edwin_m
Veteran Member
Another factor to consider is that a central ROC is likely to have technicians on site, who can attend to faults more quickly than for equipment located remotely. This may somewhat worsen the consequences of losing the central site but ought to speed up the response to various lesser faults.I wasn't suggesting a new generation of relay interlockings Edwin! (Fairly) distributed remote processor-based interlockings near the track-side are the best compromise and are entirely feasible today as Tio Terry noted was the original ROC plan up thread. An orderly handover between control centres can then be orchestrated without interlocking shutdown/changeover, subject to all those other systems mentioned being similarly enabled, staff and workstations being available etc. A particular interlocking might even be left with simple auto working in 'through routes' during the changeover, just as many relay interlockings can be set in various degraded mode override control states when the primary remote control medium is disabled today.
Not just equipment, staff too. A traditional AB box is likely to be single-manned and if someone calls in sick or has transport problems etc (or even gets locked in the toilet!) the box may be left empty. Several disruptions from these causes have been reported on this forum, including a possible one today. As mentioned boxes can't always be switched out, for example if controlling a level crossing, and it can't be done remotely. Even some of the smaller power boxes might struggle if say one out of three rostered staff wasn't available, but the bigger the establishment the easier it is to cover if someone is unexpectedly absent.If you think about it, some random event taking out an old wooden AB box in the middle of nowhere means that box is essentially switched out, becoming one big section.
The more boxes you have the more likely a random/accidental event is.
So therefore having one box diminishes the chance of a random catastrophe such as fire etc(not unlikely) but increases the chance of an organised atack (less likely)