Relevant Question

Q. Describe a starting air system showing starting & reversing.
Or Q. sketch block diagram of starting air-line.

Starting and reversing sequences will be as follows:

At stop condition:

• Telegraph in stop position.
• Air/ fuel interlock ’on‘.
• Puncture v/v air open.
• Fuel pump cut out.

Starting in ahead direction:

• Telegraph set to start or dead slow ahead position.
• Start in ahead signal from remote control system.
• Ahead signal on.
• Fuel injection timing change to ahead direction.
• Turning gear, air/fuel and reversing interlocks are all cleared.
•  Air distributor timing changed to ahead direction.
• Automatic v/v pneumatically open & distributor gets pneumatic signal, engine turn on air.
• Starting momentum rpm is reached (8-12% of MCR speed)
• Governor will set fuel p/p rack to fuel run position.
• Air fuel interlocks will stop starting air supply to cylinder. Puncture v/v air supply stopped & vented.
• Now engine run on fuel.
• Signal to governor for desired speed.
• Desired RPM achieved and feed back to governor.

Stopping engine:

• Telegraph set to stop position.
• Puncture v/v air on.
• Fuel pump cut out.

Starting in astern direction:

• Same sequence as starting in ahead direction but only telegraph will be in dead slow astern
• Astern signal will ’on‘ from remote control system which will change fuel injection and starting air distributor timing in astern direction.