Stealing Electricity from the Railway.
Alasdair Baxter
When I was reading law some years ago, I came across a case where a farmer
was convicted of "stealing" electricity from BR without leaving his own land.
Farmer X had a large field adjoining an electrified railway track. The track
went round a wide curve at this point. X discovered that if he drove two
copper stakes into the ground, one at each end of his field and near the track,
he could collect sufficient electricity from the two wires connected to the
stakes to power his house.
BR were baffled because, when trains came on to this section of track, they
seemed to lose power for no apparent reason. Various tests were carried out
to no avail and it was only after several years when a platelayer noticed a
stake with a wire attached to it that the mystery was solved.
Although no part of Farmer X's apparatus was connected to BR's wiring or even
encroached on BR's land, X was convicted of illegal abstraction of electricity
under section 13 of the Theft Act.
Can any of the experts on this group explain the technicalities of this
phenomenon to me please?
--
Alasdair Baxter, Nottingham, UK.Tel: +44 115 970 5100; Fax: +44 115 9423263.
"It's not what you say that matters but how you say it.
It's not what you do that matters but how you do it".
Karl Meyer
Alasdair Baxter wrote:
>
> When I was reading law some years ago, I came across a case where a farmer
> was convicted of "stealing" electricity from BR without leaving his own land.
>
> Farmer X had a large field adjoining an electrified railway track. The track
> went round a wide curve at this point. X discovered that if he drove two
> copper stakes into the ground, one at each end of his field and near the track,
> he could collect sufficient electricity from the two wires connected to the
> stakes to power his house.
> phenomenon to me please?
Its basically a wacking great inefficient transformer. A
transformer works by inducing a current in one coil by passing
an AC current through another coil next to it. (Remember 'O'
Level physics with lots of wire and a lump of iron)
In this case both 'coils' are straight and instead of an iron
core there is an air core. This makes it very inefficient but as
someone else is (was) paying, 1% efficiency still makes the
electricity free. The term stealing comes in because the power
from BR was used to induce power for the farmer - BR lost power
Farmer gained it - The fact that no electrons were stolen is
immaterial.
Similar cases include being able to light neon tubes by waving
them under National Grid pylons.
Other people have been convicted by building similar apparatus
in their lofts when they live near pylons.
It would not surprise me if many more farmers don't steal
electricity from the Grid by burying the coils under the fields
--
Karl Meyer +44 (0) 1223 250100
ext 2434
Unipalm Ltd Email:
ka...@unipalm.pipex.com
216 Science Park URL:
http://www.unipalm.pipex.com
Milton Road
Cambridge
CB4 4WA
Bill Robertson
In article <832034...@dram.demon.co.uk> Alasdair Baxter
<Alas...@dram.demon.co.uk> writes:
> When I was reading law some years ago, I came across a case where
> a farmer was convicted of "stealing" electricity from BR without
> leaving his own land.
> Farmer X had a large field adjoining an electrified railway track.
> The track went round a wide curve at this point. X discovered
> that if he drove two copper stakes into the ground, one at each
> end of his field and near the track, he could collect sufficient
> electricity from the two wires connected to the stakes to power
> his house.
Not quite in the same league, but when I was commuting weekly by train
to Glasgow I used to work on a laptop with crap batteries. I found
that there were standard 3-pin sockets at each end of the carriage...
- Bill -
--
Bill Robertson --- <B.Rob...@lancaster.ac.uk> --- 01524 65201 x3149
Dept of Mathematics and Statistics, Lancaster University, Lancaster, UK.
AKA bi...@plumtree.demon.co.uk -- Plumtree Barn, Levens, Kendal, Cumbria
Malcolm Reeves
Hi,
Alasdair Baxter <Alas...@dram.demon.co.uk> wrote:
>When I was reading law some years ago, I came across a case where a farmer
>was convicted of "stealing" electricity from BR without leaving his own land.
>
>Farmer X had a large field adjoining an electrified railway track. The track
>went round a wide curve at this point. X discovered that if he drove two
>copper stakes into the ground, one at each end of his field and near the track,
>he could collect sufficient electricity from the two wires connected to the
>stakes to power his house.
