A walk around Gunning

In the 1990s the Main South line in NSW still had charming little stations such as Gunning. All gone now, of course, so let's turn the clock back to 7th March 1994 and take a walk around the yard at Gunning to look at the signalling. I will use the present tense when describing the photographs, as if it is all still there.

First, a look at the box diagram to orientate yourself. (Sorry about the quality, the photo was taken through the box window.)

The Main South line runs from Sydney southwest to the Victorian border at Albury (where it connects with the Victorian line to Melbourne). Gunning is situated 278 km from Sydney, roughly a third of the way from Sydney to Albury. On the diagram, Sydney is to the left and Albury (and Melbourne) is to the right.

The Main South is double track from Sydney to Junee, and in the mid 1990s is worked by a mixture of automatic signalling and double line block working. The automatic signalling is still largely three position upper quadrant semaphore signalling, installed just after WWI, with a limited number of sections of modern colour light signalling. Gunning is situated in a section of automatic signalling, and all the main line running signals are upper quadrant semaphores of the NSW railways unique design (but more of that later). These automatic signals had been installed in 1920.

For train regulating purposes, Gunning has an Up and a Down Refuge siding. Indeed I was told that the only use made of Gunning at this time was to refuge out-of-gauge steel loads from Port Kembla to Melbourne. Both Refuge sidings are worked from the signalbox, and both are fully signalled.

Gunning itself is a small country town, and is the railhead for the surrounding countryside. Accordingly, facilities for both passenger and freight traffic are provided. The freight traffic is handled by two sidings on the Up side of the line: the Good Siding and the Stock Siding. By the mid '90s the local freight traffic had disappeared, and I believe that Gunning is no longer open for goods traffic. The sidings are still in existance, however, as NSW seems to have a policy of not recovering redundant infrastructure.

The Up end points (at the left) to the goods sidings are connected to the signalbox, but no signals are provided to enter or leave the siding. At the Down end the connection to the Down Main line is too far to be worked from the signalbox. The connections are consequently worked from a small ground frame. To reduce track wear, the former diamond crossing in the lead from the Down Main line to the goods sidings has been replaced by a trailing crossover between the main lines, and a facing connection from the Up Main to the sidings. This facing connection could not be used for signalled moves into the siding from the Up Main.

The 'Accept' signals (2 and 28) mentioned at the top of the diagram are the signals immediately in the rear of the first Home signal approaching the station. Conceptually, these allow the signaller at Gunning to 'accept' trains into the station from the automatic territory. From a practical perspective they are effectively a controlled automatic signal. The signaller can hold the signals at stop, but drivers can pass them under the verbal authority of the signaller.

Distant signals are provided in the rear of both accept signals. These operate automatically depending on the position of the accept signal. As all the accept and home signals through Gunning operate in three positions (and consequently acted as the distant for the next signal), a clear distant did not mean that all the signals through Gunning are clear.

A historical note. While preparing these notes, I was examining my copy of the 1944 NSW GA Part 2. On the back of one of the amendments in the GA I happened to notice a Weekly Notice entry for alterations to Gunning in 1958. In 1958 switching out facilities were provided at Gunning. The two closing levers (6 and 22) were provided at this time. Two home signals (4 and 26) were removed - these were probably on each side of crossover 15. The remaining home and starting signals (3, 5, 25, and 27) were converted from lower quadrant two position home signals to upper quadrant three position home signals, and the shunt-ahead arm (4) was provided.

An overall view of Gunning from the road bridge at the Syndey end of the yard. At the left is the Down Refuge, and on the right is the lead into the Goods Siding and Stock Siding. Signals are provided for movements to and from the Refuge, but no signals are provided for movements to and from the Goods or Stock Sidings. The upper quadrant running signals stand at clear for the next movement.

Another view of the signals at the Up end of the yard, this time from the Down Refuge siding. The lower viewpoint makes the arms stand out clearly against the sky.

All the running signals at Gunning are motorised upper quadrant semaphores that mostly show three aspects - stop, caution, and clear (The distant and Starting signals are an exception.) This is a photograph of Down Home 3. The daytime aspects are conventional: a horizontal semaphore arm means Stop, an arm at 45 degrees means Caution, and a vertical arm means clear.

The aspects in use at night are known as the 'double light' system, and are not conventional! In this system each night aspect is given by two lights, and the aspects are based on those given by a post with a two position home signal above a two position distant signal. Stop is given by two red lights, Caution by green over red (i.e. the home off and the distant on), and Clear by two green lights (i.e. both the home and distant off).

Three aspect upper quadrant semaphores, such as these, are normally only provided at interlockings. Automatic signals between interlockings normally only show two aspects (stop and clear), and are provided with an upper quadrant distant signal (showing clear and caution) at braking distance in the rear. This avoided the driver from having to remember for some miles that he has passed a caution aspect.

