Garretts produced SD drawings (Standard Details) for regularly used components, material specifications, limits and fits and instructions for various operations such as setting of piston valves and packing for export. They were numbered in the series SD1 to SD925. SD1 was issued on 14th September 1904 and titled "Foreaxles for No 21/2, 3, 4 and 5 portables". The early drawings, up to approximate number SD288, are drawn on sheets of varying size but after that they are generally drawn on a standard sheet size 131/2" x 101/2" and filed in large books. There appears to be a general misconception that copies of the SD drawings do not exist but that is not the case. There are copies in the Suffolk Record Office and we have some in our collection.
A book containing drawings SD289 onwards.
An example of one of the later SD drawings, SD749 showing the ashpan door operating gear details.
We have a large number of these drawings in two volumes, which are mainly duplicated but there are some omissions from both.
Page 6 of the alphabetical index of the small standard sheets.
The following illustrations are typical examples of the small SD drawings.
SD510 Brass mixtures. As you can see by the handwritten addition, this SD was superseded by SD907 on 20/10/21.
SD918 Plug Gauges, these give the "go/no go" limits for S fits (sliding) and P fits (press) for components. SD drawings are provided for the other fits listed on the drawings.
SD923 1/2" Asbestos Packed cylinder cocks. Incidentally, I required five of these for my wagon and found that the water gauge drain cocks supplied by the likes of Chanter Biomed and Heritage Steam Services were a very good substitute, although slight modification (removal of the spigot to support the ball in the bottom fitting) was necessary.