>
>BR were baffled because, when trains came on to this section of track, they
>seemed to lose power for no apparent reason. Various tests were carried out
>to no avail and it was only after several years when a platelayer noticed a
>stake with a wire attached to it that the mystery was solved.
>
>Although no part of Farmer X's apparatus was connected to BR's wiring or even
>encroached on BR's land, X was convicted of illegal abstraction of electricity
>under section 13 of the Theft Act.
>
>Can any of the experts on this group explain the technicalities of this
>phenomenon to me please?
>
I find this hard to believe. The current in electric traction returns
through the rails but also through the ground. With DC traction (3rd
rail) attempts are made to keep the current in the rails. With AC
traction (overhead) the current is encouraged to flow into the ground
as it reduces the rail voltage which overwise would be higher and
dangerous to personnel. The current flow through the ground could
produce a voltage but I would expect this to be less than normal
mains. It would also only be there when traction was flowing and so
would depend on the number of trains running where they were etc, etc.
These factors and the soil resistance (i.e. is wet) would effect the
voltage seen between these two stakes. Ignoring all of this current
would only flow if the farmer's house was a lower resistance than the
earth (I know it will divide, I'm just simplifying). If the
resistance lowers then the power lost is less so the farmer could have
charged BR for helping their current to return. Also the would be no
effect on the trains other than perhaps a slightly higher voltage
available to them. And this would be well within any other
tolerances. BTW as trains take very large amounts of power I can't
see, even if the farmer was managing to power his house, how the train
would notice unless the house was very VERY big.
Perhaps you could provide more details of the case, especially how BR
experts said the theft took place.
...malcolm
--| Malcolm Reeves (mre...@dial.pipex.com) WSL, Chippenham, UK |--
Peter Campbell Smith
In article <832034...@dram.demon.co.uk>, Alas...@dram.demon.co.uk wrote:
> When I was reading law some years ago, I came across a case where a farmer
> was convicted of "stealing" electricity from BR without leaving his own land.
>
> Farmer X had a large field adjoining an electrified railway track. The track
> went round a wide curve at this point. X discovered that if he drove two
> copper stakes into the ground, one at each end of his field and near the
> track,
> he could collect sufficient electricity from the two wires connected to the
> stakes to power his house.
>
> BR were baffled because, when trains came on to this section of track, they
> seemed to lose power for no apparent reason. Various tests were carried out
> to no avail and it was only after several years when a platelayer noticed a
> stake with a wire attached to it that the mystery was solved.
>
> Although no part of Farmer X's apparatus was connected to BR's wiring or even
> encroached on BR's land, X was convicted of illegal abstraction of electricity
> under section 13 of the Theft Act.
It sounds like an urban myth or something from A P Herbert perhaps, but in
theory there's a grain of credibility. If it was an AC-electrified line he
would have created a 1-turn transformer which might produce quite a few volts
but not, I suspect, enough watts to do anything much. He might have done
better to use the fence along the track. Another possibility is that it was a
DC line and he was picking up some of the return current, which tends to
wander off the running rails, but then his lights would only go on while a
train was passing.
The bit about the trains noticeably losing power is even less believable.
Bear in mind that railways are often surrounded by conductive structures, but
I've never heard of anyone being too concerned about the loss of power casued
by induced currents. (Corrosion caused by the DC return current is a problem
sometimes.)
When I was a child there was a field opposite my bedroom window which had
275kV overhead lines, lots of mud, and cows. The cows used to stand mostly
with their long axes perpendicular to the wires, and I often wondered whether
this was because the didn't like the induced currents when they stood the
other way. On the other hand, they might have just been pointing into the
prevailing wind to keep warm. The pylons have gone now, but so have the cows.