Down Home 3 is identified on the post by '173.1' which indicates that this signal is roughly 173.1 miles from Sydney. Down signals are numbered with odd tenths, and Up signals with even tenths. Strictly speaking this system is used to identify automatic signals, but it is also applied to (all?) home signals within automatic signalling areas. Curiously, no identifying labels are applied to purely mechanically operated signals in NSW.

There is a grey cast aluminium telephone box immediately in the rear of the signal. This is used to communicate with the signaller if the arm is at stop. The cast aluminium telephone box was probably introduced in the '60s, and was unpainted as an economy measure.

This photograph shows the semaphore and spectacle plates on Down Home 3.

The basis of the signal is a conventional US based upper quadrant semaphore using a GRS Model 2A signal motor, a standard RSA spectacle plate, and a semaphore arm based on a standard RSA semaphore arm.

Two spectacle plates are used to give the two lights for the aspects. The upper spectacle plate gives the 'home' aspects, and has green lenses for the caution and clear positions. The lower spectacle plate is for the 'distant' aspects. To avoid the need to provide two signal motors, the lower plate is ingeniously driven from the upper spectacle by a rod. Essentially, the upper fixing point of the rod is located such that when the arm moves from Stop to Caution, the fixing point does not move vertically. This means that the lower spectacle plate does not move. When the upper arm moves from Caution to Clear, the upper fixing point is lifted, which lifts the lower spectacle plate to display green.

The use of two spectacle plates driven by one motor was used in country areas to conserve battery power. A further power saving approach was the use of oil lamps to light the signals. In the suburban area, where electric power was available, a small two aspect light signal replaced the lower spectacle plate. From about the '70s, the country upper quadrant semaphores either had the lower spectacle plates replaced by small light signals, or the lamps were converted to electric lights.

Looking out of the Down Refuge past Shunting signal 8 with Catch 13 and the matching Up Shunting signal in the background. Shunting signal 8 is mounted on a tubular steel post with a flat circular cap for a finial. This suggests that it is a replacement for an older mast - possibly a timber post.

The layout of Catch 13 should be compared with Catch 18 (seen later). In this case, Catch 13 has a single blade to derail movements. A rail is fixed at about 45 degrees from the track beyond the heel block to force the derailed wheels away from the main line.

The top of the rails in the Refuge are quite shiny, suggesting that Gunning had been recently switched in to refuge a train.

A close-up of the 'mechanical high' Shunting signal 8 at the exit of the Down Refuge. Shunting signals are used for shunting movements between running lines and sidings, and within sidings. NSW shunting signals have a short arm with horizontal red/white/red strips. A very small red light is displayed when on, and the caution (off) position shows a green light in an elongated slot to allow the arm to come off at a range of angles. This is apparently not to the proper design; the proper design is two elongated curved slots as will be later seen with shunting signal 17.

The mechanical design of the signal is worthy of note. The bearings for the arm spindle are mounted on the side of the post, rather than the spindle running through the post. Most of the counterweight to ensure the arm returns to danger is provided by the casting into which the arm is secured. The spectacle is also bolted into this casting.

Up Shunting Signal 10 for moves from the Down Main Line into the Down Refuge. This signal is mounted on a wooden mast, but the fittings are otherwise similar to Shunting signal 8. However, the glasses in the spectacle are quite different. It would appear that this signal is fitted with spectacles that give a medium sized light (supposedly used for entering loops or facing refuges), not those giving a small light. Like shunting signal 8 this also is also apparently not the proper design! The arm of a shunting signal had quite a pronouced flare with the outer end being substantially broader than the inner end. This can easily be seen in this shot.

In the background can be seen the Down Home and Down Shunting signal on either side of the Down Refuge. Just visible at the left hand edge of the photo is the Up Starting signal located on the Up side of the overbridge. The start of the 1 in 40 grade down to Gunning Creek can be easily seen. Main line points 9 at the entry to the Refuge are actually lying reverse. In the normal position Points 9 lie towards the refuge to form a set of catch points to stop vehicles running away from the station. Consequently, the main line points leading to the Down Refuge are worked by a different lever to the Catch points in the siding.

A close-up of the front of Shunting Signal 10. NSW preferred to mount the balance weights on signals immediately underneath the arm at right angles to the track. This meant a short down rod. No landing is provided for the ladder, just a hoop at the top to rest on. This mast is, of course, relatively short. The finial has probably lost the cast iron spike.

A close-up of the back of shunting signal 10. The back of the shunting signal is enamelled white with a thin black horizontal line.

