Still on signals

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Hermann Kuhne
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Still on signals

Post by Hermann Kuhne »

A great, big thanks to all that gave some info on signals. Especially signals used on the Pietermaritzburg to Ladysmith line. A special thanks to Steve for valuable information.
I still need some info/help if possible.
I obtained two videos and lots of pics. The videos are in-cab videos, showing the whole route, from Pietermaritzburg to Mooirivier and then Mooirivier to Ladysmith. A great help indeed. Unfortunately the resolution of the videos is not always of highest quality and the signals are sometimes blurred and not of much help.
My question: How do they actually place signals? Most of the times I see a series of two two-lens signals (especially the part from Mooirivier to Ladysmith), followed by a 4 lens (4 aspect) signal and then the junction signal at cross-overs or the entry to stations. On longer stretches there are more than two two-lens signals, followed by a 4 lens signal and then the junction signal.
On the stretch from Pietermaritzburg to Mooirivier I can sometimes see three lens signals, two lens signals and the four lens signals.
Is there a specific way these signals are placed? Distances? I am sure there is a very, strict way these signals are placed, depending on the stretch of route.
Any info please.
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Steve Appleton
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Re: Still on signals

Post by Steve Appleton »

Hermann, because I am not familiar with that particular route, it is difficult to identify what signals you have seen from descriptions. Signals sometimes date from different eras and, on occasions, the layout of the lenses is varied to suit the location and space available. There is no one "standard" for signal layout except that the clear (green proceed) aspect is usually the top-most lens and the red is located below the first yellow. In some areas, single lens "search light" signals are used wherein the displayed colour is selected by electro-mechanically moving colour filters into the light path.

If the signal is only a warning signal (sometimes called a distant signal - incorrectly, that term applies to distant semaphore signals) it may only have two lenses (usually but not exclusively side by side - horizontally) that display either a clear (green) aspect or a caution (yellow) aspect only. Such a signal will also have a small white board with a diagonal black line on the post below to identify its nature. A warning signal has no danger (red) aspect. If such a signal is faulty or not lit, the driver may pass that signal on the assumption that it is at caution but knowing that the next signal could be displaying a danger (red, stop) aspect.

Most signals are three or four aspect and contain green, red and either one (three aspect) or two (four aspect) yellow lenses. These signals are "absolute stop" signals and can display a danger, a caution (warning) or a clear (green) aspect. Caution and clear are both "proceed" aspects. If such a signal is displaying a danger (red) aspect or is faulty or not lit, the driver must assume it is at danger and stop indefinately to obtain authority before passing it. The lenses in such signals can be arranged horizontally, usually in two stacked rows (as a rectangle) of two lenses (one row of two lenses and one row of a lens and a blank - three aspect). Alternatively the lenses can be stacked vertically above each other or can even be a combination!

Therre may be repeater signals in places too where visibility is restricted (they have an "X" on the post -- usually illuminated).

Indeed the signals are not placed randomly and depend very much upon the track layout and visibility and where the sections (block) joints are positioned. The aspects a signal is able to display are also goverened by how far ahead the signal reads. In open country, warning signals often placed some distance ahead of the related stop signals placed at the approaches to stations, sidings and loops. However in urban areas where the block lengths are short then most signals serve a variety of uses, being a stop signal for the section ahead and if that is clear, a warning signal for the section ahead of that and if that is clear, then a green aspect will be shown, unless... There is a turn-out or turn-in set up ahead, in which case a warning aspect is displayed usually in conjunction with an appropriate route or direction indicator (row of white lights).

Believe me, there is more than that and this is a complex topic. The above is just a short part of it. Best you send me pictures or frame grabs by PM and I will try to identify them. Not easy, because unless you know the route, it is not always possible to know what aspects the signal is capable of dispaying using lenses that are unlit. All drivers are required to know the routes they drive over and are familiar with the likely displays on the signals they encounter.

Hope that helps.
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Steve Appleton
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Re: Still on signals

Post by Steve Appleton »

Hermann, may I suggest that you also join the SAR signals Facebook page at:
http://www.facebook.com/groups/southafricansignals/
There are a number of pictures there and some explanations.
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Steve Appleton
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Re: Still on signals

Post by Steve Appleton »

Re-reading my write up above I have to add that the number of lenses a signal has doesn't necessarily equal the number of aspects it can show. the two are different. Lenses are the individual coloured lights on the signal head and the aspect is the meaning or "display" that a signal shows.

For instance, a three lens signal (green, yellow and red lenses) can display more than three aspects. The common aspects would be red (danger), yellow (caution) and green (proceed clear) aspects. However such a signal placed just before a turnout or entrance to a goods yard or siding can also be used to display combined red and yellow lights ("goods or siding" aspect), an aspect that indicates to the driver that he must proceed slowly with caution and that he will be entering a goods yard or siding where he can be expected to stop or receive further indications from a shunter.

Thus such a three lens signal can be used to display four distinct aspects.
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John Ashworth
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Re: Still on signals

Post by John Ashworth »

Isn't a goods and sidings signal usually a completely separate yellow lens mounted below the main signal?
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Steve Appleton
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Re: Still on signals

Post by Steve Appleton »

Only place where I have positively seen that is at Capital Park yard on approach to control point 35 from the old loco depot, which is a single lens red signal is permanently set to danger. A separate yellow lens is mounted below the red lens and lit to admit a train up to the control point.

