Magnetic compass

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The magnetic compass is fitted on the upper bridge exactly center line of the ship   It is referred to as standard compass     1. D ry C ard    2. W et C ard   A compass point north because all magnets have two poles north pole, south pole.   The north pole of the one magnet attracted towards the south pole of another magnet     DRY CARD COMPASS   A light aluminum ring about 254mm in diameter is attached to a brass hub by silk cord which is threaded in and out through holes in the ring.   This tight silk cord is act like bicycle wheels.   There is no other connection or support between the ring and the hub.   Silk cord is used because it doesn’t shrink or stretch due to moisture or change in atmospheric temperature.     Card support: -     The bottom of the hub has small cap fi tt ed with a sapphire bearing surface.   This rests on a pivot tipped with iridium which is hard nonmagnetic metal.   This arrangement provides practically friction-less support, for the compass card a
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Recovery of Person from Water

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Learning Objectives:
  • factors to be taken into account when recovering persons from water
  • risk assessments to be done
  • use of rescue craft, merits, demerits and other options
  • recovery plan
  • first aid after recovery from cold water


Factors for consideration:

  • manoeuvrability of ship:

For a large ship it is very difficult to come alongside a small target like survival craft or a person in the water. The other danger is that of running over and / or crushing the target. 

Manoeuvring your own ship at slow speed judging its movement and that of survival craft/ person in water is a skill. Appropriate training shall be encouraged by operators and owners of all ships. 

  • freeboard of the ship:

Small crafts are vulnerable if they are in close proximity with the ship as there is a danger of crushing or other damages. Also people awaiting recovery may not have experience of such operations.

  Survivors need to be lifted considerable distances to get into the ship. Climbing a pilot ladder is impossible for a person who is not fit. 

For vessels with high freeboard it may be difficult to see the target , hence there is great danger of running over the target. Thus additional lookouts with direct communications to the Bridge must be posted. 

  •   Risk assessment:

Recovery operations should be conducted at a position clear of the ship's propellers and usually within the ships parallel mid-body section. All areas need to be risk assessed for the conditions at the time of rescue. Some of them are:
  1. Ship specific characteristics such as manoeuvrability, access points etc. The risk assessment must be done in accordance with company's SMS.
  2. The equipment's that shall be used
  3. weather conditions
  4. will it cause any risk to stability of ship 
  5. can means of recover be safely rigged
  6. points of entry 

  • Equipment:

Even if some purpose built recovery equipment's are there, it may not be enough in certain circumstances. 
It is always better to lift a person as the person may not be fit to climb a ladder. 
Lower ends must be 2m below the water line to help people in water get on them. Safety lines should be rigged alongside with rescue strops and someone must be posted to lookout the operations.
 

  • Horizontal recovery:  

When lifting the people, if possible, it must be done in a horizontal or near-horizontal position. This minimizes the risk of shock induced by sudden transfer from the water and from hypothermia.   

Lifeboats and life-rafts may also be used to transfer people from survival crafts and lifted to embarkation deck. 
 
If winch-fitted helicopters are on scene, it may be used. Transferring people from helicopters has special requirements which is described in IAMSAR   manual

  • Good seamanship:

 Approach with the significant element ( wind,sea or swell) on weather bow and the target on your lee bow. 

As you approach, turn away from the weather and stop to create the lee, with recovery target on lee side. 

It will be very difficult to spot the target from the Bridge, thus sufficient lookouts with communication arrangements with the Bridge must be posted.

 

Advantages and Disadvantages of using lifeboats/rescue boats:

    •  easier for people to get in due to low freeboard
    • easy to manoeuvere . Thus approaching the target is easier
    • can be used  to lift causalities back on to the ship
       
Disadvantages: 
  • only limited number of people can be brought at a time
  • it is  only safe to launch lifeboats in good to moderate sea and weather conditions
The people in charge of such operations must be familiar with guidance given in IMO circular MSC 1182, guide to recovery techniques.

Recovery Plan

The conditions at recovery scene cannot be predicted, but a recovery plan must be drawn up based on different scenarios like weather conditions, number of survivors, equipment's to be used etc.

Thus in an emergency situation most of what has to be done is already known by the crew. Every rescue is unique and good consideration of risks have to be applied to the situation that presents itself.

Drills should be conducted on board to ensure that crew are familiar with plans,procedures and equipment's for recovery of persons from water. The ships Master should ensure that there are enough drills and instructions to make sure that all crew know their duties during the recovery of persons.  


First aid after recovery from cold water

Always obtain medical advice as soon as possible. 

 











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