Hi, can anyone explain the operation of the headlights and tail lights on a Class 42? There is 1 white lamp showing forwards and one red at the rear of the engine, but they are on opposite sides.
Now clearly if you see a white light it's a train coming towards you, and if it's red then the train is travelling away from you.
But why is there only one light of each colour?
A non-trainy friend thought that maybe it was red=left and white=right but on a moving vehicle this doesn't seem to make as much sense as it does for e.g. roadside bollards with reflectors.
All insights welcome, especially specific to the class 42.
Cheers
Slate
Class 42 single head/tail lamps
Re: Class 42 single head/tail lamps
Because the UK railway system had long operated on the basis that 'one light is sufficient for the purpose' based on the previous practise of use of an oil lamp, and this was a very conservative industry. The typical light used on BR's 1950s and 60s diesels was a 40W filament lamp, so it was actually 'one feeble light is sufficient for the purpose', as had been the case with the oil lamps, which could only be seen to be emitting light when there was real darkness...
This kind of ingrained 'old world' thinking was finally significantly checked by government when a BR chairman was asked 'And how many fatalities do you plan to cause this year?' there having been an established culture of 'this shit happens'. Some might think this exagerated, but within living memory incidents such as a derailment which killed the fireman of a steam locomotive, saw the driver of that loco go back to the loco shed and sign on for another turn, which he then operated - he was still within his shift hours...
Re: Class 42 single head/tail lamps
Depends on the date also to what regs were in at the time.
When I was working on the railway as a guard in the late 90's to the late 00's, the regulations stated as follows. One large front light (White) for trains that had a top "Official booked speed" (Many classes could easily exceed this but officially one was not supposed to) of under 100mph. (I think it was 100mph if I recall). Two large white lights for those that exceeded 100mph. So a HST would have two large white lights. There were also small marker lights which were just to indicate the train was there.
The reason for these one or two white lights was to indicate to PW staff on the track if a train could be travelling towards them had the potential to be travelling faster than they would think.
Now most of the trains below this speed actually had two large white lights even though only one was illuminated. There was a reason for this. One would be called a "Day light" for daytime running and the other was a night light for running at night. The difference between the two was the daylight beam shone straight ahead so that track workers could see it. The night light would illuminate a small portion of the track so if a driver had to do a slow speed check (15mph or less) of the track they could. There wasn't enough beam to actually see the track under normal lines peed conditions as it is not like a car where one needs to see where one is going.
I remember when American built trains first came in and also the odd few other trains started having an extra white roof light. The unions via the drivers wanted to try to ban these lights because drivers at night found them dazzling so they struggled at times to see the signals. I don't know what was done about it as they were still being discussed (Under review) when I left the railways as far as I know.
Now at the back of the train there is either one flashing or steady red handlamp or built in red lamp or two taillampa. If on the back of a train such as an engine and coaches passenger train or a freight train of wagons, tankers or vans etc, they will have a large portable handlamp which flashes red. The flashing red helps signal boxes and others realize the train is likely to be longer than an ordinary loco or DMU. Guards and drivers always carried portable handlamps which could display clear, greed and red. PW workers had the same lamps (Called "Bardic lamps" but theirs also contained a yellow light as well for calling on trains to the next signal if needed. These lamps were multipurpose in that a train can use them if their lights are not working, as the back of these lamps were made to fit to train lamp brackets which all railway vehicles have, be they freight, passenger or locos or DMU's etc, etc.. The small portable handlamps could also be used to signal to drivers in shunting work etc.
Now while I remember. When shunting work is carried out, trains will (Or should!) display both red lights and white marker lights at the SAME END).
In the past they used to have the illuminated headcode boxes. These could be 2 character but most were 4 character. After the great train robbery where they could easily see the headcode box on display, they decided it wasn't wise to display train headcodes due to the ease that the robbery was made, so they decided to abandon the headcodes displayed at the front of locomotives. The change began in 1976 to 1977 where traincrew were told they had to display 0O00 instead (The second character being the letter "O" and the first and the last two characters were number "0"'s. By the time 1979 to 1980 came along, they started replacing the headcode blinds with the two white circles instead so one had the headcode boxes lit up by two white dots. These became known as "Domino lights" amongst railway enthusiasts. Later if a bird hit or stones thrown hit and smashed these headcode box windows, they plated them over with steel plate instead with two holes drilled to display the "Lights". In the early 1980's trains working the Heart of Wales line were allowed to carry a brighter white light so drivers at night could pick out any stray sheep on the line, so one had Swindon built DMU's and class 03's used up there fitted with these brighter single white lights at a high level. The idea was seen as a success, so after this locos such as class 47's started being fitted in the mid to late 1980's with these extra single bright lights (Though positioned lower down than the ones on the Heart of Wales line), and the rest is history! (As from then on all trains had to have a brighter lamp be it a single brighter one for trains that had a top speed of less than 100mph or two for trains above 100mph top speed. They did actually have trains of above 100mph running with two bright lights from the introduction of the HST's onwards).
