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G'day,
The ATSB investigation into the Sydney Trains A set Richmond buffer snot is still in progress.
However, alterations have been made to signal RD5 (Down Home) at Richmond.
Signal RD5 is now timed to check that train speed on approach is not above 20 kph.
The train stop at the signal will remain raised until the train speed is checked not in excess of 20 kph.
RD5 indications being either Green over Red to proceed to platform 2 or Yellow over Red to turnout into platform 1.
Platform 1 here in NSW is always the UP direction platform, 2 the Down Direction platform.
Richmond being a terminal station, trains can arrive and then depart from either platform, 2 being the usual.
Once speed is confirmed, the train stop will lower permitting the train to continue into the designated platform.
Temporary Speed Restriction warning and caution boards have been installed until a Permanent Speed Board can be installed.
This timed situation is normally applied to the Low Speed indication (small green below Red over Red).
The Low Speed permits trains to close up and reduce the normal double overlap applied on the Inner Metrop.
How ever, within the Underground, the train stop will remain raised on a Green over Red (Caution) indication.
Signals within the Underground are positioned much closer than above ground, hence speed check is applied.
The indication of RD5 to proceed into the storage siding is via the small Yellow (Calling On).
Frame D must be manually operated to access the storage siding, hence the train must be stopped at RD5.
Previously, the only Permanent Speed board on approach to Richmond displays 50 kph prior to East Richmond platform.
50kph descending the 1 in 77 grade into Richmond platform is a tad aggressive.
ROAD KNOWLEDGE is VITAL.
But, with this change, I am wondering what will occur during wet weather when a Tangarbage works to Richmond.
T sets have an aggressive wheel slide sensor, to prevent wheel lock up.
When the wheel slide sensor starts ticking, EP brakes are released.
Worse still, Westinghouse air brake can also be released.
This be the reason that Tangarbages have snotted numerous things in the past, including the Richmond buffer stop.
Tangarbages have refused to stop even when on a climbing grade in wet weather.
Signal RD5 is situated just before the 1 in 77 falling grade.
So, even if train speed on approach is ok for 20 kph, such could quickly increase on descent to the platform.
Without an intermediate train stop positioned between the signal and buffer stop, I can still see buffer snots occurring.
And, I am guessing that if another buffer snot does occur, that an intermediate train stop will be quickly installed.
Simple solution, detrain at East Richmond and hoof the 800 metres to Richmond.
Steve.
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