Wheels and What They’re Worth

Elisabeth Meier of the Winterthur Program in American Material Culture just wrote on learning about the art and mystery of the wheelwright at Colonial Williamsburg:

I’d already been passed by several carriages in Williamsburg, and each time, I’d had no idea how much specialized knowledge was rolling by under the bright coats of paint—which, incidentally, the wheelwrights also mix. Underneath that paint, the wood is specially chosen for the task it serves. The hubs are elm, because the tight, twisted grain resists splitting even when the spokes are driven in. Colonial wheelwrights also used oak and black gum. The spokes themselves are oak, a hard, durable wood that rives well and, therefore, can be shaped quickly. The fellies, which make up the wooden rim of the wheel, can be oak, ash, or elm. These are protected from the stress of passing over rough roads by iron rims that can be replaced relatively easily, thus prolonging the life of the wheel and the minimizing the expense of maintaining a vehicle.

…eighteenth-century wheels were beautifully engineered so that use would strengthen rather than weaken them. To start with, the mortises that the spokes in the hub are cut on an angle, so that the joint gets progressively tighter as the spokes are driven in. But this alone wouldn’t save a wheel from loosening under the constant jostling from horses and uneven roads. To avoid that, wheels have a concave shape, or ‘dish,’ built into them. The dish helps focus the forces on the wheel inwards, so that the joints would be driven together over time rather than being shaken apart. However, this only works if the wheel touches the ground at a right angle, meaning that the hubs also have to be angled. The result gives carts and carriages something of a flamboyant look—something I will no longer interpret as artistic license!

Wheelwrights were essential craftsmen in any community, and their craft supported much of the mobility that enabled the consolidation of England, and later America, in the eighteenth century. As a result the huge demand for wheels, wheelwrights on both sides of the Atlantic could count on purchasing timber that had been pre-processed into rough hubs, spokes, and fellies, considerably cutting down on the labor needed to shape a wheel. However, processes that were efficient for wheelwrights were often at odds with the needs of newly empowered governments and the infrastructure they were beginning to build. Public roads were a case in point. For wheelwrights, it was cheapest and easiest to nail on an iron rim in pieces, or strakes, using large bolts, but these bolts were tough on road surfaces. Continuous iron rims, or tire irons, were easier on pavement, but it took considerably more fuel and space to heat them evenly enough to fit around a wheel.

I gained a new respect for wheels in researching The Road to Concord. In 1774, the Massachusetts Provincial Congress’s Committee of Safety and Supplies set out to build an artillery force. Between politically supportive merchants, shore batteries, and the Boston’s militia gunhouses, they gathered dozens of cannon by early the next year. But those guns needed field carriages to roll across the countryside and maneuver around battlefields. And field carriages needed good, strong wheels.

As Meier’s essay shows, wheels were complex artifacts requiring skilled labor. Gun carriages were specialized vehicles, assembled by blacksmiths from iron and wood. What’s more, many of the cannon were damaged and needed special mounting. All that work was expensive. As a result, putting guns on carriages proved to be a chokepoint for Massachusetts’s Patriot committees, both at the provincial level and for towns that had decided to form their own artillery companies.

And that made the effort vulnerable. When Dr. Benjamin Church first sent intelligence to Gen. Thomas Gage, his information was mostly about blacksmiths making gun carriages—which blacksmiths and where. Days later, Lt. Col. Alexander Leslie nearly intercepted a bunch of cannon at Robert Foster’s smithy in Salem, where they were being mounted. When fighting finally broke out on 19 Apr 1775, the provincials didn’t take any cannon into battle—perhaps because none was fully ready.