Please can anyone tell me exactly how a ships anchor stops it from floating off?

Question

Its always puzzled me even when i was a kid.
What if a ship is 200 tonnes and the anchor is only 2 tonnes how does it stop it moving.
Surely the anchore only falls to the bottom of the sea bed and lays on top of the sea bed. It doesnt anchor itself into the sea bed does it! come on.
so how does it work please?

Answer 1

The ships anchor is only part of the answer in holding the ship to the sea bed, the chain holds the major weight and is payed out whilst the ship goes astern this lies on the bottom and the ship swings on the chain.
.Should the ship drag anchor more chain is let out.

Answer 2

Alex T has the right answer. On large ships its not really the anchor that holds the ship in place, its the weight of the tons and tons of cable on the ocean floor, along with the anchor that holds the ship in place. Even then, in a storm or during a bad sea state a ship can drag her anchor and move, hence the reason when large ships go to anchor they have an anchor watch to keep an eye on things. My ship is 5,146 tonnes and when we go to anchor, depending on sea room and bottom depth, we usually drop 4-7 shackles, 360-630 feet of cable. I don't know exactly how much one shackle weighs although I'd estimate it's upwards of three tons, so taking a rough estimate 4-7 shackles of cable would be about 12-22 tons on the ocean bottom when we go to anchor, enough to keeps us relatively in one location except in severe weather.

Answer 3

Well the anchor is made so that when it is on ground,
the "hook" part of it is held so that it "hooks" into the sea bed and the chain holds it in that position. The weight of
the chain helps to hold the ship too but it's the shape of the anchor that does it really. A "Sea Anchor" is a funnel shaped "THING" with a smallish hole at the narrow end, so the water goes in the wide end and out the small end. That does not actially stop a boat/ ship but slows it
down and hold the bow "Into" the wind or tide

Answer 4

Many anchors are designed with two blades, shaped much like plows, which dig into the seabed after the anchor is dropped. The ship can either try to pull away under its own power or let the current drag it away from the anchor. The weight of the anchor pushes the blades into the sediment, which bite deeper into the sea floor as the anchor is dragged, and eventually the ship is held fast.

Answer 5

An anchor works by resisting the movement force of the vessel which is attached to it. There are two primary ways to do this — via sheer mass, and by "hooking" into the seabed. It may seem logical to think wind and currents are the largest forces an anchor must overcome, but actually the vertical movement of waves develop the largest loads, and modern anchors are designed to use a combination of technique and shape to resist all these forces

Answer 6

It's a fact, the weight of the anchor dragging along the bottom of the ocean depth keeps the boat from drifting away. Sometimes the anchor itself gets caught in a coral reef or canyon. Most of the time an anchor embeds itself in silt or thick mud. Large ships use a sonar system to determine where to anchor based on the thickness of the sea bed.

Answer 7

Anchors are designed in different shapes for different bottoms. They are designed with flukes and stabilizers to dig into the bottom to hold. With the proper size anchor for a particular boat(there is a formula), it is set with the proper angle of rode(anchor line) and chain and it holds for those conditions. Sometimes with a change in conditions such as tide, wind, current or storm changes need to be made.The anchor is set by backing off and pulling it into the bottom, it does not just lay there.Also a proper scope of anchor rode is let out to make the proper angle for hold. The amount of scope varies by depth and conditions.It is at least 7 times the depth.

Answer 8

anchor weight has little to do with holding power...I anchor my 14,000 pound sailboat....even in hurricane conditions.....with a 60 pound anchor...and the big ships anchor/weight ratio is similar.

An anchor works by, yes, you guessed it: actually digging into the bottom....the shank ..the long rod the chain is attached to...is at an angle to the flukes.....the blades....and when the ship's anchor rode ( chain) pulls on the stock, the flukes dig into the bottom and the harder the pull the deeper the anchor 'sets".....think of a garden rake..that short handled three prong tool...once that is dug in, you'll notice how much force it takes to pull it out........or you can dangle a two hundred pound man on a half pound ice ax if its dug in......there are four or five different basic anchors styles for different bottom conditions.,.........hard sand to soupy mud....
but the ships anchor with the rounded triangle flukes and the Danforth with the sharp pointed flukes work fairly well in almost all conditions because they dig in......I had a 40 pound Damforth dig five feet down in hard sand in Hurricane Marilyn in ST Thomas.....it held a 30,000 pound boat in 100 knots of wind
a simple explanation to something people have been working on for two thousand years

Answer 9

it lies on the ocean floor and anchors it to one point, then being ship shaped the boat turns into the wind, and it takes advantage of its ship shape... the waves ride around it! quite ingenious really... and yes, it digs into the seabed... when the ship weighs anchor huge motors assisted by the ships bouyancy rip it out of the seabed, and its been going on since we had a navy.

Answer 10

I don't really know but i think the sand is hard to move on that the anchor just stops the ship!!!!