Question about the anchor

[BillB48]

This debate has got me thinking....just how many anchors does a large cruise or any ship have? Aren't there two on the bow, one on either side? And BillB48 brought up that incident a while back when some drunken passenger released a rear anchor. Are there two in the stern as well?

 

Maybe a picture is worth a bunch of bytes.......

 

[DFD1]

.....Looks like the rear end of a fat duck....

[serendipity1499]

 

<SNIP>

 

Topsham/Capt Card, can you weigh-in here please? I'll believe whatever you say.

 

I was just thinking the same thing..:D:D:D

It's def. time for Capt. Card/Topsham to weigh-in here..I too will believe whatever he says..

 

Come on Stephen please chime in & settle this once & for all..

 

This thread is making me laugh..

Cheers...Betty

[Hawaiidan]

Airplanes have a minimum controlable air speed below which the stall. On the ground for example large passenger jets are steered by a tiller untill the aircraft gets going to 80 kts. At that point thre is enough air flow over the control surfaces and rudder to steer the plane. They have flaps that lowers the mimimum speed and leading edges that give the Wing more lift and control

 

A large ship has to have way on it ( speed) in order for the rudder to actualy steer the ship. I think its about 8 kts for a carrier. Below that speed the ship is manouvered by her engines and thrusters for the most part. The rudder is below that speed useless. At times when backing a hard over rudder can be used to defelect and direct force from the screws ( propellers) The larger the ship the higher the speed.

 

Some one wrote it is not so much the anchor weight as the chain. Thats only part true. What really holds an anchor is the angle ( called Scope) between the ship and where the anchor lies. As I recall 6:1 scope is good for most, A 9:1 scope for storm weathering. So a 50 lb anchor using rope would hold not because of its weight but because of angle of anchoring between the vessel and the anchor on the sea bed !.

 

A chain is used not so much for the weight but for the fact it does not stretch like mooring lines and will not let any inertia or kenetic energy develop .

So.... set the special sea and anchor detail, all ahead 1/3 right standard rudder.........

 

As my physic proff once said, just because you dont understand physics dosent mean it wont kill you. But I liked John Wane.s analogy best" life is hard, its even harder if your dumb"

[Boytjie]

That TOTALLY makes sense to me.....I see it the same as if i'm carry my purse with all my junk in it. If i carry in my hand with my arm down by my side it will make my body lean to that side, if I carry the same purse close to the center of my body, it will be more balanced an not feel as heavy. See, it's really easy just use one of my favorite thing (a purse) and I get it.:D:D

 

You crack me up :)

[josie724]

You crack me up :)

 

That made me smile :) thank you.

[ASIWISH]

Airplanes have a minimum controlable air speed below which the stall. On the ground for example large passenger jets are steered by a tiller untill the aircraft gets going to 80 kts. At that point thre is enough air flow over the control surfaces and rudder to steer the plane. They have flaps that lowers the mimimum speed and leading edges that give the Wing more lift and control

 

A large ship has to have way on it ( speed) in order for the rudder to actualy steer the ship. I think its about 8 kts for a carrier. Below that speed the ship is manouvered by her engines and thrusters for the most part. The rudder is below that speed useless. At times when backing a hard over rudder can be used to defelect and direct force from the screws ( propellers) The larger the ship the higher the speed.

 

Some one wrote it is not so much the anchor weight as the chain. Thats only part true. What really holds an anchor is the angle ( called Scope) between the ship and where the anchor lies. As I recall 6:1 scope is good for most, A 9:1 scope for storm weathering. So a 50 lb anchor using rope would hold not because of its weight but because of angle of anchoring between the vessel and the anchor on the sea bed !.

 

A chain is used not so much for the weight but for the fact it does not stretch like mooring lines and will not let any inertia or kenetic energy develop .

So.... set the special sea and anchor detail, all ahead 1/3 right standard rudder.........

