Tuesday, September 8, 2009

A Day In The Life Of A KAAY Engineer

Dave M. was gracious enough to share this info with us about a fire at the transmitter site; nothing of KAAY's was harmed, though. When we were honing this story, either Dave M. or David Treadway mentioned that Felox McDonald never used curse words, but said "sapsucker" when he was perturbed. Mine is "dadgummit", so, I suppose one could holler, "Dadgummit, you sapsuckers!" at someone in the story below:

"Arkansas Power and Light had been asked to replace the three big pole-mounted transformers at the back of the KAAY transmitter building in Wrightsville. This would among other things help our raw AC input power consumption by providing more stable regulated AC to the transmitter inputs. Our 50kw RCA transmitter used about 135kw of raw AC input to produce its 50kw output.

AP and L showed up early one summer morning with a big truck and began the process of removing the old transformers from the poles, then they set some new stronger poles and began mounting the new larger transformers. When they were hoisting the third transformer into place, well, that’s when the accident happened.

First, though, I must digress and make the tie-in with the Cuban missile crisis.

KAAY transmitter had a monster generator set behind the building. It was HUGE and fed by an underground propane tank. The AP&L truck was parked over the spot in the ground where the propane tank was located. Felix used to tell me stories of how long the transmitter would run at full output power on that propane tank – days stretching into weeks! The underground tank was eventually replaced with an above ground tank nearby, but the underground tank was never removed from its resting spot, next to the generator set. Felix said the generator would power the transmitter during a national emergency and KAAY was designated one of the "Conelrad" stations because of its clear channel status. The generator set would also be useful in case a national emergency such as the Cuban Missile Crisis would cause the country to plunge into war. We would have power when others did not.

(KAAY also had a fallout shelter in the transmitter building, with a food and water supply - - did you know that?)

Now, back to the action: When the transformer fell off of the boom arm of the A P and L truck, it also fell through the overhead AC main line coming into the property – 14,000 volts! The main power line broke and fell across the top of the A P and L truck, and the 14,000 V electric charge on the truck’s wheels and chassis arced across the tires and caused the tires to catch fire. Eventually the diesel tanks on the truck caught fire and burned the truck to the ground. Remember, the truck was parked directly over the underground propane tank, and the fire was hot and fierce.

In the meantime, the now broken AC main line was draped across the barbed wire fence surrounding the transmitter property, causing the wire fence to be charged with the same 14,000 volts! Someone on the AP and L crew decided to bypass the circuit breakers upstream of our building, so when the accident happened, there were no circuit breakers to "trip" and take our circuit off-line. And the closest sub-station (and closest circuit breakers) were about 6 miles away, on the other side of the electrified fence!

Several small grass fires broke out. All the A P and L workers were trapped inside the fence and could not leave because the fence was still electrified by the fallen power lines. One of the A P and L supervisors called the fire department by radio, and the Wrightsville volunteer fire department trucks came, but would not put out the fire until power was removed from the broken AC main line – at the substation several miles away.

All the while, our massive generator set was grinding away at full capacity, keeping us on the air, and only 20 feet away from the inferno. Luckily the radiator fan on the generator set blows "away", and help fan the flames away from our building.

We finally went home after dark that night, and the property was still swarming with A P and L insurance investigators snapping pictures and asking a lot of questions. And the generator set, installed in support of the Cuba Missile Crisis helped save the day."

And, some afterthoughts from Dave M.:

"I seem to remember the generator set was already installed at KTHS/KAAY transmitter as part of a government program to equip the transmitter for use as the main Conelrad station for Arkansas. This was no trivial generator either – it was rated at ~150kw continuous output, was very large, and expensive as well. We ran it regularly to keep it operational, and occasionally ran the transmitter from it, providing a full load to the generator. Generator operation and maintenance was logged into the station’s official maintenance logbook along with all other transmitter maintenance and repairs.

[SIDE NOTE] On cold days the big generator was extremely cantankerous and did not want to start. So we installed a smaller generator, 4 cylinder caliber, inside the building that was used to "jump start" the big one on the cold days. Birds liked to build nests inside the mufffler for the big generator, and when it started, it "blew" bird nest, eggs, feathers, and anything else that had managed to crawl inside the muffler across the yard."

From what I'm told, no one at KAAY got fired for this mistake....thank you, Dave M.!

Bud S. (staceys4@hotmail.com)

1 comment:

  1. And there is more to that story. The burning AP&L truck tires produced a lot of soot that was sucked into the 50,000 watt Harris MW-50B transmitter. Nobody ever bothered to clean this out.

    I consider a dirty transmitter to be a bad reflection on an engineer. When I became Chief Engineer of KAAY in 1982, I spent at least 2 hours of the first four Monday morning maintenance periods cleaning the inside to that transmitter. I used pure ammonia and water in a bucket and I would make one pass with a sponge, turn it over, make another pass, and wring it out. Three sponges full of soot required ammonia water. And in the process, I discovered every sharp edge in the MW-50B. And although I did clean most of the transmitter, I never did get the soot off of the white high voltage cables.