anchors, and there are many types of anchors under each type, and the anchor commonly used by domestic ships is hall anchor, which is a kind of rodless anchor. The anchor is mainly composed of several parts such as anchor crown, pin shaft, anchor claw, anchor handle, anchor rod and anchor unloading buckle, which is generally in a triangular shape.
After the ship breaks anchor, the anchor in the anchor chain of the traction sinks to the bottom of the water, the anchor claw and the bottom of the water contact, deep into the seabed to achieve the effect of fixing the ship; in order to make the anchor successfully fall to the seabed, usually the length of the anchor chain is much greater than the depth of the water, once under the water there is a part of the anchor chain is lying flat, when the ship continues to drive The anchor chain is pulled, and the connection between the anchor and the anchor chain is subjected to a horizontal force, plus the gravitational action of the anchor itself, so that the anchor is embedded deeper, and finally the ship is firmly stuck in a predetermined position.
According to the different waters, meteorological conditions and operating requirements, the anchor throwing method is also different, generally there are bow anchor, stern anchor, side anchor and end anchor; in addition, different tonnage ships, the weight of the anchor is also different, such as 100,000 tons of cargo ships, its anchor is at least 5 tons of weight.
After talking about anchoring and mooring, let's talk about how to retrieve the anchor. When the ship wants to retract, it will drive in the direction of the anchor, and slowly retract the anchor chain, and then the hull and the anchor chain form a right angle, the anchor force direction changes, the anchor claw is first pulled out of the sediment, the anchor chain continues to rise until the anchor is completely retracted; if the driving to the anchor can not be pulled out smoothly, then the ship will circle around it to successfully retract it.
For ships, anchors are a major safety guarantee, but there are also frequent cases of anchor loss. Anchor unloading buckle is the key to the connection between the anchor and the anchor chain, the anchor unloading buckle has a pin bolt, and the anchor is usually hoisted on both sides of the bow outboard, for a long time by the wind and waves, when retracted to suffer an impact, which will cause the pin bolt to loosen off, once the pin bolt is off, the anchor will also fall off and lose; in addition, the anchor chain is used for too long, the wear is serious, if the anchor is just thrown in a relatively hard place, it is easy to cause the anchor chain to break and lead to the loss of the anchor when anchoring.
Of course, not all sea areas can be anchored, usually the length of the giant anchor chain is about 500 meters, in the deep sea of several kilometers is not enough to see, then it can rely on the ship's own power system to support.