|Display of Skagit Towers|
When Old growth logging reached its final crescendo in the Pacific Northwest in the 1970's, the Skagit Tower was king. The photos shown here were taken in the late 1970's at the annual Oregon Logging Conference in Eugene Oregon. Skagit is now out of business, and alas, a collection of this many large towers will probably never be assembled again.
What you see here is the steel replacement for the wooden spar tree used in steam logging days. these steel tubes were usually actually a tube within a tube and would telescope up to about 100 feet in hight. Like Wooden spars, the towers were secured in position with numerous guylines. they were then used in conjunction with a powerful slackline yarder. The towers were mounted in a variety of ways. Some as you see here were mounted on the back of a semi trailer. This was one of the less expensive solutions. The double drum slacker could ride on the trailer in front of the tower (which folded down and forward for transport).
When the combination needed to become highway legal, the tower could be lifted free of the trailer and hauled like a log on a log truck and as necessary the double drum unit could be lifted out of its saddle as well. The task of moving these things on steep soft roads, is one that will send any old logger off spinning yarns for hours. No one knows for sure how steep, how crooked or how soft a road one of these things can traverse, because that move hasn't been made yet.
Usually loggers put a tandem axle dolly under the front and hitched that to a D-8, and then provided a second D-8 behind for a push Cat, but other alternatives sometimes worked..
Besides trailer mounts, You would also see self propelled units. Washington, for example, used an extended wheelbase version of the chassis shown under the TL-6 which is featured elsewhere on this site. The Third alternative most commonly used by Madill was a 'tank mount'. They would buy an army tank and cut it down to track level and mount all this stuff on top of it. Tracks or not, a good place to hook a D-8 on to one of these things always is helpful.