OTD - 13th February 1941 - Rail mounted gun test fired

[whole diary]

[grahame]

13th February 1941, First test firing of the rail mounted gun on the Elam Valley line (Canterbury to Folkestone).   

From a long article at https://en.wikipedia.org/wiki/BL_18-inch_railway_howitzer

The BL 18-inch railway howitzer (formally Ordnance BL 18-inch Mk I howitzer on truck, railway) was a British railway gun developed during World War I. Part of the progression of ever-larger howitzers on the Western Front, it did not enter service until 1920.

[snip]

n 1940 there were concerns that an enemy invasion was imminent, crossing the English Channel from France. Three heavy rail-mounted guns were deployed on the Elham Valley Railway line in Kent. The railway route followed a meandering course, enabling the guns to be trained by moving them along the line to a suitable location. The wooded landscape also gave cover for the guns.

[snip]

The gun was first fired, for calibration tests, on the morning of 13 February 1941, when the equipment was towed to a stretch of track near the Black Robin public house, Kingston. Several rounds were fired out into mid-channel, the results of which were sighted and marked by observation posts on the cliffs at Dover. In the Kingston and Barham area villagers were warned to open doors and windows, but the blasts were so severe that in many cases houses were damaged.

See also

http://www.disused-stations.org.uk/features/index6.shtml        i
https://en.wikipedia.org/wiki/Railway_gun 

[bradshaw]

In October/November 1940 two siding were laid on the Bridport branch for rail mounted anti aircraft guns. One at Bradpole near the crossing and the other at Loders by Boarsbarrow hill. However by 1941 they were moved away from the line. The photo shows the location of the Loders siding, the branch was to the left of the photo.

[stuving]

I've just found a reference to an American railway gun, which did make it into service in France before WW1 ended (though only by a couple of months). Part of the USN contribution to the allied effort from 1917 on, which you don't hear a lot about. As some of them were based at Scapa Flow, they too would have been on the Jellicoe Express (q.v.).