RUDDER SURVEY
Checks on rudder in drydock
When ship enters
dry dock and pumping out water, check water whether water is coming out from
rudder or not. If yes, then rudder is breached.Open the
top and bottom plug and check...
VIBRATIONS
Types of Vibration
Resonance is when Excitation
frequency meets naturally frequency.
Excitation – Primary
- Secondary
Primary Excitation :
Combustion Forces
Rotating forces
Reciprocating forces
these are part of engine specifications calculated in
advance characteristics
of engine at given...
FUEL VALVE WORKING
The fuel is supplied by the fuel pumps to the fuel injectors or fuel valves. For the fuel to burn completely at the correct time it should be broken up into tiny droplets in...
HEAT EXCHANGERS
LMTD: it’s a logarithmic average
of the temperature difference between the hot and the cold fluid stream at each
end of the heat exchanger.
The larger the value of
LMTD, higher the heat transfer rate
Rate of heat transfer...
VARIABLE DELIVERY PUMP
The variable delivery pump can run continuously in one direction, but
have the cabpability of infinitely changeable discharge i.e., from zero to
maximum in either direction.This is attained by changing the stroke of the pump piston....
DAMAGE STABILITY
How do ships get damaged?
Compounded operator errors - Improper maintenance over time - Multiple improper procedures leading to collisions with ships, rocks,reefs, piers, etc. Storms, hurricanes, etc. -Water on deck -Physical damage to...
NAVAL ARCHITECTURE NOMENCLATURE
Aft Peak Bulkhead is a term used for the first main transverse watertight bulkhead forward of the stern. The aft peak tank is the compartment in the confine part of the stern aft of...
SHAFT EARTHING
When steel is immersed in sea water (e.g. a ships hull) small galvanic current are initiated at anodic areas of the metal surface, causing corrosion.
Such corrosion prevail at the stern of a ship, where...
PROPELLER WITH SLEEVE
Precautions are necessary to prevent the propeller jumping at release. A development of the keyless method involves a cast iron sleeve which is bonded into the propeller boss with a special form of Araldite...
SURFACE PREPARATION
IMPORTANCE OF SURFACE PREPARATION
Cleanliness is essential for steel surface to hold coating. Paint will not adhere or bond to steel surface if there is loose rust, oil, grease, dirt, salts, chemicals, dust, etc. are...