More MSR lumber from Canada

ANe ANSWER to expanding Vtimber's structural use capabilities to the limit, getting the most out of one of nature's most renewable resources, has been found in machine stress rated lumber (MSR). This is a system of non-destructive machine testing that marks a tested stress value on each piece of lumber.

Simpson Timber, at its Whitecourt, Alberta, Canada, manufacturing plant, is now produc ing some of the first MSR spruce-pine-fir structural light framing lumber from this Northern Canadian species. Simpson's new Whitecourt forest operations include the largest and most modern mill in Alberta with a production capacity of 100 million board feet annually for markets in the United States and Canada.

Two grade levels in machine stress rated lumber are being produced initially: 1650f/1.58 and 2100f/1.8E. Primary end users are the firms manufacturing truss and component systems for whom assured lumber strengths are important. While two stress ratings are being initially produced in MSR lumber, other ratings will be added as the demand warrants.

With production emphasis placed on 2x4 and 2x6 dimensional lumber, upper grades of structural lumber are machine stress rated (MSR). After passing rigid visual selection, each piece of spruce-pine-fir passes through a continuous lumber testing machine. Stiffness is tested and measured in two directions at 6" interryals to arrive at a working design value which is stamped on each piece.

The latest in gas-fired kilns reduces lumber moisture content to a uniform level that guarantees maximum dimensional stability when lumber is shipped and stored in dry climates.

Simpson Timber is not a newcomer to production of MSR lumber. At the Shelton, Wa., operations they have been involved in production of machine stress rated lumber since 1963. lt is, however, a new process for Canada and for the spruce-pinefir species being rated at the Simpson Canadian location.

Over 1.13 million acres of forest lands in Alberta are managed by

Story at a Glance

Some of the f irst Canadian machine stress rated spruce- pine-fir structural light fram- ing lumber is now being produced at Simpson Timber's Alberta operations the modern mill has a production capacity of 100 million b.f. annually.

Simpson in cooperation with the Alberta Provincial Government. The sustained yield management of these lands assures a continuing availability of raw material.

PRlf{ClPtES of machine stress rating of lumber are shown using a weight t0 cause deflection in a 2x4 and then recording the amount of deflection with a gauge in arriving at the stiffnes of the piece. Two grade levels in MSB lumber are being produced initially: 1650f/1.5E and 2100f/1.8E.