Lesson 1. Warming through and Preparation for Stand by

WARMING THROUGH AND PREPARATION FOR STAND BY

Warming Through

Main engines are to be warmed through gradually following any occasion when they have been shut down. The jacket water circulation temperature is to be raised over a period of time to as near to the operating temperature as possible. The period of time is dependent on the jacket water temperature prior to the beginning of circulation, the heating medium and size of main engine, etc. As a general rule circulation should start not less than 12 hours before the estimated time of departure. Other circulating systems are to be put on line during this period i.e.

·                     Lubricating oil systems.

·                     Fuel circulating systems.

·                     Steam tracing systems as is appropriate to the type of engine.

Preparations for standby

1. Before a large diesel is started it must be warmed through by circulating hot water through the jackets, etc. This will enable the various engine parts to expand in relation to one another.

2. The various supply tanks, filters, valves and drains are all to be checked.

3. The lubricating oil pumps and circulating water pumps are started and all the visible returns should be observed.

4. All control equipment and alarms should be examined for correct operation.

5. The indicator cocks are opened, the turning gear engaged and the engine turned through several complete revolutions. In this way any water which may have collected in the cylinders will be forced out.

6. The fuel oil system is checked and circulated with hot oil.

7. Auxiliary scavenge blowers, if manually operated, should be started.

8. The turning gear is removed and if possible the engine should be turned over on air before closing the indicator cocks.

9. The engine is now available for standby.

The length of time involved in these preparations will depend upon the size of the engine.

Engine starting

1. The direction handle is positioned ahead or astern. This handle may be built into the telegraph reply lever. The camshaft is thus positioned relative to the crankshaft to operate the various cams for fuel injection, valve operation, etc.

2. The manoeuvring handle is moved to 'start'. This will admit compressed air into the cylinders in the correct sequence to turn the engine in the desired direction. A separate air start button may be used.

3. When the engine reaches its firing speed the manoeuvring handle is moved to the running position. Fuel is admitted and the combustion process will accelerate the engine and starting air admission will cease.

I. Complete the sentences.

1. As a general rule circulation should start (…).

2. All control equipment and alarms should be examined (…).

3. Before a large diesel is started it must be warmed through (…).

4. The indicator cocks are opened, the turning gear engaged and (…).

5. When the engine reaches its firing speed (…).

II. Mark the sentences “true” or “false”.

1. The various supply tanks, filters, valves and drains don’t need any check up.

2. The length of time involved in these preparations will depend upon the type of the engine.

3. The manoeuvring handle is moved to “start”.

4. The engine is now available for standby.

5. A built-in air start button may be used.