7-22.
What must you do if the bull gear churns
and aerates the oil?
1.
Slow or stop the engine until normal
conditions are restored
2.
Remove some of the oil without
changing the engine speed
3.
Stop the engine, and drain and
replace the oil
4.
Stop the engine and add some fresh
oil
7-23.
Gears should be slowed down or stopped
altogether when which of the following
conditions occur?
7-24.
1.
Oil is emulsified in the gear case
2.
Unusual noises are heard
3.
Both 1 and 2 above
4.
Bearing temperature are below normal
When should the main shafts be locked?
1.
When the divers are inspecting
damaged propellers
2.
When strong currents are present at
anchorage
3.
When the ship is underway
4.
At all of the above times
7-25.
Which of the following conditions should
be in effect when the main shaft of a
ship is allowed to trail?
1.
The windage temperature in the low-
pressure casing is kept at a maximum
2.
The lubricating system must be
operating
3.
The shaft brake must be engaged
4.
The turning gear must be engaged
7-27.
7-28.
7-29.
7-30.
7-31.
7-26.
Which of the following gears must be
disengaged before the main engines are
started?
1.
Reduction
2.
Turning
3.
Pinion
4.
Bull
7-32.
Learning Objective: Point out factors
that affect the power output of an
engine and recognize the terms and
formulas used in computing engine
performance and efficiency.
Which of the following characteristics
will affect the efficiency and perform-
ance of internal combustion engines?
1.
Engine design
2.
Compression ratio
3.
Operating temperatures
4.
Each of the above
To calculate the indicated horsepower of
an engine, you need to know the indicated
mean effective pressure and what other
factor?
1.
The engine speed
2.
The brake horsepower
3.
The fuel consumption rate
4.
The brake mean pressure
What is the speed of a piston if the
rotation speed of the crankshaft is
1,000 rpm and the piston stroke is
12 inches?
1.
1,260 fpm
2.
2,000 fpm
3.
12,000 fpm
4.
24,000 fpm
When the engine rpm drops below rated
speed, what usually happens to the
brake mean effective pressure?
1.
It remains the same
2.
It decreases
3.
It increases
4.
It increases and then decreases
If an engine is operated for long periods
at idling speed, how frequently will
overhaul be necessary?
1. More frequently than if operated at
50% of load
2. Less frequently than if operated at
100% of load
3. As frequently as if operated at 75%
of load
4. Less frequently than if operated at
90% of load
An unbalanced cylinder load is indicated
by which of the following conditions?
1.
Black exhaust smoke
2.
High exhaust temperatures
3.
Low cooling water temperature
4.
Low lubricating oil temperature
44