Whether a separate yellow lens is necessary on a three lens signal, would depend on the signal's layout. Most that I have seen are organised with green at top, red in the middle and then yellow at the bottom. However, at Hercules where most signals have 4 lenses (two yellow lenses, one immediately above and one located some distance below the red lens), the bottom yellow is used in conjunction with the red as a "goods or siding" aspect.

The latter signals are also capable of displaying several extra aspects including: double yellow (warning, about to turn out of in over one or more sets of low speed points, next signal is displaying a proceed aspect); green and yellow (warning, about to turn in or out over higher-speed points, next signal is displaying a proceed aspect).

In some configurations, a white lens is mounted alongside the red lens near the top (usually to the right). This signal can display even more aspects using combinations that include the white light.

There is of course often an entirely separate lens mounted low down (below the signal number plate) on many posts. This is the blue "emergency" aspect lens which is only lit if all else fails, authorising the driver to drive slowly "on sight" to the next signal checking that all points are correctly set on the way.

Lastly, many signal posts also carry a one-position-light shunt signal, below the signal number plate. This consists of two small white light lenses placed diagonally at about 45 degrees on a rectangular backing plate. When lit, this is to admit a train into a section that is occupied or onto the wrong line for a shunting movement. Sometimes also used instead of the blue light when there is a problem with the track circuits.
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John Ashworth
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Re: Still on signals

Post by John Ashworth »

Thanks, Steve. I was just thinking of the driver's manual, 40.2, which states:
A colour-light goods or siding signal, where provided, is fixed on the same post as the main colour-light signal, but below it...

A colour light goods or siding signal displays only a yellow light which indicates "proceed with caution". When the signal displays a yellow light, the main colour-light signal is at "danger".
This implies to me that the goods and siding signal is a separate signal, mounted on but below the main signal, not simply an optional use of one of the yellow lenses of the main signal. But I'm ready to be corrected.

I think there is more than one example at Capital Park. As well as the one controlling entry into the yard from the eastern leg of the triangle coming out of the old loco depot (Rovos and FOTR depot), you also encounter one when coming into the yard off the top leg of the triangle (parallel to the main line), if I remember rightly.
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Mike Haslam
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Re: Still on signals

Post by Mike Haslam »

John, yes there are other examples of the goods and siding signal, including a semaphore signal, at Capital Park. There are G&S signals on all the approach roads from the main line. We do not usually see the one going to the 'electrics' shed. They are the type you describe, a yellow light on the same mast as the main signal.

However, The Train Working Rules states only that : "A colour-light goods or siding signal, where provided, is fixed on the same post as the main colour-light signal, but below it." and shows a picture of one. Unfortunately I am not able to copy the picture into this message, but the picture is of multi-lens signal, the same type as display a double yellow, also has the attached white lens, and in the picture it shows the red lens and the bottom yellow lens, both lit.

I suspect the G&S signals at C.P. are merely 'upgrades' to existing signals, by addition of a separate lens.

Another thing to be aware of are the 'trap points' beyond the signal. When the danger aspect only is displayed, the points are set to dump the train into the veldt! Only when the yellow aspect is also displayed are the points set for entry into the yard.
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John Ashworth
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Re: Still on signals

Post by John Ashworth »

Thanks, Turtle. This is what I've just received from our old instructor, Uncle Cliff:
Uncle Cliff wrote:The Goods or Siding signal

1 The old colour light signals:

Single lens or multi lens (NOT multi aspect): The goods or siding
signal is mounted below the main signal. Eg Koedoespoort station.

Main signal MUST be at danger, then goods or siding (yellow light)
may be operated, remember the 15km/h past the signal

2 The new colour light signals

These signals are multi aspect signals: The goods or siding signal
is mounted below the main signal. Eg Pyd. South station

Main signal MUST be at danger, then goods or siding (yellow light)
may be operated, remember the 15km/h past signal

Remember that the goods or siding signal has its own aspect on the same as
the main signal but below the main signal just like the emergency aspect
(blue light).

Hope this makes it clearer
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Mike Haslam
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Re: Still on signals

Post by Mike Haslam »

Forgot to mention that there are differences in approach for 'attended' yards and 'un-attended' yards.

The fireman (train assistant!!) gets to do a lot of walking and hand signalling at an unattended yard. An attended yard may become unattended - especially when all the staff have left for the rugby/cricket match.
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Steve Appleton
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Re: Still on signals

Post by Steve Appleton »

Mike, The yard at Hercules is not always attended and we usually have see ourselves in on return in the evening.
John, the signals at Hercules are 4 lens type with double yellow lenses. The bottom yellow is mounted quite some way below the red and appears functionally equivalent to a separate yellow lens. I suspect this large gap between the yellows is also necessary so that an approaching driver can more easily see a double yellow aspect from a distance.
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John Ashworth
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Re: Still on signals

Post by John Ashworth »

But do we ever actually get admitted into Hercules yard using a goods and sidings aspect? I seem to recall that we are admitted by a one-position light signal mounted on a main signal at danger.
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Steve Appleton
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Re: Still on signals

Post by Steve Appleton »

Yes we have when we come in from Pretoria Station through Hercules platform 1. I have also acted on a G+S aspect on the signal at the Daspoort end of Hercules platform 3 when propelling back into the yard from shunt signal HER 2460. Rare because mostly we get the shunt signal, but it has happened and is strictly more correct!
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