by abacus
Looking for info about a unique control system for a switching yard. I think this would have been in the 1950s, possibly mid-continent.
A standard switching yard with a hump. As cars coasted downhill they’d be switched to end on a track for cars with a common destination.
What was unique was the computer control system. It was digital but ferociously non-electronic. A command word consisted of eight balls, each either steel or glass. The word was assembled to designate the outgoing track on which a car was to end up. The balls of the word were allowed to fall through parallel glass tubes. Coils were wound around the tubes; a set of coils corresponded to each of the sorting track switches in the yard. As the balls fell and passed through the coils, steel balls
generated electromagnetic pulses; glass balls did not. So the eight-bit command word triggered control signals to the track switches.
This system, though you might be skeptical, really was in regular service...
Given the racket it made it was labelled, of course, 'Hailstorm.'
Regards
A standard switching yard with a hump. As cars coasted downhill they’d be switched to end on a track for cars with a common destination.
What was unique was the computer control system. It was digital but ferociously non-electronic. A command word consisted of eight balls, each either steel or glass. The word was assembled to designate the outgoing track on which a car was to end up. The balls of the word were allowed to fall through parallel glass tubes. Coils were wound around the tubes; a set of coils corresponded to each of the sorting track switches in the yard. As the balls fell and passed through the coils, steel balls
generated electromagnetic pulses; glass balls did not. So the eight-bit command word triggered control signals to the track switches.
This system, though you might be skeptical, really was in regular service...
Given the racket it made it was labelled, of course, 'Hailstorm.'
Regards