Before the Industrial Revolution, most smaller cities and towns depended on local blacksmiths to make the iron tools and fasteners needed for daily life. Without a doubt, blacksmithing was hot, hard work. But the invention of the foot-operated hammer, or Oliver, made it possible for the smith to produce more items faster and with a bit less effort.

Constructing the Big Hammer of the Middle Ages

If you examine the nails that hold medieval European buildings together, you’ll find they are very different from the nails available at today’s hardware stores. Believe it or not, in many ways, medieval nails were better than the modern ones we use now. Modern nails are sliced from a strand of hardened wire by machines; the end of each nail is then cut mechanically so it becomes round and pointed. When you pound a modern wire nail into wood, the hammer blows force it between the individual fibers of the wood. Such nails work adequately in softwoods, like pine and fir, but they often split hardwoods, like maple or walnut.

The medieval iron nail is an entirely different animal. Each nail was wrought individually by a blacksmith; that is, it was beaten into shape by hammer blows. The wrought iron nail is rectangular in cross section with a hand-filed chisel point. The chisel point doesn’t simply push wood fibers aside; it actually cuts through the wood fibers. Wrought nails can even be driven into oak without splitting it, and once they’re in, they are nearly impossible to remove.

Of course, wrought nails, like just about everything else a smith made, required a lot of effort. To make a nail, the muscular smith heated a bar of iron to red hot in his forge. Then, he hammered the bar into a thin, square rod and squashed one end into a flattened point. Next, he reheated the nail and, using a special form, he banged the other end with an even bigger hammer to form the nail head.

Large-scale nail making was invented by the Romans and continued on without much change until a nameless, but clever, 14th-century blacksmith in the north of England came up with a better idea—one that allowed him to leverage gravity and substitute the far larger muscles in his legs for the relatively puny muscles in his arms. This invention, which came to be called the Oliver, revolutionized ironworking.

An Oliver is a type of machine also known as a lift hammer. The Oliver uses a sapling (the wood of the holly tree was preferred by English smiths) as a tension spring to pull up a hammer attached to an axle that is operated by a foot-operated treadle (see Figure 6-1). To pound the metal, the smith stomps hard on the treadle, bringing the hammer down on the work. When he releases the pedal, the springy pole brings the hammer back up.

The earliest records we have of Olivers come from the north of England in the early 1300s. They continued to be used into the 18th century, when water- and steam-powered hammers made the springy pole method of raising the hammerhead obsolete. For about 500 years the Oliver was one of the most important machines in the world. With it, nails and other valuable pieces of ironwork could be made more quickly and less expensively.

Making a Model Oliver

A real Oliver is a massive machine, often weighing over a ton. Though our project is only a working model of the medieval lift hammer, the machine works using the same principles as the large Olivers used by 14th century blacksmiths.

Building the Oliver

To build your Oliver, first take a look at how to assemble it, as shown in Figure 6-2. Then use the following steps:

1. Assemble the treadle and hammer frame according to the assembly diagram in Figure 6-2. Note that some connections are to be screwed together tightly and others left loose.
   1. Start assembling the frame at the bottom, beginning with the flanges, and work your way up.
   2. Because all the pipe threads are right handed, you may find it difficult to screw the last pipe nipple into the last elbow. To work around this problem, temporarily over-tighten the nipple into the upper tee fitting, moving the nipple into place between the tee and elbow.

      

   3. Then rotate the nipple into the elbow while you simultaneously loosen the connection into the tee. If you’re careful, this will allow the horizontal shafts to pivot smoothly and easily.

      Figure 6-2 shows which joints to twist tight and which to leave loose.Note also the location of the last joint.

   4. When you’ve completed the assembly, attach the flanges to the plywood base with wood screws.
2. Assemble the hammer and attach it to the open end of the upper tee fitting.
3. Assemble the two yokes from the flanges, the 18-inch pipe nipples, and the tees.
4. Fasten the treadle and hammer frame and the two yokes to the plywood base with #10 wood screws as they are in Figure 6-3.
5. Insert the dowel or branch through the tees at the top of the yokes so that one end is just above the middle of the hammer.
6. Move an anvil or other suitable hammering surface into place below the hammer.

   

7. Adjust the hammer and treadle tees so the treadle and hammer levers are roughly parallel.
8. Connect the hammer to the tip of the green branch with string as shown in Figure 6-3.

When you depress the treadle, the hammer will strike the anvil. When you release the treadle, the green branch will pull the hammer back up (see Figure 6-4).

The Smithy

The brick- or stone-lined fireplace in which the blacksmith heated metal is called a hearth and the building that contained the hearth is called the forge or smithy. (Never call a blacksmith a “smithy”—that’s a bit like referring to a chef as a kitchen.)

For centuries, the smithy was one the most important buildings in any city or town. Medieval craftsmen and farmers depended upon the smith for the iron tools they needed to do their jobs; knights depended on iron weapons and armor to maintain their fiefdoms. And since nearly everyone relied on horses for transportation, those animals had to have iron horseshoes to protect their hooves. So, the improvements made possible when Oliver hammers appeared in the smithy was an important advance, not simply in metalworking, but in the entire Western economy.

Pound away, mighty smith!