G'day BW,
The specifics of this run-away are not detailed as yet.
From memory the long yard at Whyalla falls downhill into the complex.
The narrow gauge ore trains are a decent length and are normally shunted and held in the yard just to the inland of the complex.
The motive power utilized was bashed by Morrison Knudsen.
When I was there last, some many moons ago, some of them bashed units had failed.
Aussie weasels etc do possess a Vigilance system.
No many possess a Dead Man system.
A Dead Man system only operates when the loco brakes are released and the reverser placed in gear.
Likewise the Vigilance system only operates when the locomotive brakes are released, and or the train brake is not in suppression.
I know from experience with stupid single brake block per wheel weasels that the locos may not hold a train stationary without a train brake application.
Single brake block per wheel being an attempt to prevent skidded wheels.
You slam on the loco independent brake or make a full service train brake and the loco has double blocks per wheel and you risk skidding them wheels.
Also, from experience, our A7EL and B7EL brake valves were prone to accidental independent release due to vibration.
The notch for full service independent can become worn and with the loco idling away over a period that handle can vibrate itself towards release position.
I don't know just what type of brake valve is on the bashed Whyalla locos.
One of the things that caused management angst in smog hollow on the squirts (suburban emus) was the hogger placing his bag on the deadman throttle.
One bloke worked out that he could use a large rubber band to tie around the T-bar deadman throttle on a Tangarbage and connect it to the reverser handle.
Get caught doing that and INSTANT dismissal.
You gotta shudder at the antics of some idiots.
The safety systems are there to KEEP YOU ALIVE as well as the cattle.
Smog hollow squirts today possess both the Deadman and Vigilance systems.
The most amusing run-away caper happened out at Cowra in 1994.
The Lachlan Valley Railway hystericals were having a weekend of soot belching etc.
So, I went out to take a gander.
I arrived just in time to take pot shots at the pair of CPH railmotors (tin hares) depart the depot.
They rattled past and I suddenly caught a glimpse of something in the corner of me eye.
A water gin was rolling down the slight grade chasing them Tin Hares down to the station.
E GADs.
One bloke went chasing after it attempting to crank on a handbrake.
Numerous nutters nearby were yelling at him to NOT do that.
He musta succeeded in halting the run-away.
Had he stumbled in the chase and fallen under the wagon, I hate to think of the consequences.
Had he not managed to halt it, then the LVR pride and joy tin hares woulda been snotted.
Obviously, the tin hares were parked in the same road at the depot ontop of the water gin.
And obviously there was NO handbrake applied to that water gin.
When the tin hares blasted off, the water gin then decided to follow.
The LVR did suffer some incidents and after a fatality, the rail regulator kyboshed them for a period.
The newbie moniker of the Independent Railway Australia was then concocted.
I will let you determine the context of that moniker.
https://youtu.be/cbeUO-l8ls8
Steve.