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Which way should GWR semaphore blades face?


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I have read the big threads on GWR signals and finally have a vague idea of where they go. However, I have been watching Youtube videos and studying the ohitis and diagrams in my GWR BLT books and I am lost as to which way the semaphore blades should face and in some cases on which side of the track the entire semaphore should be placed. It seems that in most case the semaphore is located on the left side of the track except when it is on the right side. And the semaphore blades generally face to the left and away from the track except when they face the right and towards the track. Can anyone (Ststionmaster) provide some rhyme or reason for where they go and which way they should face? Thanks

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Signals are usually placed on the left of the track, unless there is some kind of sighting issue that would make it easier to see if it was on the right. I think the GWR were particularly fond of putting signals on the rights because their locos were right-hand drive(?). 

 

The red side of the signal arm (blade) faces oncoming trains (or yellow arm if it’s a Distant, etc). The arm always points to the left of the signal. Of course, if you walked round to the back of the signal it would be pointing the opposite way! The back of the signal arm is usually painted white with a black stripe. 

 

 

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Basically you've had the answers.  The normal thing with siting a semaphore signal was to ensure that the Driver of an approaching train got the best, and generally earliest, possible view of it.  Thus in many cases on the GWR (and BRWR) signals were placed on the 'wrong' side of the line to which they referred - i.e. to the right of that line and not on its left.  Equally in many locations the signals would be placed further right beyond the adjacent line - normally due to track curvature but sometimes due to other features such as station canopies obstructing the view.

 

On former broad gauge lines it was quite common toi find signals in the six foot interval between adjacent lines, i.e, thus placing them to the right of the line top which the signal applied.  This was particularly common at and near stations  where canopies and/or footbridges would otherwise prevent the earliest possible sighting of the signal by a Driver.  Siting in the six foot or ten foot could also be found at places where construction post dated the broad gauge but sufficient room was available to place signals between running lines to improve sighting.

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10 hours ago, Titanius Anglesmith said:

Signals are usually placed on the left of the track, unless there is some kind of sighting issue that would make it easier to see if it was on the right. I think the GWR were particularly fond of putting signals on the rights because their locos were right-hand drive(?). 

 

The red side of the signal arm (blade) faces oncoming trains (or yellow arm if it’s a Distant, etc). The arm always points to the left of the signal. Of course, if you walked round to the back of the signal it would be pointing the opposite way! The back of the signal arm is usually painted white with a black stripe. 

 

 

That is pretty clear then.

Edited by Cofga
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12 hours ago, Cofga said:

I have read the big threads on GWR signals and finally have a vague idea of where they go. However, I have been watching Youtube videos and studying the ohitis and diagrams in my GWR BLT books and I am lost as to which way the semaphore blades should face and in some cases on which side of the track the entire semaphore should be placed. It seems that in most case the semaphore is located on the left side of the track except when it is on the right side. And the semaphore blades generally face to the left and away from the track except when they face the right and towards the track. Can anyone (Ststionmaster) provide some rhyme or reason for where they go and which way they should face? Thanks

 

Can you please alter the thread title - it makes me wince to see the word 'blade'

 

Semaphore signals have NEVER had 'blades' in UK terminology - the sticking out bit which moves up or down have always been known as a signal 'arm'

 

To most folk the word 'blade' will refer to points - i.e. 'switch blades' (even through the professional term is 'switch rails')

 

 

Edited by phil-b259
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58 minutes ago, phil-b259 said:

 

Can you please alter the thread title - it makes me wince to see the word 'blade'

 

Semaphore signals have NEVER had 'blades' in UK terminology - the sticking out bit which moves up or down have always been known as a signal 'arm'

 

To most folk the word 'blade' will refer to points - i.e. 'switch blades' (even through the professional term is 'switch rails')

 

 

I thought Teddy Boys had Switch Blades:)

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1 hour ago, phil-b259 said:

 

Can you please alter the thread title - it makes me wince to see the word 'blade'

 

Semaphore signals have NEVER had 'blades' in UK terminology - the sticking out bit which moves up or down have always been known as a signal 'arm'

 

To most folk the word 'blade' will refer to points - i.e. 'switch blades' (even through the professional term is 'switch rails')

 

 

An interesting view, but is that true? I have regarded the term 'arm' to mean something which is composed of (usually) two components - the spectacle/pivot casting and the 'blade', the latter being the wooden or metal red or yellow bit which is attached to the former.

