Tail lamps

[11B]

Hi all,

 

A random question which had never occurred to me untill my 4yr old grandson pointed it out!

 

Why do locos, units, driving trailers have fixed non flashing tail lights whilst the battery powered tail lamps flash? Granted that the battery ones were a replacement for the oil ones could gave the impression of flashing, but is there any need for them to flash,?

 

Thanks in advance.

 

Ian

[stewartingram]

I'm guessing that the battery powered ones are saving energy (ie they last longer) by flashing,

[Wheatley]

That. They were introduced when battery life was much more of an issue, having them off as often as they're on doubles it. 

 

(Probably not exactly double I bet there's some hidden something or other somewhere which messes up the calculation. )

[Wickham Green too]

I'd always assumed that they'd been made to flash so they're more conspicuous !!?!

[iands]

My assumption is that the flashing tail lamp indicates that it is a "portable tail lamp" (battery operated), e.g. as placed on the rearmost wagon of a freight train, as opposed to "fixed" tail lamps (hard wired) on the rear of locos, DMUs/EMUs, IEPs/IETs etc., which display a 'steady' light (non-flashing).

[11B]

33 minutes ago, Wickham Green too said:

I'd always assumed that they'd been made to flash so they're more conspicuous !!?!

I had wondered that myself, but then the fixed/inbuilt ones could be made to flash 🤔

[Steadfast]

As @Wheatleyand @stewartingram said the flash is to prolong battery life.

 

They flash at 2 Hz (so twice a second) and are only lit for a small portion of the half second cycle, so would have a significantly longer battery life than a steady battery lamp.

 

Most model tail lamps fail to replicate the distinctive look of the the flash. Once you've noticed it, it makes many models look wrong.

 

Jo

[Wheatley]

1 hour ago, 11B said:

I had wondered that myself, but then the fixed/inbuilt ones could be made to flash 🤔

Do you mean the 'hazard warning' indication on 2nd gen (onwards) units? 

 

They flash either both together or alternate (I can't remember which) and are impossible to mistake for anything else. They shouldn't be flashing in normal use. 

[Steadfast]

31 minutes ago, Wheatley said:

They flash either both together or alternate (I can't remember which) and are impossible to mistake for anything else. They shouldn't be flashing in normal use. 

66s are both headlights together, with the markers remaining steady. Don't know about other types.

 

Jo

[Wheatley]

Of course - flashing headlights, or tail lights on (at the 'wrong' end) where flashing headlights aren't fitted. It's been a while since I had anything to do with them ! 

 

Ignore earlier answer then, ta. 

 

[Fredo]

Hi, 

I know that during the steam era Oil Lights were used and these stayed in place till the 70’s. Do you know exactly when battery powered lights started being used. Thanks Fred

[45125]

On 12/02/2024 at 08:31, Fredo said:

Hi, 

I know that during the steam era Oil Lights were used and these stayed in place till the 70’s. Do you know exactly when battery powered lights started being used. Thanks Fred

The very first battery tail lamps appeared around 69/70. These were the ones with two red lamps.

 

Al Taylor

[RetiredBod]

On 12/02/2024 at 08:31, Fredo said:

Hi, 

I know that during the steam era Oil Lights were used and these stayed in place till the 70’s. Do you know exactly when battery powered lights started being used. Thanks Fred

Battery lamps were used on block tank trains I believe from the early 1970s, the lamp brackets on the tank wagons were fitted with a peg to stop oil tail lamps from being used. 

 

I also remember still using oil tail lamps on RTC test trains until the mid 1980s.

 

https://www.flickr.com/photos/82085846@N02/44189626922

Edited February 13 by RetiredBod

[SM42]

My understanding was that the flashing lamp came about after a rear end collision where there was an empty container flat at the rear of the train with an oil tail lamp. 

 

It didn't show well in the dark and one of the recommendations was to make the tail lamp more conspicuous, especially where the vehicle le it's attached to is less conspicuous. 

 

The flashing, battery lamp was the result IIRC. 

 

 

 

Andy

Edited February 13 by SM42

[uax6]

A tail lamp is really only of use to us Bobbies, to tell us that the train is complete. Its not really there to stop other trains hitting that one (though of course they do, especially on permissive sections and in yards etc), which seems to be the misconception that the general public seem to live with

 

There have been many things used as tail lamps over the years, from newspapers to bog roll!

 

I can recall oil lamps well into the '80s, and I've got a sneaking idea that they made it into the '90's as well.

