TOT Newbury

wrote in message
...
On Sun, 13 Feb 2011 18:42:14 -0000, "Graham." wrote:
"Bill Wright" wrote in message
...
I wonder if the panel has anyone from the electricity distribution
industry who might like to comment about the incident at Newbury
races yesterday.
in farms etc will (should) know that there are recognised issues with
large four-legged
animals being at risk of shock or electrocution simply because of the
extra PD across
their front and hind limbs,

Happens with lightning strikes , charge travels through the ground
from (or is it to?) the strike point, warm mammal full of fluids
provides an easier path between front and back legs than the soil and
passes the vital organs on the way. Humans standing on two legs are
less vulnerable, it might well go up one leg and down the other but
won't pass your heart though I'm not sure I want a million + volts
through the ********. Daresay there are some who would pay for it
though. If your missus gets scared in a storm and wants to hold your
hand it's not actually a good idea if a strike hits close,you have
become a four legged animal.

Next thunderstorm I'll hop home.

--
Max Demian

On Mon, 14 Feb 2011 00:27:48 +0000, Bill Wright
wrote:

Java Jive wrote:
As you say, mains is quite a different matter. If IUIC, it's the
total power delivered in the shock that matters.

Electric fences used in agriculture are commonly powered by batteries,
and when you get near them, you can often hear a regular clicking once
a second or so as it delivers a brief, timed kick to the fence under
the control of a timer.

The ones of my youth had a mechanism like the thing that serves as a
pendulum in a watch (can't think of the word).

Two words: a "balance wheel".

A large wheel with a
spring, so the wheel oscillated backwards and forwards. There was an
adjustment screw to alter the spring tension and thus the frequency. The
wheel had a contact which energised an HT coil.

This arrangement generated a lot of RF, which the fence radiated
efficiently, putting a momentary but annoyingly regular flash across
every (VHF) TV set within half a mile, and putting a crackle on every
(AM) radio within an even larger radius.

Bill

--
Peter Duncanson
(in uk.tech.digital-tv)

In article , Mark Carver
scribeth thus
On 13/02/2011 18:42, Graham. wrote:
"Bill wrote in message
ioe.org...
I wonder if the panel has anyone from the electricity distribution industry
who might like to comment about the incident at Newbury
races yesterday.

Bill

I do know, but only from lurking on uk.d-i-y over the years, that any
electrician working
in farms etc will (should) know that there are recognised issues with large
four-legged
animals being at risk of shock or electrocution simply because of the extra PD
across
their front and hind limbs, not to mention the extra current due to their bare
feet or
even nailed-on steel shoes.

AIUI it's even a problem in grazing fields that have 11, 33, or 66kV
overhead transmission lines. The wooden pole has a metal cross bar which
the three insulators sit upon. The cross bar is earthed via a bonding
cable that runs down the pole. I was told by an SEB engineer years ago,
that the lekky boards pay out thousands each year to farmers that have
had quality of milk affected due to the currents those earth bonding
points induce into the field, and consequently into the livestock as
they wander around. I assume he wasn't winding me up ?!




Think he must have been having you on. The currents involved would be
next to nothing and I doubt that there would be any significant
potential at all developed!.


--
Tony Sayer

In article , Jeff Layman
scribeth thus
On 13/02/2011 21:50, Brian Gaff wrote:
Well as around here they had to dig up the whole footway to try to find
where the wire went to put in an extra street light, it does make me wonder
how accurate the schematics of where things go actually is...

Brian
A relative worked for the GPO and then BT for 35 years repairing
telephone lines - above and below ground. He said that the utility
company records were a vague guide to what you /might/ find when looking
underground to find wiring breaks. And then you didn't know for certain
what was there until the pick or spade hit something!


We had this when we needed to dig up some old ducts and came across a
power cable where it shouldn't have been.

By that I mean that it wasn't as deep as it should have been owing to
someone scraping off a layer of earth on that site for some reason!...
--
Tony Sayer

"Peter" wrote:

On Sun, 13 Feb 2011 18:42:14 -0000, "Graham." wrote:


"Bill Wright" wrote in message ...
I wonder if the panel has anyone from the electricity distribution industry who might like
to comment about the incident at Newbury
races yesterday.

Bill

I do know, but only from lurking on uk.d-i-y over the years, that any electrician working
in farms etc will (should) know that there are recognised issues with large four-legged
animals being at risk of shock or electrocution simply because of the extra PD across
their front and hind limbs, not to mention the extra current due to their bare feet or
even nailed-on steel shoes.