 

I would agree that 'blade' also refers to points. IIRC there were also 'blades' in Sykes instruments - which also contained 'tablets' that were nothing to do with single-line tablet instruments! 

Edited by RailWest
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22 hours ago, RailWest said:

An interesting view, but is that true? I have regarded the term 'arm' to mean something which is composed of (usually) two components - the spectacle/pivot casting and the 'blade', the latter being the wooden or metal red or yellow bit which is attached to the former.

 

I would agree that 'blade' also refers to points. IIRC there were also 'blades' in Sykes instruments - which also contained 'tablets' that were nothing to do with single-line tablet instruments! 

 

I have 18 years professional experience in UK mainline signalling and involvement in a Heritage railway, plus have read many books on signalling over the years.

 

NOBODY has EVER refereed to the sticking out bit o a semaphore arm as a 'blade'

 

If a railway wants to order a new one they order an 'arm' - see https://www.unipartrail.com/catalogue.html (Signalling > Signals & Structures > Mechanical Signals > Running Signal)

 

Cat Number:-  0088/000003 

Pt/ID Description:- Arms, Iron, Enamelled, Without Boss Plates & Spindles, 4 ft 0" Stop Signals

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On 26/09/2019 at 05:34, Titanius Anglesmith said:

................................................................................... The arm always points to the left of the signal. ..................................... 

 

 

Just to be pernickety, and as we are talking GWR signals, Disc and Crossbar type signal arms stuck out equally both sides!

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57 minutes ago, brianusa said:

Its more common in the US to refer to it as a semaphore blade:excl:

    Brian.

Looking at my big piccy book of American trains, looks like you sometimes have the thing sticking out to the right as well (but doesn't appear to be universal).

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13 minutes ago, eastglosmog said:

Looking at my big piccy book of American trains, looks like you sometimes have the thing sticking out to the right as well (but doesn't appear to be universal).

All the photos I have seen of US semaphores show them pointing to the right.

such as these lower quadrant ones:

4a11368a.preview.jpg

https://www.shorpy.com/node/7451?size=_original#caption

 

Click link for original

Edited by melmerby
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1 hour ago, eastglosmog said:

Looking at my big piccy book of American trains, looks like you sometimes have the thing sticking out to the right as well (but doesn't appear to be universal).

 

Its basically two arms on the same post for the same track, the White horizontal stop, depending on direction, the Red vertical has the ROW.  Now back to GWR:clapping::) The BNSF Railway is the only major US railroad to run on the same side as the UK.

     Brian

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I guess it all depends on what your sources are, this is from Wikipedia:

 

The British semaphore signal arm consists of two parts: A wooden or metal arm (or "blade") which pivots at different angles, and a spectacle holding coloured lenses which move in front of a lamp in order to provide indications at night. Usually these were combined into a single frame, though in some types (e.g. "somersault" signals in which the arm pivoted in the centre), the arm was separate from the spectacle. The arm projects horizontally in its most restrictive aspect; other angles indicate less restrictive aspects.

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Looking at where the first posting was made, the use of American terminology seems reasonable!

 

There were also some GWR signals that had a pivot and the spectacle glasses in the centre of the arm and rotated, with approximately equal amounts of arm left and right of the post.

 

https://signalbox.org/signals/walnuttree.jpg

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8 minutes ago, RLWP said:

I've just checked, and LNWR drawings refer to the component as an arm

 

Which means the GWR component is probably a blade, finger, board, plank... anything but arm

 

Richard

Post mounted Signalman operated device coloured movable, locomotive drivers for the use of, track occupation information display.

:jester:

 

Edited by melmerby
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