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September 2006 - The Logging and Sawmilling Journal


—how log scanning got started

As part of our series on some of the most significant innovations in sawmilling, we take a look at how scanning and optimization started, a colourful history that includes—at one point—car lights and operators wearing sunglasses to shield themselves from bright scanning lights.

By Alan Froome

Scanning and computer optimization is universally accepted today as the method to get the most from any log supply, whether it’s measured in lumber volume or profit (and that’s not always the same thing). But like a lot that we now take for granted in the sawmill, it wasn’t always so. It really was not so long ago that operators made every decision in the sawmill using only their eyes and experience.

In the course of only 35 years or so, the industry has come from eyeballing logs to today’s computer-run automated machine systems in a never-ending attempt to squeeze the most out of that tree.

In terms of the introduction of basic log scanning, it all started in the 1970s, with the introduction of the first lineal scanners. Transverse scanning for edgers, trimmers and log carriages came later. We apologize upfront to anyone who may have been inadvertently left out of this story. Others may have been working in the field at the same time, but research indicates that the Swedes were the first in this area.

Those long Scandinavian winters have often given rise to new ideas in sawmilling. From what we can tell, log scanning began there, and one of the first companies to develop a practical system was Rema Electronics of Vasteros, Sweden. At first, all the installations were in Europe. But in 1972, Oddgeir Uglum and Goran Bollden relocated from Sweden to the US and installed their first four lineal systems in North America in 1974. The first systems were sold to:

JD Irving, New Brunswick; Federation Chantiers Co-operative, Quebec; Wickes Corp Idapine Mills, Idaho. By 1975, Rema had a total of 30 scanners in Canada and the US, plus another 150 systems working in Europe.

It’s interesting to note that of the first 30 sold on this continent, 18 were in Eastern Canada, three were in Western Canada and nine were in the US. The similarity of log sizes and climate from Sweden to Eastern Canada prompted Rema to start marketing there first.

Unfortunately both Uglum and Bollden are now deceased, but RemaControl AB, as it is known today, continues to do scanner development, working on x-ray and bark-on log scanning systems from its base back in Sweden. It’s quite remarkable to think that the same company has been in business all these years and we thank Mathias Karlsson and Leif Antonsson of RemaControl, Sweden for the pictures and history of the first log scanners Rema installed in North America.

The first Rema scanners operated a bit like “smoke and mirrors,” in that they used a rotating mirror mounted at the focal point of a parabolic mirror. The scanners were located in a gap in a log conveyor and functioned by measuring the time that the mirror was blocked by the log passing by.

The software was developed in Sweden and was fairly primitive at first, but good enough for log scaling, with log diameters measured every one inch at 150 feet per minute conveyor speed. An encoder was used in combination with the scanner to track the log length. Accuracy was quite good, and the system was soon accepted in Sweden as a standard method of log scaling to pay woodlot owners for their logs. The computer used in those days, incidentally, was a 16-bit Digital Equipment PDP 11/04. Quite a throwback from the high powered computers employed in sawmills these days.

As is the case with most good ideas, others were also working on scanner design in the 1970s. Although we can’t mention everybody active at the time, it’s important to mention some of the North American pioneers.

An electronics engineer, Leon Chasson, based in Sunnyvale, California found himself sitting next to a Weyerhaeuser engineer on a long flight and their conversation resulted in Chasson designing a Reticon CCD camerabased scanner, which was probably the first camera based system. It was installed in front of a Chip-N-Saw at the Weyerhaeuser mill in Everett, Washington. Chasson’s company was named Applied Scanning Technologies, which went on to become one of the leading US suppliers, specializing in camera scanners (and was later absorbed into Coe Manufacturing).

Many companies became involved at about the same time, recognizing the improved lumber recovery potential of scanning and optimization. Among these were North American Controls of Oregon, headed up by Ed Rickford. Rickford was one of the first to introduce parallel ray scanning with no moving parts, an alternative to the Rema rotating mirror system. Others who developed scanners at that time included Accuray, (now part of Coe /Newnes), Lloyd Controls of Burnaby, BC and Opcon Inc of Everett, Washington. Opcon focused on the hardware and soon made parallel ray scanners, using arrays of pulsed diodes, available to everyone.

