Page 375 - Introduction to Marine Engineering

Watchkeeping and equipment operation 345

outlet temperature for cooling water would indicate a lack of supply to
that point.
Various parameters for the main engine turbo-blowers are also
logged. Since they are high-speed turbines the correct supply of
lubricating oil is essential. The machine itself is water cooled since it is
circulated by hot exhaust gases. The air cooler is used to increase the
charge air density to enable a large quantity of air to enter the engine
cylinder. If cooling were inadequate a lesser mass of air would be
supplied to the engine, resulting in a reduced power output, inefficient
combustion and black smoke.
Various miscellaneous level and temperature readings are taken of
heavy oil tanks, both settling and service, sterntube bearing temperature,
sea water temperature, etc. The operating diesel generators will have
their exhaust temperatures, cooling water and lubricating oil tempera-
tures and pressures logged in much the same way as for the main
engine. Of particular importance will be the log of running hours since
this will be the basis for overhauling the machinery.
Other auxiliary machinery and equipment, such as heat exchangers,
fresh water generator (evaporator), boiler, air conditioning plant and
refrigeration plant will also have appropriate readings taken. There will
usually be summaries or daily account tables for heavy oil, diesel oil,
lubricating oil and fresh water, which will be compiled at noon. Provision
is also made for remarks or important events to be noted in the log for
each watch.
The completed log is used to compile a summary sheet or abstract of
information which is returned to the company head office for record
purposes.
The log for a medium-speed diesel driven ship would be fairly similar
with probably greater numbers of cylinder readings to be taken and
often more than one engine. There would also be gearbox parameters to
be logged.
For a steam turbine driven vessel the main log readings will be for the
boiler and the turbine. Boiler steam pressure, combustion air pressure,
fuel oil temperatures, etc., will all be recorded. For the turbine the main
bearing temperatures, steam pressures and temperatures, condenser
vacuum, etc., must be noted. All logged values should correspond fairly
closely with the design values for the equipment.
Where situations occur in the machinery space which may affect the
speed, manoeuvrability, power supply or other essentials for the safe
operation of the ship, the bridge should be informed as soon as possible.
This notification should preferably be given before any changes are
made to enable the bridge to take appropriate action.
The engineer in charge should notify the Chief Engineer in the event
of any serious occurrence or a situation where he is unsure of the action