Though I have only skimmed through two and a bit decades of history, but no doubt there will be more to learn. Just to note. Warships were last used around 1976, with most scrapped around 1973. So you will see them with the proper headcode boxes in use with the last survivor possibly carrying headcode boxes with domino dots in them. The other white lights will be marker lights and red for tail lights. Marker lights are to show the train is present on the track so are used wherever the loco is running. The white marker lights at the back of the train are turned off with the ONLY exception is when they are shunting where white and red is displayed at the back and the front. Obviously trains in use will dhow the white marker lights at the front.
Now this is often where modellers make a mistake. When locos are coupled onto their train of coaches or wagons etc, one turns the red lights off by the railway rules, and the very back of the train formation displays the red light instead. This is so the signal an can tell if the train is "Complete" just incase a coupling breaks and only half the train is passed. This is why it is the traincrews job to ensure the loco lights are turned off when coupled to an item of rolling stock. So there will be white at the very front and red at the very back of a train formation. If two DMU's or sprinters etc are coupled together, all lights where the two middle cabs must be turned off, for signalmen to know that if they see a train pass with no red lights at the very back, they know to stop the train at the next signal as it indicated the possibility that half the train has split. (Most of the time it is traincrew error if a train passes with its rear lights off at the back, but signalmen are trained to stop trains anyway just incase).
I think that is it... What you need to know is your Warshipneeds a red rear light (Or two if fitted) being red at the back if it is running with just the loco. White illuminated headcode boxes at the front with an additional small white marker light (If fitted).
Any train left on the line at night in a busy siding loop will have red lights displayed at either end. (A large proper handlamp showing red (Portable taillamp) or the guards bardic lamp showing red... large marshaling yards with a many long term parked vehicles maynot have lights displayed. But in general, if it is a well used running line, parked vehicles will display red at both ends of the formation UNLESS one end is where a buffer is so no lights are necessary against the buffer end of the train... Unless they expect the vehicles will soon be moved...
Haha! Think I have given too much detail... But modellers remember. No red loco lights at the back if the loco is coupled onto its train! The very back vehicle needs a red light instead (Usually flashing red in later years but steady red if no flashing lamp is available).
When I was working on the railway as a guard in the late 90's to the late 00's, the regulations stated as follows. One large front light (White) for trains that had a top "Official booked speed" (Many classes could easily exceed this but officially one was not supposed to) of under 100mph. (I think it was 100mph if I recall). Two large white lights for those that exceeded 100mph. So a HST would have two large white lights. There were also small marker lights which were just to indicate the train was there.
The reason for these one or two white lights was to indicate to PW staff on the track if a train could be travelling towards them had the potential to be travelling faster than they would think.
Now most of the trains below this speed actually had two large white lights even though only one was illuminated. There was a reason for this. One would be called a "Day light" for daytime running and the other was a night light for running at night. The difference between the two was the daylight beam shone straight ahead so that track workers could see it. The night light would illuminate a small portion of the track so if a driver had to do a slow speed check (15mph or less) of the track they could. There wasn't enough beam to actually see the track under normal lines peed conditions as it is not like a car where one needs to see where one is going.
I remember when American built trains first came in and also the odd few other trains started having an extra white roof light. The unions via the drivers wanted to try to ban these lights because drivers at night found them dazzling so they struggled at times to see the signals. I don't know what was done about it as they were still being discussed (Under review) when I left the railways as far as I know.
Now at the back of the train there is either one flashing or steady red handlamp or built in red lamp or two taillampa. If on the back of a train such as an engine and coaches passenger train or a freight train of wagons, tankers or vans etc, they will have a large portable handlamp which flashes red. The flashing red helps signal boxes and others realize the train is likely to be longer than an ordinary loco or DMU. Guards and drivers always carried portable handlamps which could display clear, greed and red. PW workers had the same lamps (Called "Bardic lamps" but theirs also contained a yellow light as well for calling on trains to the next signal if needed. These lamps were multipurpose in that a train can use them if their lights are not working, as the back of these lamps were made to fit to train lamp brackets which all railway vehicles have, be they freight, passenger or locos or DMU's etc, etc.. The small portable handlamps could also be used to signal to drivers in shunting work etc.