<> Peter Campbell Smith, Logica, London, UK
<> opinions are mine alone <> mailto:camp...@logica.com
Howard of Effingham
In article <wkeivdz...@mathssun4.lancs.ac.uk>,
Bill Robertson <robe...@mathssun4.lancs.ac.uk> wrote:
[snipped]
>Not quite in the same league, but when I was commuting weekly by train
>to Glasgow I used to work on a laptop with crap batteries. I found
>that there were standard 3-pin sockets at each end of the carriage...
you do realise that the plug that you probably used is supposedly only safe
when used in the depot when the said carriage goes in for an exam.
well this is what i have heard. apparently the supply is only earthed when
in the depot, and when on the road not.
others who are more well up on this might know more.
==============================================================================
Trevor Williams|
~~~~~~~~~~~~~~~| Available on request, full editions of
|
| "Lord Howard's Gen Files"
|
| Gen, on a loco by loco basis of every single Class 87 loco.
|
==============================================================================
Thomas Sippel - Dau
In article <319852...@unipalm.pipex.com>, Karl Meyer <ka...@unipalm.pipex.com> writes:
- Its basically a wacking great inefficient transformer. A
- transformer works by inducing a current in one coil by passing
- an AC current through another coil next to it. (Remember 'O'
- Level physics with lots of wire and a lump of iron)
Don't know about "inefficient". Inefficient as a transformer maybe
(i.e. different coils and core may have given more power for the
same amount of copper, but is it inefficient for the amount of
electricity abstracted ? (I.E. was the heat loss by this transformer
significantly bigger for the purloined power than for an efficient
design ?)
N.B. does the fact that the railway goes through a bend matter ?
- In this case both 'coils' are straight and instead of an iron
- core there is an air core. This makes it very inefficient but as
- someone else is (was) paying, 1% efficiency still makes the
- electricity free. The term stealing comes in because the power
- from BR was used to induce power for the farmer - BR lost power
- Farmer gained it - The fact that no electrons were stolen is
- immaterial.
-
- Similar cases include being able to light neon tubes by waving
- them under National Grid pylons.
-
- Other people have been convicted by building similar apparatus
- in their lofts when they live near pylons.
-
- It would not surprise me if many more farmers don't steal
- electricity from the Grid by burying the coils under the fields
I think that the "theft" part comes from the crass design of such
abstraction devices, which were not constructed for deniability.
For example, running lights from it means you clearly knew what
you were doing. But what about just having a well laid concrete
driveway with steel re-inforcing. Hey presto, you get a heated
frost-free driveway and you never knew what was going on.
On a point of interest, there was a parallel case in Germany in the
early thirties where running a radio antenna (near a high-power
transmitter station) to provide lighting for a chicken shed was
deemed in order, as there was no "thing" being taken away.
Consequently electricity meter tampering and riding the railway
with out a ticket (see, I am back on transport :-) is construed
there as fraud rather than theft.
Thomas
--
*** Why not use metric units and get things right first time, every time.
* email: cma...@ic.ac.uk (Thomas Sippel - Dau)
* voice: +44 171 594 6904 (day), +44 171 594 6958 (fax), +44 171 385 6540
* snail: ICSTM, Computing Services, Kensington SW7 2BX, Great Britain
Roger Keenan
In article <832034...@dram.demon.co.uk>, Alasdair Baxter
<Alas...@dram.demon.co.uk> writes
>When I was reading law some years ago, I came across a case where a farmer
>was convicted of "stealing" electricity from BR without leaving his own land.
>
A householder living near a World Service shortwave transmitting station
had installed an aerial in his loft tuned to one of the BBC's more
popular shortwave frequencies. Shortwave transmitters are very powerful
(typically 250KW of rf power out of each transmitter unit) and he found
he could get enough power through the aerial to power his house.
Eventually, the BBC started investigating why the radiation pattern had
a funny shape at that frequency and discovered him. He was successfully
prosecuted for stealing the BBC's electricity.