Design practice in NSW is for the arm spindles and bearings to be mounted on the side of the posts. This avoided the need to drill a spindle hole through the mast. A back blinder is provided for this signal even though the signal faces the signalbox. As will be seen with other signals at Gunning, this appeared to be standard practice in NSW.

Catch point 7 at the Up end of the Goods Siding is provided with an arrow type point indicator. A point indicator is coupled directly to, and works with, the points. Its purpose is to indicate the position of the points. It is not a signal, and even if it shows that the points are set correctly for the movement, the train cannot move until the employee in charge of the operation gives the appropriate hand signal.

The arrow type point indicator is the standard type of point indicator in NSW. When applied to a set of catch points, a red target (seen here), or red light at night, is used to indicate that the catch is open. When the catch is closed, the target is revolves 90 degrees and displays a white arrow by day and night.

The mechanism of the point indicator is almost identical to the McKenzie and Holland point indicator (which can also be found in NSW), and can be seen in this photo. A vertical bar, pivoted half way, works in a cam slot in the base of the target. The back of a catch point indicator shows a black rectangle (blank) when the catch is open, and an arrow when it is closed.

The back of the Up Second Home at Gunning. Standard naming conventions in NSW is that the first home signal reached by a train at an interlocking is the 'Home'. Subsequent home signals are named the 'Second Home', 'Third Home', and so on, up to the Starting Signal which controlled the entry into the next section.

The tubular steel mast is made up of two sections swagged together about halfway up the mast. The joint is quite abrupt, and the finial is the flat cap seen on Shunting signal 8.

Looking north from the Up platform at Gunning.

Gunning signalbox is situated on the Down platform adjacent to the station building. Like many signalboxes in NSW (and in other Australian states), classified signalmen would not be assigned to work the box. At this time there are probably no station staff stationed at Gunning, and a signaller is probably sent from Goulburn or Harden when it is necessary to switch Gunning in. When Gunning was staffed, the box would be worked by the station staff as part of their general duties. Each shift would have one person qualified to work the box.

Gunning signalbox is a typical NSW platform level box. The design could be, not unfairly, described as a glorified garden shed and it has absolutely no ornamentation. The box is constructed of timber with an asbestos tile skillion roof (it would have originally had a galvanised iron roof). The frame is at the rear of the box and only a couple of windows are provided in the front wall. Although these photos were taken on a crisp, clear, morning, a couple of features show that the weather at Gunning is not always so clemmant. A weather shield has been constructed next to the door to stop the rain beating in during winter, and a deep awning has been added over the front windows to reduce the heat in the summer afternoon. A chimney in the far front corner indicates the presence of a stove in the box for the cold winter's days. Just beyond the box can be seen a large galvanised water tank to collect run-off from the signalbox roof, although the station probably has a reticulated water supply from the town.

Inside the box is a 28 lever NSW standard cam and tappet frame. Designed just before the first world war, the first frames were constructed by private contractors (Thornley, and McKenzie & Holland). Construction by the NSW railways in their own workshops commenced in 1914. The tappets are indirectly driven by means of a cam plate from the movement of the levers. The whole layout, in fact, is identical in principle to the McKenzie and Holland cam and tappet frame. This is not surprising, given that all these designs were derived from the 1873 McKenzie and Holland pattern frame. One odd feature of the frame, to those used to the vertical levers of McKenzie and Holland frames, is that there is no bend in the levers at floorplate level. This means that the levers, when at normal, lean back quite a long way (it, of course, in no way changed the lever travel). I found the NSW frame hard to pull for this reason, but that was probably more due to its strangeness than poor ergonomics.

The frame is shown switched out with the main line signals and the blue closing levers (6 and 22) reversed - a separate closing lever is provided for each main line. Each closing lever is equipped with an Annett lock to hold the lever reverse. When the closing keys are removed, they are secured in the green painted box that can be seen on the wall of the box behind the levers. The SM has keys to the box, and so the station staff can unlock the box and switch the station in. The box has a glass front, but anyone, in an emergency can break the glass and obtain the keys to switch in the box.

The box diagrams at Gunning. It is common in NSW in boxes of this vintage to provide two diagrams - the signalbox diagram proper and a track indication diagram that shows the occupancy of the main line track circuits. The rules for automatic signalling require an indicator in each signalbox that shows the state of the track approaching the Accept signal, between the Accept and the Home, and the first section beyond the starting signal. A diagram is a convenient way of providing these indications, and track indications are also provided for the main line tracks within station limits. I believe this is an 'eyeball' diagram where a small ball is painted red on one side and white on the other. The ball is rotated by a relay.

A view from the end window of the box. The train register desk can be seen near the door on the left, surmounted by a wonderful collection of wooden cased phones.