 

As my physic proff once said, just because you dont understand physics dosent mean it wont kill you. But I liked John Wane.s analogy best" life is hard, its even harder if your dumb"

 

That's what I was going to say...

[jtl513]

FWIW, none of the six ships that left PEG today had the anchor hanging down near the water. The Eurodam backed up to leave pier 26, if that makes any difference.

[GregnChris]

A couple of years ago we took the BCFerry to Salt Spring Island from Vancouver. As they approached the narrow channel between a couple of islands (I forget the name, something like the Standard or Main channel) a crew member came out on the front deck and loosened the clamps on the forward anchors. I asked him why and he said so that they would be ready for use if they lost power while in the narrow channel. I would assume it is the same for HAL.

 

There is a difference between having the anchor locked in its stored position, and hanging down. It takes some time and crew to free the anchor from its stored position. Once it is free hanging, it can be let go very quickly.

 

And they use a chain for a couple of reasons. One is that the anchor is very heavy, and a chain is stronger than a cable. Second is that an anchor's holding power depends on the angle of the pulling force. If the force can be directed to be parallel to the ocean floor, the anchor will hold. If the anchor is pulled straight up (perpendicular to the ocean floor) it will release. (If it didn't do this, they would never be able to raise the anchor!) So they use a heavy chain cause the pulling force to be more parallel to the ocean floor.

 

Frequently on small boats, the first 10-20 feet of anchor "rope" is actually a chain for this very reason. Consult a seamanship manual for more about anchors and how they work.

 

Greg

 

Greg

[mariner]

The purse example actually was a very good one.

 

Stephen is sailing, so I doubt he'll drop anchor here at the time.

 

But I know about the anchor from him because in a painting I commissioned from him, the ship had the anchor down a bit as it sailed. I asked. He answered.

 

It does help the turn. And captains get bonuses based on fuel consumption. Those boys will use every trick they can.

[jtl513]

But I know about the anchor from him because in a painting I commissioned from him, the ship had the anchor down a bit as it sailed. I asked. He answered.

Great! Now if he can just explain the physics to me I'll be happy. :)

It does help the turn. And captains get bonuses based on fuel consumption. Those boys will use every trick they can.

So how come none of the six cruise ships that left PEG yesterday did it?

[ASIWISH]

The purse example actually was a very good one.

 

Stephen is sailing, so I doubt he'll drop anchor here at the time.

 

But I know about the anchor from him because in a painting I commissioned from him, the ship had the anchor down a bit as it sailed. I asked. He answered.

 

It does help the turn. And captains get bonuses based on fuel consumption. Those boys will use every trick they can.

 

I want to support you, believe me I do..... But, you've got to do a better job explaining this... Come on!

[jtl513]

The Westerdam left today with the anchors in the up position.

[Copper10-8]

It's already been stated a couple of times in this thread; the reason some ships (captain's discretion) lower their anchor to a position above the waterline when departing port is for added safety!

In case of a power failure/propulsion problem/blackout, etc, the anchor being dropped will slow the vessel down and allow a captain to hold position until an engine is back on line again. By having the anchor at, or just above, the waterline and out of the pipe, more weight is out of the chain locker so, if deployed, the anchor will fall quicker

[kenevenpar]

It's already been stated a couple of times in this thread; the reason some ships (captain's discretion) lower their anchor to a position above the waterline when departing port is for added safety!

In case of a power failure/propulsion problem/blackout, etc, the anchor being dropped will slow the vessel down and allow a captain to hold position until an engine is back on line again. By having the anchor at, or just above, the waterline and out of the pipe, more weight is out of the chain locker so, if deployed, the anchor will fall quicker

 

Now that is one source I would take to the bank!

[jtl513]

... the reason some ships (captain's discretion) lower their anchor to a position above the waterline when departing port is for added safety!

Thanks! That's been the more plausible explanation to me through this whole thread. :)

Now that is one source I would take to the bank!

