(viii) Relationship With Manufacturers.
(a) Close control over production. This was discussed when we considered the role of the Outside Engineering Branch. For many items produced by the Trench Warfare Department, the manufacturing model, as mentioned previously, involved having components manufactured by numerous small engineering concerns. These components were then brought together at a central factory for assembly into the completed munition. Maintaining consistent standards and ensuring the required number of items were produced on time necessitated close central control and monitoring by members of the Outside Engineering Branch, and although the term would have been unknown at the time, the Trench Warfare Supply Department operated what we recognise as a ‘just in time’ manufacturing strategy. For some munitions, such as the Mills bomb, this was critically important, for with an output of 1,000,000 or so a week in 1916, any break in a very fluid and fast-moving supply chain from providing iron to cast the grenade bodies to the delivery of completed grenades to the trenches would bring the whole system to a juddering halt.
(b) Sub-contracting and Cooperative Manufacturing. As demand for trench warfare munitions increased, certain firms began receiving orders that exceeded their capacity to deliver within the specified time and resorted to subcontracting component manufacturing, thereby speeding up production. The Outside Engineering Branch, while appreciating the necessity for sub-contracting, disliked the practice as it added to their difficulties in maintaining quality, for they now had additional workshops to inspect over which they had no contractual control, other than rejecting inferior workmanship and added to costs as a profit for the sub-contractor, as well as the main contractor, had to be built into the final price. After several temporary crises in supply when sub-contractors failed to deliver components of the required quality, the Ministry Contracts Department stepped in to forbid sub-contracting, which presented the Outside Engineering Branch with the problem of how to maintain high output when the resources of the primary contractors were inadequate, a dilemma they resolved by creating cooperative, or group, manufacturing, a practice rare in British industry at the time.
In its most straightforward form, the manufacture of a munition was organised by spreading the contract over several firms, each contracted to produce one or more components, which were brought together at a central collection point or factory to be assembled into the completed munition. This form of cooperative manufacturing had many advantages; it reduced costs, not only through the elimination of the double profit, but also because the smaller firms contracted to make the components soon became skilled in making their particular item, increasing their productivity and making savings through a reduction in the number of items failing quality inspection. The downside was that it added to the logistics of their ‘just in time’ supply chain by providing many more workshops with materials and then transporting the completed components to the final assembly point.
The first example of cooperative manufacturing developed in Birmingham in July 1915 between two grenade manufacturers where one loaded the grenades made by the other with high explosives while at the same time manufactured components that the first company required to complete the assembly of the grenade bodies and by February 1916 the practice had been extended so that a large number of small workshops were producing the thousands of fittings necessary to assemble the hundreds of 3-inch Stokes mortar on order. The motor manufacturers in Coventry that held the contract to deliver the assembled mortars oversaw the entire process, providing the drawings, special measuring gauges, worker training, and inspection of the individual components. In Glasgow, a similar cooperative arrangement existed between the companies that collaborated in the manufacture of the 9.45-inch heavy mortar.
(c) Determination of Costs. Once set up, the cost of producing trench warfare munitions was considerably less than that for standard items of ordnance, as their manufacture was relatively simple, the materials used were common and not subject to wartime shortages that pushed up their price, and the wage bill was less, as most workers were semi-skilled. In contrast, start-up costs could be extremely high; the initial cost of filling a thousand Mills bombs was priced at £11 11 shillings, as it had never been done before. However, once the process was understood, firms were willing to accept £4 per thousand for repeat orders. This illustrates one of the additional difficulties the Trench Warfare Supply Department had to overcome when forced to comply with the procedures of the Ministry of Munitions’ Contracts Division: reaching agreement on initial costs when negotiating with an inexperienced company to manufacture an entirely novel munition. Under such circumstances, the first order was, out of necessity, small, and the costs were high, as the most effective manufacturing method would have to be worked out through trial and error. To determine the cost of manufacturing the 240 mm mortar bomb, which involved the novel technique of electric welding, the Trench Warfare Supply Department placed experimental orders with six manufacturers for 50 bombs each and from their detailed records of all the costs incurred calculated that they would offer a contract cost of 62 shillings and 6 pence per bomb, plus setting up and training costs to manufacturers willing to undertake supply.
