disengaging the clutch firstly, then stopping the main engine
stopping the main engine firstly, then disengaging the clutch
stopping the cooling water pump firstly, then stopping the main engine
stopping the main engine and disengaging the clutch at the same time
第1题:
When the ship, its main propulsion device equipped with clutch, arrived at the port and finished with the engine, the correct operation should be______.
A.disengaging the clutch firstly, then stopping the main engine
B.stopping the main engine firstly, then disengaging the clutch
C.stopping the cooling water pump firstly, then stopping the main engine
D.stopping the main engine and disengaging the clutch at the same time
第2题:
Every ship should hoist ______ when approaching and entering ports.
A.its flashing light
B.the ship’s name
C.its identification
D.its signal letters
第3题:
On a ship, the locker or space containing the self-contained breathing apparatus must _____.
A.be located in close proximity to the main control station
B.be equipped with battery powered emergency lighting
C.be marked SELF-CONTAINED BREATHING APPARATUS
D.All of the above
第4题:
Our ship is equipped with automatic hatch covers.
Our ship is equipped with folding-type hatch covers.
Our ship is equipped with side-rolling hatch covers.
Our ship is equipped with rolling-type hatch covers.
第5题:
Ⅰ + Ⅱ
Ⅰ ~ Ⅲ
Ⅰ ~ Ⅳ
Ⅰ + Ⅱ + Ⅳ
第6题:
材料:
Spark erosion is caused by a voltage discharge between the main bearing and journal surface. The cause of the potential is the development of a galvanic element between the ship’s hull, sea water, and the propeller shaft/crankshaft.
The oil film acts as a dielectric. The puncture voltage in the bearing depends on the thickness of the oil film. With increasing engine ratings, the specific load in the main bearing is increased. his will reduce the oil film thickness, and enable the discharge to take place at a lower voltage level.
Since the hydrodynamic oil film thickness varies through a rotation cycle, the discharge will take place at roughly the same instant during each rotation cycle, i.e. when the film thickness is at its minimum. The roughening will accordingly be concentrated in certain areas on the journal surface. In the early stages, the roughened areas can resemble pitting erosion. but later, as the roughness increases, the small craters will scrape off and pick up white metal-hence the silvery white appearance.
Therefore, to ensure protection against spark erosion, the potential level must be kept at maximum 80 mV, which is feasible today with a high efficiency earthing device. If an earthing device is installed, its effectiveness must be checked regularly. Spark erosion is only observed in main bearings and main bearing journals.
问题:
According to the paragraph one, a voltage between the main bearing and journal surface is produced by______.
A.propeller rotation
B.leakage from M/E electric control unit
C.a galvanic element
D.friction between the main bearing and journal surface
______engine ratings increase, the hydrodynamic oil film between the main bearing and journal surface is______.A.The lower/thinner
B.The higher/the thicker
C.The lower/thicker
D.The higher/thinner
When will the spark erosion take place on the journal surface during each rotation cycle?A.when the film thickness is at its minimum
B.when the film thickness is at its maximum
C.when the engine is on its compression stroke
D.when the engine is on its exhaust stroke
During the engine room watch keeping, which equipment must be noted to ensure protection against spark erosion?A.the antifouling plant
B.the earthing device
C.the main engine electric heating coils
D.the shaft generator
请帮忙给出每个问题的正确答案和分析,谢谢!
第7题:
Certificate of Inspection
List of ship stations
Copy of ship to shore channels
Radio station license
第8题:
When a ship were found its equipment does not correspond substantially with the particulars of the Certificate by a nominated surveyor and corrective actions unable to be taken, then
A.the Certificate would be withdrawn
B.the ship owner would be fined
C.the shipping company must be notified immediately
D.the ship must proceed to the nearest appropriate repair yard for a repair without delay
第9题:
steam engine
steam turbine
gas turbine
diesel engine
第10题:
to work as overload characteristic
overspeed
over mechanical load only
over thermal load only