 

Andy G

 

 

[adb968008]

On 12/02/2024 at 09:31, Fredo said:

Hi, 

I know that during the steam era Oil Lights were used and these stayed in place till the 70’s. Do you know exactly when battery powered lights started being used. Thanks Fred

Late 1980’s flashing tail lamps became very common, same timescale as headlamps being fitted to locos and orange safety stripe being standard.

 

[Fredo]

Thanks 

[Sabato]

In the deep recesses of what passes for my memory, I recall a Home Service broadcast of Down Your Way. Probably in the late 60's, where the presenter (Franklin Engleman?) used to visit a town and interview various personages in the town.

 

On this particular occasion he spoke to manager of a company manufacturing railway oil lamps, including tail lamps. When asked why diesel locos carried oil tail lamps when they had fixed electric red lamps, the response was "well, the tail lamp is very important, and  the filaments of the electric lamps were not reliable enough to survive the vibration and shocks of the working diesel loco."

 

I just put it out there.

 

(Deary me, I must get out more.)

[Pete the Elaner]

On 09/02/2024 at 20:04, Steadfast said:

 

Most model tail lamps fail to replicate the distinctive look of the the flash. Once you've noticed it, it makes many models look wrong.

 

 

I made that observation at the club a while back when somebody brought it a model with a flashing tail lamp. Its flash was more reminiscent of the way a cursor flashes than the very quick 'on pulse' of a tail lamp.

Making a circuit board small enough is beyond my capabilities & resources but I am sure a manufacturer will oblige before long.

[65179]

The phasing out of oil tail lamps has been discussed here before:

 

 

 

January 1991 is suggested as the date for the instruction to cease use of oil lamps.

 

Around then, but probably a little earlier, I remember a massive pile of the things being assembled behind the buffers in the bay at the end of Warrington Bank Quay which was usually occupied by a pair of Class 20s whistling away in between MGR workings. I resisted the urge to stuff one in my bag at the time.

 

Simon

Edited February 15 by 65179

[Jeremy Cumberland]

1 hour ago, Sabato said:

On this particular occasion he spoke to manager of a company manufacturing railway oil lamps, including tail lamps. When asked why diesel locos carried oil tail lamps when they had fixed electric red lamps, the response was "well, the tail lamp is very important, and  the filaments of the electric lamps were not reliable enough to survive the vibration and shocks of the working diesel loco."

 

I just put it out there.

I forget exactly how the rule was worded so I am not sure about locomotives, but for DMUs, the rule book specifically mentioned an oil lamp, and the unions insisted on this, even though most (but not all) DMUs had either a red bulb or provision for a red glass over one or more marker light, specifically to act as a tail lamp.

 

Oil lamps might have been easier for signallers to see in daytime than illuminated tail lights. Remember that until reasonably recently (1980s?), there was no requirement for an ordinary tail lamp (ie not one that was built in) to be lit during daylight, unless the line ran through a tunnel.

Edited February 14 by Jeremy Cumberland

[Edwin_m]

1 hour ago, Pete the Elaner said:

I made that observation at the club a while back when somebody brought it a model with a flashing tail lamp. Its flash was more reminiscent of the way a cursor flashes than the very quick 'on pulse' of a tail lamp.

Making a circuit board small enough is beyond my capabilities & resources but I am sure a manufacturer will oblige before long.

The real crime to me is seeing a model locomotive with tail lamps lit when hauling a train.  Any rail staff seeing this should report it immediately*, because if the train should become divided behind the loco in an Absolute Block area, the next signaller will consider the line as clear on seeing the tail lamp lit.  

 

*I once did so by shouting across to the driver on the avoiding lines at Derby.  He replied that it must have been like that all the way from St Pancras.  Oh well...

Edited February 14 by Edwin_m

[keefer]

I'm sure I've read that tail lamps continued on DMUs as there was not a reliable/adequate battery back-up for the electric tail lights.

[Wickham Green too]

Even if there WAS a reliable/adequate battery back-up for the electric tail lights it's less than guaranteed that the bobby would see such a light in daylight - a physical lamp is far more conspicuous. The exception is the red blinds adopted on Southern units - a lot more visible though not necessarily recognised off region !

[Pete the Elaner]

2 hours ago, Edwin_m said:

The real crime to me is seeing a model locomotive with tail lamps lit when hauling a train.  Any rail staff seeing this should report it immediately*, because if the train should become divided behind the loco in an Absolute Block area, the next signaller will consider the line as clear on seeing the tail lamp lit.  

 

*I once did so by shouting across to the driver on the avoiding lines at Derby.  He replied that it must have been like that all the way from St Pancras.  Oh well...

 

DCC users have had the ability to turn off tail lights on the latest D&E models for 4-5 years now, so the model world is getting there.