Trench Warfare's (Supply) Department.
Following the decision by the War Office in late 1915 that the Mills bomb was to be the only explosive hand grenade issued to the army, and the 3-inch Stokes mortar the only light mortar, the idea that the research and development of these weapons, and others adopted in a similar manner, were essentially complete gained traction in the Ministry of Munitions. This led to an increased emphasis on the production of trench warfare materiél and Alexander Roger responded by reorganising his new department along lines similar to the structure of other manufacturing departments in the Ministry.
He instructed his deputy, Mr A.V. Haig, to undertake a root and branch reorganisation to improve productivity while at the same time reducing manufacturing costs. Haig started with the Trench Mortar Section, which was reorganised into two sub-sections: one responsible for the 3-inch Stokes and Heavy mortars along with their ammunition, the other for the medium mortars and aerial bombs for the RFC, the development of which was given to the section because of their similarities to mortar bombs. To reduce costs, this sub-section also became responsible for the manufacture of all components common across the mortars and their ammunition. The sections previously responsible for grenades, fireworks and flares were amalgamated, enhancing productivity through the amalgamation of research and development resources and manufacture of common components.
The Watford filling station was expanded to cope with the final assembly and filling of the 3-inch Stokes mortar bombs, aerial bombs, fireworks and flares, and in 1917 grenade assembly and filling was transferred to Watford. The Outside Engineering staff at Watford now became responsible for enforcing the Factory Acts, the maintenance and improvement of buildings, staff training, and all other functions that impacted upon the health and safety of workers across the factories awarded contracts from the Trench Warfare (Supply) Department.
At this time, May 1917, the main outputs of the department were,
trench mortars with their ammunition,
chemical shells and other appliances for delivering chemicals, such as the Livens projector,
grenades,
helmets and body armour,
signal cartridges,
a wide range of miscellaneous items such as equipment to support the Tunnelling Companies, and non-trench warfare munitions, such as mines and mine-sinkers for the Admiralty, and aerial bombs for aircraft.[1]
During the period December 1916 - May 1917, the Department issued 1,926 trench mortars, covering all three patterns in service, and had filled 2,000,000 mortar bombs with high explosives and issued 14,800,000 grenades overseas, or to the training schools, and issued 1,500,000 helmets. The production of 4-inch Stokes bombs with chemical fill increased from 8,000 per week in January to 23,000 per week in May, and the monthly output of chemical shells for artillery shells filled with lethal chemicals and lachrymators rose from 23,960 in January 1917 to 88,283 in May.
To meet the increased use of chemicals and smoke, the department made a substantial investment in building up the chemical industry through grants and loans to manufacturers, with additional investment in Captain Livens’ special mortar, or projector. In two months, April and May, 20,000 projectors and 20,000 bombs, filled with lethal chemicals, along with the special electrical fuses, propellants, and other accessories, have been sent overseas. Finally, the department has done a great deal to meet the Government’s commitment to support the Russians, dispatching a large proportion of the grenades, trench mortars, and ammunition manufactured in the first months of 1917.
[1] TNA: MUN5/195/1600/5. Resume of work done by TWSD from Dec. 1916 to May 1917.