THE CGC COMMUNICATOR

                            CGC #393

                     Thursday,  June 1, 2000

                 Robert F. Gonsett, W6VR, Editor

     Copyright 2000, Communications General Corporation (CGC)



  CGC #392 carried the following story:

     "Veteran KABC-TV news reporter Adrienne Alpert was
     seriously burned last Monday when the mast on her ENG
     van contacted high voltage overhead power lines.

     "Do you have specific information on this accident
     that would help others avoid disaster?  What practical
     safety measures could be built into ENG gear?  Have you
     seen other accidents or "near misses," and what lessons
     were learned?  What safety videos does your station use?

     "Our prayers are with Adrienne."

  In response to this story, the following comments were
  received.  Our "nine line limit" for Letters to the Editor
  was temporarily waived due to the importance of the subject.



  Three CGC Communicator readers observed that the Alpert
ENG mast was leaning toward overhead power lines.  Some
individuals reported that the van was parked on sloped terrain.
Perhaps the mast itself was not square to the van, or wind may
have contributed to the lean; we simply do not know.  A small
picture of the leaning mast is available at:

16969.jpg (6618 bytes)16967.jpg (1788 bytes)
  Obviously, the person deploying the mast may have seen a
clear (but tenuous) opening directly overhead, while in fact
the mast deployed at an angle - right into one of the lines.



  Only one CGC Communicator reader offered a citation for
ENG safety training material.  Our thanks to Larry Bloomfield
for the following URL:




  Fearing lawsuits and not wanting to spawn misinformation,
many insiders have been reluctant to discuss the specifics of
the Alpert accident.  Was Adrienne "blown out of the van" as
some press accounts had it, or did she deliberately bail out
because of smoke and/or fear of an explosion?  Was there in fact
an explosion as some press accounts reported, or simply arcing?

  While the press was focused on the ENG antenna contacting a
34,000 volt line, we engineers knew that two points of contact
would be necessary to complete a circuit.  Exactly what did
Adrienne (and the two other injured individuals) touch to
draw electrical current?  It is tempting to say that Adrienne
stepped out of an electrified van thereby completing a circuit
to ground, but the details may be more complex.

  One engineer wrote:

  "I have now heard from two sources about some kind of arc
from the door to the building wall, presumably an arc through
to the stucco mesh.  I saw a lot of pooling of water around the
van from a drainage pipe, perhaps from an air conditioner on
the roof.  There was a pretty large char mark where the pipe
exited the building.  There seems to have been a complex set of
paths involving the door, the mesh, the drain pipe, Adrienne's
body, and the drain water.  No one has said that video cable
was let out at that time."

  The bottom line is that there are a few hints as to the
mechanics of the accident, but we need to wait for authoritative
reports.  Once the true facts are known, accident prevention
programs can be fine tuned.



  Two CGC Communicator readers asked if ENG vans have windows
in their roofs above the mast operating position so the operator
can see overhead.  While some vans have the mast deployment
controls inside, others require the operator to stand outside.
A southern California TV broadcast engineer familiar with van
construction explains:

  "(Our) homemade vans of seven years ago and before had
controls inside the working area at the top of the rack, so
that an operator could engage the mast without ever getting out
of the van to look for obstructions.  No roof window, not even a
flood light mounted at the bottom.  The newer vans, from ENG Corp.
of San Leandro, have the controls inside the rear door and a
floodlight shining up which can't be extinguished.  An operator
must get out of the van, open the door, reach inside, and engage
the air valve upward."



  Will-Burt Co. (a major manufacturer of telescoping masts for
ENG and remote broadcast applications), has for years offered a
special sensor that can be ordered as an accessory for a new mast,
or retro-fitted to existing masts.  There are three different
types of sensor feedback systems in this package, one of them
being an E-field sensor, that sends a signal in the presence of
a high voltage conductor.  I've been reading about this product
for several years now.  I understand that if any or all of the
separate sensor elements are activated, the air pump to the mast
is disabled and the mast will not telescope any higher.  I
suggest you contact Will-Burt Co. for more details
<http://www.wilburt.com/>.  They also advertise in Radio World
on a regular basis.

  I personally think the person(s) responsible for raising
the mast on that KABC-TV ENG truck should have made certain that
the antenna would be in the clear.  I myself have done hundreds
of live remotes for KLSX/KRLA from 1994 to 1999, and a number of
times I know that the mobile studio (with a Will-Burt 35 foot
telescoping mast) was parked in a "compromised" position, where
being under high voltage power lines was unavoidable (considering
the time left to set up on location and make the air schedule on
time).  In those few instances, I always made sure that I never
raised the RPU antenna mast anywhere close to the power lines
overhead.  RPU signal strength may have suffered a bit, but
nobody got burned!

  I feel it is incumbent on station managers and CEs to make
certain that anyone who operates an ENG van, truck, or mobile
studio makes certain, in writing, that all their staff have been
fully trained, educated, and understand fully the dangers involved
where overhead power lines, etc. are an unavoidable part of the
broadcaster's job.

  My deepest sympathy to Adrienne and her family.

  Bill Wysock, N6UXW, wysock@ttr.com 



  The last couple of vans I have built for radio field work
with pneumatic masts, I set up like this:

  First of all, I use a marine grade 'ignition' type key switch
for control (available from www.westmarine.com).  Buy the three
position key switch with OFF / ON / START contacts.  I wire the
switch so that in the OFF position, the 12 volts to the air hold
relay is switched off, therefore the mast comes down.  In the ON
position, the air hold relay is energized and the mast will hold
pressure.  In the START position, it runs the compressor and the
mast goes up.

  Now, here's how it saves lives:

  Locate the key for the mast switch on the same key ring as the
van ignition key and door keys.  Make sure to tack the key ring shut
so the keys cannot be removed by field personnel.  This makes them
HAVE to get out of the van to work the mast, and also ensures that
they don't drive with the mast up, since they have to remove the
key from the mast control switch to use the ignition key, and to
remove the key from the mast switch, it must be in the OFF position,
therefore lowering the mast.

  Locate the control switch behind the spring loaded license
plate (you may have to install the spring loaded hinge yourself
on some vans).  This hides it nicely, but still mandates that mast
control is done from the outside of the van in plain view of the
overhead situation.

  Using smaller wires added to the van's factory bundle is
simple and clean looking.  The mast key switch actuates relays
in the equipment rack that handle the higher current required
for the air pressure switch and the compressor.

  Paul Shinn, paul@kstn.net 



  (A local) TV station had two incidents involving ENG vans.
I am not sure what happened the first time, but an engineer was
working on the truck and a photographer took off in the truck
as two engineers chased him a block and caught him just in time.

  The second incident involved driving at 30+ miles per hour
with the mast extended through a set of 30 KV lines by Salton
City.  Then the truck died and fires started around the truck.
They now have a mast/transmission interlock.

  Dennis Doty



  A KGAN-TV (Cedar Rapids, Iowa) photographer was shocked
and burned on Saturday, May 27, as he was raising the mast on
a microwave news van.  The mast came in contact with an overhead
power line that was carrying 115,000 volts of electricity.  As
of Sunday evening, 30-year-old Peter MacNaughton was in critical
but stable condition in the burn unit at University Hospitals
in Iowa City.  MacNaughton was preparing for a live news report
at Squaw Creek Park in Marion when the accident happened.
(Via: Shoptalk Magazine)

  Frederick R. Vobbe, w8hdu@wlio.com 

  Editor's Note:  An update on MacNaughton's condition has
been posted at:


  Peter suffered burns over 25% of his body similar to
Adrienne Alpert.  An update on Adrienne's condition is
currently available at:


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