SIGNALS
Swedish State Railway (SJ)
by Per Olofsson and John Hinson
Semaphores delivered from the end of the 19th century to the Swedish
State Railways were normally manufactured in iron with 8, 10, 12 or 14 metre
height and equipped with one, two or three arms. T-semaphores were normally 8
metres in height. Semaphores could be locally or centrally operated from a
mechanical frame using double-wire or electrical interlocking.
Signals could be mechanically or electrically operated. Mechanical
signals could be controlled in several different ways.
- with the signal wire controlling both the semaphore and its
associated advanced (distant) signal - the latter usually being a disc
type
- with signal wire run above ground (on pulleys, UK-style)
- with signal wire run below ground (in ducting)
- locally, by hand-crank
One of the first fixed signals used in Sweden was the T-semaphore. The
design of this was influenced by British practice, of lower quadrant type and
built in timber. It would be placed on the platform in front of the station
building. T-semaphores had two arms, one for each direction.
It was decided in 1915 that all semaphore signals should be of the upper
quadrant type.
The last semaphores on Banverket (Swedish National Rail Administration)
track were replaced in 1999 but on Inlandsbanan there are still (2002) two or
three stations equipped.
T-semaphore signals
Photograph from the collection of
Per
Olofsson |
|
Although the original function of a T-semaphore became redundant
as stations became interlocked, some survived at intermediate sidings to
protect the siding from movements in either direction when shunting was taking
place.
The picture on the left shows a station signal at
Jämsjöslätt in the 1930s. One arm has been lowered inside the
post to show clear. A wooden T-semaphore protecting a siding is shown to
the right. As with early British signals, any driver approaching such a signal
showing danger would be expected to bring his train to a stand before any
points, rather than stop at the signal itself.
A few T-semaphores survived on private (or former-private)
railways at stations into the 1950s. Some protecting intermediate sidings
existed as late as the 1970s. |
Photograph from the collection of
Per
Olofsson |
|
Drawing of later, iron-built T-semaphore
Single-armed semaphore stop signals
Photograph from the collection of Dr. J W F
Scrimgeour |
A pair of single-armed semaphore signals at a junction station. The
signal on the left is locally operated by crank-handles at the foot of each
post - the signal man has a hand on this in the photograph. These rotate
the large pulleys mid-way up the post, which in turn raise the signal arm.
However, it appears that the other signal is worked remotely - note the
ducting. The barriers are wire-operated, controlled from the signal hut.
The location is Ostersund. Here, the station was interlocked, worked
from a double-wire frame of the type shown at Stocksund. In 1911 a new railway was built
between Uppsala and Enköping and it is probable that the left semaphore
protects the line towards Uppsala and that signal was not integrated (at the
time for the picture) in the interlocking frame.
The signal arms have similarity to German signals in style (with the
"blob" at the end) but are pivoted at the right-hand end. The arms were painted
with the top half red and the bottom half yellow. The post, or mast was
also painted in these colours.
Semaphores were most commonly installed to the left of the track, and at
interlocked stations would be wire-operated from the centralised crank-handle
or lever frame. The T semaphores installed on the platform were also
operated by hand-crank.
Multiple-armed semaphore stop signals
In the early 1900s Sweden switched to speed signalling and the meaning
of the signals was altered. Speed signalling does not inform the driver which
route he is taking, only the speed at which he may travel through a
junction.
Most Swedish speed signals were provided with two arms, but a third arm
was provided in more complex areas. The indications were as follows:
Top arm
horizontal
Middle arm vertical
Lower arm vertical |
Stop |
 |
Top arm at
45°
Middle arm vertical
Lower arm vertical |
Clear |
Top arm at
45°
Middle arm at 45°
Lower arm vertical |
Clear with caution and 45
km/h speed restriction |
Top arm at
45°
Middle arm at 45°
Lower arm at 45° |
Clear with caution and 45
km/h speed restriction; route is unusually short or the route is set only to
the shorter of two alternative routes |
Photograph from the collection of
Dr. J W F Scrimgeour |
|
In the left view, the signal is cleared for the main, or higher
speed, route. The two arms below are barely noticeable as they are flush with
the signal post.
The signal on the right is cleared for a lesser route (of lower
speed) and displays two arms at 45º.
It is interesting to note that present-day signalling in Sweden
reflects the same principles, and the colour-light signals are capable of
displaying one, two or three green lights for the same circumstances. |
Photograph from the collection of
Dr. J W F
Scrimgeour |
|
Disc advanced signal
Photograph from the collection
of
Dr. J W F Scrimgeour |
|
These two photographs show a mechanically-operated disc signal,
worked by double-wire. The colour of this disc is green with white surround,
but at night the light displays a flashing green aspect when the signal is in
the "warning" position.
When the signal is cleared, the disc pivots to the horizontal
position out of sight, and the lamps is exposed to show (by night) a flashing
white light. |
Photograph from the collection of
Dr. J W F
Scrimgeour |
|
These signals are called Advanced signals because they give
advanced warning of the signal ahead - very similar in function to the
Distant signal of the UK.
About the
photographs
Additional notes by Lars-Henrik Eriksson
and Gunnar Ekeving
 |
Comments about this article should be
addressed to John Hinson |