This is about my experiences in Western Australia.

In The Beginning

By Today's Standard - Primitive.

The mining industry led the way with automation in the late 1960's. The mining companies had foresight and could see the benefit of automating their operations. This was initially driven by cost and labour shortages. I spent ten years with Hamersley Iron in Dampier, from 1970 and was involved in the birth of SCADA there. The initial control system at the Parker Point facility was all 110vac hard wired relay based system. Operational control was from a control room (CCR) attached to the screening plant. This consisted of a mimic panel wall with indicator lights and push buttons, with a basic alarm panel mounted above. The Car Dumper, Stacker, Bucket Wheel Reclaimer, Load-Out Tunnels and Shiploader all were locally operated and interlocked with the conveyor system. The two Load-Out tunnels were the source for lump ore and the Bucketwheel Reclaimer was for fines product. The Load-out tunnels were beneath the lump stockpile and had pneumatically operated gates which allowed material to gravity feed directly onto the conveyors. These were both an operational and maintenance nightmare. The dust in the tunnels during operations made work down there unpleasant.
The major drives were all 3.3kV and fed via English Electric oil circuit breakers (OCB's). These were all located in the Conveyor Substation along with the relay control panels. The control relays were all large Sprecher + Schuh devices and all timers were discrete pneumatic devices. All pretty primitive, but it got the job done and was fairly straight forward to fault find.

Stage 2 - East Intercourse Island Facility.

This facility was developed along with the Paraburdoo mine to increase export capacity in 1970 - 1972.

EII had five 33kV fed substations. Each had 33/3.3kV and 33/415kV transformers feeding the MCC's. The 3.3kV MCC's utilised spring operated "Load-Break" isolators. These used in conjunction with vacuum circuit breakers allowed a significant size reduction in the space required. The original switches installed had a number of failures resulting in one of the three poles not opening. If the earth switch was closed this caused a flash-over, ionisation and significant damage. To be the person actually operating the earth switch actuating lever and standing in front of a steel door, watching the paint blacken, peel off and the door glow bright red, before the protection circuit tripped the 33kV feeder, could be a trifle scary.
The switches were all finally replaced under warranty.
The major drives were all 3.3kV and fed via vacuum circuit breakers (VCB's). These were all located in the Substations adjacent to the drives. Relay controls were again used, but completely different. The control system was all done by Siemens and used a rack style system with plug in cards. In a major departure from previous systems this system was all 60Vdc with the negative grounded. This was a significant safety improvment. The system also allowed fault finding by testing for voltage anywhere using earth for reference.
The other major change concerned the control wiring which utilised instrument style twisted pair cabling. Field devices were cabled to marshalling boxes which then used anything from 12 pair to 50 pair Dekoron cables back to local substation MDF panels. These panels used vertical risers with communications style solder termination blocks. Another set of termination risers was connected to the control card racks by plug leads. Interconnetions between the two sets of termination risers was by grey fly wiring draped through loose ram's horn guides and soldered each end. This looked untidy but was very efficient and practical.
The control logic was all incorporated in the card racks. This was ahieved by jumper wiring on pin connections which were plugged into the rear of the card connectors. This allowed normal electrical schematic diagram logic to be applied to the card rack. The cards contained miniture relays, latches, diodes and timers. The output contacts then drove interposing relays which in turn controlled the motors, valves, lights and other items. Most of the cards had indicator lights on the front which could be used for status indication, "Ready", "Fault" etc." The fault indication was connected to a flashing bus. The flash was generated by a large device which contained a tube half filled with mercury. The timers were adjusted by a red knob, at the front of the card, which was attached to a potentiometer.
This project also saw the installation of the first computer in process control in the Pilbara. This was a DEC PDP-8 installed in the Sample Plant. It was a in a nice cabinet in the Sample Control Room. This was a very basic 12 bit machine with ferrite memory, piano-key panel for initial data entry and real flashing lights on the front panel. The beast used "octal" notation and was programmed in assembly language. It had a DEC teletype for printing reports and command entry. A paper tape reader allowed loading of the operating system and application program. Before the tape reader worked the reader program had to be loaded by hand using the piano keys on the front panel. This entailed setting the 12 keys to either 0 or 1 as per the code sheet, pressing enter and then increment. The process was repeated until the program was loaded then it was run. Then the paper tape for each application program was loaded. This took a while. The program was stored on memory cards which used ferrite memory. This was my first "hands on" experience with computers.

PDP-8 Data Panel.

EII & Paraburdoo Stockyard.

The operating equipment and plant layout were completely different to that used elsewhere in the Pilbara. Both Paraburdoo and EII used the design based on coal handling in Germany. This was a stockyard layout with multiple parallel stockpiles and rail mounted stackers and reclaimers which could be driven off the stockpile area, onto a rail mounted transfer car, moved to a new stockpile, driven off the transfer car and re-atached to the conveyor system. The machines had trailing cables which were plugged into 3.3kV outlets at each runway.
The reclaimers were "Bridge" type which straddled the complete width of the stockpile, rather than the "Slewing" type used elsewhere. A cross-cariage which traversed accross the face of the pile had a bucket wheel for digging the ore. After each traverse the machine stepped forward and repeated the process. The cross-cariage was moved by a winch. The winch motor was DC and supplied from a variable speed drive. The control system varied the speed based on the bucket-wheel motor current. The control equipment was all Siemens.

This is a work in progress and will be expanded, time permitting.