By Jim Philp
Reprinted with permission from the Oct/Nov 1997 issue of Independent Sawmill & Woodlot Magazine.
The new "portable" sawmills of today are only updates of machines that have existed since the days of pyramid building.
Portable sawmilling used to be two slaves carrying their owner's bronze pit saw into the woods, hoping to saw a single log in a day. Today a modern woodlot owner or logger can save up to buy a versatile, powerful portable sawmill that can produce 2,000 or more board feet of lumber on a good day-all for the price of a new pickup truck.
With so many wonderful machines currently on the market, just for the fun of it, let's take a look at what has gone before. The first portable sawmills were simply two men, most likely serfs, carrying a pit saw. The men took turns carrying the saw into the woods where trees were felled and a pit was dug. Once milling began, the man on top was called the "Top Man." He lifted the saw and guided it along a line scribed on the log. The man on the bottom was the "Pit Man," who pulled the saw down, supplying the energy that cut the wood. He often got sawdust in his eyes, and always in his hair and down the back of his neck. The saw cut only on the down stroke. This technology was developed by the Egyptians and was later improved upon by the Romans, who eventually adapted it to water power. The pit saw remained fairly common into the 18th century, and can still be found in some places today.
The pit saw may not fit the modern definition of a mill, a term now implying mechanical power. But the original concept of a mill was to bring the logs to a central area for processing, a place where there were many pit saws. Notice how the terminology has reversed-once again loggers are taking the saw to the logs rather than the logs to the saw. Of course, today both systems are in operation.
A Water-Powered Industrial Revolution
When the industrial revolution began in the mid-18th century, the concept of the water-powered pit saw was reinvented. The saw was mounted in a wooden frame that reciprocated, up and down, on wooden guides. The saw frame was connected to a water wheel by a series of wooden gears and a "pitman arm." Thus the water wheel became the pit man. Frequently the top man was replaced by a wooden spring pole that helped pull the saw frame up after the cutting stroke.
As water-powered technology advanced, the single saw was replaced by double, and then multiple, saws in the same frame. This developed into the sash-gang saw that could process a log into boards in a single pass. Such water-powered mills were distinctly not portable. They usually required a mill pond and extensive stonework for a mill foundation. The mill building, water wheel and sawmill were usually of "unitized construction" where everything was tied together. If a mill were torn down, parts of it could have been used in another location, but it was probably easier to build an entirely new mill
at the next location.
Water Turbines Speed Mills
As the industrial revolution accelerated, change came rapidly to manufacturing in general, and the sawmill industry was no exception. An early breakthrough was the development of the water turbine, which replaced the water wheel. The turbine produced much more power for the same amount of water and made higher speeds possible.
By the 1860s, large rivers in the east, such as the Penobscot in Maine, were dammed and sawmills occupied the river below the dam from bank to bank. It was not uncommon for dams and mill blocks to be repeated down the river, as close together as the river fall would permit. Nor were the big rivers of the East the only ones with mills on them. Nearly every trickle of water in timber country was used to power some sort of sawmill during those times. Although steam power was available by this time, the mills still used water power.
The rivers were highways for transporting the logs, and having the
mills on the river bought the logs right to the mill yard and provided free power besides. During those days, mill waste was discharged directly into the rivers. Tales are told of the Penobscot flowing solid sawdust through the center of Bangor.
The mills used mostly up-and-down sash gang saws powered by water turbines. These mills were certainly not portable. They were permanent, at least until they burned down, which most of them eventually did. Mill fires were common in the days of wood frame construction, where friction from wooden shafts and falling sparks from continually smoldering waste fires were normal working conditions.
The Age of Steam
Next came band saws and circular saws. At about the same time, steam engine technology saw rapid advances, and someone invented the concept of railroad logging and steam-powered log haulers. Smaller railroad logging operations at the time often did not use steam engines, or even steel tracks. Loggers looked to a nearby hill to provide the power and built wooden "tracks" on which a log truck was mounted. These wooden-framed log haulers often had only a hand brake to slow their speed down a hill, adding to the already dangerous world of logging for the driver of a load of logs speeding down the hill.
The new band sawmills tended to be large steam-powered affairs. There were several mills in Pennsylvania that had hourly production far in excess of the daily capacity of the largest mill in that state today. These mills were clearly designed to be permanent, as they were far too large and too costly to set up to consider moving. Since virtually none of them have survived the changing economies of wood production, the owners were probably overly optimistic in calling them permanent. Temporary would have been a better word.
Portable Sawmills Come Full Circle
The circular sawmills were the portable ones. They were usually steam powered, although some had a mill pond and water turbine power. In later times, such mills have been powered by gasoline and diesel engines, electricity and farm tractors. The Frick, American, Lane and Corley mills are good examples of the type. These mills were made in modules with wooden frames and were assembled into a complete mill. The three modules were; husk, containing the saw arbor and carriage feedworks; log carriage, and tracks. A fourth module was the power supply, but this was the responsibility of the owner and was not supplied with the mill. A majority of these mills also included a board edger, available from the mill manufacturer, but many got by
edging on the big saw.
Portability was a matter of perspective. A crew of six to eight men could dismantle and reassemble one of these "portable" mills in about four days depending on how far they were moving. It was generally considered that a minimum of one-half million board feet of timber was required to justify moving a mill.
At the new location, the mill was reassembled on a prepared foundation, frequently poles set into the ground. The alignment and leveling of a portable circular sawmill were critical if good quality lumber was to be produced, and realigning and releveling was needed at least twice a year. This was necessary because wooden foundations tend to move with the frost. Unfortunately, this necessity was too often not understood, or perhaps ignored. The portable circular sawmill, and its mismanagement, was largely responsible for the
aphorism "Thick and Thin Lumber Company." Those sawmill operators who could not produce consistent lumber were quickly tagged with the thick and thin label, something modern sawyers try to avoid at all costs.
Reprinted with permission from Independent Sawmill & Woodlot Magazine. Subcription information is available at their website, www.sawmillmag.com.
