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Ahoy BW,
Cam shafts, now you are talking my technology.
One of my reasons for liking our 85 and 86 class buzz boxes, the use of pilot motor driven cam shafts for notching.
On a heavy grade you had to manually notch them out of resistance.
9 banks of resistance.
On a very light grade with a light load train, you could just whip the controller into notch 4 and let them step out themselves.
But, that was no fun at all.
You could also manually notch up on the older smog hollow squirts and interurbans with cam shafts and resistance.
But, once they went to chopper gate rheostat control, you only had the individual four notches, five on an interurban.
In wet weather on the Big Hill climbing away from a station with a cam car urban, you could notch up gradually.
Only notching completely out of series resistance for full field when no more wheel slipping occurred.
But, with a chopper gate urban, you had to drop back from full field series (notch 2) to starting series (notch 1).
Allow the wheel slip to cease and then shove it into notch 2 again, but by that stage you had virtually stopped.
And, when they combined cam cars with chopper cars in the same set, E GADs, bang crunch wallop.
Mind you, with a cam car urban or squirt, you could NOT remain in notch 1 for very long.
NO resistance cooling fans so you could cook the resistance if remaining in notch 1 for too long.
Rattling with the controller in notch 2, after having notched up to weakies was verboten.
Notch two being a more comfy possie of the controller handle, it also being the deadman control.
Notch 5 being further away from you requiring more oomph to hold down the controller handle dead man.
BUT, should you get a No Volt Relay trip under an air gap or section insulator when in notch 2 it would go back to notch 1.
OK, if occurring on the car you was in, but you would not know this occurring on a trailing motor car.
Manually notching up, 1 up to 2 then back to 1 to hold, repeating until all series resistance was removed.
Notch 3 being parallel full field.
Notch 4 being Weak field.
Notch 5 on an urban being second stage Weakies; WHACKO, when in notch 5 on an urban you were FLYING.
With our squirts and urbans all being double deckers from the mid 1990s, the cams were in the roof above the cab.
The big 1500 vDC main fuse, high speed circuit breaker is also up there.
Blow a main fuse / circuit breaker and you definitely know it, KABOOM in the roof.
The high speed breaker being inside the high tension room of an 85 or 86'er you still heard it, but not as loud.
Should yer 85 or 86er get stuck in resistance and not notch out, you went back to spin the cam shafts.
Had to do this a couple of times when a novice driver was just whipping it into notch 4 and she stalled.
YOU SHOULD BE MANUALLY notching out, I barked at him.
The cam shafts had become jammed.
Shut her down, drop the pans, grab the reverser to unlock the high tension room door.
Go inside and flick the cam shafts with yer boot.
Once reset to Zero, go back out and fire her up and he whips it straight into four again.
E GADs.
Manually notching up on 85 / 86ers, notch 2 was holding.
You could drop her down to notch 1 to reinstate a bank of resistance to arrest wheel slip and back to 2.
But, once stepped fully out of resistance, you had to shut off power to recommence back in resistance.
The old Metro Vic butter boxes were fully manual with 19 resistance notches.
You could reinstate resistance on them after going to notch 20 full field without shutting off.
One old bloke was great at mimicking the butter box wheel slip sound.
You woulda got her mobile and eventually stepped out of resistance battling wheel slip.
Letting the amps settle before going for weakies or second gear, he would make the wheel slip sound.
He knew that he got you when you put the controller back into resistance notches.
He only got me the one time before I cottoned on.
But he bragged about getting others many times in the dark on wet nights.
Bring back them good ole days, they were fun.
Steve.
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