I know diddley squat about horse raciing or horses, but ISTR reading
that race horses are shod with lightweight aluminium shoes in
preparation for them galloping along a field

I heard that the two fatalities were shod with steel while most of the others were
in aluminium plates and were less affected.

In article , Brian Lawrence
scribeth thus
"Peter" wrote:

On Sun, 13 Feb 2011 18:42:14 -0000, "Graham." wrote:


"Bill Wright" wrote in message
ioe.org...
I wonder if the panel has anyone from the electricity distribution industry
who might like
to comment about the incident at Newbury
races yesterday.

Bill

I do know, but only from lurking on uk.d-i-y over the years, that any
electrician working
in farms etc will (should) know that there are recognised issues with large
four-legged
animals being at risk of shock or electrocution simply because of the extra PD
across
their front and hind limbs, not to mention the extra current due to their bare
feet or
even nailed-on steel shoes.

I know diddley squat about horse raciing or horses, but ISTR reading
that race horses are shod with lightweight aluminium shoes in
preparation for them galloping along a field

I heard that the two fatalities were shod with steel while most of the others
were
in aluminium plates and were less affected.


You've been reading the "Current bun" haven't yer;?..
--
Tony Sayer

In article ,
tony sayer writes:
In article , Brian Lawrence
scribeth thus

I heard that the two fatalities were shod with steel while most of the others
were
in aluminium plates and were less affected.


You've been reading the "Current bun" haven't yer;?..

The same information was in the Telegraph, which perhaps gives it rather
more credence.
--
John Hall

"The covers of this book are too far apart."
Ambrose Bierce (1842-1914)

Jeff Layman wrote:
On 13/02/2011 21:50, Brian Gaff wrote:
Well as around here they had to dig up the whole footway to try to find
where the wire went to put in an extra street light, it does make me
wonder
how accurate the schematics of where things go actually is...

Brian
A relative worked for the GPO and then BT for 35 years repairing
telephone lines - above and below ground. He said that the utility
company records were a vague guide to what you /might/ find when looking
underground to find wiring breaks. And then you didn't know for certain
what was there until the pick or spade hit something!

When my dad was highways superintendent for part of Doncaster one of his
lads, who'd been 'bottoming' a road ready for a new basecourse and
surface, called in the office to say that a hole had appeared in the
middle of the job. It turned out to be a sewer that no-one knew existed.
They found an access hole in the corner of the churchyard, under a slab.
I went down it and it was astonishing. 8ft high and six feet wide. You
could look up and see how some of the street gulleys discharged into it
directly. It ran across the main A18 only 2ft below the surface, and
down a side street for 200 yards to the river. It was still in use
carrying surface water, and a few properties were discharging sewage
into it. It wasn't shown on any maps and even the old stagers who'd
worked there since the rural council days didn't know it existed.

Bill

Max Demian wrote:
"Bill Wright" wrote in message
...
Java Jive wrote:
As you say, mains is quite a different matter. If IUIC, it's the
total power delivered in the shock that matters.

Electric fences used in agriculture are commonly powered by batteries,
and when you get near them, you can often hear a regular clicking once
a second or so as it delivers a brief, timed kick to the fence under
the control of a timer.
The ones of my youth had a mechanism like the thing that serves as a
pendulum in a watch (can't think of the word). A large wheel with a
spring, so the wheel oscillated backwards and forwards.

"Spring balance wheel" - doh!

Yes.

Bill

Jim Lesurf wrote:
In article , Mark Carver
wrote:


AIUI it's even a problem in grazing fields that have 11, 33, or 66kV
overhead transmission lines. The wooden pole has a metal cross bar which
the three insulators sit upon. The cross bar is earthed via a bonding
cable that runs down the pole. I was told by an SEB engineer years ago,
that the lekky boards pay out thousands each year to farmers that have
had quality of milk affected due to the currents those earth bonding
points induce into the field, and consequently into the livestock as
they wander around. I assume he wasn't winding me up ?!

I'd be interested in seeing a reference for that. So far as I know all the
high power high voltage lines tend to be three-phase balanced. And I assume
the insulators *are* supposed to 'insulate' the potentials from reaching a
strap provided for safety purposes or lightning strike.

Slainte,

Jim

I suppose one dirty insulator (a track of bird ****) could put a voltage
onto the earth conductor, probably current limited by the resistance of
the said guano.

It's well known that a fairly distant lightning strike to ground can
cause potential differences across a yard of ground -- a distance equal
to that between a large quadruped's legs. But that's millions of volts,
not thousands.

Bill