--
Roger Keenan
Hoppy
t...@coventry.ac.uk (Howard of Effingham) wrote:
>In article <wkeivdz...@mathssun4.lancs.ac.uk>,
>Bill Robertson <robe...@mathssun4.lancs.ac.uk> wrote:
>
>[snipped]
>
>>Not quite in the same league, but when I was commuting weekly by train
>>to Glasgow I used to work on a laptop with crap batteries. I found
>>that there were standard 3-pin sockets at each end of the carriage...
>
>you do realise that the plug that you probably used is supposedly only safe
>when used in the depot when the said carriage goes in for an exam.
>
>well this is what i have heard. apparently the supply is only earthed when
>in the depot, and when on the road not.
>
>others who are more well up on this might know more.
Trevor is quite right. You have good potential of completely wrecking your
power supply for your laptop by doing this. During running conditions the
supply is highly prone to surges etc. Normally its only used when the units are
connected to a shore supply at depots where the cleaners use the sockets.
Of course if your power supply can cope with this..........
______________________________________________________________________________
Paul D. Lee Division Limited
"Hoppy" 19 Apex Court, Woodlands
Bristol BS12 4JT, UK
Tel: +44 1454 615554
Fax: +44 1454 615532
Email: ho...@division.co.uk
Clive Page
>Not quite in the same league, but when I was commuting weekly by train
>to Glasgow I used to work on a laptop with crap batteries. I found
>that there were standard 3-pin sockets at each end of the carriage...
For many years there has been a 13-amp socket in the luggage area at each
end of an HST carriage. I've always thought that if I ever got a laptop
this would be a good place to recharge its batteries. But a few months
ago, these sockets started to sprout a label saying "not for public use".
Presumably up till then it was perfectly legal to use them?
--
-------------------------------------------------------------------------
Clive Page, Internet: c...@star.le.ac.uk
Dept of Physics & Astronomy,
University of Leicester.
Malcolm Reeves
Karl Meyer <ka...@unipalm.pipex.com> wrote:
>Its basically a wacking great inefficient transformer. A
>transformer works by inducing a current in one coil by passing
>an AC current through another coil next to it. (Remember 'O'
>Level physics with lots of wire and a lump of iron)
>
>In this case both 'coils' are straight and instead of an iron
>core there is an air core. This makes it very inefficient but as
>someone else is (was) paying, 1% efficiency still makes the
>electricity free. The term stealing comes in because the power
>from BR was used to induce power for the farmer - BR lost power
>Farmer gained it - The fact that no electrons were stolen is
>immaterial.
>
This is an interesting theory. The impedance of a 25kV railway
caternary, and rails (double rail with return conductor and booster
transformer) is about 0.3j/km. So with trains pulling about 300A, 1 km
of rail would give 90V on the primary of the transformer (at 50Hz).
Suppose farmer x with his loop (transformer secondary) managed to get
as close as the next pair in a two track situation (10ft). His wire
would see the field from the rails and an opposite field from the
caternary. The difference in mutual inductance in these is 0.1mH/km
so the inducted voltage on the secondary is only 30V. This is with a
km of wire so I'm not sure it's worth it. The voltage would also
collapse quickly when you tried to take any power.
Howard of Effingham
In article <4ncn53$r...@hawk.le.ac.uk>, Clive Page <c...@le.ac.uk> wrote:
>In article <wkeivdz...@mathssun4.lancs.ac.uk>,
>Bill Robertson <robe...@mathssun4.lancs.ac.uk> wrote:
>
>>Not quite in the same league, but when I was commuting weekly by train
>>to Glasgow I used to work on a laptop with crap batteries. I found
>>that there were standard 3-pin sockets at each end of the carriage...
>
>For many years there has been a 13-amp socket in the luggage area at each
>end of an HST carriage. I've always thought that if I ever got a laptop
>this would be a good place to recharge its batteries. But a few months
>ago, these sockets started to sprout a label saying "not for public use".
>Presumably up till then it was perfectly legal to use them?
i cannot comment on the legality of this, but see my points in this thread
about how bloody unsafe such a idea is, and there you are you have a reason
for the said label that you have seen clive.
i'll bet that some one had the same idea that you have had, only when they
did this, there was a surge and their nice little laptop was wrecked.
silly stupid billy! ok so they may have been given something in compensation,
but the safety aspects are more important than the laptops, ok?
