By Rachel Dworkin, archivist
There’s something neat about shows like How It’s Made. If you, like me, have never worked in manufacturing, industrial processes can feel like something of a mystery. Over the years, Elmirans have made everything from aluminum cans to woolen cloth. From 1861 to 1883, the Elmira Rolling Mill Co. made iron.
The Elmira Rolling Mill Co. was founded in 1860. On May 16, 1861, the plant, located on Hatch Street between East 5th and East Washington Streets, began operation. The original structure was 180’ by 80’ and had five furnaces and three steam engines. The plant grew substantially during the 1860s with the addition of two new buildings. By 1865, the mill consisted of three buildings housing the original rolling mill, plus two pudding mills, and a merchant bar mill. The equipment included 24 furnaces, 8 steam engines, 5 trains of rolls, two roll lathes, and one Burden squeezer. The company was using all this equipment to manufacture 22,000 tons of iron each year.
Here’s how it all worked.
Step 1 – Arrival of Raw Materials
In order to make their iron, the Elmira Rolling Mills needed massive amounts of raw iron and coal. These materials arrived at the plant on canal boats and on the dedicated rail spurs which ran to the factory.
The raw iron needed to be heated in order to burn off any impurities and to make it malleable. It was usually heated to somewhere above 462 degrees Fahrenheit. This is iron’s recrystallization temperature, or the point at which the iron’s previous crystalline structure is broken down and reformed anew but not yet melted.
At the Elmira Rolling Mills, this was done in coal-fired pudding furnaces. Pudding is the process of converting raw iron into usable wrought iron by heating it in a special furnace where the metal and the fuel were not in direct contact. The process was first developed in England in the 1780s. I have no idea why it’s called pudding. Heated iron can absorb chemical impurities given off by the burning fuel. Coal, for example, gives off sulfur which can make the metal brittle. By using a pudding mill, the Elmira Rolling Mills could heat their iron using coal without having to worry about introducing sulfur to their iron.
Once the iron was removed from the pudding furnace, it needed to be forced into a useable shape. Traditionally, this was done by teams of strong men with big hammers. In 1840, Henry Burden of Troy, New York, invented his rotary concentric squeezer which performed the same task with a lot less time and effort. The Elmira Rolling Mills had a Burden squeezer they used to force their heated iron into shape.
Step 4 – Rolling
Rolling is a metalworking process where heated metal stock is forced through one or more pairs of rollers to reduce thickness or give it a more uniform shape. A series of multiple rollers is known as a train. The first roll produces a plate of metal. A slitting, latte, or bar roller is used to slice the metal up into bars of various widths, shapes, and thicknesses.
The Elmira Rolling Mills had five trains of rolls which could produce square bars, round bars, oval bars, half-round bars, and half-oval bars in various thicknesses. The company used coal-fired steam engines to power their rollers.
Step 5 – Sale
Initially, the Elmira Rolling Mill’s main clients were railroads for whom they made rails. In 1863, the company added a merchant bar mill so they could offer iron bars in more shapes and sizes to a wide variety of clients.
At its peak, the Elmira Rolling Mills employed around 400 people and was one of the city’s largest employers. By the 1880s, the railroad industry had switched to using steel for their rails. The company was not equipped for steel manufacturing and found it could not keep up with the manufacturing centers of Harrisburg and Pittsburgh. In 1883, the workers went on strike for higher wages. In response, the company permanently shut their doors. Although iron is no longer made in Elmira, the process used at the Elmira Rolling Mills is largely still used today, abet with different power sources.