A familiar name, Porter Engineering of Richmond, BC used Rema scanners at first, later moving on to the Opcon pulsed diode type and other technologies. They focused their main attention on the development of optimization software, however. Morvue Electronics and Dynatech Corporation, based in Oregon, were also very active in the scanning field at that time.

Artwork from marketing materials of the time (left, top of this page) reflect the evolution of scanning systems. Due to the slow computers available in the 1970s, a series of cutting solution “Look up Tables” sometimes had to be used to select the best sawing pattern to suit the log scan data.

Pretty soon all the primary breakdown machinery companies like Canadian Car (Chip- N-Saw) and Letson & Burpee (sharp chain bandmill systems), had agreements with the scanning people so they could offer a complete machinery package—with scanner and controls—which the industry demanded.

The industry was changing fast. At least one sawmill, Sun Studs, designed its own scanner system during this period, complete with their own proprietary software.

During the 1970s, Best Opening Face (BOF) became recognized as the most advanced optimization software for log breakdown. This was developed at the US Forest Service laboratory in Madison, Wisconsin where they were working on a general sawmill improvement program known as SIP. Key personnel were Stan Lunstrom and Hiram Hallock, who came up with the BOF concept, and Dave Lewis, who wrote the software with the help of Jean Danielson.

The concept: a best sawing solution for each individual log, starting with the first best cut. At the time, all the scanning companies were working hard to write their own proprietary software. But when the BOF software was made freely available, most dropped what they were working on and adopted it.

John (Rusty) Dramm, who today is utilization specialist at the Madison lab, says an anticipated log famine by the year 2000 was the main impetus for their research and development. “Oregon consultant Carl Mason did a mill study in the early 1970s, identifying areas of potential recovery improvements for a typical sawmill. This got people thinking and later we presented our paper on BOF at the Portland sawmill clinic in the spring of 1973. Hiram Hallock subsequently received the forest industry award for the BOF concept.

“Black Clawson was one of the first machinery makers to adopt the BOF software,” he adds. “However, due to the slow computers available in the 1970s, a series of cutting solution ‘Look up Tables’ had to be used to select the best sawing pattern to suit the log scan data.”

The industry has come a long way since then in terms of optimization; faster computers have become available, allowing individual log cutting solutions to be selected at today’s feed speeds.

Transverse scanning systems came along a few years later, with yet another Swedish company, Saab (the car and airplane company), teaming up with Totem Equipment of Seattle to introduce the first transverse edger optimizer systems at three Weyerhaeuser mills in Cottage Grove, Oregon, Dierks, Mississippi and another mill in Mississippi, in 1976.

The first Saab-Totem transverse systems used CCD cameras and two banks of car headlights to scan boards every three to four inches along their length. Many operators who worked with these systems wore sunglasses, as the bright lights flashed on for each scan. Saab later bought out the Totem interest, formed Saab Systems and set about North Americanizing the software to suit our mainly unsorted logs.

Vern Pittman of USNR, who worked for Saab in the 1970s, says the first systems required the board be stationary to get scan data. “Later we developed ‘Scan on the Fly’, monitoring the reflected light from fluorescent lamps instead of the flashing car lights.

“The first cant optimizers were installed at Pope & Talbot, Port Gamble, Washington, and Roseburg Lumber in 1979,” he says. “Simpson Timber at mill 3 Shelton, Washington, got the first trim optimizer around 1980.”

In late 1985, Coe Manufacturing bought out Saab Systems and continued the development of transverse scanning and optimization systems. Those systems were achieving solid results, recalls Mark Maleta of Coe. “Those first Saab systems were getting 95 per cent recovery, which was pretty remarkable at the time, and it’s taken us all these years to really improve on it.”


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