interchangeable parts -- 9/28/22

Today's selection -- from Exactly: How Precision Engineers Created The Modern World by Simon Winchester. The revolution that came from interchangeable parts:
"Lewis Mumford, the historian and philosopher of technology, was one of the earliest to recognize the major role played by the military in the advancement of technology, in the dissemination of precision-based standardization, in the making of innumerable copies of the same and usually deadly thing, all iterations of which must be identical to the tiniest measure, in nanometers or better. The stories that follow, in which standardization and precision­-based manufacturing are shown to become crucial ambitions of armies on both sides of the Atlantic, serve both to confirm Mum­ford's prescience and to underline the role that the military plays in the evolution of precision. The examples from the early days of the science are of course far from secret; those from today, and that might otherwise be described in full to illustrate today's very much more precise and precision-obsessed world, are among the most se­cure and confidential topics of research on the planet -- kept in per­manent shadow, as the dark side necessarily has to be.

"It was in the French capital in 1785 that the idea of producing in­terchangeable parts for guns was first properly realized, and the precision manufacturing processes that allowed for it were ordered to be first put into operation. Still, it is reasonable to ask why, if the process was dreamed up in 1785, was it not being applied to the American musketry in official use in 1814, twenty-nine years later? Men were running, battles were being lost, great cities were being burned -- and in part because the army's guns were not being made as they should have been made. There is an answer, and it is not a pretty one.

"Two little-remembered Frenchmen got the honor of first introducing the system that, had it been implemented in time and implemented properly, would have given America the guns it should have had. The first, the less familiar of the pair, despite the evidently su­perior nature of his name, was Jean-Baptiste Vaquette de Gribeau­val, a wellborn and amply connected figure who specialized in designing cannons for the French artillery. He supposedly came up with a scheme, in 1776, for boring out cannons using almost ex­actly the same technique that John Wilkinson had invented in England, that of moving a rotating drill into a solid cannon-size and cannon-shaped slug of iron. Wilkinson had patented his pre­cisely similar system two years earlier, in 1774, but nonetheless, the French system, the système Gribeauval, as it came to be known for the next three decades, long dominated French artillery mak­ing. It gave the French armies access to a range of highly efficient and lightweight, but manifestly not entirely originally conceived, field pieces. (Gribeauval did employ what were called go and no-go gauges as a means of ensuring that cannonballs fitted properly in­side his cannons, but this was hardly revolutionary engineering, and it had been around in principle for five centuries.)

French gunLock (true Flintlock) as that made by and improved upon by Blanc

"The second figure, the man who did the most to bring the sys­tem of interchangeable parts to the making of guns, and whose technique was, unlike Gribeauval's, unchallengeable, was Honoré Blanc. He was not a soldier but a gunsmith, and during his appren­ticeship he became well aware of the Gribeauval system. He decided early in his career that he could bring a similar standardization to the flintlock musket, for the benefit of the man on the battlefield.

"Yet there was a difference. A cannon was big and heavy and crude -- a gunner simply touched his linstock, with its attached lighted match, to the vent, and the cannon fired -- and so such parts as there were proved easily amenable to standardization. With the flintlock, however, the lock (that part of a musket that delivered the spark that exploded the priming powder that ignited the main charge and drove the ball down the barrel) was a fairly delicate and complex piece of engineering, made of many oddly shaped parts and liable to all kinds of failure. To the uninitiated, the names of the bits and pieces of a flintlock alone are bewildering: a lock has parts that are variously known as the bridle, the sear, the frizzen, the pan, and any number of springs and screws and bolts and plates as well as, of course, the spark-producing (when struck by the aforementioned metal frizzen) piece of flint. To render the lock into a standard piece of military equipment, with all its parts made exactly the same for each lock, was going to be a tall order.

"Cost, rather than the well-being of the infantryman or the con­duct of the battle, was the prime motive. The French government declared in the mid-1780s that the country's gunsmiths were charging too much for their craftsmanship, and demanded they improve their manufacturing process or lower their prices. The smiths not unnat­urally balked at the impertinence of the suggestion, and promptly tried selling their products to the new armories and gun makers across the Atlantic in America, a move that alarmed the French government, as it imagined it might well run out of weaponry as a result.

"It was at this point that Honore Blanc entered the picture, taking a civilian job as the army's quality-control inspector. His brother gunsmiths expressed their dismay over the fact that one of their number was going over to the other side, was a poacher turning gamekeeper. Blanc dismissed the criticism and got on with his job, his own motivation being the welfare of the soldier out in the field rather than allowing the government to cut costs. He was greatly in­fluenced by M. de Gribeauval, and decided he could ape his system of standardization, ensuring that all the component parts of a flint­lock he made as exact and faithful copies of one perfectly made master.

"This master he made himself, carefully and with great precision, and with all the specifications laid down as precisely as possible (us­ing the arcane system of the Ancien Régime, which still employed dimensional measures such as the pointe, the ligne, and the pouce) to tolerances of about what today we would recognize as 0.02 millime­ters. He then made a series of jigs and gauges to ensure that all the locks made subsequently were faithful to this first perfect master, by the judicious use of files and such lathes as were available. The gunsmiths hired by Blanc to perform this task -- by hand, still -- made each lock exactly as the original. Providing that they did so, exactly, all the pieces would then fit perfectly together, and the whole assem­bled lock would fit equally perfectly into each completed weapon.

"Yet only a small number of gunsmiths were willing to work under these stringent new conditions. Most balked. Making guns simply by copying parts reduced the value of the gunsmith's craftsman­ship to near insignificance, they argued. Unskilled drones could do their work instead. By arguing this, the French smiths were voicing much the same complaints as the Luddites had grumbled over in England: that precision was stripping their skills of worth. This argument would be heard many times in the future as the steady march of precision engineering advanced across Europe, the Americas, the world. The kind of mutinous sentiments heard in the English Midlands half a century before were now being mut­tered in northern France, as precision started to become an inter­national phenomenon, its consequences rippling into the beyond.

"Such was the hostility in France to Honoré Blanc, in fact, that the government had to offer him protection, and so sequestered him and his small but faithful crew of precision gun makers in the base­ment dungeons of the great Château de Vincennes, east of Paris. At the time, the great structure (much of it still standing, and much visited) was in use as a prison: Diderot had been incarcerated there, and the Marquis de Sade. In the relative peace of what would, within thirty years, become one of postrevolutionary France's greatest ar­senals, Blanc and his team worked away producing his locks, all of them supposedly identical. Blanc made all the necessary tools and jigs to help in his efforts -- according to one source, hardening the metal pieces by burying them for weeks in the copious leavings of manure from the castle stables.

"By July of 1785, Blanc was ready to offer a demonstration. He sent out invitations to the capital's nabobs and military flag officers and to his still-hostile colleague gunsmiths, to show them what he had achieved. Many officials came, but few of the smiths, who were still seething. Yet one person of great future significance did present himself at the donjon's fortified gates: the minister to France of the United States of America, Thomas Jefferson."



Simon Winchester


Exactly: How Precision Engineers Created the Modern World


HarperCollins Publishers


Copyright Simon Winchester 2018


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