How would you determine if your ship is dragging anchor or not ? what action would you take as OOW ?
the detection of dragging of anchor is reliably obtained by GPS. shift of ships position beyond limits set in by OOW would be detected and indicated by audible and visual alarm.
The GPS position of the anchor and a radius of tolerance (length of cable paid out + the distance of the bow from bridge + a resonable margin) can be fed in..
if the ship's position ever falls outside the circle of tolerance an alarm would be activated,
the dragging of anchor by a ship is not always detectable by observation of visual bearings alone. Compass bearing of closeby objects may change considerably, due to yaww, without any appreciable change of position of the ship.
it is easily possible to detect the dragging of anchor by the ship, bearing in mind that:
1) strong tides tends to drag the ship in a direction away from anchor, i.e. in the direction opposite to the to the ship's head last marked by the arrow on the chart..
2) the position obtained on the chart should lie within a circle whose centre is the anchor and whose radius is the sum of length of the cable paid out and distance from bow to the bridge..
actions on dragging anchor.
1)inform master.
2)inform engine room,this is an emergency, get engines ready as soon as possible.switch on power to windlass
3)call anchor stations
4) call for a messenger on bridge because the A.B. will be manning the wheel.
5)Switch on the Steering motors.
6)Switch on radar /ARPA
7) try the pneumatic whistle and electric Klaxon,
8)the VHF would already be on channel 16.
9) keep a record of all the happenings and their timings in bridge notebook,
10) carry out master's orders.
11) if the master is ashore, the chief officer would automatically take charge of the situation,
12) in rare case of both Master and C/O ashore , the second officer would have to manage,
KEEPING THE FOLLOWING POINTS IN MIND
13) the length of the cable paid out (usually 6 times the depth of water ) is only to ensure that the pull on the anchor shank, while it in on seabed, is horizontal. once that is assured paying out more cable would not help!!
14) heaving up anchor, manoeuvering the ship and reanchoring shoulf only be the last resort by the second officer. Having insufficient experience and being without proper support on the bridge this is too risky,,
15) inform the harbour control by VHF ."My ship is dragging anchor. Require a Pilot immediately."
16) call up agents on telephone and informthem" Ship is dragging anchor, the MAster and Chief officer are ashore please contact them and send them onboard as soon as possible.
17) Pull the wheel hard over away from the first anchor and hold it there.
18) prepare the second anchor to let go,
19) when the ship has sheered away from the 1st anchor, drop the other anchor on the bottom and stop the run of the cable,
20) put both cables in gear and walk back equal equally on both,ensuring that the first anchor has at least half a shackle left in chain locker,
21) put both the brakes on, take the gears out and hold on,
22) keep anchor watch to ensure that the anchors are holding,
23) keep engines on stop at short notice.
A dangerous situation that demands prompt action
It happens to every boater sooner or later. The wind in your anchorage rises, the motion of the boat increases, and your anchor starts to drag. Sometimes the rumbling of an all-chain rode warns you. At other times, your first indication may be when other boats firmly anchored to leeward appear to be moving slowly upwind toward your stern. That’s an astonishing sight the first time you experience it.The first sign of dragging in a crowded anchorage calls for immediate action. If you have just lowered the anchor, pull it up and try again, perhaps in a different spot. If you’ve been swinging comfortably on the “hook” for a while, however, a solution other than weighing anchor and re-anchoring may be in order. First, let out more anchor line, as much as you can without fouling another boat. That will give your rode a more efficient angle of pull so that the anchor should dig into the ground instead of being pulled upward out of it.If that doesn’t solve the problem, you can start the engine and run it ahead slow to take some strain off the anchor while you think things through or wait for the squall to blow over.But what if your engine won’t run because, in all the excitement, your dinghy painter has fouled the prop? Or what if the storm is settling in for a while and you need a longer-term solution? Next, load the kedge, or secondary, anchor into the dinghy and flake its line down on top of it. Make the bitter end fast to the boat and take the dinghy to windward, paying out the anchor line as you go. When you reach the end of the line, drop the anchor a couple of boat lengths to one side of the anchor already down there so that the two lines together form a shallow V from the bow of the boat.Back on the boat, haul away on the new anchor line until you feel it dig in, and make it fast at the bow. Adjust the lines so that both anchors are now taking the strain fairly.If your primary anchor has still not reset itself or if it was fouled in the first place, allow the newly set kedge to take all the strain while you weigh the first anchor and reset it from the dinghy, just as you did with the kedge.If necessary—if you have a reef close astern, or the engine isn’t working, or other boats are too near for comfort—you can set and weigh anchors alternately to gain ground to windward, but it’s a lot of work and may be dangerous in a rising wind at night. So, having recovered your main anchor, you might want to consider making a buoy or fender fast to the kedge line, casting off, and finding a safer spot in which to anchor from scratch. You can recover the kedge when conditions improve.If the wind is onshore and the holding quality of the anchorage is uncertain, prudent seamanship might even dictate your putting to sea. That’s something you should consider every time you arrive in a new anchorage. Cautious sailors will tuck a reef or two into the mainsail before stowing it on the boom for the night because they know that if the anchor drags, it’s likely to be blowing a gale. And they will make a note of a bearing that will take them safely out of the anchorage in the pitch dark. You will probably find that if you go to this much trouble, your anchor will never drag. But do it anyway; it’s cheap insurance.
1.when anchor cable goes from short stay to long stay and vice versa or it goes out of turning circle , brg and dist. chnges frm fixed object, when SOG is not equal to zero.
IF WE PUT AN ANCHOR FROM SHORT STAY TO LONG STAY AT THAT TIME WE KNOW THAT ANCHOR WAS PLUGED BUT WE ARE NOT SURE ON THAT WE HAVE TO CHECK THE BEARING OF ANYONE OBJECT WHICH IS NOT CHANGING OR AZIMUTH IF THE ANCHOR IS DRAGGING THEN IT WONT CHANGE IF IT PLUGGED THEN THE BEARING CHANGE SO WE CAN
EASY IDENTIFED OR
FROM SHORT STAY TO LONG STAY THE TENSION IN ANCHOR CABLE IS INCREASE I GUESS THIS IS THE WAY
MMD / MCA ORALS 2ND MATE EXAM
