December 1966 QST
Wax nostalgic about and learn from the history of early electronics. See articles
QST, published December 1915 - present (visit ARRL
for info). All copyrights hereby acknowledged.
This is a story with a lesson learned
by the author and thousands of others ever since electric power appliances and tools
first became available. Fortunately, his Ham buddy was not permanently harmed, but
even today with all the effort put into educating the public, people continue to
use ungrounded (2-wire type, or with the ground prong removed) extension cords in
conjunction with 3-wire power cords on tools and end up electrocuting themselves
(or somebody else). I've told the story before about a friend of mine from high
school who shortly after graduation was making a piece of furniture in a garage
that had a damp dirt floor, and was electrocuted to death by the metal-framed circular
saw that had no ground connected. Nowadays we often have power provided by a GFCI
receptacle when working outdoors or under a house, but I sure would not rely on
it performing properly in lieu of taking prudent safety precautions. Hopefully you
For Safety's Sake
By H. W. Morgan, M.D.,* K0JTP
My quad had been in the air for six year and needed to be checked over. K0IDN,
a nearby ham friend, provided a gin pole and enough rope from his hay-lift equipment
to lower the quad for inspection. I knew there was a loose connection somewhere
in the system as a high wind caused an intermittent make and break in the signals.
I usually hire a professional climber to do my high work, ever since I spent
a summer vacation in the hospital as a result of a flag pole breaking with me at
the age of 16. However, two young hams, Tom and Cap, volunteered to do the climbing
for me. A safety belt was provided and a safety rope was rigged for the second climber.
The quad came down easily. We had thought about that when we put it up; only
two bolts twisted off in the removal process and these were easily replaced. The
bad connection was found to be a coax fitting which had been improperly soldered.
A slight modification had to be made to the yoke supporting the quad boom. The
old yoke was removed and replaced with a new one. This necessitated the drilling
of four holes in a floor-flange bearing plate attached to the upper end of the pipe
used in rotating the quad from the ground. The two boys accomplished this, working
together at the top of the tower with a quarter-horse electric drill powered by
a heavy-duty extension cord. Three of the four holes had been drilled and the bolts
inserted with Tom working alone at the top of the tower when the accident happened.
Cap and I were on our backs on the ground watching the procedure when a cry came
from Tom at the top of the tower. Being a physician, I first thought that Tom was
an epileptic and had suffered an epileptic attack. Cap, however, was an old lineman
and shouted that it appeared Tom had been electrocuted. Fortunately, he was mistaken.
For an old man I really made time around the corner of the house, fell as I made
the turn, but was able to grab the extension cord close enough to the plug to remove
it, even while I was falling. Tom immediately dropped the drill which he had been
unable to release before that time. I insisted that he wait at the top of the tower
before unhooking the safety belt until George could climb up to help him. He made
it down without difficulty and within thirty minutes was back at the top of the
tower helping replace the quad. There was not even a burn on his hand which held
the drill, or on his feet where he was in contact with the tower except for a pair
of tennis shoes. What had happened?
The drill is a heavy-duty job and is provided with a ground wire but this was
not used, since the extension cord was a 2-wire type. The drill was all of 25 years
old and the ground wire had long since broken off at the plug end. Only a short
length remained of the ground cord and this was doubled up inside the plug. I had
tested the drill on the previous day, using the same long extension cord at the
base of the tower, and the boys had drilled several holes on this occasion without
experiencing any difficulty. In checking the drill immediately after the accident,
I found the ground wire exposed and in close proximity to one of the rivets holding
a plug contact in place. It is possible that the ground wire touched this rivet
and the polarity was such that the metal case of the drill was on the hot side of
the line. My wife also told me that during the time we were working, the electric
current in the house went off at least twice for a few seconds. Remodeling of the
substation supplying our power is in progress and it was thought that this was responsible
for the interruption.
What can be learned from this near-fatal accident? First, never work alone. Have
someone on the ground capable of disconnecting any electric circuit. You have four
minutes in which to restore circulation to the brain either by cardiac massage or
artificial respiration. Otherwise, brain damage will result even though life may
be restored. Second, a safety belt or rope must be used. Heavy tools, such as the
electrical drill, should be secured with a line, too. Last but not least, remember
that a trusted tool may develop a defect.
My new extension cord is a 3-wire cord and the few remaining 2-wire plugs in
my home, shop, and ham shack will soon be converted, for safety's sake.
Posted May 15, 2019