Clive D.W. Feather
In article <31989689...@news.dial.pipex.com>,
Malcolm Reeves <mre...@dial.pipex.com> wrote:
>With AC
>traction (overhead) the current is encouraged to flow into the ground
No it isn't. It runs for up to 2km through one running rail, then, via a
transformer, into the wire that runs along the back of the masts.
--
Clive D.W. Feather | If you lie to the compiler,
cl...@demon.net (work, preferred) | it will get its revenge.
cl...@stdc.demon.co.uk (home) | - Henry Spencer
Tone
In article: <3199ee3d...@news.dial.pipex.com> mre...@dial.pipex.com (Malcolm Reeves)
writes:
> >
> This is an interesting theory. The impedance of a 25kV railway
> caternary, and rails (double rail with return conductor and booster
> transformer) is about 0.3j/km. So with trains pulling about 300A, 1 km
> of rail would give 90V on the primary of the transformer (at 50Hz).
>
> Suppose farmer x with his loop (transformer secondary) managed to get
> as close as the next pair in a two track situation (10ft). His wire
> would see the field from the rails and an opposite field from the
> caternary. The difference in mutual inductance in these is 0.1mH/km
> so the inducted voltage on the secondary is only 30V. This is with a
> km of wire so I'm not sure it's worth it. The voltage would also
> collapse quickly when you tried to take any power.
>
> ...malcolm
>
> --| Malcolm Reeves (mre...@dial.pipex.com) WSL, Chippenham, UK |--
>
>
>
>
>
>
--
***********************************************************************
To...@antb.demon.co.uk
Space is big....REALLY big !
***********************************************************************
Thomas Sippel - Dau
In article <4ndh7m$7...@rowan.coventry.ac.uk>, t...@coventry.ac.uk (Howard of Effingham) writes:
- In article <4ncn53$r...@hawk.le.ac.uk>, Clive Page <c...@le.ac.uk> wrote:
- >In article <wkeivdz...@mathssun4.lancs.ac.uk>,
- >Bill Robertson <robe...@mathssun4.lancs.ac.uk> wrote:
- >
- >>Not quite in the same league, but when I was commuting weekly by train
- >>to Glasgow I used to work on a laptop with crap batteries. I found
- >>that there were standard 3-pin sockets at each end of the carriage...
- >
- >For many years there has been a 13-amp socket in the luggage area at each
- >end of an HST carriage. I've always thought that if I ever got a laptop
- >this would be a good place to recharge its batteries. But a few months
- >ago, these sockets started to sprout a label saying "not for public use".
- >Presumably up till then it was perfectly legal to use them?
-
- i cannot comment on the legality of this, but see my points in this thread
- about how bloody unsafe such a idea is, and there you are you have a reason
- for the said label that you have seen clive.
Well, strictly speaking legal it ain't, never was, as you had no electricity
supply contract with the railway, only a transport one. I don't know if the
railway org would want to prosecute you if you took out electricity.
The "Not for public use" label is more likely to spring from a desire to
negate liability if you use it anyway, and to get round safety regulations
if no effective earth is provided (as somebody commented).
- i'll bet that some one had the same idea that you have had, only when they
- did this, there was a surge and their nice little laptop was wrecked.
In that case that laptop deserve to fry anyway. Any laptop worth more than
ten bob should have a universal power supply, which should provide a fixed
stabilised output of around 16 Volt or so for input voltages of 80 to 260V
and small surges or brownout (up to 10 seconds or so). For a longer brownout
the battery should take over. But yes, if the overhead voltage comes through
(or 25 or whatever kV), the power supply should blow a fuse or flipp a relay.
The laptop should still work, though.
