Back in the days of exclusive Morse Code use between stations and head office...WOLO was the code for heat speed restrictions, and there was a whole four letter language of codes used to convey all kinds of messages and safe-working instructions.
Of course this was a time long before very frequent regional trains operating to the minute lest crosses are slowed and opposing trains made to run later than they already are.
In the old days, a train every 90 mins, two hours...or even longer between services didn't matter...and people who were persevering with using the railways just accepted their lot in life and with low expectations knew they'd get home eventually.
I well recall one Summer, a visit to the Rifle Club pub in Bendigo with friends recenly arrived from Nottingham, before RFR and walking along Mitchell Street and seeing a digital temp sign reading 44c, but I don't recall the Sprinter slowing down due to the heat...though it may have.
These days, despite minimal use of timber sleepers and heavy track with individual sleepers weighing over one hundred Kg's each we have extreme heat timetables and V/Line now have a heat timetable to give some certainty to the thousands of travellers who just want to get where they are going.
Never mind that the temperature in Melbourne today when the Extreme Heat timetable was implemented was a mere 22c and Bendigo was 32c, tomorrow will be different but I digress...