Why? He may have money, but he won't give you any of it. :D :D

[innlady1]

That TOTALLY makes sense to me.....I see it the same as if i'm carry my purse with all my junk in it. If i carry in my hand with my arm down by my side it will make my body lean to that side, if I carry the same purse close to the center of my body, it will be more balanced an not feel as heavy. See, it's really easy just use one of my favorite thing (a purse) and I get it.:D:D

 

I was waiting for a woman to come along and explain the physics of this thing! Thanks, Josie...I totally understand now.

[josie724]

I was waiting for a woman to come along and explain the physics of this thing! Thanks, Josie...I totally understand now.

 

Glad I could be of service......:D

 

I'm just hoping there will be a topic where we can use shoes as an example.....my next favorite item....;)

[PathfinderEss]

It's already been stated a couple of times in this thread; the reason some ships (captain's discretion) lower their anchor to a position above the waterline when departing port is for added safety!

In case of a power failure/propulsion problem/blackout, etc, the anchor being dropped will slow the vessel down and allow a captain to hold position until an engine is back on line again. By having the anchor at, or just above, the waterline and out of the pipe, more weight is out of the chain locker so, if deployed, the anchor will fall quicker

Thanks Copper, seems like we changed the page and went off half cocked again. Thanks for straightening us out once more.

[gatorbill62]

Thanks Copper

I knew sooner or later you would come through with the correct answer.

[BillB48]

OK it's time to heave up the anchor one more time...;) I went to my neighbor's house and heaved up a few glasses of the grape, he is a former ship's pilot and I worked with him professionally as a pilot(he was the pilot, I was in the food chain). The reason for the anchor being lowered out of the pipe is one of safety as noted in some of the previous posts. The primary reason is... if they think there maybe a reason to use the anchor, they want ensure it will be free to fall when they give the command to "drop port/starboard anchor". The problem arises in modern day shipping where the anchor is infrequently dropped with ships not having to anchor with dynamic positioning and such, when they go to let the anchor go, it may be stuck or otherwise lodged in the hawse pipe and not drop when released. So if they have to wicker with it and break the seal to get the anchor to drop, it is easier to do that before the anchor drop is necessary, get it out of the pipe and just above the water so there is not question it will drop when/if needed. This is from a licensed USCG deck officer and former pilot, so I think this is close enough to the horse's mouth;):) Just to be clear the anchor needs to be in the water in contact with the bottom for it to have any significant impact on the ship.

[FrankNJ]

Last year , departing Ft Lauderdale , the captain asked everyone in the Lido to wait in line on the starboard side only to help the ship turn . Unfortunately , many didn't know which side that was and we nearly hit the Point of Americas condo ! ( Fortunately the anchor was ready !)

 

Seriously though , I am sure it's for safety , and some captains like to let out a few links in the chain to be sure the anchor winch is ready and unrestrained by any safety catches if needed as an emergency brake. On my own boat , I always remove the anchor "safety" clip for the very same reason , if I have to use the anchor as a brake, to say ; avoid hitting a bridge or going over a dam , due to a loss of power or control , I want it to be ready to drop and I want to be sure it will .

 

And anyone who thinks dropping "the hook" won't do anything at slow speed has never done it ! Those things are made to grab the bottom and will exert tremendous forces on the ship/ boat , as I have witnessed a couple of times by seeing unfortunate accidental anchor releases.

[Himself]

This is safety precaution in port. Ships do this, in case they lose propulsion while maneuvering in harbor, they can drop anchor quickly, to prevent drifting into anything.

 

This makes a lot of sense. Thanks for the explanation!

[mariner]

Believe a retired cop. Yeah, makes sense to me.

 

Copper, do you have sailing instructions from Port Everglades too?

[Copper10-8]

Believe a retired cop. Yeah, makes sense to me.

 

Copper, do you have sailing instructions from Port Everglades too?

 

No, but I stayed at a Holiday Inn Express last night;)