Jim Stobbs
In article <4ncn53$r...@hawk.le.ac.uk>, Clive Page <c...@le.ac.uk> says:
>
>In article <wkeivdz...@mathssun4.lancs.ac.uk>,
>Bill Robertson <robe...@mathssun4.lancs.ac.uk> wrote:
>
>
The HSTs in this neck of the woods have carried these signs for some years
now. I can remember one of the computer magazines featuring these 13 amp sockets
as their "tip of the month" in the late 1980s.
Another snag with using them is that the automatic doors into the vestibule
would keep opening and closing on your mains power cable ...
_____________________________________________
Jim Stobbs
Reading
jim.s...@byson.hiway.co.uk
_____________________________________________
Dan Glover
In article <319bbc67...@news.demon.co.uk>, tim
<t...@enigmas.demon.co.uk> writes
>On Wed, 15 May 1996 15:13:26 GMT, mre...@dial.pipex.com
>(Malcolm Reeves) wrote:
>
>>Karl Meyer <ka...@unipalm.pipex.com> wrote:
>
>(along with others)
>
><all snipped because I feel like it>
>
>IIRC the power to the third rail is not continuous, but only
>activated by the approach of a train, so (in theory) there
>will be no current on the lines for long periods of time.
I think you'll find the juice is on all the time. There might be a
slight safety advantage in having it powered up only on approach but it
costs practically nothing to leave it on and would introduce lots of
complexity to do the switching.
[I can cut things too :-)]
Dan
--
Dan Glover (d...@dangl.demon.co.uk)
Move along now, please! There's nothing more to see!
tim
>Karl Meyer <ka...@unipalm.pipex.com> wrote:
(along with others)
<all snipped because I feel like it>
IIRC the power to the third rail is not continuous, but only
activated by the approach of a train, so (in theory) there
will be no current on the lines for long periods of time.
Or are we talking about the main supply cables that I guess
are powered all the time...derrrrrr
tim
"Brilliant gold taps, virginal white marble, a seat carved from ebony,
a cistern full of chanel number five, and a flunky handing me pieces
of raw silk toilet roll.
But under the circumstances I'll settle for anywhere" - Trainspotting
Malcolm Reeves
cl...@stdc.demon.co.uk (Clive D.W. Feather) wrote:
>>With AC
>>traction (overhead) the current is encouraged to flow into the ground
>
>No it isn't. It runs for up to 2km through one running rail, then, via a
>transformer, into the wire that runs along the back of the masts.
>
Sorry but yes it is.
(For those they don't know there are usually two wires on the masts
the catenary, which provides the power and the return conductor that
returns the power. There are also (usually) booster transformers to
suck the current into the return wire).
In single rail traction areas the traction runs for up to 1600m down
one rail before it finds a connection to the return conductor.
However this rail is bond to every mast which is also sunk in the
ground. Each mast looks like typically 14 ohms to ground and they are
every 60m so a 1600m section has a total impedance to ground of
0.5ohm. This of course depends a lot on the soil conditions, wet
soil is a lot lower, rocky soil a lot higher. Current from the train
flows in both directions from it into the ground and then returns form
the ground from both sides of the return conductor link. A very large
proportion of the traction current flows through the ground. If it
didn't the system couldn't cope. In rocky areas double rail returns
are needed as there the ground impedance is too high. Of course this
is more expensive as impedance bonds will be required if it has
jointed track circuits.
Paul E. Bennett
In article <319bbc67...@news.demon.co.uk>
t...@enigmas.demon.co.uk "tim" writes:
> IIRC the power to the third rail is not continuous, but only
> activated by the approach of a train, so (in theory) there
> will be no current on the lines for long periods of time.
>
> Or are we talking about the main supply cables that I guess
> are powered all the time...derrrrrr
I recall differently. Third Rail supplies, LUL four rail systems and the 25kV
overheads are powered continuously unless there is a very good reason to shut
off power (like in emergencies).
If they only powered when the train came along there would probably not be so
many trains meeting on the same line.
--
Paul E. Bennett <p...@transcontech.co.uk>
Transport Control Technology Ltd.
