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 GWR Signal Gantry

GWR Signal Gantry - 7mm scale - David L O Smith

I have always been interested in signalling and signals but, not having a railway of my own, I never had a specific need to build any so I built this gantry just for the pleasure of it.

As a bit of light relief between building locos, I have worked on the occasional wagon but, about two years ago, I started to build a signal gantry and I have since been working on it ‘on and off’. The original concept did have a purpose as I had intended to build the gantry to be an ‘ornament’ to adorn my late friend’s extensive garden railway on pleasant summer running days, but that was a fair few number of years ago now. The railway had four circuits around a landscaped part of the garden and each line split into two when it entered the covered station area, so that eight trains could be handled with four running at any one time. The gantry was intended to reside outside the station throat where there was a goods line that also split into two, although none was powered.

GWR Signal Gantry with ten dolls - 7mm scale - David L O Smith

Reading from the left, the fifteen signals on ten dolls (posts) are:

  • Up goods to goods loop (on)

  • Up goods (off)

  • Up relief to goods (on)

  • Up relief to Platform 4 (on)

  • Up relief through line (fully pegged)

  •  Up main to Up relief (on)

  • Up main (half pegged)

  • Down main (on)

  • Down relief (half pegged) + shunt arm (on)

  • Down relief backing arm (on)

Etch of GWR signal arms by Colin Waite - 7 mm scale
As a starting point, I had a collection of parts that I had been given to me, probably thirty years ago (‘Here you are, David, I’ll never use these so you may have them’ - never say 'No') ; these were:
  • An etch of signal arms and parts from Colin Waite
  • 24 grain of wheat bulbs
  • 20 GWR signal lamp castings

I began by making up the signal arms from the etches and I turned up some clear acrylic cylinders to secure the bulbs within the fettled brass castings. I also turned up some balance weights, more of which later.
Parts for a GWR signal - 7 mm scale


Milling a wooden signal doll - 7 mm scale

Milling tapers on some square-section hardwood for signal doll
I had a sample casting of a GWR signal finial (from Scale Signal Supply) but I needed ten finials in total; I could have bought them but there is not much fun in that (and the cost adds up), so I decided to make them.

Milling the base of a GWR signal finial - 7 mm scale

Milling the base of a finial
The lower part of the fabrication and the spike were simple milling and turning tasks, and I made the ‘hollow balls’ by milling inexpensive plastic beads so, although they have only flutes rather than being truly hollow (Modelu if you want that) they look the part once painted.
GWR Signal finial parts - 7 mm scale

Machined parts for a finial

GWR Signal finials - 7 mm scale

Finials: casting by Scale Signal Supply (left), fabrications and with painted ball (right)​

GWR signal post parts - 7 mm scale

Next, I turned to the wooden dolls and their fittings. I made up brackets to take the arm spindles and, along with the lamp brackets, I glued and pinned them in place. To ‘lose’ the wires to the lamps within the dolls, I milled slots from just below each lamp to the bottom of the doll. I used five-minute epoxy resin glue to keep the wires in place whilst I applied filler to make good.

GWR signal balance levers

Etching from Scale Signal Supply (left), arm drilling jig, lever with balance weight and retaining screw, single lever in braket, levers for starter (section signal) and distant with additional lever for slotting (right)​

Not having etchings for the levers and balance weights, I decided to make them, using an etching from Scale Signal Supply as a guide. The levers are strips of scrap etch that I sized with a file to fit within a drilling jig to drill the small holes at the correct spacings and in the centre of the lever. The balance weights are simple turnings with the characteristic circular depressions machined into the faces with a slot drill in the tailstock; I added cosmetic retaining screws from domestic pins with their heads filed to a hexagon.

Parts of GWR signal dolls (posts) ready for assembly - 7 mm scale - David L O Smith

Parts for the dolls ready for assembly on the gantry

Within the original concept, as an occasional accessory to a garden railway, I would have built my model with far less detail, I would not have installed working lamps and the supports would have been just two long narrow feet set parallel to the tracks. As it turned out as an indoor ornament, I decided to build it with a wooden base and five short lengths of ballasted Finescale track.

Signal lamps on a 7 mm scale GWR signal gantry

The real players in this bit of static theatre (I would like to think) are the signal arms and the fittings on the dolls so I decided to make the remainder of the gantry and the base rather more impressionistic, and certainly not accurate to GWR prototype construction. I made the beam of the gantry from three pieces of 1 mm thick plastic card, assembled as an inverted U, and I topped it with a strip of 0.5 mm plastic card that I scored with a scrawker to represent individual planks.

GWR signal gantry, looking in the Down direction - 7 mm scale

Andlooking in the Down direction

I made the handrail from 0.6 mm diameter nickel silver wire; 880 mm were required for the uprights alone. There are a few details that I might add one day, such ladders to the lamps on the taller dolls and a ladder from the ballast to the platform (I formed a suitable Ω in the horizontal handrail to accommodate it) and some brackets between the posts and the gantry.  For the time being, it will just sit on a shelf.

Signal lamps in the dark on a GWR signal gantry - 7 mm scale - David L O Smith

It’s sobering to think that, in the days before there was much electric light about, an array of coloured lights is all that the enginemen would see to pick out their road.

I am rather disappointed with green (blue) glasses in the spectacles, which came as coloured sheets with the Colin Waite etches. The blue looks acceptable in daylight, but it is not sufficiently deep in front of the incandescent bulbs to render a convincing green, soI shall experiment with a mix of varnish and dye to deepen the blue of the blue glasses.

More 7mm scale railway models