(ix) Redundancy.
By their very nature, trench warfare munitions were experimental and subject to constant change, even into the last year of the war. This naturally resulted in a high level of component redundancy and often complete weapons, leaving the Trench Warfare Supply Department responsible for disposing of the surplus munitions. Throughout most of 1915, this was not a serious problem as the volume of redundant weapons, usually one of the experimental hand grenades, was relatively small but, at the end of the year when GHQ proposed to standardise its supply of trench warfare munitions around the Mills bomb and three calibres of trench mortar the Trench Warfare Supply Department found itself with large volumes of redundant weapons on its hands. Their first instinct was to try to convince the Army Council to reverse its decision concerning particular munitions, such as the 4-inch light mortar, that they felt were still valuable, but they lost the argument because there were no significant reserves of ammunition for that particular mortar. In contrast, the 3.7-inch, also declared redundant in December 1915, remained in service until the middle of 1916, when its ammunition stocks were depleted.
The decision to adopt the Mills bomb as the only hand grenade to be issued made, at a stroke, all other grenade patterns obsolete. This impacted the Leach catapult and West Spring Gun, which practically disappeared as front-line weapons. At the same time, those grenades where large stocks existed, such as the Ball and Lemon grenades, were offered to allies, particularly the Russians and Serbs, at a discounted price, or, in the case of the Ball grenade dispatched to that dustbin for munitions considered no longer suitable for the Western Front, the Dardanelles. Those remaining grenades were broken down, with their components either reused or their materials recycled.
By 1917, the salvage and recycling of damaged or redundant munitions was big business, not only because there was more to recover from the battle zone consequent on the consumption of the vast volume of munitions considered necessary to attack the enemy, but there was an urgent economic imperative due to the growing shortage of materials for munitions production and the significant losses to imports through the activities of enemy submarines. Infantry battalions appointed salvage officers who, with their salvage teams, scoured the battlefield and lines of communication for anything salvageable and submitted daily reports of their findings. To deal with the volume of salvage, both that repatriated from France and redundant stock in storage at home, the Trench Warfare Supply Department created special recycling units at each of its munition stores to break down discarded weapons. However, those still containing explosives had to be dealt with at the Ministry of Munitions National Filling Factories, as only they had the specialised facilities required. In November 1917, as a result of congestion at the National Filling Factories, the Trench Warfare Supply Department proposed to build a facility to deal with explosive munitions at Chipping Sodbury, near Bristol, but the plan was knocked on the head when it was pointed out that the proposed site was adjacent to the main Great Western Railway.
(x) The Last Year of the War.
A large proportion of the Trench Warfare Department's manufacturing capacity was devoted in 1918 to producing Mills bombs, trench mortars, and ammunition to equip Allied armies, such as the Italians and the American Expeditionary Force. There was also a continuing demand from the War Office for new weapons. On April 28, 1918, the Army in France requested 500,000 anti-tank grenades. When the War Office notified the Ministry of this demand, it was found that the Trench Warfare Department was working on a prototype, having independently concluded that such a weapon might be needed in the future. However, it was not until August 24 that the first batch of 4,000 such grenades was dispatched to France. At home, the necessity to make economies in munition production proceeded apace with the filling of mortar bombs, now combined with that of artillery shells, for, as a result of a fall-off in demand for artillery shells, there was spare capacity in the National Filling Factories conveniently filled by the mortar bombs. In contrast, the capacity freed up in the Trench Warfare Filling Stations was absorbed by the new requirement to fill and assemble aerial bombs and chemical shells, whose demand was increasing and for which large orders were being discussed if the war continued into 1919.