[Boatanchors] Tower Climbing Video and BC-610 hazards!

Sun Dec 12 15:00:28 EST 2010

I have had two almost MAJOR events while operating or working around 
transmitters.

The first was in a AN/GRC-26 radio shack.  The one that mounts on a 4X4 
truck if desired.  Ours was mounted on a concrete pad alongside a hanger in 
the LA Air Guard outfit I was in for years and worked for as "permanent 
Party" for a few years.
One "drill" day, I was operating in an Air Force net ending practice crypto 
traffic up to Selfridge AFB.  The messages were very long and boring and 
conditions were extremely poor on the new frequency.  In order to speed 
things up, I got the crypto guys to come into the radio shack and cut the 
teletype tapes for the messages so I could get them off to Selfridge without 
a big hassle.  Selfridge NCS was like some of the Maritime Coast stations on 
HF.  If you were slow doing a "QSY" to another frequency, you might find he 
called you once or twice then abandoned the frequency for someone else.  In 
my haste to change frequencies of the BC-610-I we had in this installation, 
I had to open the access door in the top of the transmitter, pull the PA 
coil and plug in another one, the exciter module/unit already setup and 
ready to be used.  I forgot that switch off the High voltage in my haste, 
opened the door , grabbed the tank coil and got ZAAPPED!  I got set on my 
butt hard in the shack and the coil in my hand went all the way across the 
shack and landed behind the receiver rack!  Someone had "jumped" the damned 
interlock!  I did survive OK, but the tank coil was smashed beyond use. 
Also my traffic was never sent as the NCS listened for me and I never showed 
up on the RTTY working frequency!

2nd Time this happened.....Many years later and in a different setting:  I 
was on a foreign flag ship, but working on a relatively new at the time, 
Mackay MRU-35A HF CW/SSB transmitter that would run a kilowatt out.  Was 
troubleshooting it, forget what the malfunction was now, but it involved 
connecting up some metering leads in the 2900 volt supply to see if the 
internal plate current monitoring circuitry in the transmitter was faulty. 
I pulled all the interlocks, switched off the power to the primary contactor 
for the power supply that fed the 3 phase AC to the HV transformer primary. 
All appeared safe.  I DID NOT kill the power going to the rack coming from 
the electrical switchbox that was in the radio room.  When I attempted to 
connect up my series milliamp meter in the HV bus I saw a flash and got set 
on my ass on the radio room!  The high voltage blew three craterlike wounds 
in my left hand and burnt thru a gauze bandage that was on my right hand. 
(The bandage covering a cut wound I had gotten the day beforewhile moving 
gear in the warehouse at the shop)  Again Iwas spared, but that was a very 
close one!  What caused the problem was the primary contactor in the power 
supply had failed previously and someone had replaced it with a makeshift 
relay.  This relay had two phases of the armature contacts welded shut! 
There was no indication that it was HOT!  I bitched to the factory people as 
to why there was no neon "telltale" lamps in the unit indicating the HV was 
present even though all the switches on the transmitter were off and the 
interlocks pulled (these only denied "control" power to the 3 phase 
contactor's coil and didn't disconnect power from the contactor itself!) 
"Stupid design" Safety Wise but still stupid on my part for not thinking 
about this and cutting off three phase 220 volt primary power at the source!

One tends to become complacent after many years of maintaining the same 
piece of gear.  I got very rudely informed of my mistake be the equipment 
and probably came close to being electrocuted.  Gotta think of everything no 
matter how mundane it seems like it might be and stay alive!  I was lucky 
TWICE!

73 to all,

Sandy W5TVW----- Original Message ----- 
From: <WQ9E at btsnetworks.net>
To: <mharmon at att.net>; <boatanchors at mailman.qth.net>
Sent: Sunday, December 12, 2010 1:19 PM
Subject: Re: [Boatanchors] Tower Climbing Video

> Mike's comments should be taken to heart by everybody who does tower work. 
> Safety equipment really earns it keep when the unexpected happens.  You 
> may get away many times free climbing down those last few sections after 
> working on the tower but when that wrench left on top bounces off your 
> hand (or head) or the angry hornet  nails your neck you may let go but you 
> won't fall far with the proper equipment in use.  I don't like the hassle 
> of un-belting/re-belting to get around guy wires but even though the 
> potential for a bad outcome is very low the bad outcome is extremely bad 
> so I use the belt.
>
> I had a similar discussion with a fellow vintage gear enthusiast last year 
> who didn't like dealing with safety interlock systems and routinely 
> defeated them.  If every user knew proper operation AND MOST IMPORTANTLY 
> never became distracted then they wouldn't be that important.   But one 
> time trying to change coils with your mind focused upon the whereabouts of 
> your teenage children or if you are going to be the next to suffer a 
> layoff is all it takes to send your gear to an estate auction.   I just 
> acquired a BC-610 and mounted a safety shorting stick so I will see it 
> every time I pop open the final cover just as a reminder not to trust the 
> interlocks and bleeder system.
>
> I have spent a lot of years involved with risk management so I am probably 
> more safety conscious than many but I have a lot of vintage gear and I 
> want to have plenty of time to enjoy it.
>
> Rodger WQ9E
>
> ----------------------------------------
> From: "Michael D. Harmon" <mharmon at att.net>
> Sent: Sunday, December 12, 2010 12:04 PM
> To: boatanchors at mailman.qth.net
> Subject: [Boatanchors] Tower Climbing Video
>
> I've climbed a few towers in my life, and I have to say, this video made
> me naseous (which is something that almost NEVER happens!).
>
> It wasn't so bad when the guy was climbing the ladder and looking down,
> but watching him go out over the top of the tower and start up the pegs
> scared the crap out of me.   I've ALWAYS used a belt and hooks when
> climbing anything higher than an extension ladder!  Free-climbing
> something like that is just plain reckless!  All it would take is one
> bad weld on those pegs and the guy would be a statistic.  Not to mention
> hooking his hook over a peg!  What if he got a wind gust that threw him
> sideways so that his hook slid off the end of the peg?
>
> The scariest tower pic I ever saw before this was one I saw in Broadcast
> Engineering about 40 years ago that showed an ironworker standing on one
> of the bowtie TV antenna elements on the tower on top of the John
> Hancock Center in Chicago, holding with one hand to the element above
> his head.
>
> I may be crazy, but I'm not stupid.  I didn't live to 61 by doing stuff
> like this!
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