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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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SOLAS REQUIREMENTS::LIFEBUOY

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A lifebuoy is a ring shaped floating life preserver. All ships must carry adequate number of lifebuoys as per SOLAS regulation. Lifebuoys provide an additional flotation to crew/passengers until they are rescued. lifebuoy specifications: Have an outer diameter of not more than 800 mm and an inner diameter of not less than 400 mm. Be constructed of inherently buoyant materi al. Be capable of supporting not less than 14.5 kg of iron in fresh water for a period of 24 hours. Have a mass of not less than 2.5 kg and more than 6kg. Not sustain burning or continue melting after being totally enveloped in a fire for a period of 2 seconds. Be constructed to withstand a drop into t he water from the height at which it is st owed above the waterline in the lightest seagoing condition or 30 m, whichever is the greater, without impairing either its operating c apability or that of its attached components. If it is intended to operate the quick re lease arrangement provided for the self-
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dew point and three degree rule

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  DEW POINT MEASUREMENT. All decisions regarding cargo ventilation are based on the dewpoint temperature, comparing the dew point temperature ambient air with the dew point of the air inside the hold. One of the simplest methods to find the dewpoint temperature is using a whirling psychrometer By swinging the instrument inside the hold until the wet bulb temperature has stopped falling and remains steady. All readings should be taken well away from air inlets ensuring that only hold air is tested. ● Enclosed space entry procedure should always be observed. ● Once the above information has obtained, VENTILATE if the dewpoint of the air inside the hold is higher than the dewpoint of the air outside the hold. DO NOT VENTILATE if the dewpoint of the air inside the hold is lower than the dew point of the air outside the hold. THREE DEGREE RULE FOR DECIDING VENTILATION. Sometimes, it is impossible to measure hold dew point accurately or a
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Types of ship

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On the basis of cargo carried, dimensions,etc..ships are classified into: Container ships Bulk carriers Ro-Ro Ferries Passenger ships Offshore vessels Tanker ships Naval ships Fishing vessels Specialist ships Reefer ship Dredgers Container ships A vessel designed specifically for transporting huge quantities of cargo compacted in different types of containers. Types of Container Ships On Basis Of Sizes: Panamax Suezmax Post-panamax Post-suezmax Post-malaccamax The initiation of the container shipping forms in the maritime cargo industry is considered a huge development for the industry. IMO's International Convention for the Safety of Life at Sea (SOLAS) includes, in its chapter VI on carriage of cargoes , requirements for stowage and securing of cargo or cargo units (such as containers) Bulk carriers A vessel which is specifically designed for carrying large quantities of non-pack
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