Tel: +44 (0)117-9499861
Going Forth Safely
Clive D.W. Feather
In article <832457...@tcontec.demon.co.uk>,
Paul E. Bennett <p...@transcontech.co.uk> wrote:
> I recall differently. Third Rail supplies, LUL four rail systems and the 25kV
> overheads are powered continuously unless there is a very good reason to shut
> off power (like in emergencies).
Right.
Though LUL turn off power overnight (roughly 0100 to 0500) to allow for
maintenance work, except in depots which are powered 24 hours.
Malcolm Reeves
Dan Glover <d...@dangl.demon.co.uk> wrote:
>In article <319bbc67...@news.demon.co.uk>, tim
><t...@enigmas.demon.co.uk> writes
>>
>>IIRC the power to the third rail is not continuous, but only
>>activated by the approach of a train, so (in theory) there
>>will be no current on the lines for long periods of time.
>
>I think you'll find the juice is on all the time.
The juice is on all the time but what I took tim to mean was the
current doesn't flow all the time, only when there is a train about.
Which is true. And without current flow there would be no induced
voltage in the farmers wire i.e. no train, no power. Which is also
true, leaving aside the fact I don't think it would work anyway :-).
Jon Rouse
Alasdair Baxter <Alas...@dram.demon.co.uk> wrote:
>When I was reading law some years ago, I came across a case where a farmer
>was convicted of "stealing" electricity from BR without leaving his own land.
>
that BR were polluting his land with stray EMF and that the farmer was
providing a helpful service by disposing of it safely.
--
J...@timewarp.demon.co.uk http://www.geocities.com/Athens/1992/index.html
Usenet comments do not necessarily reflect the views of my employees.
Work related email: rou...@royalmail.co.uk
Ian Jones
In article <319bbc67...@news.demon.co.uk>, t...@enigmas.demon.co.uk (tim) writes:
|> On Wed, 15 May 1996 15:13:26 GMT, mre...@dial.pipex.com
|> (Malcolm Reeves) wrote:
|>
|> >Karl Meyer <ka...@unipalm.pipex.com> wrote:
|>
|> (along with others)
|>
|> <all snipped because I feel like it>
|>
|> activated by the approach of a train, so (in theory) there
|> will be no current on the lines for long periods of time.
|>
|> are powered all the time...derrrrrr
|>
|> "Brilliant gold taps, virginal white marble, a seat carved from ebony,
|> a cistern full of chanel number five, and a flunky handing me pieces
|> of raw silk toilet roll.
|> But under the circumstances I'll settle for anywhere" - Trainspotting
Are you sure? I was at New Brighton Station on Merseyside a few weeks ago and as
my wife and I walked down the platform, we noticed a burning smell, I mentioned
this to the guard thinking it might be a brake problem but he pointed me to a
smoking heap on the third rail on an adjacent line. This was a dog that had
wandered onto a third rail. The guard told me that he could not remove it until
Railtrack came along and switched off the power. There was no train on this
siding.
Ian Jones
=========================================================================
E-Mail : i.j...@axion.bt.co.uk
"Insanity is hereditary - You get it from your kids"
=========================================================================
Howard of Effingham
In article <NEWTNews.8328887...@pc17.isc-queens.co.uk>,
<lib...@ISC-QUEENS.CO.UK> wrote:
>
>> |>
>> |> IIRC the power to the third rail is not continuous, but only
>> |> activated by the approach of a train, so (in theory) there
>> |> will be no current on the lines for long periods of time.
>
>who will fry first....
and there was the _DANGEROUS_ trick i saw on the p.way
when there was nowt better to do with a hammer.... and a detonator. an
excellent means, mind of getting rid of out of date ones!
i _also_ knew a means of blowing insulation pots on the d.c. lines. but that
would be telling. ;)
==============================================================================
Trevor Williams| Available on request, full ed's of"Lord Howard's Gen Files",
| on a loco by loco basis of every single Class 87 loco.
;}=+| |
| Ex-p.way. watford [north] p.way mtce gang 1988-1989. And
| may i add still _very proud_ to have served.
