This is the simplest form of arch found today on modern logging equipment like this Caterpillar 518 wheeled skidder (see insert). The winch line (not shown) passes up through the arch fairlead and out the back to the chokers and logs. By winching up the logs tightly to the rear of the skidder, the front ends of the logs being skidded are raised clear of the ground and friction is lessened. Also, a portion of the load (often close to 50% of the total weight of the logs) is transferred to the skidder and this increases the skidding ability due to increased friction between the wheels and the ground.

Also, see "Grapple" definition for more elaborate version of integral arches on skidders.

In the past, may have been a separate trailer (sulkey) pulled by the skidder, as shown below. Notice how high the arch fairlead is above the ground. This was to accommodate large old-growth logs. If you look closely through the dust, you can see the large rubber tires the sulkey arch rides on. These arches were sometimes referred to as "big wheels". Today, you will only see these types of arches in museums or scrap yards.