Occasionally I go into the "electrical alcoves" along the Klystron Gallery. There is one for each of 30 sectors. Every other sector has a bathroom. Operators ran the machine from these areas, back in the beginning. I always look at two banks of relays, and reminisce fondly about my dad, and his involvement designing the old Central Control system. The?same relay banks and indicators appear in each sector.? I imagine Dad's team calling out those relays from some catalog, ordering them in bulk, then drawing the wiring diagrams. It all?looks abandoned now. . .? relics of a bygone era. . . .? Whole panels full of indicators are dark. Labels in strips under the indicators have faded into oblivion, now hanging by failing glue, sagging oddly. Modulator # XX available, blue ones read. Modulator # XX Unavailable, Amber ones read. A few bays down, a couple unlabeled indicators still glow, though it's not clear why.?
Two of ten "Sectors" died in the Klystron Gallery the other night,?sectors?25 and 27. I was there alone. Two big breaker panels should have been providing 600 volts, 150 amps, to each of eight modulators. Two big contactors weren't pulling. 16 Klystrons fell silent.
Central control sent me to check the fuses in Sector 26. They sent some kid out there to meet me. He was told to check Fuse 43, in a specific bank of fuses. We looked, but none were blown. (These fuses give a visual indication when they blow.) It was coolant related. Someone told us by phone to look at the flow meter/switches in the mechanical alcove, across the Klystron Gallery, near the pumps. Those showed plenty of flow.
That was intimidating. Two miles of wiring. Thousands of wires. No schematic. I could never figure that out.
Our?department head dispatched an old Asian guy, Sony Nguyen, who brought his schematic. I met him in the dark of night, out at the front guard shack.
Thousands of wires drop into those cabinets, from cable-trays above. These terminate into square terminal boards, each with about 72 terminals. Two "bays"?are filled with them, floor to ceiling, located at the end of a 40'-foot-long rack of equipment. Each bay is four terminal-boards deep, 15 terminal-boards high, packed tightly with wires and terminals. It somewhat resembles a telephone-distribution-center.
Sony went to those terminal blocks, armed with his schematic. He asked me to measure the voltage on a specific terminal. No voltage was there. He checked another terminal. Again nothing. Then he checked the voltage at fuse?43. It was bad. He knew where there was a spare in the fuse-bank, so he replaced it.?
Sony had me pop the plastic cover off one of those old relays, K10. He pushed the armature to verify it was already pulled. It was. I replaced the cover. ?
He had me call Central Control, to see if it was fixed.?
An announcement came over the PA system, warning people the system was coming on.?
Red lights illuminated all along the Klystron Gallery. Then with a clunk, very stern buzzing filled the place. It went back off again briefly. Then it went on and stayed on.?
That¡¯s the way it sounds when it¡¯s running. That buzz?is the pulse repetition rate, 120 pulses per second.?
The operator called to thank us. Sony went home.?
Grasshopper type fuses were chosen for this design. These come mounted in odd black plastic frames, about the size of memory cards for cameras. Each has three terminals, with each sporting a spring loaded lever and relay contacts. The spring tugs the fuse-link taught. When a fuse-link blows, it releases the lever, which pops into view. The relay contacts close, hopefully lighting an indicator at the end of the fuse bank. But 60 years of corrosion only broke the fuse element. The?lever never?changed positions, so we couldn't see it. Contacts never closed. The indicator didn't glow.
. . . those relays weren¡¯t abandoned after all.?
I remember seeing a plexiglass cabinet full of relays, all different brands, endlessly clicking away near Dad¡¯s office. A mechanical counter tallied the operations. Life testing was underway.? A nearby Geiger Counter clicked semi-randomly too.
Recently I went into the building where Dad's office once was. I almost expected to see that plexiglass box, full of relays, clicking away, still undergoing an eternal life test,?with the Geiger Counter still randomly ticking. They're gone.?
The real life-test is still running, 60 years and counting now, out there in the Klystron Gallery.?
I pulled up Sony's schematic on my computer, and started looking at it. As with any old hand drawn schematic, I'm pretty sure a couple of mistakes are making it hard to understand. I'll print it and go to Sony for clarification. I love the feeling of a two-mile-long machine, with 100?relays in each of 30 electrical alcoves, all shown on a three-foot-long schematic (well enough for Sony to troubleshoot it). The plot thickens. . . .?
Cliff Sojourner K6CLS