Marine Engineers Q and a series part 4
Welcome to the fourth installment of our Marine Engineer Q&A series! In this blog, we’ll be answering some of the most frequently asked questions about the exciting and challenging field of marine engineering.
Marine engineering is a highly specialized field that involves the design, construction, and maintenance of ships and other ocean-going vessels. It is a dynamic and constantly evolving industry that requires a blend of technical expertise and problem-solving skills. Whether you’re a seasoned marine engineer or just considering a career in this field, this blog will provide valuable insight into what it takes to be a successful marine engineer.
So, let’s dive into some of the most commonly asked questions and get started!
Read the related post:- The Best tips on Marine Engineers Questions and answers series part 3
Q 1- How Slippage Occurs in Fully Assembled or Semi-Assembled Crankshafts During Shrink Fit Identified?
Ans- In a fully-built or semi-built type crankshaft, the witness mark is a reference point to identify any slippage that might occur during the shrink-fit process. A witness mark is a minor groove or line created on the surface of the crankshaft before it is subjected to the shrink-fit process. The witness mark serves as a visual reference point to determine if any movement or slippage occurred during the crankshaft installation in the engine block.
If the crankshaft has moved or slipped during the shrink-fit process, the witness mark will no longer align with the corresponding reference mark on the engine block. The witness mark can indicate that the crankshaft is not adequately secured in the engine and may cause issues with the engine’s performance and reliability.
Therefore, it is important to carefully inspect the witness marks after the shrink-fit process to ensure that the crankshaft has been properly installed and secured. Inspection of the witness mark is a critical step in ensuring the proper function and longevity of the engine.
Q 2- Why is the start of injection delayed on a jerk type fuel pump with VIT?
Ans- Raising the barrel can delay the beginning of injection in a VIT (Variable Injection Timing) equipped jerk-type fuel pump. The VIT system is used to adjust fuel injection timing in internal combustion engines. It allows the fuel injection timing to be advanced or retarded depending on the operating conditions of the engine
Q 3- What harm does it do when a diesel engine generator over speeds?
Ans- The over-speeding of a diesel engine driving an electric generator can cause damage to the windings and result in reduced performance and efficiency. Over-speeding occurs when the engine exceeds its maximum operating speed, which can be caused by various factors, such as a failure in the speed governor, an increase in load on the generator, or a malfunction in the engine’s fuel system.
When an engine over-speeds, it can strain the generator and its components, including the windings. Over time, this can cause the windings to break down, leading to insulation failures and short circuits. Winding damage can result in reduced performance, increased heat generation, and increased risk of loss, which can cause significant downtime and repair costs.
It is essential to closely monitor the engine’s and the generator’s operating speed and perform regular maintenance to ensure that the speed governor and other critical components are functioning correctly, To prevent over-speeding and the resulting damage to the windings. In addition, it is essential to follow the manufacturer’s recommendations for maximum operating speed and to avoid overloading the generator.
Q 4- In a large, slow-speed main Engine, which parts are under tension when the engine is running?
Ans-In a large, slow-speed main engine, tie rods are typically under tension when the engine is running. Tie rods are components of the engine’s assembly, which connect the cylinder block and engine bed plate.
The up-and-down motion of the pistons generates tension in the tie rods as the engine runs. This creates a force that tries to pull the connecting rod away from the crankshaft, which counteracts the tension in the tie rods.
Maintaining proper tension in the tie rods is essential, as this helps to ensure the stability and reliability of the engine’s assembly. Insufficient tension can cause the engine assembly to loosen or become misaligned, resulting in increased wear and tear on the engine components and reduced performance and efficiency.
To ensure that the tie rods are correctly tensioned, it is essential to follow the manufacturer’s recommendations for maintenance and inspection. This typically involves regular tightening and checking the tie rods to ensure they are in good condition and functioning correctly.
