Post by mrfs42 on May 3, 2010 13:08:02 GMT
Some of you might be aware of UndergrounD routesetting signalling discussion elsewhere.
<whisper> different forum, more signalling based</whisper>.
However, as I've typed the following up, I think that it is possibly worth sharing here too.
This dates from 1929, and the supporting text reads:
To bring automatic operation into work, King Lever No 14 must be reversed. Providing D E and F track circuits are clear. This will lock all other levers normal and cause No 8 points to be thrown reversed. No 8 points will be held reversed until train has travelled from Heston Hounslow to Hounslow Barracks. When C D and E tracks are again clear, No 8 points will be thrown normal and held normal until train has travelled from Hounslow Barracks to Heston Hounslow and when D E and F tracks are again clear, No 8 points will again throw reversed and the above procedure will be repeated for each train.
During Automatic Operation, signals 1, 2, 19 and 22 will assume clear position when their track circuit and point controls are complete.
So far so good, but Heston Hounslow also needed to be open, as not all trains went to Hounslow Barracks to reverse:
King Lever No 14 may be replaced at anytime provided D track circuit is clear and manual operation may be commenced.
No 8 points will be track locked on the actual point gear as follows:
Having now seen lots of Westinghouse blueprints for 3-aspect semaphores, the possiblity of their installation needs to be investigated.
Well, it is an entertaining possiblity! ;D
<whisper> different forum, more signalling based</whisper>.
However, as I've typed the following up, I think that it is possibly worth sharing here too.
This dates from 1929, and the supporting text reads:
To bring automatic operation into work, King Lever No 14 must be reversed. Providing D E and F track circuits are clear. This will lock all other levers normal and cause No 8 points to be thrown reversed. No 8 points will be held reversed until train has travelled from Heston Hounslow to Hounslow Barracks. When C D and E tracks are again clear, No 8 points will be thrown normal and held normal until train has travelled from Hounslow Barracks to Heston Hounslow and when D E and F tracks are again clear, No 8 points will again throw reversed and the above procedure will be repeated for each train.
During Automatic Operation, signals 1, 2, 19 and 22 will assume clear position when their track circuit and point controls are complete.
So far so good, but Heston Hounslow also needed to be open, as not all trains went to Hounslow Barracks to reverse:
King Lever No 14 may be replaced at anytime provided D track circuit is clear and manual operation may be commenced.
No 8 points will be track locked on the actual point gear as follows:
- during automatic operation
- by E and D track circuits when points are normal
- by C and D track circuits when points are reversed
- by E and D track circuits when points are normal
- during manual operation by D track circuit when points are normal or reversed.
Having now seen lots of Westinghouse blueprints for 3-aspect semaphores, the possiblity of their installation needs to be investigated.
Well, it is an entertaining possiblity! ;D
