Im in the process of building a spar tree with a log loadder and high line. I have a basic idea of how it works but not suree 100% on how the cable rigging goes from the steam donkey to the loader and then to the high line. I understand high lines from high angle rescue end. I am having a hard time finding any good information like detailed pictures etc… Anyone have any good links or pictures?
There are a lot of different ways that a spar tree could have been rigged, depending mostly on the terrain and the type of donkey in use. A very basic system used a two drum machine consisting of a main line and a haulback line. The haulback would be routed through a series of blocks (pulleys) to keep it out of the way of the main line. The mainline would be pulled out into the forest and then the chokers placed around a log or if the timber was small, several logs. Then the mainline would drag the logs back to the spar. After all the logs that could be reached had been recovered then the tail block would be moved to another stump and the next bunch of timber would be brought in. Each line was called a road and moving the tail block was referred to as changing the road. This would continue until all the wood on one side of the spar had been recovered, then the donkey would be moved to the other side of the spar tree and the wood on that side would then be recovered. Remember in the early days, only the best wood was taken out, the rest was left behind.
There were lots of other systems used with a spar, depending on how many drums the yarder had. A small operation may use the same machine for both skidding and loading. For loading a minimum two drum machine was needed. One line for lifting and the other usually used to swing the boom over the rail cars or trucks being loaded. The boom was then returned by a line connected to a large counter weight, usually a piece of log suspended from a tree.
Some of the larger machines may have five or six drums and could skid the logs in and load at the same time.
There are many ways to hook the system up depending on whether you had to move the logs uphill, downhill, over uneven terrain, etc. The size and amount of timber, the value, and the yarding distance also were determining factors.
My dad was a west coast logger using wooden spar trees for most of his life, by the time I got into it the towers were made of steel, but the principles and the methods used were mostly the same.
If you google, logging with a spar tree, a number of informative sites come up.
Ron
Not sure how good it is…
(http://content.lib.washington.edu/curriculumpackets/logging/images/indiv449.jpg)
More here: http://content.lib.washington.edu/curriculumpackets/logging/index4.html
You might want to take a look at this book: The Model Railroader’s Guide to Logging Railroads By Matt Coleman I found an excerpt on the web, and it includes this diagram.
(http://www.jbrr.com/_forumfiles/Loader.jpg)
Here’s the link to the pdf: http://lib.store.yahoo.net/lib/yhst-22106725251441/12423spread.pdf And a lot cheaper on Amazon! http://www.amazon.com/Model-Railroaders-Guide-Logging-Railroads/dp/0890247021/ref=sr_1_39?ie=UTF8&s=books&qid=1280838843&sr=8-39
Thanks guys Ron great info, sounds like you have a lot of knowledge about the operations. Bruce thanks, the last two pictures is what I was looking for. I ended up ordering that book, seems like a great book to have. Thanks again.