==============================================================================
lib...@isc-queens.co.uk
Malcolm Reeves
t...@coventry.ac.uk (Howard of Effingham) wrote:
>In article <NEWTNews.8328887...@pc17.isc-queens.co.uk>,
> <lib...@ISC-QUEENS.CO.UK> wrote:
>>
>>> |>
The voltage is on all the time!! The current only flows when a train
is drawing current, OR somebody walks on the 3rd rail!
>when there was nowt better to do with a hammer.... and a detonator. an
>excellent means, mind of getting rid of out of date ones!
Not recommended! On my PTS course we were told of a guard, bored,
thought he would try this. Lost an eye and hand AFAIR and his job of
course.
...malcolm
John Robinson
tim writes:
>[and some other people do too]
>>> |> IIRC the power to the third rail is not continuous, but only
>>> |> activated by the approach of a train, so (in theory) there
>>> |> will be no current on the lines for long periods of time.
>>
>>Ah, OK! Let's all go for a walk on the rail lines, then. Let's see
>>who will fry first....
>
>no point being earthed - eg both feet in the air, then onto
>the rail. It doesn't bother pigeons does it... would rubber
>soles make a difference?
No. Your hair might stand on end through electrostatic phenomena, but
not very much. (25kV would be better for that.)
>The dog would be earthed as it put one paw on the track
>unless it was very clever (like that fox that led the pack
>of hounds onto a live line in the SE many years ago).
Clever! I bet this only happened because the fox was too small to step
onto the live rail, and had to jump onto it, but the dogs were big
enough not to have to leave the ground (in both senses).
>It's a bit like two wires in a socket - no current flows
>until there is a connection to the opposite or earth. There
>are other complications with mains though - like I heard
>someone tell me that by wiring a light bulb to neutral and
>earth you would get some light generated from the phasing
>differences along your street circuit or something... this
>may be urban legend though and I'm not up on this stuff.
>Anyone know?
Yes. With a three phase system, the neutral wire is redundant when the
phases are equally loaded (though when present, it still serves
as a zero volts reference, which may be different from earth
potential). When they are not, there will be a current in the neutral
wire, perhaps as large as the load in one of the phase
wires. (Consider: when only one phase is in use, the return current is
as large as the live current.) Now, there may for whatever reason be a
difference between the 'zero' reference of the mains (the neutral
wire) and your earth potential, most likely because of natural
differences in earth potential - your neutral wire will go into the
ground at the substation. So, you have a voltage, and current. You may
be able to light a lamp bulb for nothing.
Hmm. I've just gone and confused myself again. There's something wrong
with this. Hmm.
John.
-- _ _
_ | |___| |_ _ _ John Robinson email: jdr...@cam.ac.uk
| |_| / . \ ' \| ' \ D9 Adrian House, 56a Grange Road, Cambridge CB3 9DH, UK
\___/\___/_||_|_||_| Tel: +44 1223 329 121 Mobile: +44 370 301 669
I'm goin' fishin'... Gonna bate me a line... --Chris Rea
tim
On Thu, 23 May 96 14:57:30 PDT, lib...@ISC-QUEENS.CO.UK
wrote:
>
>> |>
>> |> IIRC the power to the third rail is not continuous, but only
>> |> activated by the approach of a train, so (in theory) there
>> |> will be no current on the lines for long periods of time.
>
>Ah, OK! Let's all go for a walk on the rail lines, then. Let's see
>who will fry first....
>
Hmm, right, now what if I jump onto a live rail, whilst at
no point being earthed - eg both feet in the air, then onto
the rail. It doesn't bother pigeons does it... would rubber
soles make a difference?
The dog would be earthed as it put one paw on the track
unless it was very clever (like that fox that led the pack
of hounds onto a live line in the SE many years ago).
It's a bit like two wires in a socket - no current flows
until there is a connection to the opposite or earth. There
are other complications with mains though - like I heard
someone tell me that by wiring a light bulb to neutral and
earth you would get some light generated from the phasing
differences along your street circuit or something... this
may be urban legend though and I'm not up on this stuff.
Anyone know?
tim