Forget leaves
on the line!
Techno Talk
Mark Nelson
Why? Because Britain’s railways may soon face a far greater threat to the running of their trains. It’s
something far more malign and hazardous – solar flares. And if the sun’s ability to affect technology
on Earth is as real (and imminent) as some experts think, essential infrastructure may be at risk. Time
to panic? Let’s investigate…
T
he origin of this concern is a
presentation at a conference held
in July by the Royal Astronomical
Society at the University of Warwick.
Cameron Patterson, a PhD student at
Lancaster university, made the stark
statement that fluctuations in space
weather have the ability to disrupt
railway signals and cause significant
delays (and risk) to trains. Electric
currents induced in signalling cables
caused by solar activity can interfere
with the normal operation of signals,
even turning green signals to red when
no other trains are operating nearby,
he asserted.
Wild claim?
Outlandish as this may sound, his pronouncement was based on research by
a team of researchers at the University
of Lancaster, who have modelled the
impacts of solar storms on two geographically separated stretches of the
UK railway network. This followed investigations made in Sweden, where
electrical field strengths of higher than
7V/km have been detected. Further
investigation will now take place.
Patterson stated: ‘We are now working
on looking at the case where trains are
present on the line, and how strong a
storm needs to be to turn a red signal
back to green – a hazardous scenario
potentially leading to crashes.’
Is this for real? Are railway signalling systems truly as vulnerable as this?
Well, yes. What’s more, according to
a recent article in Forbes magazine,
there is a genuine risk that a geomagnetic storm triggered by a burst of
solar energy could also overwhelm
our power grids, shutting down cell
phone towers and crippling worldwide
communications. A NASA webpage
confirms that during solar storms,
earth currents induced by the changing terrestrial magnetic field can be
sufficient to induce voltages in long
cables as well as in oil and natural
gas pipelines.
In March 1989, during the peak of
a sunspot cycle, the sun produced
one of the most powerful storms ever
8
recorded. Surges in electrical power
lines plunged large portions of Quebec
into darkness and caused hundreds of
million dollars of damage to power
transformers. In the same year, a powerful pipeline explosion demolished
part of the Trans-Siberian Railway, engulfing two passenger trains in flames
when gas from a leak in the pipeline
was ignited by the two passing trains.
How does this happen?
The solar cycle is around 11 years in
length, and every 11 years or so the
Sun’s magnetic field flips completely.
This means that the Sun’s north and
south poles switch places. It then takes
about another 11 years for the Sun’s
north and south poles to flip back again.
According to NASA, the current solar
cycle is expected to peak in July 2025
and may well be weaker than average.
This is fortunate, as effective precautions and the cost of replacing destroyed
infrastructure would be horrendously
expensive. The earth currents induced
by high levels of solar activity develop
only along lengthy metallic structures,
so domestic electrical wiring and electronic devices are not affected. Another
consideration is that solar flares impact
territory only on the side of the Earth
facing the sun.
Something more cheerful!
That’s enough doom and gloom, so how
about some comic relief? Following on
from last month’s selection of humorous or techie jargon words that some
people use for electronic stuff, here are
a few more funnies, thanks to my rediscovery of a long list I had misplaced.
Boatanchor (or BA or anchor for short):
any radio, ‘scope or other test gear made
in a steel case (usually military types)
may be considered a ‘boatanchor’. Units
produced from WWII until the mid1960s are the most popular examples
of the genre. Why ‘boatanchor’? It soon
becomes self-evident after carrying one
of these to your car and you notice how
much longer your arms have become.
Bottle: a valve or tube.
Bug, dead bug: integrated circuit.
Cheater cord: Some older TV sets had
plug-in power cords that were captive to
the back of the set, so when their owners
removed the rear cover to look inside,
they couldn’t get shocked. The mains
cord that repair shops used to bypass
this safety feature and plug into the
chassis was known as a ‘cheater cord’.
Deck level: chassis potential of live
Hi-Fi, radio or TV equipment.
Firebottle: another nickname for a
valve or tube.
Fluid state: alternative term for hollow state (the opposite of solid state).
Freezing lotion: aerosol can of freezing
liquid (ever so useful for identifying
faulty capacitors, ICs and transistors
that are overheating).
Griefkit: rhyming name applied to a revered brand of do-it-yourself radio and
electronics construction kits, popular
in Britain and the US from the 1950s to
the 1980s. The name is stupidly misleading because the quality of these kits
(and their superb manuals) has never
been surpassed (although not every
constructor could afford them or was
up to the task of assembling them).
Muff: microfarad (µf).
Puff: picofarad (pf).
Rat Shack: US nickname for the muchloved but now defunct national chain
of electronics hobby shops in the US;
known in Britain as ‘Tandy’.
Rattle can: aerosol squirt can.
Spaghetti: Systoflex (or similar) varnished fabric sleeving for protecting
bare wires.
Suicide cord: a mains lead or power
cord with a plug on one end and either bare wires or alligator clips on
the other. It is or was used in radio
and TV workshops to apply power to
a chassis that had been taken out of
the cabinet.
Three-wire fuse: contemptuous early
term for transistor.
Tranny: transformer or transistor.
Tuning wand: a non-metallic (usually
Delrin) tool made to fit and adjust a
screw, slug or core of a tuned circuit
component.
Widow-maker: See ‘suicide cord’ above.
Practical Electronics | October | 2022
