ORAL
QUESTIONSADD YOUR
QUESTIONS
CHIEF MATE EXAM ORAL QUESTIONS AND ANSWERS - LATEST QUESTIONS | Page 201
Q. 2001) Lights for sailing vessel at anchor ? separtion / spacing between lights for the above lights ?
X
Q. 2002) PV valve and PV breaker difference ?
XQ. 2003) What is boil over & boil off ?
X
A Boilover type of fire refers to an extremely hazardous situation where a semi-enclosed oil or petrochemical fuelled fire is being attempted to be extinguished with water. This situation is caused by the relative density difference of oil/petrochemicals and water. Oil, being lighter than water, causes it to always want to be the surface layer.
As water is being pumped onto the surface of the fuel (where the flames are evident) it will quickly sink below the fuel, to collect at the bottom of the container, doing little to extinguish the flames. As the temperature of the fire slowly builds, descends down through the fuel, it will eventually reach the water that has collected at the bottom of the container. The descending heatwave will have a temperature sufficient to cause the water to vaporise into steam, expanding to more than 1700 times its volume as compared to in its liquid state. The rapidly expanding (possibly superheated) steam expels the fuel upward to boilover and out of the container discharging the, still ignited, fuel onto a large and uncontrolled area outside of the container
Boil off : A small amount of LNG evaporates from the tank during storage, cooling the tank and keeping the pressure inside the tank constant and the LNG at its boiling point.
Q. 2004) River water echosounder is showing a depth of 10 metre , what is actual depth ?
X
actual depth 9.71m
if the echo sounder correctly callibrated for sea water it will show 3% higher than actual depth
Q. 2005) Explain tanker calculation procedure.
XQ. 2006) Various chart projections and their features .
XQ. 2007) Lateral mark & cardinal buoy cards .
XQ. 2008) How many grades of chains are there , which one is strongest ?
X
Q. 2009) What is tidal stream atlas and what informationsare given on them ?
X
rate and drift of tidal streams in the diagram form. rate and drifts are shown in the maps of the areas of which the tidal streams are given.
Q. 2010) You go to rope store in search of wire rope , you find a wire rope but tag of wire is missing , how will you find the swl of r
XSee the no.of strands & wire in each strand..for ex : 6x24,6x37,also measure dia of wire rope and from dia & construction you can find the SWL
