The Charles Close Society for the study of Ordnance Survey maps

Digital Images Archive

96. GSGS 3957 (Air), Experimental Civil Aviation Edition, sheet 4, 1946 proof (CCS 218B/49/7)

This experimental map was printed in ten colours, including four shades of brown for use in the hill layers. There are also a black plate, two blues, one green, one red, and a magenta plate for the aviation information overprint. The map reached proof stage in 1946 before being cancelled. We are fortunate also to be able to reproduce the Military Survey index card on which its progress was documented.

There are many versions of the quarter-inch Fourth Edition map of Great Britain, which was constructed in the mid-1930s on National Yard Grid sheet lines. These include the post-war civilian form with National Grid, and many different versions of GSGS 3957 and GSGS 3958, some overprinted with the War Office Cassini Grid (modified British system), some with a graticule, for military and air use up to and during the Second World War. While grids, overprint detail and the colour of hills may have varied, the basic mapping between these editions changed very little, the most obvious adjustments being the enhancement of railway lines, the thinning out of minor place names, and the use of a heavy blue band to represent shallow water (replacing marine contours) for the benefit of air crews.

The map reproduced here possesses features radically at odds with this norm. Most seriously affected is the black plate, with churches, road and woodland casings all deleted. The detail of built-up areas is gone, with large built-up areas shown wholly without detail, and small communities replaced by black squares (though the job has yet to be completed – see, for instance, the Wirrall, Codsall, and south of Halesowen). Still in place are thickened railway lines, with the added enhancement of a single cross bar for single track and double for multi-track lines. Shoals are transferred from the black plate to a brown. Heights are given in italics. There is a graticule at ten-minute intervals. Changes affecting the blue plate include the deletion of narrow waterways. The five-fathom marine contour (but not the ten-) is preferred to the heavy band of blue, enhanced by a second marine layer, while coastal water names are transferred from the black to the blue plate. The red plate is reserved solely for classified road infill – its previous use for railway stations, level crossings, road numbers, and additionally in GSGS 3957 and 3958 for viaducts and golf courses, is abandoned, while race courses are transferred to the black plate.

The magenta overprint of aviation information contains different features to those required by the military, the most obvious being danger areas around the coast and on land. Tall obstructions have a special symbol, their heights measured both from land and mean sea level. Isogonals, local mean time, airfields, powerlines all remain, though revised. There is no compass rose.

From a copy now transferred to Cambridge University Library