Identification & quantity of components on fret:
1. 5ft distant arm (1)
2. 5ft home arms (2)
3. 4ft distant arm (1)
4. 4ft home arms (4)
5. 3ft home arms for sidings etc. (2)
6. Spectacle plates (10)
7. Backlight blinders (10)
8. Cranked balance levers (10)
9, 9a, 9b. 3ft restricted clearance centre balance arm, spectacle plate and boss (1)
10. Calling-on arms (2)
11, 11a, 11b. 4ft restricted clearance centre balance arm, spectacle plate and boss (1)
12. 2ft4in disc for use under platform canopies (1)
13. Rule 55 track circuit diamonds (2)
SN14 2mm scale Great Western Railway wooden lower quadrant signal arm fret
This pattern of signal arm was introduced by the GWR in 1887, and was used for new installations and renewals until the advent of steel arms (SN15) in 1930. Note that the 5ft arms are for use on posts greater than 26ft tall.
The actual size of the fret is 42½ x 27mm; it is etched in 0.008" brass. For clarity, the photo shows the equivalent 4mm scale fret.
To model a complete signal similar to the 4mm scale one shown below, you will need a post (SN17) and a ladder (SN9/3 or SN9/7). Other parts such as the finial, lamp and platform, will have to be scratchbuilt.
To see exactly what is involved in using these parts, download the instruction sheet as an Adobe Acrobat® file (100kb).
Model by Ken Gibbons