Donkey, Washington Iron Works 12x17 Simplex Slackline Yarder, #3643
As steam yarders grew more powerful and could reach greater distances, the ability of the machine to slack the skyline was critical for maintaining productivity. Washington Iron Works designed both the Simplex “Slacker” and the Duplex “Slacker.” The Simplex machine used one set of steam cylinders to power all three drums, skyline, mainline and haulback. The larger Duplex machines utilized one set of steam cylinders for the skyline drum, and another set for the mainline and haulback. The yarder used a Westinghouse steam powered air compressor to produce air for the controls. The machine came equipped with an extended firebox Washington Iron Works boiler. This boiler was scrapped in 1953 by Washington Machinery Company, and replaced with a Willamette Iron and Steel double extended firebox boiler.
This yarder was shipped December 8, 1923 to the Fobes Logging Company of Wickersham, Washington. It later went to work in the woods for the Eatonville Lumber Company of Eatonville, Washington. The yarder was purchased and rebuilt by Washington Machinery Company of Seattle and sold to Judson Pacific Murphy Kiewit Company for a second life working on various waterfronts on the Pacific Coast constructing breakwaters. It was finally purchased by Harry Schildwachter of Alaska Tug and Barge who stored the yarder for many years at the Antique Gas and Steam Engine Museum at Vista, California. Harry Schildwachter and the Antique Gas and Steam Engine Museum donated the slackline yarder to Roots of Motive Power in September 1993.