I just found a few interesting videos involving UK signalboxes. The first two involve the Banbury North Signalbox , which was recently decommissioned, but then opened for public tours (a somewhat rare occurrence due to all the health and safety BS their railways are tied up in). Unfortunately the signalbox, like many others, is slated for eventual demolition so little other purpose than it being there. Britain's attitude towards its decommissioned signalboxes is downright baffling seeing as every foot of railway infrastructure is publicly owned and almost everything in the UK is covered by some sort of historic preservation law. Network Rail also seems to be chronically pressed for cash and where they can find the funds for these demolitions is beyond me.
The first video shows the full tour that was given to the public and the second video shows the view from the locking room as the levers are manipulated. Those of your from North America should keep in mind that mechanical British signalboxes such as this, typically work on the manual block system. Some track circuits may be provided, but train movement is primarily by manual block using block instruments instead of voice or message communications.
The third video is from Harrow On The Hill signal cabin on the London Underground in 2002 and shows a Westinghouse Style N machine, which is basically a US&S Model 14 with the levers pivoted around 90 degrees so that they throw in the traditional "back and forth" orientation, instead of left and right. Even the tri-positionality of some of the signal levers is retained. The most fascinating thing about this video is the use of a pneumatic assist to move levers at the far end of the frame when certain route levers are pulled in the primary operating area. It's basically a non-vital intra-tower remote control system that doesn't require additional relay logic, a serious expense in pre and post war Briton. This technology was later extended to create the Style V frame where all the levers were moved primarily by remote control pneumatics.
BTW, if you are wondering why the model board is all lit it, is it because that was considered safety critical information and any bulb out had to mark the track circuit as "occupied". Of course with the bulbs burning by default I am sure there would be plenty of bulb out opportunities.
No comments:
Post a Comment