Operation of Passenger Trains during Lightning Storms?

[Chrius56000]

. . .During last Saturday evening (the 21st) from late afternoon/early evening much of the South Western, Southern, Midlands and Central UK was blanketed by very heavy rain, flash flooding and a considerable number of major lightning storms.

. . .This brings me to a historical question – where semaphore–signalled AB routes relatively immune to lightning (apart from a direct lightning strike to a line side pole route) to a greater extent than TCB?

. . .Did B.R. (and it's predecessors) have any special instructions to signalmen/drivers/general p.w. staff, etc., for operation during lightning storms, or was lightning only considered a minor hazard?

. . .Do any other Members recall any instances where normal operations were directly affected by lightning over a wide area?

. . .I don't recall any of the B.R. Rule Books/General Instructions, etc., etc., mentioning lightning anywhere in them, but please correct me if I'm wrong on this!

 

[Ashley Hill]

You used to get static electricity dancing along the tops of the levers. Block bells often had lightening protectors built in. The block bells would also ring by themselves during lightening and the needles on the signal and block instruments would move. Far worse where the wires were on pole routes.

 

[randyrippley]

I don't know anything about signal boxes, but it's possible to get a hell of an electrical belt off a normal phone line. I was once operating a small 4-line switchboard using a headset when the incoming lines (on the roof of an old mill) were hit by lightening.
Knocked me sideways literally and metaphorically and made me see stars for a few minutes. Presumably the switch was earthed and took most of the shock, but it was still damned unpleasant.
Based on that I'd have thought the risk in a signal box was much higher, though I guess no-one would be wearing headphones

 

[John Webb]

The lever frame in a signal box is usually well-earthed, hence Ashley Hill's comments about static electricity above ("St Elmo's fire" I think it's referred to and was often seen on ship's masts in stormy weather.)
The old block instruments had 'arresters' in them - usually serrated plates, one of which was earthed, and the serrations separated by thick paper or a thin sheet of mica. These allowed the usual voltages to work without shorting to earth, but high voltages induced by a lightning strike passed through the separator to earth to minimise damage. Example below is from a MR Pegger instrument with some modern wiring.
The centre plate is connected to earth.

 

[Towers]

You used to get static electricity dancing along the tops of the levers. Block bells often had lightening protectors built in. The block bells would also ring by themselves during lightening and the needles on the signal and block instruments would move. Far worse where the wires were on pole routes.

Yikes that’s creepy!

 

[Llanigraham]

The barriers at the level crossing controlled by Onibury Box (south of Craven Arms) were once struck by lighning whilst they were open/up. They melted and knocked out most of the electrics in the Box. A friend was on duty at the time.

 

[EveningStar]

Article by D.E. Canning in the March 1976 Railway Magazine has a first hand account of being inside the now abolished Hampstead Crossing Signal Box when it was struck by lightning. Quoted this section in my PhD thesis on signal boxes:

“At 03.20 … eerie, dark and silent … I don’t know why, but for the first time since I have been a signalman I felt scared, alone, miles from no-where; and something seemed wrong. Don’t be stupid, I thought, and made for the box. As I entered the door there was a blinding flash, and a crack, followed instantly by an almighty crash as a fork shot from the sky into a clump of trees no more than twenty yards from where I stood. The lights went out, bells rang and all hell was let loose.

I made for the chair in the centre of the box and sat down shaking like a jelly. Within seconds another crack behind the box was followed by a crash, and another; I sat glued to the chair, wondering what would happen next. I soon found out. A fork seemed to come straight at the box. There was the familiar crack and crash, but this time the structure shook, sparks came through the wall and everything in the box glowed, every bell and phone rang together, and the smell was nauseating."

 

[LowLevel]

Manea in the Fens has kit blown up by lightning with tedious frequency!

 

[Tio Terry]

In East Anglia, back in BR days, most of the AHB's and there were lots of them, often lost their Electricity Board feeds due to lightning. Of course, that wasn't an immediate problem because they had back up battery supplies. That was until they introduced the neon flashing "Another Train Coming" signs which were not battery backed. This meant that the trains had to be stopped at the signalbox on the approach side of any crossings and cautioned to proceed.

I was once on a rather late running Birmingham - Norwich which was stopped and cautioned by almost every signalbox between Peterborough and Norwich, an extremely late arrival in to Norwich!

Can't remember when the neon signs were removed, I know it was an update programme.