A ship anchor is a device commonly made up of metal, this device is attached to the vessel or boats by means of chains and sometimes cables too. The function of the anchor is to hold the craft at the particular area and prevent drifting of the craft caused due to ocean currents, the anchor is lowered to the seabed through the cables and the flukes or the pointed projections dig into the sea bottom holding the ship.
Anchors in ancient times used to consist of large stones, basketfull of stones, sacks filled with sand or wooden logs. This held the craft by its weight and friction at the bottom. As the size of the vessel is increased the demand of a more effective device increased. Then the anchors evolved, wooden hooks that dug into the sea came into the picture, by the passage of time wood was replaced by iron and the flukes/teeth were also added that helped the anchor to dig into the seabed more effectively. The evolution of anchors is still continuing and researches are still going for further advancements.
Table of Contents
Types of Anchors:
There are basically two types of anchors-
- Permanent Anchor- These types of anchors are deployed for a long period of time. They remain at their offshore place with minimum movement. As the equipment used by the oil rigs and energy harvester are expensive enough and sensitive too, they can not be moved more than a few millimeters, hence the permanent anchors are used for better and long term holding.
Permanent anchors are further of following four types-
- Mushroom Permanent Anchor
- Auger Permanent Anchor
- High Holding Permanent Anchor
- Dead Weight Permanent Anchor
- Temporary Anchor- These anchors are used for short period of time. Usually they come into action during the mooring of vessel at the berths or to stop the craft dead in the water for various reasons. These anchors are not like permanent ones they are clamped or hooked on the seabed or ocean bed in order to reel back easily.
Temporary anchors are of six types-
- Northill Temporary Anchor
- Grapnel Temporary Anchor
- Herreshoff Temporary Anchor
- Danforth Temporary Anchor
- Bruce Temporary Anchor
- Plough Temporary Anchor
What is Dropping of Anchor?
It is the process of releasing anchor from the craft and allowing to fall down on the seabed to settle down and hold the vessel to prevent drifting, caused by oceanic currents.
What is Weighing Anchor?
The process of lifting up the dropped down anchor of a vessel whenever the allotted work is done in order to move the ship to another place is called as weighing anchor.
What is a Cable Stopper?
Cable stopper is a device that is used for securing the anchor chain while riding at anchor, thereby relieving strain of the windlass and also for securing the anchor in the placed position.
Ship anchor is a very useful and necessary device for holding the vessel through different anchors and techniques in order to minimize or prevent drifting due to sea waves or ocean currents.