ENGINEMAN 1 & C
2. The assistant chief observers assist the chief
observers as directed; supervise the performance
of the observers; check the taking of fuel oil
soundings and meter readings; and make out the
trial reports.
3. Assistant observers take fuel soundings,
meter readings, counter readings, the ship’s draft,
and collect all other data that may be required
for the trial reports.
The following items should be accomplished
or considered before starting the trial:
1. When requested by the observing party, the
ship under trial should provide or designate a
suitable signaling system so that fuel soundings
and the readings of counters and meters may be
taken simultaneously.
2. The ship under trial should furnish the
chief observer with a written statement of the date
of last undocking, and the authorized and actual
settings of all main machinery safety devices and
dates when last tested.
3. The ship should have its draft, trim, and
loading conform to trial requirements. In case a
least draft is not specified, the liquid loading
should equal at least 75% of the full load capacity.
4. The chief observer should determine draft
and trim before and after the trial, verify the
amount of fuel on board and correct this amount
of the time of beginning the trial. The draft
observer should also determine the rpm required
for the full power trial, at the displacement and
injection temperature existing at the start of the
trial.
5. The observing party should detect and
promptly correct any errors in recording data,
since it is important that the required data be cor-
rect within the limits of accuracy of the shipboard
instruments.
6. The chief observer should instruct members
of the observing party to detect any violation of
trial instructions, of instructions in the Naval
Ships’ Technical Manual, or of good engineering
practice, and then verify any such report and pro-
vide the commanding officer or a detailed account
of each violation.
MANNER OF CONDUCTING TRIALS.—
Some of the requirements in regards to the
manner of conducting full power and economy
trials are as follows:
1. Unless otherwise ordered, a full power trial
may be started at any time on the date set.
2. The trial should be divided into hourly
intervals, but readings should be taken and
recorded every half hour. Data are submitted as
hourly readings in the trial report.
3. Fuel expenditures for each hourly interval
of the trial should be determined by the most ac-
curate means practicable, normally by meter
readings corrected for meter error and verified by
soundings.
4. The appropriate material condition of the
ship should be set during the different trials.
5. During all trials the usual “housekeeping”
and auxiliary loads should be maintained and the
minimum services provided should include nor-
mal operation of the distilling plant, air com-
pressor, laundry, galley, ventilation systems,
elevators (if installed), and generators for light and
power under load conditions similar to those re-
quired for normal operations at similar speeds
under the prescribed material condition.
6. All ships fitted with indicators, torsion-
meters, and other devices for measuring shaft or
indicated horsepower should make at least two
observations during the full power trial to deter-
mine the power being developed.
7. The chief observer’s report of the trial
should state whether all rules for the trial have
been complied with.
SOME HINTS IN REGARD TO FULL
POWER TRIALS.—There are special forms
used for full power and economy trial reports.
Illustrations of these forms are not given in this
training manual, but you can obtain copies from
your log room, and in this way get an idea of the
data and readings that are required for full power
and economy trials.
Trial forms, and such items as tachometers,
stop watches, and flashlights, should be available
to the observing party and to the personnel who
take readings. Any gages or thermometers which
are considered doubtful or defective should be
replaced before trials are held. A quartermaster
must check and adjust all clocks in the engineer-
ing spaces and on the bridge before any trials are
held.
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