Question

(a) Fire in the exhaust gas boiler on a motor ship may develop in two or three stages.

With reference to such situations, discuss 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.

Answer 1

Part (b)

As Second Engineer, in the event of a boiler uptake fire, I would instruct the watchkeepers as follows:

Immediately inform the Chief Engineer (C/E) and Senior Engineer.
Start the standby generator and bring it online. This secures power in case the main engine needs to be stopped.
Stop the main engine AFTER informing the bridge. This reduces oxygen supply to the fire.
Continue operating the boiler water circulating pump. This helps manage boiler temperature.
Do NOT use soot blowers. Using them will only accelerate the fire.
Ensure all exhaust valves are closed after the main engine is stopped to prevent further air supply to the fire.
Cover the turbocharger air filter. This prevents additional air from fueling the fire.
Start external boundary cooling. This helps to control the fire's spread.
If fitted, use water dosing to extinguish the fire.

If the soot fire cannot be controlled and escalates to a hydrogen or metal fire:

Stop the main engine (if not already stopped).
Stop the boiler water circulating pump.
Shut all inlet and outlet valves in the water circulating lines.
Drain water from the pipelines.
Continue boundary cooling.
If fitted with a fixed fire extinguishing medium, activate it.
Monitor the boiler uptake temperature.
Once the fire is extinguished, carry out thorough water washing.
Inspect the inside of the boiler uptake to assess the extent of damage.

✓ Verified Model Answer (Text Solution)

As Second Engineer, in the event of a boiler uptake fire, I would instruct the watchkeepers as follows: