Semaphore and colour light signal questions.

[The Silver Jar...]

Right i've been wondering over these few questions over the last few
days and it's got me thinking, i need answers! (plus i think we need a
long interesting knowledgable thread).

All these questions are with regards to the UK mainline (excluding
islands, underground, non-standard gauges and preserved railway
lines).

1) Right (now i haven't got a clue here), but i presume before the
introduction of colour light signals they would have been tested out
on short stretches of line, if so which were the first lines to
recieve the new signals?

2) Presumably if the above statement is true there was a period where
semaphore's were still the main but the colour variants existed side
by side but the decision to actively go about replacing all the
semaphores (or most) had not yet been reached. In what year did they
(presumably BR) decide to actively go about removing semaphores in
favour of colour signals.

3) Has there ever been a case (however unlikely, but strange things
happen in the railway world) where a colour light signal has been
replaced by a semaphore signal? [remember excluding preservation
railways].

4) Where are the remaining Semaphore signal strongholds?

5) Are semaphores still actively being replaced or has it kinda all
ground to a halt?


Mat.

[Ronnie Clark]

Post by The Silver Jar...
1) Right (now i haven't got a clue here), but i presume before the
introduction of colour light signals they would have been tested out
on short stretches of line, if so which were the first lines to
recieve the new signals?

The Great Central Railway was one of the early pioneers of colour-light
signalling, immediately after the first world war, IIRC. Re-signalling the
main line from Manchester to London Marylebone in the post-war years led to
a number of innovations (not all strictly "brand-new", but amongst the first
wide-spread installations) were included. There was the change from
lower-quadrant to upper-quadrant signalling. Distant signals being given
given yellow spectacles. A large number of distants being replaced wholly
with colour lights.

This resulted in schemes similar to that at Quorn and Woodhouse today - a
colour light distant, with semaphore home and distant, then plain semaphore
starters and advance starters.

Post by The Silver Jar...
2) Presumably if the above statement is true there was a period where
semaphore's were still the main but the colour variants existed side
by side but the decision to actively go about replacing all the
semaphores (or most) had not yet been reached. In what year did they
(presumably BR) decide to actively go about removing semaphores in
favour of colour signals.

The out-lawing of lower-quadrant sempahores prompted BR(WR) to re-signal,
and I think it was then that the first wide-spread all-colour-light
signalling took place - but I'm a bit shaky on the date. Probably 50s/60s.

Post by The Silver Jar...
3) Has there ever been a case (however unlikely, but strange things
happen in the railway world) where a colour light signal has been
replaced by a semaphore signal? [remember excluding preservation
railways].

There are probably hundreds of such instances, where lines have been
completely reduced in scale and capacity, and signalling would be removed
and replaced by fixed semaphore signals. Latterly, signal boards are used,
though in the case of a distant signal board, they still depict a distant
semaphore signal painted onto the sign. This happened on the section of the
Great Central north of Loughborough, which BR retained, but singled, and
treated as a long siding. Only now the line recently entered preservation is
signalling (semaphore and colour-light) being restored.

Post by The Silver Jar...
4) Where are the remaining Semaphore signal strongholds?
5) Are semaphores still actively being replaced or has it kinda all
ground to a halt?

I can't answer these last two, but I do think it is about time that
semaphores were gotten rid of, as much as I personally love them. The man
power that goes into maintaining them is phenomenal, as it is a mainly
mechanical system (although there are examples of electrically operated
semaphore signals).

Ronnie
--
Volunteer guard on the Great Central Railway, Loughborough, Leicestershire
Visit the world's only double track preserved steam railway!
http://www.gcrailway.co.uk

[BH Williams]

Post by Ronnie Clark

Post by The Silver Jar...
1) Right (now i haven't got a clue here), but i presume before the
introduction of colour light signals they would have been tested out
on short stretches of line, if so which were the first lines to
recieve the new signals?

The Great Central Railway was one of the early pioneers of colour-light
signalling, immediately after the first world war, IIRC. Re-signalling the
main line from Manchester to London Marylebone in the post-war years led to
a number of innovations (not all strictly "brand-new", but amongst the first
wide-spread installations) were included. There was the change from
lower-quadrant to upper-quadrant signalling. Distant signals being given
given yellow spectacles. A large number of distants being replaced wholly
with colour lights.
This resulted in schemes similar to that at Quorn and Woodhouse today - a
colour light distant, with semaphore home and distant, then plain semaphore
starters and advance starters.

Post by The Silver Jar...
2) Presumably if the above statement is true there was a period where
semaphore's were still the main but the colour variants existed side
by side but the decision to actively go about replacing all the
semaphores (or most) had not yet been reached. In what year did they
(presumably BR) decide to actively go about removing semaphores in
favour of colour signals.

The out-lawing of lower-quadrant sempahores prompted BR(WR) to re-signal,
and I think it was then that the first wide-spread all-colour-light
signalling took place - but I'm a bit shaky on the date. Probably 50s/60s.

Mid 1930s for the Bristol, Cardiff and Paddington schemes, which were
renewed and extended in the mid 1970s. I don't think that lower-quadrant
signals were ever 'outlawed' for like-for-like renewals, but after the
closure of Reading Signal Works, new parts would have to have been sourced
elsewhere

Post by Ronnie Clark

Post by The Silver Jar...
3) Has there ever been a case (however unlikely, but strange things
happen in the railway world) where a colour light signal has been
replaced by a semaphore signal? [remember excluding preservation
railways].

There are probably hundreds of such instances, where lines have been
completely reduced in scale and capacity, and signalling would be removed
and replaced by fixed semaphore signals. Latterly, signal boards are used,
though in the case of a distant signal board, they still depict a distant
semaphore signal painted onto the sign. This happened on the section of the
Great Central north of Loughborough, which BR retained, but singled, and
treated as a long siding. Only now the line recently entered preservation is
signalling (semaphore and colour-light) being restored.

Post by The Silver Jar...
4) Where are the remaining Semaphore signal strongholds?

The North and West line , once it leaves the Newport suburbs, is almost all
semaphore as far as Shrewsbury- Hereford must be one of the largest UK
stations still mechanically signalled.

Post by Ronnie Clark

Post by The Silver Jar...
5) Are semaphores still actively being replaced or has it kinda all
ground to a halt?

.

Post by Ronnie Clark
I can't answer these last two, but I do think it is about time that
semaphores were gotten rid of, as much as I personally love them. The man
power that goes into maintaining them is phenomenal, as it is a mainly
mechanical system (although there are examples of electrically operated
semaphore signals).
Ronnie
--
Volunteer guard on the Great Central Railway, Loughborough, Leicestershire
Visit the world's only double track preserved steam railway!
http://www.gcrailway.co.uk

Most, if not all, recent resignalling work has been the renewal of 60s era
multi-aspect signals,notably the West Coast main-line. There has been a
small amount of resignalling in the SE, where the Ashford- Canterbury line
has been dragged from the 19th to 21st centuries. The main problem is not
the maintenance of the lineside signalling, but the repair of the mechanical
interlockings and lever frames, which has become something of a lost art.
Sometimes, elements of these mechanical interlockings remain, even when the
line is colour-light signalled- Stockport, for example

Brian

[Exjims]

Post by The Silver Jar...
4) Where are the remaining Semaphore signal strongholds?

North Wales Coast, Hope Valley Line, Chester to Warrington Line

[Robert Wilson]

I'm interested in getting hold of a colour light signal, possibly three
aspect, or four aspect. Who would I need to speak to?

Cheers,

Rob.

Post by Exjims

Post by The Silver Jar...
4) Where are the remaining Semaphore signal strongholds?

North Wales Coast, Hope Valley Line, Chester to Warrington Line

[Cadman]

Post by Robert Wilson
I'm interested in getting hold of a colour light signal, possibly three
aspect, or four aspect. Who would I need to speak to?
Cheers,
Rob.

Keep a look out on ebay. Only last week there was a 4 aspect signal for
sale.
Neil

[Nigel]

On Tue, 12 Oct 2004 15:22:08 +0100, Robert Wilson

Post by Robert Wilson
I'm interested in getting hold of a colour light signal, possibly three
aspect, or four aspect. Who would I need to speak to?
Cheers,
Rob.

Try ECML, they've just replaced all their singals around Stow Hill to
a newer versions.

It is 4-aspect, but only two actual lamps.
The top one does the 2nd amber, and the bottom lamp does red, primary
amber and green. Not quite sure how it works, but work it does. I
think they've actually made the sections slightly closer; the line is
cleared very quickly indeed when the trains are going at full tilt!

Nigel

[BH Williams]

Post by Nigel
On Tue, 12 Oct 2004 15:22:08 +0100, Robert Wilson

Post by Robert Wilson
I'm interested in getting hold of a colour light signal, possibly three
aspect, or four aspect. Who would I need to speak to?
Cheers,
Rob.

Try ECML, they've just replaced all their singals around Stow Hill to
a newer versions.
It is 4-aspect, but only two actual lamps.
The top one does the 2nd amber, and the bottom lamp does red, primary
amber and green. Not quite sure how it works, but work it does. I
think they've actually made the sections slightly closer; the line is
cleared very quickly indeed when the trains are going at full tilt!
Nigel

Fibre optics, I believe...
Brian

[Exjims]

Post by Nigel
Try ECML, they've just replaced all their singals around Stow Hill to
a newer versions.
It is 4-aspect, but only two actual lamps.
The top one does the 2nd amber, and the bottom lamp does red, primary
amber and green. Not quite sure how it works, but work it does. I
think they've actually made the sections slightly closer; the line is
cleared very quickly indeed when the trains are going at full tilt!
Nigel

Do,nt you mean WCML, Stowe hill? Which if correct is apart of the Rugby
resignalling using Dorman LEDs Signals.

[Nigel]

Post by Exjims

Post by Nigel
Try ECML, they've just replaced all their singals around Stow Hill to
a newer versions.
It is 4-aspect, but only two actual lamps.
The top one does the 2nd amber, and the bottom lamp does red, primary
amber and green. Not quite sure how it works, but work it does. I
think they've actually made the sections slightly closer; the line is
cleared very quickly indeed when the trains are going at full tilt!
Nigel

Do,nt you mean WCML, Stowe hill? Which if correct is apart of the Rugby
resignalling using Dorman LEDs Signals.

I was referring to the down signal at Nether Heyford, just out of Stow
Hill Tunnel which was removed about six weeks ago.

Nigel

[Exjims]

Post by Nigel

Post by Exjims

Post by Nigel
Try ECML, they've just replaced all their singals around Stow Hill to
a newer versions.
It is 4-aspect, but only two actual lamps.
The top one does the 2nd amber, and the bottom lamp does red, primary
amber and green. Not quite sure how it works, but work it does. I
think they've actually made the sections slightly closer; the line is
cleared very quickly indeed when the trains are going at full tilt!
Nigel

Do,nt you mean WCML, Stowe hill? Which if correct is apart of the Rugby
resignalling using Dorman LEDs Signals.

I was referring to the down signal at Nether Heyford, just out of Stow
Hill Tunnel which was removed about six weeks ago.
Nigel

Post by Exjims

Post by Nigel
Try ECML, they've just replaced all their singals around Stow Hill to
a newer versions.
It is 4-aspect, but only two actual lamps.
The top one does the 2nd amber, and the bottom lamp does red, primary
amber and green. Not quite sure how it works, but work it does. I
think they've actually made the sections slightly closer; the line is
cleared very quickly indeed when the trains are going at full tilt!
Nigel

Do,nt you mean WCML, Stowe hill? Which if correct is apart of the Rugby
resignalling using Dorman LEDs Signals.

I was referring to the down signal at Nether Heyford, just out of Stow
Hill Tunnel which was removed about six weeks ago.
Nigel

Nether Heyford and Stowe hill tunnel are on the WCML.
Part of the Rugby resignalling using Dorman LEDs signals

[The Fish]

Post by Nigel
On Tue, 12 Oct 2004 15:22:08 +0100, Robert Wilson

Post by Robert Wilson
I'm interested in getting hold of a colour light signal, possibly three
aspect, or four aspect. Who would I need to speak to?
Cheers,
Rob.

Try ECML, they've just replaced all their singals around Stow Hill to
a newer versions.
It is 4-aspect, but only two actual lamps.
The top one does the 2nd amber, and the bottom lamp does red, primary
amber and green. Not quite sure how it works, but work it does. I
think they've actually made the sections slightly closer; the line is
cleared very quickly indeed when the trains are going at full tilt!
Nigel

tut tut tut. ask any driver, and they will tell you there is no such
thing as an amber signal. The colours on a 4 aspect signal would be
red, YELLOW, double YELLOW and green.

The resignalled Cherwell Valley line between Leamington Spa and
Banbury has such equipment (made by a company called Dorman, so i
belive)
The Signals are LED, rather than bulb, and are a lot better then the
bulb versions in my opinion. The colours are richer, and brighter, but
with a lot less glare. All the light is beamed in the direction of the
mainline, which is good. The signals look like a solid mass of colour
from a distance, but as you get closer, its clear to see that the
individual LED's are spaced apart so as not to blind the drivers as
the approach the signals. There is a "hot strip" of bright light at
the top of the signal so you can cleary see the aspect wherever you
are in relation to it. It works really well.

The red aspect is always at the point where it is closest to the
drivers eyeline. Usually this means that it is at the bottom, because
most signals are on posts or gantrys, but if a signal were on the
floor (say, in a tunnel) then the red aspect would be at the top.

The LED's are brilliant. Much better than the semaphore that they
replaced. I can understand the attraction of the old stuff from a
romantic point of view, but id rather have to obey signals that i can
actually see at night, or in the fog. And the four aspect system is
infiantley superior to absolute block. The two yellow > one yellow >
red gives the driver two warnings before having to stop, thus reducing
SPAD risks, and as the sections are smaller, trains can move through
an area much more quickly. Im a fan.

[David Hansen]

On 18 Oct 2004 17:50:18 -0700 someone who may be

Post by The Fish
The resignalled Cherwell Valley line between Leamington Spa and
Banbury has such equipment (made by a company called Dorman, so i
belive)
The Signals are LED, rather than bulb, and are a lot better then the
bulb versions in my opinion. The colours are richer, and brighter, but
with a lot less glare.

I travelled (as a passenger) between Crewe and Stafford a week and a
bit ago. I was impressed by the new LED signals. In particular the
green was not as washed out and indistinct as it can be with
conventional signals. The yellow and red were also very distinct.
They seemed an excellent idea to me.

[Clive D. W. Feather]

Post by The Fish
tut tut tut. ask any driver, and they will tell you there is no such
thing as an amber signal. The colours on a 4 aspect signal would be
red, YELLOW, double YELLOW and green.

Correct.

However, there *are* amber signals, or at least signal indications, that
a train driver needs to look at while driving a train (that is, I'm
excluding road lamps at level crossings). I don't know how many are
left, but there were certainly some in London less than a year ago.

I'm not trying to excessively mysterious - I've talked about this before
on this group - but I wonder how many drivers know what I'm referring to
unprompted.

[Owen Dunn]

Post by Exjims

Post by The Silver Jar...
4) Where are the remaining Semaphore signal strongholds?

North Wales Coast, Hope Valley Line, Chester to Warrington Line

Ely-Norwich, Wherry Lines, East Suffolk Line, Aberdeen-Inverness...

I'm sure it's not a short list.

(S)

[Flob]

Post by Owen Dunn

Post by Exjims

Post by The Silver Jar...
4) Where are the remaining Semaphore signal strongholds?

North Wales Coast, Hope Valley Line, Chester to Warrington Line

Ely-Norwich, Wherry Lines, East Suffolk Line, Aberdeen-Inverness...
I'm sure it's not a short list.
(S)

The east suffolk (lowestoft to ipswich route) is colour light where there
are actually signals on the route (due to most of it being RETB) with a few
semaphores at the Lowestoft end.

[The Silver Jar...]

Post by The Silver Jar...
4) Where are the remaining Semaphore signal strongholds?

North Wales Coast, Hope Valley Line, Chester to Warrington Line.

It was whilst travelling from Man Picc to Chester that this quwestion
popped into my head, i glanced up and saw the white side of a
semaphore disappear into the distance... i thought i was just
imagining it, but surely then came another. That got me thinking about
this cos i really didn't expect to see any semaphores on that trip.

I dunno if i'd call the Hope Valley a stronghold, there certainly are
a few around but there but the colour light ones are there for most of
it.

Sheffield - Lincoln on the other hand! Plenty of semaphores there.
Lovely sight.

Mat.

[The Silver Jar...]

Post by BH Williams

Post by Ronnie Clark
I can't answer these last two, but I do think it is about time that
semaphores were gotten rid of, as much as I personally love them. The man
power that goes into maintaining them is phenomenal, as it is a mainly
mechanical system (although there are examples of electrically operated
semaphore signals).
Ronnie
--
Volunteer guard on the Great Central Railway, Loughborough, Leicestershire
Visit the world's only double track preserved steam railway!
http://www.gcrailway.co.uk

Most, if not all, recent resignalling work has been the renewal of 60s era
multi-aspect signals,notably the West Coast main-line. There has been a
small amount of resignalling in the SE, where the Ashford- Canterbury line
has been dragged from the 19th to 21st centuries. The main problem is not
the maintenance of the lineside signalling, but the repair of the mechanical
interlockings and lever frames, which has become something of a lost art.
Sometimes, elements of these mechanical interlockings remain, even when the
line is colour-light signalled- Stockport, for example
Brian

I agree that they really need replacing (see top post), as much as i
personally like them and they do have some advantages over their
colour light counterparts... like not being set to red by lightening
hitting the line. But overall the maintanence is an issue as it
winter.

My father when he worked for BR used to be if i recall correctly a
semaphore signal repair man at Retford in the 1980s and was working on
some resignalling work on the East Coast main line. But as Retford
shut and semaphores went out in favour of Colour light he became
surplus to requirements, along with many many other railway workers in
the 1980s.

Mat.

[1577+2260]

On Tue, 12 Oct 2004 13:49:00 +0100, "BH Williams"

Post by BH Williams

Post by The Silver Jar...
4) Where are the remaining Semaphore signal strongholds?

The North and West line , once it leaves the Newport suburbs, is almost all
semaphore as far as Shrewsbury- Hereford must be one of the largest UK
stations still mechanically signalled.

Going west there are also several semaphore locations:

Various Cardiff Valley routes - e.g. many boxes up the Rhymney Valley,
and I guess Abercynon.

Vale of Glamorgan: Barry, Aberthaw

Tondu, Pantyffynnon (connected with a long NSTR section with no proper
signals once clear of the immediate PF control area)

West Wales: Alternates between mechanical and panel boxes: Pembrey and
Ferryside have semaphores; Whitland is interesting: mostly colour
light signals, including at least one 4 aspect IIRC; but semaphores in
the bay and on the branch line.

[g***@hotmail.com]

Post by The Silver Jar...
4) Where are the remaining Semaphore signal strongholds?

Suprisingly no one mentioned Barnetby, possibly the best semaphore
signal stronghold in the UK?

[Ross]

Post by g***@hotmail.com

Post by The Silver Jar...
4) Where are the remaining Semaphore signal strongholds?

Suprisingly no one mentioned Barnetby, possibly the best semaphore
signal stronghold in the UK?

Except me, two days before you posted, but that might have gotten lost
in the ether. :)

[Salaried Minion]

Post by The Silver Jar...
4) Where are the remaining Semaphore signal strongholds?

The Peak District boxes , Great Rocks and Peak Forest are all all semaphore
and still use oil for lighting the signals.

[David E. Belcher]

Post by The Silver Jar...
Right i've been wondering over these few questions over the last few
days and it's got me thinking, i need answers! (plus i think we need a
long interesting knowledgable thread).
All these questions are with regards to the UK mainline (excluding
islands, underground, non-standard gauges and preserved railway
lines).
1) Right (now i haven't got a clue here), but i presume before the
introduction of colour light signals they would have been tested out
on short stretches of line, if so which were the first lines to
recieve the new signals?

See comments below about the GC main line; I think this was a
'demonstration' resignalling in conection with the 1924 British Empire
Exhibition at Wembley. The Southern were also quick to enter the
field; they erected the very first 4-aspect units at (I think) Holborn
Viaduct and Cannon Street.

Post by The Silver Jar...
2) Presumably if the above statement is true there was a period where
semaphore's were still the main but the colour variants existed side
by side but the decision to actively go about replacing all the
semaphores (or most) had not yet been reached. In what year did they
(presumably BR) decide to actively go about removing semaphores in
favour of colour signals.

Not sure - there are still sometimes additions to existing semaphore
schemes (such as at the new turn-back siding at Kidderminster). BR's
last totally new mechanical signalbox was erected at Uttoxeter in
1983. Worcester saw the last big all-semaphore resignalling project on
BR in the early 70s.

Post by The Silver Jar...
3) Has there ever been a case (however unlikely, but strange things
happen in the railway world) where a colour light signal has been
replaced by a semaphore signal? [remember excluding preservation
railways].

Yes; the mid '20s trial searchlight installation on the GC main line
out of Marylebone by the Hall Signal Co. of New York; this seems to
have reverted to semaphores some time in LNER days. They could also be
seen on the same post sometimes; the North Eastern Region of BR seemed
keen on mixed home & distant signals using a semaphore home arm and a
2-aspect colour light distant unit - the areas around Huddersfield and
Normanton both had some.

Post by The Silver Jar...
4) Where are the remaining Semaphore signal strongholds?

Worcester, Stirling and Shrewsbury, amongst others.

Post by The Silver Jar...
5) Are semaphores still actively being replaced or has it kinda all
ground to a halt?

Depends on the area, I guess; what used to be the London Midland
Region of BR seems keen on eliminating semaphores, given recent
modernisation/rationalisation projects on the Bletchley-Bedford and
North Wales coast lines; they're also doing away with mechanical
signalling on the Nuneaton-Leicester line in a few years.

Hope all of the above is of use.

David E. Belcher

[Jock Mackirdy]

Post by David E. Belcher
See comments below about the GC main line; I think this was a
'demonstration' resignalling in conection with the 1924 British Empire
Exhibition at Wembley. The Southern were also quick to enter the
field; they erected the very first 4-aspect units at (I think) Holborn
Viaduct and Cannon Street.

The changeover from semaphore to colour light approaching Holborn Viaduct was
somewhere near Herne Hill. I remember a signal post with a semaphore home and a 3-aspect colour light "distant (2 yellows
and a green). The colour light only displayed if the semaphore was "off".

[David Hansen]

On Tue, 12 Oct 2004 20:03:26 GMT someone who may be Jock Mackirdy

Post by Jock Mackirdy
The changeover from semaphore to colour light approaching Holborn Viaduct was
somewhere near Herne Hill. I remember a signal post with a semaphore home and a 3-aspect colour light "distant (2 yellows
and a green). The colour light only displayed if the semaphore was "off".

Such an arrangement was not in place at Woking on 23/12/1955 and
caused a crash, fortunately with only minor injuries. Perhaps this
led to the adoption of the arrangement you mentioned.

[Clive D. W. Feather]

Post by David E. Belcher
They could also be
seen on the same post sometimes; the North Eastern Region of BR seemed
keen on mixed home & distant signals using a semaphore home arm and a
2-aspect colour light distant unit - the areas around Huddersfield and
Normanton both had some.

This isn't particularly a NER thing.

This arrangement (with the colour light unit unlit when the semaphore is
at Danger) was common where a small box was replaced by an Intermediate
Block Signal. For example, at one point the order of boxes on the GWR
main line was Challow - Circourt - Wantage Road. At some point Circourt
box was abolished, replaced by IBS controlled from Challow on the Ups
and Wantage Road on the Downs.

Now consider the process involved in making the change. The IBS Home at
Circourt needs to be colour light because of the distance involved. The
IBS Distant will be worked off the same lever, so it might as well be
colour light as well. This lever doesn't require any interlocking with
other levers, since it's released by Line Clear from Wantage Road and
the Challow starter is released by the track circuits between it and
Circourt (previously it would be released by Line Clear from Circourt).
So the entire Challow box and interlocking can be left alone apart from
adding the new lever and a minor change to the electrical interlocks.
Changing the starter to three aspect is significantly more work.

[David Hansen]

On Wed, 13 Oct 2004 18:42:22 +0100 someone who may be "Clive D. W.

Post by Clive D. W. Feather
Now consider the process involved in making the change. The IBS Home at
Circourt needs to be colour light because of the distance involved.

To be pedantic it could be worked by a motor just as easily. The
original IB signals were thus. Colour lights probably started making
a serious appearance after 1945.

[Clive D. W. Feather]

Post by David Hansen

Post by Clive D. W. Feather
Now consider the process involved in making the change. The IBS Home at
Circourt needs to be colour light because of the distance involved.

To be pedantic it could be worked by a motor just as easily.

Good point.

However, doing this to the IBS Distant means adding slotting at the post
or interlocking at the box. A coloured light here is simpler.

[David Hansen]

On Thu, 14 Oct 2004 07:06:46 +0100 someone who may be "Clive D. W.

