This haul-rope transport system is one of the most challenging project in the world, in terms of scale, length, and shape of travel.
The investigation from EMSD pinpoints it is
1) a mechanical failure
2) abnormal vibration at bullwheel No. 3 and No. 4
3) this abnormal vibration triggers the vibration sensor, and cause emergency stop of the system
cause of failure
wear and tear of linings ( rubber ) at the bullwheel
upper raceway of inner bearings : spalling
pits and dents in running element :
lower raceway - outer bearing : corroded metal fragments ( Hmmm, may have been running without lubrication and high temperature....)
high moisture content of lubricant
The remedial actions include:
1) replace all bull-wheel bearings
2) enhance the vibration monitoring system of all bull-wheel bearings to capture data on an ongoing basis,
3) increase scrutinising frequency to fortnightly.
Frankly speaking, the bearing inspection and maintenance is well below normal engineering practise. The emergency stop was triggered by the position sensor, and not by the technical staff.
The sensor safety stop is just one of additional measures to prevent castastrophic incidents. So actually someone is not doing the job regularly.
It's like when you are driving a car, you'll do perioidic check and observe any abnormalies. One traditional way to do, is to listen to abnormal screeches, noise and vibration.
It seems no such level of care and attention is done to this complex system.
Also, there's no sense of continuous improvement to prolong the lifetime of consummable items, and to reduce the vibration, wow and flutter if possible.
One of the thing the report didn't mention, is how come there's so much water in the lubricant? Shouldn't the bearing system be sealed to prevent moisture and dirt ingress? Besides checking the wear of the lining, did they also check internals of the bearing?
There's a precise and polite conclusion:
Most of the measures are of recurrent nature, requiring the staff of Ngong Ping
360 to discharge them in a professional and diligent manner under close and thorough
supervision of its management team.
full report here
The investigation from EMSD pinpoints it is
1) a mechanical failure
2) abnormal vibration at bullwheel No. 3 and No. 4
3) this abnormal vibration triggers the vibration sensor, and cause emergency stop of the system
cause of failure
wear and tear of linings ( rubber ) at the bullwheel
upper raceway of inner bearings : spalling
lower raceway - outer bearing : corroded metal fragments ( Hmmm, may have been running without lubrication and high temperature....)
high moisture content of lubricant
The remedial actions include:
1) replace all bull-wheel bearings
2) enhance the vibration monitoring system of all bull-wheel bearings to capture data on an ongoing basis,
3) increase scrutinising frequency to fortnightly.
Frankly speaking, the bearing inspection and maintenance is well below normal engineering practise. The emergency stop was triggered by the position sensor, and not by the technical staff.
The sensor safety stop is just one of additional measures to prevent castastrophic incidents. So actually someone is not doing the job regularly.
It's like when you are driving a car, you'll do perioidic check and observe any abnormalies. One traditional way to do, is to listen to abnormal screeches, noise and vibration.
It seems no such level of care and attention is done to this complex system.
Also, there's no sense of continuous improvement to prolong the lifetime of consummable items, and to reduce the vibration, wow and flutter if possible.
One of the thing the report didn't mention, is how come there's so much water in the lubricant? Shouldn't the bearing system be sealed to prevent moisture and dirt ingress? Besides checking the wear of the lining, did they also check internals of the bearing?
There's a precise and polite conclusion:
Most of the measures are of recurrent nature, requiring the staff of Ngong Ping
360 to discharge them in a professional and diligent manner under close and thorough
supervision of its management team.
full report here
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