Looking from the Down end of the Goods Siding towards the Up Refuge. The signal on the left is Shunting signal 17 for moves from the Up Main (at the extreme right) across the crossover into the Refuge. Tucked away at the foot of the post is Dwarf Shunting signal 16 for moves from the Goods Siding straight ahead to the Up Refuge. Signal 17 is a tall post so that it can easily be seen from the loco when pushing a train back into the refuge. Dwarf 16 is probably low down so that at caution it cannot be mistaken for Signal 17. The set of points in the background is actually a set of catch points. Unlike the catch points at the Up end of Gunning, this set has two point blades and a curved closure rail to assist in directing a derailed train well clear of the main line.

A closeup of Shunting signal 17. Like Signal 10, this is also a wooden post, but this time the spike on the finial is still present. This is the third type of spectacle on a shunting signal at Gunning - and this is how the spectacles for a shunting signal should be arranged. Both the red and green spectacles are partially covered to give long thin curved slots.

Looking back towards the station from the Up Refuge. On the left are the two Shunting Signals 20 and 21 mounted on a tubular steel mast. The topmost arm applies to the leftmost route, in this case straight ahead to the Goods Siding. The bottom arm applies across Crossover 19 to the Up Main line. It is standard practice in NSW to mount the balance lever just below the arm, and in this case there is little room between the balance lever for the upper arm and the lower arm.

A NSW station would not be complete without at least one ground frame :-) Frame B works the lead from the Down Main line to the Goods Siding and Stock Siding. The frame is a standard NSWR Type G frame using direct tappet locking. Lever 1 works the points to the Stock Siding and associated catch. Lever 2 works the facing crossover between the Up Main Line and the Refuge, and Lever 3 is the FPL in the Up Main line for this crossover. Lever 4 works the main line trailing crossover. There are no less than 2 Annett locks and a mechanical crosslock interlocking this ground frame with the main frame in the signal box. One Annett key is provided for moves between the Up Main line and the Refuge Siding. This Annett lock is on lever 3 - reversal of this lever would free lever 2 which, in turn would free lever 4. The second Annett key secures the points between the Refuge Siding and Stock Siding. The crosslock prevented Point 1B from being reversed when either Catch 18 or Crossover 19 is reverse (or vice versa).

Looking towards Albury from Frame B. The 279 km post is at the left of the picture, and a concrete relay hut is adjacent to the Down end of the trailing crossover. On the right, the Up Refuge curves around the bend. In the middle of the picture are the Down Starting signal 5 (facing the camera), and the Up Home 27 (facing away from the camera). The Down Home is just beyond the toe of the trailing points leading from the Down main line into the Goods Sidings. Any trains shunting from the Down main line would have to pass the starting signal, and to allow this when the starting signal is at danger, a Shunt-Ahead arm (4) is provided on the post.

Another view of the Down Starting and Up Home.

A closer shot of the Down Starting signal (also identified at '173.3'), This is a tubular steel post with the same type of cast iron finial used on the wooden posts (e.g. Shunting signal 17). While the Down Starting signal itself is a motor operated upper quadrant semaphore, the Shunt-Ahead signal is a mechanically worked lower quadrant semaphore. Three lamp brackets are provided from the staging - one for the motor and upper lamp, the second for the lower lamp, and the third for the shunt ahead arm. A modern telephone box is provided in the rear of the signal, of the style probably introduced in the period 1980 to 1985.

A close up of the Down Starting signal.

Careful examination of the upper spectacle plate shows that the starting signal only shows two aspects - stop (red over red) and clear (green over green). The 45 degree glass in the upper spectacle plate is red, so this signal will show red over red when the arm is in the 45 degree position (i.e. when moving from stop to clear or vice versa). (I missed this the first in the first version of these notes!)

Like all the running signals at Gunning, this mast is of tubular steel construction, almost certainly introduced from the US around the time of the first World War. The final section of the pipe is quite small diameter, and the finial looks decidedly insecure on the top. The U bolts securing the upper arm to the mast have had to be packed out. A number of different sized fittings and finials were available to suit the different diameters of the masts, but perhaps the correct size was not available when this mast was put together.

The Shunt ahead signal is almost identical to the Shunting signal, except that the arm is painted solid red, and a white 'S' is fixed to the front. Notice that again a back blinder is fitted even though there is no-one to see the back of the signal.

In preparing these notes, I regretted that I didn't take more photographs at the time. An interior view of the box showing the stove would be nice; perhaps a long hike to take a photo of one of the accepts or distants. Oh well, I should be happy I visited Gunning at all!


I'd like to thank some of my fellow signalling enthusiasts for providing additional information and correcting some of my mis-statements.

Version 1 - 20120712 - released Version 2 - 20120713 - corrected some information.