What is the role of the 2nd Engineer?
The second engineer directly reports to the Chief engineer with regards to daily machinery space operations and maintenance as per the planned maintenance system, to ensure safe and efficient operation of the equipment.
In addition, the 2nd is responsible for supervising and mentoring the junior staff, including carrying out training.
2nd engineers are the team leader for the department in the event of a emergency.
What is strength?
Strength is the ability to resist an applied load. This can be Tensile, Compressive or shear stress.
What is ductility?
The property of a material which when subjected to a tensile force, allows permanent plastic deformation. for example drawing a wire out
What is toughness?
toughness is the property of a material which absorbs the energy from an applied force/ this can be impact or shock loading without failure
What is Elasticity?
The Ability of a material to return to its original shape when the load is removed
What is Plasticity?
Plasticity Is the property that allows the material to flow in a solid state when under pressure, then to retain that shape when the force is removed. Deformation is permanent
What is Hardness?
The ability of a material to resist abrasion, indentation, wear and penetration. Rockwell hardness test.
What is Malleability?
Malleability is the property which allows plastic deformation under a compressive load. For example, Hot steel which can be forged.
What is brittleness?
The property of a material where it absorbs very little or no energy before fracture. Shows no plastic deformation
What does carbon do to steel?
Increases:
Hardness and tensile strength
Decreases:
Ductility and Weldability
What does manganese do to steel?
Increases:
Surface quality
Harden-ability
Strength
Decreases:
Weldability
Ductility
What does Phosphorous do to steel?
Increases:
Strength and hardness
Decreases:
Ductility
Impact toughness
What does Silicon do to steel?
Deoxidiser in steel making
What does Copper do to steel?
Increases Atmospheric corrosion resistance
What does Chromium do to steel?
Increases:
Corrosion Resistance
Oxidation Resistance
Harden-ability
High Temperature Strength
What does Nickel do to steel?
Increases:
Harden-ability
impact strength
What does molybdenum do to steel?
Increases Harden-ability
What does Titanium do to steel?
Increases:
Toughness by controlling grain growth
Ductility
What does Vanadium do to steel?
Increases:
Yield strength
Tensile strength
How to measure Performance of a Cylinder?
Blow through the indicator cock
Use a Indicator card attached to the indicator cock and cord attached to the camshaft lever.
Analyse the graph using Planimeter
To find Mean Indicated Pressure:
(Area/ length of graph) x K (spring constant)
The area of Pmi will have the same area of the graph
Indicated Power = Pmi x Length of stroke x Area of bore x number of power strokes per second
RPM/60 for 2 stroke
RPM/120 for 4 stroke
What is the diesel cycle?
The Diesel Cycle is the compression ignition cycle.
Adiabatic Compression
Constant pressure Heating
Adiabatic Expansion
Constant Volume Cooling
What is the Otto cycle?
Spark Ignition
Two adiabatic processes
Two isochoric processes
Two isobaric processes
What is the Miller cycle?
The Miller cycle controls the inlet valve opening time to vary the compression ratio and thus combustion temperatures. It Can make the expansion ratio higher than the compression. Increases thermal efficiency and lowers Output
What is a light spring card?
By fitting a light spring to the indicator card it can indicate the exhaust and scavenge pressures.