Post by Clive D. W. Feather

Post by David Hansen

Post by Clive D. W. Feather
Now consider the process involved in making the change. The IBS Home at
Circourt needs to be colour light because of the distance involved.

To be pedantic it could be worked by a motor just as easily.

However, doing this to the IBS Distant means adding slotting at the post
or interlocking at the box. A coloured light here is simpler.

Can the Distant not be driven via the contacts that will be there to
detect the position of the Home arm? These are the same contacts
that will prevent a colour light Distant from displaying an aspect
when the Home is at danger in your example.

[Clive D. W. Feather]

Post by David Hansen
Can the Distant not be driven via the contacts that will be there to
detect the position of the Home arm? These are the same contacts
that will prevent a colour light Distant from displaying an aspect
when the Home is at danger in your example.

It depends on whether such contacts are used. If the control of the
lighting of the distant is taken off the starter lever rather than
contacts on the arm, the only time it matters is if the home lever wire
snaps. So it's failsafe either way. The tradeoff is that you don't need
to maintain the contacts, which are in an exposed location.

But I accept your main point: there's rather less difference in
difficulty between semaphore and colour light IBS than I first assumed.

[Stephen Furley]

Post by The Silver Jar...
Right i've been wondering over these few questions over the last few
days and it's got me thinking, i need answers! (plus i think we need a
long interesting knowledgable thread).
All these questions are with regards to the UK mainline (excluding
islands, underground, non-standard gauges and preserved railway
lines).
1) Right (now i haven't got a clue here), but i presume before the
introduction of colour light signals they would have been tested out
on short stretches of line, if so which were the first lines to
recieve the new signals?

I believe the Liverpool Overhead Railway was the first line in Britain
to install colour light signals, but I don't know the date.

[David Hansen]

On 12 Oct 2004 03:53:30 -0700 someone who may be

Post by The Silver Jar...
1) Right (now i haven't got a clue here), but i presume before the
introduction of colour light signals they would have been tested out
on short stretches of line, if so which were the first lines to
recieve the new signals?

Signalling is a continuum, not a series of discrete points. On
underground lines (not just what became London Transport) semaphore
signals without arms were introduced fairly early. These were a
spectacle frame moving over an oil lamp. From there to two coloured
lights in separate lanterns is easy. Placing such signals in the
open air is the next step and that is the first version of the
common multi-lens colour light signals.

A slightly later development was to produce a signal with a bright
electric light and a spectacle moving before this light. That is a
searchlight signal and this type featured in many of the early
colour light schemes that have been mentioned.

Multi-lens signals used to be preferred by BR, but searchlight
signals are now being re-introduced (though working via fibre
optics).

The first open air colour light signals outside what became London
Transport were probably Intermediate Block signals. The Great
Central may well have introduced them. The Liverpool Overhead
Railway was an early example of automatic signalling, initially with
semaphores but later with colour lights.

Post by The Silver Jar...
2) Presumably if the above statement is true there was a period where
semaphore's were still the main but the colour variants existed side
by side

That would be confusing for drivers. I have never heard of it being
employed.

[Chippy]

Post by David Hansen
On 12 Oct 2004 03:53:30 -0700 someone who may be

Post by The Silver Jar...
2) Presumably if the above statement is true there was a period where
semaphore's were still the main but the colour variants existed side
by side

That would be confusing for drivers. I have never heard of it being
employed.

I'm not sure if the OP meant literally alongside, but there were many
examples of colour light signals co-existing with semaphores.

For instance, for several years in the 1970s the line on Holloway bank
had colour lights on the fast lines but semaphores on the down slow
line, controlled by Holloway South Down and Holloway North Down boxes.


Less obviously, it is quite common to have semaphore disk shunting
signals in a colour light area. In fact, miniature semaphore arms
were not unknown (Harrow No.2, on the Watford DC lines was an example
of this).

[Ross]

On 12 Oct 2004 03:53:30 -0700, The Silver Jar... wrote in
<***@posting.google.com>, seen in uk.railway:

[...]

Post by The Silver Jar...
4) Where are the remaining Semaphore signal strongholds?

Lincoln has quite a few, although most of the distants are fixed.

Barnetby area is good, with Wrawby Junction being a good shot - 3 x 3
arm gantries, slightly staggered. Especially good at night when they
appear from a distance to be all part of one gantry.