• Any initial design flaws or manufacturing defects that may have been missed during the initial construction and testing phases will likely manifest themselves during the initial operational period
• During the initial trial, the engine is slowly started, and various parameters are monitored. The speed of the engine is gradually increased, and all parameters are monitored.
• The inspection of the gearbox after commissioning will reveal the characteristics of the gearing system as to how it responds to various speeds and load
• The strength of the gearing system is tested during actual operation. Any design fault or defect may be indicated during the trial run itself.
• The first inspection reveals the compatibility of gearing with the engine and the propeller. Based on the result of various inspections, parameters like oil pressure, flow volume, cooling required for the oil, torque, maximum stress levels, and vibration levels are identified.
• This will also enable the setting up of various running parameters and the frequency of inspection required

• The gear teeth should be carefully inspected for cracks, pitting, or signs of misalignment. The contact pattern on the gear teeth reveals how well the gears are meshing. Misalignment can lead to uneven wear, increased stress, and eventual failure of the gears.
• The gear shafts should be checked for bending or cracks, which could result from overloading or misalignment during installation. Any defects in the shaft could compromise the transmission of power and lead to vibration and further damage.
• The condition of the shaft seals should be inspected for wear or damage. A broken or worn-out seal can lead to oil leakage, which not only reduces lubrication efficiency but can also lead to contamination of the oil with dust or water, accelerating wear and corrosion.

Possible defects that might be found during this inspection include increased gear backlash, which can affect torque transmission and lead to excessive stress, and shaft end play, which can cause misalignment and vibration. Smoke from seals or the breather can indicate overheating, suggesting inadequate lubrication or excessive friction within the gearbox.

1. Pitting: This is a form of localized corrosion where small holes form on the metal surface of the gears due to cyclic loading. These pits can grow over time, leading to larger surface defects and reduced gear efficiency.
2. Scuffing: If the oil film between the gear teeth fails, metal-to-metal contact can occur, leading to scuffing. This process involves the tearing apart of welded metal on the tooth surfaces, resulting in rough, damaged surfaces.
3. Intense Wear: If the gear teeth tips and roots have not been properly stress-relieved or rounded, they can dig into each other, causing excessive wear and reducing the lifespan of the gears.
4. Abrasive Wear: This occurs when foreign particles are present in the lubricating oil, leading to scoring or scratch marks on the gear surfaces. This type of wear can be minimized by ensuring that the oil is clean and properly filtered.
5. Flaking: Flaking is typically seen in case-hardened gears and can result from poor heat treatment or conditions that stress the metal beyond its yield point. Small flakes of metal break away from the gear surface, leading to surface degradation.
6. Plastic Flow: High local stresses can cause the metal to deform plastically, leading to a wave-like distortion ahead of the contact point. This can result in subsurface fatigue failure, where flakes of metal shear off, further damaging the gear surface.