Shown here is a drawing of what is known as the "High Lead Logging" configuration. Here the lower main line is used for the skidding line. The upper secondary line is looped out around the woods with several blocks on the back side of the job. As the area is logged the blocks are disconnected one at a time, causing the main line to realign itself with the next tail block, thus changing roads.
No carriage is required in this configuration, just butt rigging. This doesn't have to be anything fancy, but is the place where the main line, the haulback line and the chokers all come together. This is essentially a ground logging system, in that the logs normally drag on the ground on their way to the landing. It is called 'high lead' because the main line is elevated and this assists the logs in riding over obstacles.
In many ways, the high lead system is simply 2 winch lines: One to drag logs in to the machine and a second to drag the winch line back out in the woods. Unlike the shotgun system, it will work on flat ground, and in locations where it is not possible to get enough deflection to keep the yarding lines off the ground. The rigging is simple, and only a 2 drum machine is required. the useful distance for this logging method is usually recognized as being 800 feet, with occasional reaches to 1000 feet for long corners. It is best used for uphill logging, usable on the flat and nearly unusable on downhill logging, because in the latter configuration you are pulling the logs down into the obstacles assuring that you will never get a log to pull free.
This method has been around for a long time, and is just one step improved from a single drum yarder which required the cable to be pulled out by hand or with a horse. It is the principal alternative available on a 2 drum machine where a shotgun system won't work. Other systems need three lines, though the North Bend system uses a standing skyline which is never lowered so you can pull up a skyline and either tie it off or anchor it to a dozer or even a second yarder since no ability to raise or lower the skyline is required during the logging operation.