American Rifle - Alexander Rose [163]
All kudos to the Ordnance men, then, who pulled shift after shift to get production up and running in record time. The first step was the preparation of detailed production drawings for every part of the rifle and painstakingly ensuring that their tolerances (that is, the possible variations in a characteristic such as hardness, density, or weight) stayed well within fixed maximums so that each piece would fit together absolutely perfectly. If something went even slightly awry in the smallest minutiae of these blueprints, then interchangeability—the touchstone of the Ordnance Department for a hundred years—would be rendered impossible from the get-go.
Once the drawings were completed, the second step consisted of planning how each part was to be made in a sequence of operations. Every stage, from a piece’s rough hewing to its exacting final state, was traced on a “route sheet” that also listed the manner of every operation, the type of machine that would perform it, and the gauges that would be needed to ensure the piece’s standard dimensions.
With much of the paperwork done, the armory set about ordering the required amounts of material, a process that could take several months owing to the need for competitive bidding with outside contractors and possible delays resulting therefrom. Meanwhile, the planning division’s production control section ensured that when the shops dealing with the smaller components received the material, they would have an efficient system of production ready so they could coordinate with the assembly room, which was where the major parts would be assembled.
As raw materials began to arrive, practical plans were drawn up to lay out exactly how each piece would be manufactured. During this stage the machines that would help make other machines were designed, adapted, or purchased and laid out on the factory floor according to the principles of scientific management. To make an M1 some two thousand separate operations were required, and nearly all of them called for a jig or a fixture to hold it still, a tool for the cutting, and several gauges to measure the finished article in all its dimensions. Thus multiple copies of, and spares for roughly six thousand pricey, precise accessories were required before manufacturing the M1 could even begin. Ammunition production was simpler but only relative to rifle manufacturing. Making a single cartridge took fully 111 operations from raw material to finished product: 64 mechanical operations, 19 washing operations, 16 drying operations, five pickling operations, and seven annealing operations (a process that softened the metal made hard and brittle by the mechanical procedures).
Now, some of these accessories were already available in the Springfield storerooms, owing to work on previous makes of rifles, and they could be quickly modified to fit the new model. But the great majority weren’t, and because every single one had to be designed and made, an outside contractor for the armory estimated that twenty thousand hours of engineering study would be needed even to plan making these accessories, and two hundred thousand more to actually produce them. Moreover, over the past thirty years new machining methods, such as internal and surface broaching, and coining in cold dies instead of hot forging, had been developed, demanding additional research and investment in brand-new equipment. In turn, armory representatives had to canvass the market, advertise the open contracts, negotiate discounts with manufacturers, have the funds approved, and then wait for delivery and hope the manufacturer didn’t screw up the order.73 Ultimately, Springfield purchased nearly one thousand different machines at an average cost of $20,000 each, in addition to the jigs and fixtures.74 Gunmaking is, it seems, more complex and wondrous a matter than most people assume.
Bearing