Q1. Explain the advantages and disadvantages of an inert gas smothering system from flue compared to an inert gas generator. Explain why inert gas generator is more advantageous.
Why it is unsuitable for use in machinery spaces. (20)
Q4. (a) Sketch a line diagram of a mechanical low expansion foam fixed firefighting system suitable for machinery spaces.
(b) Describe the operation of the system sketched.
(c) Explain how a mixture of foam making compound and sea water are converted into foam.
Q4. Fire protection for the accommodation spaces of passenger vessels incorporates means of detection, fighting and containment to reduce the spread of any fire.
A. Describe the means of detection and firefighting commonly installed;
B. State how the spread of fire is prevented and how the containment is used with the firefighting and detection arrangement to locate the fire.
Q1. A fire in the exhaust gas boiler on a motor ship may develop in two or three stages. With reference to such situations; discuss: A. The factors which could be responsible for initiation and development of: i) Ignition of soot; ii) Small soot fires; iii) High temperature fires; B. State the standing instruction you, as Second Engineer Officer, would issue to watch keepers with respect to the action to be taken in the event of a boiler uptake fire.
Q1. A. What are the general requirements of fixed gas fire-extinguishing systems for shipboard use? B. What are the specific requirements related to CO2 systems with respect to quantity, piping, controls and volume of free CO2
Q1: With reference to an emergency fire pump state – A. The regulation that influence its location, capacity and power; B. How the power supply to emergency pump is ensured? C. Why a relief valve is necessary on the deck main?
Q1. With reference to automatic sprinkler system for firefighting purposes:
a) Explain, with the aid of a heat release versus time diagram, the difference between fire control and fire suppression
b) State the limitations of using glass bulb to activate sprinkler heads and suggest, with reasons, an alternative mechanism
c) The safety devices incorporated in the system
d) The parameters governing the volume of the pressure tank
Q5. a) Sketch the following detection heads and for each give a brief description of their operation.
(i) Rate of air temperature rise detector.
(ii) Flame detector,
(iii) Fixed temperature fire detector of the quartzoid bulb sprinkler type.
b) (i) What type of space is the rate of temperature rise detector used to protect? Give two spaces on board the ship where it would be fitted.
(ii) State where the fixed temperature fire detector is fitted on board the ship. Name
three places on the detector where its working temperature is indicated.
(iii) Where are flame detectors usually required to be fitted on ship?
Q4. A. Sketch a simplified circuit that may be incorporated in a control panel for an array of fire detectors.
B. Describe the following features that may be found in a control panel for fire detectors:
i) Audible fire alarm circuits;
ii) Identification, of zone of fire;
iii) Automatic change, over from normal power supply