How To Start The Ship's Main Engine : From Preparation to Full Away

Summary

The script details the complex process of starting a ship's main engine, which involves more than just turning a knob. It requires the preparation of four ancillary systems: fuel, lubrication, cooling water, and starting air. The process includes starting an extra generator for power, using the turning gear for lubrication, compressed air for initial piston movement, and air blowing to clear cylinders. After ensuring all systems are ready, the engine undergoes trial starts, fuel running, and gradual speed increase to full ahead, overcoming critical vibration speeds, and finally reaching the desired operational speed for open sea passage.

Takeaways

• 🔧 Starting a ship's main engine requires preparation involving ancillary systems such as fuel, lubrication, cooling water, and starting air.
• ⏱️ Engineers receive a one-hour notice before departure to prepare the engine for startup.
• 🔋 An extra generator is started to ensure sufficient electrical power for the engine's startup process.
• 🛠️ Lubrication is crucial; the engine is turned using a turning gear to pre-lubricate moving parts and cylinder components.
• 💨 The starting air system uses compressed air stored at 28-30 bar to initiate the engine's reciprocating motion.
• 🔄 The air bottles must contain enough air for 12 consecutive engine starts without needing to replenish from compressors.
• 🚀 The main valve and starting air control valve are opened to begin the air injection sequence for engine startup.
• 🌬️ Air blowing removes moisture and residues from the cylinders without fuel injection or combustion.
• 🚢 After air blowing, engineers proceed with fuel running, testing the engine at dead slow ahead and reverse.
• 🔄 The engine must be stopped and reversed to change propeller rotation direction, which is a critical step in maneuvering.
• 📈 Once controls are verified, the engine is handed over to the bridge for maneuvering and speed adjustments.
• 🌊 The engine experiences heavy vibrations during the barge speed range due to equal frequency of engine impulses and torsional vibration.
• 🌀 At full ahead, the exhaust gas pressure powers the turbocharger, reducing the need for auxiliary blowers.
• 🎼 A whistling sound from the turbocharger indicates it's running at high speeds, supporting the engine's combustion process.
• 🛳️ The engine speed is gradually increased to its normal continuous rating, usually around 75% of the maximum continuous rating.

Q & A

What are the four ancillary systems required to start up and operate a ship's main engine?

The four ancillary systems are fuel, lubrication, cooling water, and starting air.

Why are the fuel, lube oil, and cooling water systems kept in continuous circulation even when the ship is in port?

They are kept running to ensure that the main engine can be started within a few minutes if needed.

What is the first step engineers take to prepare the engine for the ship's departure?

The first step is to start up an extra generator to ensure there is enough electrical power to handle the added load.

What is the purpose of using the turning gear on the engine?

The turning gear is used to ensure that the lubricating oil covers the contact surfaces of all moving parts and to pre-lubricate the cylinder liner and piston rings.

How are large ship engines commonly started?

Large ship engines are commonly started by means of compressed air stored in large air bottles.

What is the pressure range maintained in the air bottles for starting the engine as per SOLAS regulations?

The pressure range is maintained at around 28 to 30 bar.

What does the distributor control during the engine starting process?

The distributor controls the air injection sequence during starting.

What is the purpose of air blowing in the engine cylinders?

Air blowing is the injection of compressed air into the cylinders to release any moisture or other residues without fuel injection, preventing combustion at this stage.

What is the term used for the process of reversing the engine's rotation to change the direction of the propeller?

The term used is 'reversing the rotation of the propeller'.

Why is there a critical speed range that the engine needs to get through as fast as possible?

There is a critical speed range where the engine experiences heavy vibrations due to the equal frequency of engine impulses and torsional vibration.

What happens at full ahead to allow the turbocharger to run at a sufficient speed without the need for auxiliary blowers?

At full ahead, the engine runs at around 50 percent load, and the exhaust gas pressure becomes powerful enough to run the turbocharger at a sufficient speed.

What is the normal continuous rating for a ship's engine in terms of its maximum continuous rating?

The normal continuous rating is usually at around 75 percent of the maximum continuous rating.