I'm guessing it has a lot to do with the new safeworking procedures put in place last November in the North - West/New England regions. No more old staff changes along the line. Just one safeworking order filled out by the crew at Werris Creek before proceeding to Moree. So if there is no radio, then there would be no way of contacting control to obtain the safeworking instructions.
Well it's actually CTC to just north of Gunnedah now as far as I'm aware, then Train Order after that.
Also I'm reasonably certain that all trains carry mobile phones these days.
Surely train order safeworking could be carried out using mobile phones in the event of a radio failure.
Someone correct me if I'm wrong.
OK, it's CTC to Turrawan, then train order to Narrabri and beyond. Pretty sure the leading motive power unit needs a working train radio, or other reliable means of communication need to be established. The acceptable standard of the other reliable means is open to interpretation.
Only the proper onboard Countrynet radio has an emergency feature, for priority contact to the train controller in an emergency. The train radio is also the usual method of open channel "WB" radio on trains thus fitted. Mobile phone coverage is never 100% reliable, and can't be used to call other trains directly. Countrylink crews should have access to hand portable WB radios, but they probably aren't much good to contact control and almost certainly lack an emergency feature.
The nature and timing of the failure of the train radio may also play a part in the decision to truncate the service. It may be a different issue if the radio is found to be faulty prior to the train entering service as opposed to half way through a run. It may have failed before the train left Eveleigh, or before it divided at Werris Creek, and allowing it to go past Werris Creek on it's own might have been deemed to much of a risk and hassle. And Countrylink just love a nice bus or three.