Gun in the garden

25 cm Trench Mortar M1916 sMW n/A (Schwerer minenwerfer neuer art or new model) XIX.953. 

This “Trench mortar” is on display at Fort Nelson in the Voice of the Guns gallery.

Tucked away in an unobtrusive corner of the Voice of the Guns Gallery at Fort Nelson lies a German First World War trench mortar. Apart from its obvious interest as an artillery piece it has two great stories to tell with regard to its acquisition and its restoration.

I was first alerted to the potential offer of its donation in 2004 from a lady in the Midlands. The story went that it had been brought back from the Western Front after the war by her father, a Lieutenant Colonel A. W. Brewill who had commanded the Robin Hood Rifles, Nottingham’s Territorial Army Battalion of the Sherwood Foresters. According to the regimental history, he had enlisted as early as 1878 and although well over the accepted age for military service by the time of the First World War, led the battalion on the attack of the Hohenzollern Redoubt in October 1915. Luckily, he survived the war and was able to return with this trophy before passing away in 1923 when aged only 61.

Once on the farm, the mortar had apparently remained in the same place for around 85 years and the donor remembered playing on and around it as a small girl. More recently, it had first been offered to the modern descendant her father’s regiment, the Worcestershire and Sherwood Foresters, based at Chetwynd Barracks, Chilwell, Nottingham, who, as it transpired, had neither the financial resources for its restoration and on-going care nor a suitable location in which to display it. Fortunately for the Royal Armouries and the national collection, their commanding officer recommended Fort Nelson as the proper repository for such a weapon. When I saw a picture of it for the first time, my heart sank and I wondered what we might be letting ourselves in for.

The gun was in bad condition when Royal Armouries staff came to collect it

Would its delicate condition permit transport without causing it further damage and deterioration? As can be seen in the picture, it was looking very sorry for itself surrounded by a ring of rust that had accumulated over the years. Undaunted, myself and a colleague ventured north in a Luton van to collect it once the formalities had been completed. As I recall, after the mortar had been carefully manoeuvred onto the van’s tail lift, it failed to operate! Luckily enough, a friendly neighbourhood farmer watching the proceedings was able to bring a JCB in to complete the lift! Once safely delivered to the fort, the project was not started immediately due to other conservation work in progress at the time. When eventually it did, it occupied our conservation technician, Mick Cooper, for around five years of painstaking application to bring it to completion.

Perhaps one of the trickier aspects of the work related to the replacement of several of the wheel’s wooden spokes without upsetting its balance and visual appearance. In addition, small areas of the metal bed had completely rusted through and flaked away. Building up progressive layers of filler was also a challenge requiring patience and consuming a great amount of time. The elevating gear was missing which we decided not to replace. As Mick and I gave great thought to these and other difficulties we wondered how many rounds this weapon had fired and how it came about?

Germany was amongst several countries to notice that one of the principle artillery failings during the 1904/5 siege of Port Arthur in the Russo-Japanese war, was the age-old one of heavy artillery’s inability to reduce fortifications. What was required for the future was a short-range weapon such as a mortar capable of delivering a heavy explosive charge onto a target with relative accuracy – and plenty of them. Further, if that could also include the destruction of barbed wire obstacles which field artillery found difficult to clear then so much the better. In Germany, a committee of engineers was formed to seek a solution by devising a suitable launcher. Their objective was aided immeasurably with their alignment to the new German arms manufacturer Rheinmetall rather than with their rival, the long-established firm of Krupp. Three models were planned: heavy, medium and light with the former receiving attention first and introduced in 1910 as the sMW a/A (alter art or old model), heavy mine launcher. It had a rifled bore of 25 cm (9.84 in), was muzzle-loaded with a recoil mechanism and the laying facility of a gun. Its 97 kg (215 lb) shell, with an explosive charge of 50 kg (110 lb), equated to the bigger-bored mortars of 28 cm (11 in) and 30.5 cm (12 in) yet was a tenth of their weight. Regarded therefore as portable with a mass of only 768 kg (1693 lb), the five man detachment could emplace it in a trench and expect to fire up to 20 rounds a minute to a range of 880 m (960 yd).

This new model was manufactured in 1916 with a longer barrel for further range – which was always a desirable characteristic in any artillery piece. It meant that the mortar did not need to be deployed in the trench but emplaced further behind the lines to prevent the counter battery fire that it usually always attracted. Its range therefore increased to 1250 m (1368 yd).

It is curious to note that the trench mortar found little favour in both Britain and France during the early stages of the First World War. That was until Sir Wilfred Stokes, Managing Director of Ransomes & Rapier of Ipswich, managed to persuade the Minister of Ammunition at the time, David Lloyd George otherwise, following a favourable demonstration of his Stokes mortar in June 1915. He was sufficiently impressed to order one thousand paying for them with money donated by an Indian maharaja! The sMW was powerful and robust and could also deliver a phosgene gas D-Mine. As a measure of its importance to the Germans during the First World War, 44 examples were available at the commencement of hostilities which, by the war’s end had grown to 1234 in service.

More information about the gun can be found in our Collections Online.

Phil Magrath

Philip Magrath is the Royal Armouries Curator of Artillery at Fort Nelson.

Philip has a First Class Honours Degree in History and a Master’s Degree in Museum Studies. He is passionate about artillery and was delighted to accept an invitation to join the Royal Artillery Historical Trust as one of the very few non-service Trustees. He is also a member of the Royal Artillery Historical Society where he has delivered several papers. In more distant times he was employed by Gosport Borough Council at Explosion! The Museum of Naval Firepower at Priddy’s Hard, Gosport and by English Heritage at Fort Cumberland, Portsmouth.

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