The Stokes Mortar

Some of you might remember this rusted wine bottle-shaped thingy, one of the occasional live pieces of ordnance that I have stumbled over on my travels over the years.

Or rather haven’t stumbled over, as I might not be here to tell you these tales otherwise.  Nonetheless, this is the closest I have come to actually treading on one of the damned things, and here we see the likely result had I done so.

Sir Wilfred Stokes* poses with his self-titled mortar, left, along with various shells, although, let’s be honest, most of these are not going to fit in the 3-inch mortar shown in the photograph, its light weight & portability ably demonstrated by the designer himself on the right.  And if you spot a passing resemblance between the two shells that do (second from left & second from right) and the rusted example I just showed you, then you are quite right, because that was indeed a round for a 3-inch Stokes Mortar, lying in the German positions near Thiepval on the Somme.  And you really don’t want to tread on one of those, particularly after it’s been lying in the undergrowth for a hundred years.

*He received a knighthood in 1917.

The Stokes Mortar consisted of a smoothbore cast iron metal tube attached to an anti-recoil base plate.  Dropping a mortar bomb with a primer charge at its base into the tube would impact a firing pin at the bottom of the tube, the detonation sending the bomb on its way.  Twenty five bombs could be fired per minute, and it had a maximum range of around eight hundred yards.

Soldiers fitting fuses into Stokes mortar rounds, the coloured bands around the shell cases denoting the type of filling used, as the diagram (actually Plate XII of one of the following pamphlets – click to enlarge) on the right details.

So we are going to get a bit technical now – you can always scroll through a bit – and take a look at two Stokes Mortar handbooks, one from late in the Great War (right), and one from the immediate post-war years (left), and if you bear in mind that the Stokes remained in service with certain armed forces until the 1940s, this was still the early days.  ‘The Handbook of the M. L. Stokes 3-Inch Trench Mortar Equipments’, on the left, is the more sensible place to start, for obvious reasons,…

…and begins with a list of contents and list of plates, along with a note at the bottom of the page; ‘This book is corrected up to December 1919’ (left), and a description of the mortar (right).

The first plates show stand & base plate manipulation to vary elevation,…

…with the text on both base plates & stands here on Page 4 (left), with diagrams, on the right, of the Mark II & Mark III base plates, both mentioned in the text, which continues with a section on stands,…

…with Plates II & III seen here.

Here we have the optional shield and accompanying text, followed by how to mount the mortar for an anti-aircraft role (good luck!),…

…with accompanying photos (Plates VIII & IX (above), and (below) Plates VII, X & XI),…

…the anti-aircraft role text continuing onto Page 7 (right).  There follows ‘Nomenclature of Equipment’,…

…before we move on to ‘Care and Preservation’, and some technical details.

This is Page 13, out of order to allow me to show it horizontally,…

…and here are Pages 12 & 14.  You’ve already seen Plate XII (mentioned top right) earlier in the post,…

…so here’s Plate XIII,…

…Plate XIV (left), Plate XV (top right) & Plate XVI (bottom right, with accompanying text at the top of Page 15 below).

The rest of Page 15 is concerned with the Mark 1 percussion fuze,…

…which continues at the start of Page 16, two different images of which are seen above.  The line that has been crossed out on the page on the left is replaced by the inserted addendum leaf on the right.  The plate referred to…

…Plate XVIII, is shown here.

Page 17 and Plate XIX,…

…and the final page on the left, with the final plate, Plate XX, on the right.

A line-up of Stokes mortars, from left, according to the original annotation, 3-inch, 4-inch, a second 3-inch & 6-inch.  The 4-inch version of the Stokes Mortar was primarily used to fire smoke, gas and thermite rounds,…

…which leads us nicely on to this second booklet, published in August 1918 and only, you will note, for chemical, incendiary & smoke mortar shells, and therefore the 4-inch mortar.  According to the cover, this pamphlet was closed to the public until 1969.

William Stokes looks down (inset) on a demonstration of his 4-inch mortar at Helfaut in France, 5th July 1917.  Helfaut is right next to Wizernes, where I spent an interesting afternoon not so long ago exploring the Second World War V2 bunker complex.

So, what have we all learned this post?  Loads of stuff, including, I would suggest, ‘If you find one of these, leave well alone.’  Big thanks to Duncan the Younger for uncovering the two Stokes handbooks during his at-the-time daily delvings in the National Archives or wherever he used to go, plans that, incidentally, don’t appear to be readily available elsewhere on the interweb on a quick search.