Now while I remember. When shunting work is carried out, trains will (Or should!) display both red lights and white marker lights at the SAME END).
In the past they used to have the illuminated headcode boxes. These could be 2 character but most were 4 character. After the great train robbery where they could easily see the headcode box on display, they decided it wasn't wise to display train headcodes due to the ease that the robbery was made, so they decided to abandon the headcodes displayed at the front of locomotives. The change began in 1976 to 1977 where traincrew were told they had to display 0O00 instead (The second character being the letter "O" and the first and the last two characters were number "0"'s. By the time 1979 to 1980 came along, they started replacing the headcode blinds with the two white circles instead so one had the headcode boxes lit up by two white dots. These became known as "Domino lights" amongst railway enthusiasts. Later if a bird hit or stones thrown hit and smashed these headcode box windows, they plated them over with steel plate instead with two holes drilled to display the "Lights". In the early 1980's trains working the Heart of Wales line were allowed to carry a brighter white light so drivers at night could pick out any stray sheep on the line, so one had Swindon built DMU's and class 03's used up there fitted with these brighter single white lights at a high level. The idea was seen as a success, so after this locos such as class 47's started being fitted in the mid to late 1980's with these extra single bright lights (Though positioned lower down than the ones on the Heart of Wales line), and the rest is history! (As from then on all trains had to have a brighter lamp be it a single brighter one for trains that had a top speed of less than 100mph or two for trains above 100mph top speed. They did actually have trains of above 100mph running with two bright lights from the introduction of the HST's onwards).
Though I have only skimmed through two and a bit decades of history, but no doubt there will be more to learn. Just to note. Warships were last used around 1976, with most scrapped around 1973. So you will see them with the proper headcode boxes in use with the last survivor possibly carrying headcode boxes with domino dots in them. The other white lights will be marker lights and red for tail lights. Marker lights are to show the train is present on the track so are used wherever the loco is running. The white marker lights at the back of the train are turned off with the ONLY exception is when they are shunting where white and red is displayed at the back and the front. Obviously trains in use will dhow the white marker lights at the front.
Now this is often where modellers make a mistake. When locos are coupled onto their train of coaches or wagons etc, one turns the red lights off by the railway rules, and the very back of the train formation displays the red light instead. This is so the signal an can tell if the train is "Complete" just incase a coupling breaks and only half the train is passed. This is why it is the traincrews job to ensure the loco lights are turned off when coupled to an item of rolling stock. So there will be white at the very front and red at the very back of a train formation. If two DMU's or sprinters etc are coupled together, all lights where the two middle cabs must be turned off, for signalmen to know that if they see a train pass with no red lights at the very back, they know to stop the train at the next signal as it indicated the possibility that half the train has split. (Most of the time it is traincrew error if a train passes with its rear lights off at the back, but signalmen are trained to stop trains anyway just incase).
I think that is it... What you need to know is your Warshipneeds a red rear light (Or two if fitted) being red at the back if it is running with just the loco. White illuminated headcode boxes at the front with an additional small white marker light (If fitted).
Any train left on the line at night in a busy siding loop will have red lights displayed at either end. (A large proper handlamp showing red (Portable taillamp) or the guards bardic lamp showing red... large marshaling yards with a many long term parked vehicles maynot have lights displayed. But in general, if it is a well used running line, parked vehicles will display red at both ends of the formation UNLESS one end is where a buffer is so no lights are necessary against the buffer end of the train... Unless they expect the vehicles will soon be moved...
Haha! Think I have given too much detail... But modellers remember. No red loco lights at the back if the loco is coupled onto its train! The very back vehicle needs a red light instead (Usually flashing red in later years but steady red if no flashing lamp is available).
Modelling On A Budget ---》 https://www.newrailwaymodellers.co.uk/F ... 22&t=52212
Re: Class 42 single head/tail lamps
Not at all. Very interesting reading, and explains a lot of things for me.Mountain wrote:
Haha! Think I have given too much detail...
I should print it out, because I'm bound to forget most of it. But then I'll forget where I put the printout. It's a rabbit hole...