Washington 78SL Perfect For 2nd Or 3rd Growth

May 17, 2023 - 2 years ago

The original Washington 78SL was the last of the 78 series, with the 78-40 in the 1960s, 78-A in the 1970s, the 78-T in the mid 1970s, and the 78SL in the mid 1980s. Yarders built by Washington were purpose-built for second growth forests and corridor logging.

Only a few 78SLs were ever built, as Washington went out of business shortly thereafter. The 78SL was designed by Washington’s Chief Engineer Fred Langford, who was much admired by Wheeler Equipment’s founder, Stuart Wheeler Sr.

The 78SL was actually the prototype in many ways for the Washington 88, with improvements in the interlock which made both machines faster, creating the extremely fuel-efficient machines of today.

The modernization of the 78SL for today’s regen growth conditions and corridor logging, has been a decade’s-long dream of Stu Wheeler, Sr. — who saw the need for an economically priced yarder that lowered operating costs, was fuel efficient, and was easy to maintain and operate. The ease of training makes the 78SL a winner for most small contractors on the coast or the interior.

The 78SL is a versatile, one-piece move — weighing in 90,000 lbs fully dressed, including fuel lines and rigging.

Washington 78SL Perfect For 2nd Or 3rd Growth

Running Skyline, or Slacking Skyline Mobile Yarder

Washington Logging Equipment Model 78-40s and 78As have been the industry standard for mobile swing careers operating running skyline systems. Good logging practice dictates most efficient logging is accomplished at distances less than 1,000 feet. Actual practice requires longer distances to handle the layout in some cases — and WLE has developed the Model 78SL to operate as a running skyline, or as a slackline system for the longer distance. The skyline drum (or rear main for running skyline applications) can be converted easily in the field by adding or removing lagging as needed for the type of yarding to be done.

The 78SL maintains the swing capability permitting the logs to be decked on small landings. The swing capability eases the movement of the log through narrow roads when selective logging. The yarder can be swung to lead when changing roads, thus minimizing set up time. Two of the guylines are “walking type” so the yarder can be moved down the road, relocating only one guyline while leaving the other in place.

Versatility on the lot

Ideal for today’s multi-generational growth, thinning, and corridor operations, the 78SL can be configured in the following ways:

Running Skyline — using MSP carriage or grapple

Standing or Slacking Skyline — using motorized carriage or grapple, shotgun carriage, or drift carriage

Highlead — using butt rigging in various configurations such as waistband, scablocking, North or Southbend

Skyline drum or rear main drum (running Skyline)

The 78SL can also be converted easily in the field by adding or removing lagging as needed for the yarding conditions to be done.

Wide Drum Design

The 78SL maintains the wide drum design which keeps speed and pulls as close to equal at the head tree and tail tree as possible. Fewer wraps also means less pressure and damage on the bottom layers of line.

Why yard?

When yarding is done correctly, it can be more cost-effective and efficient than ground-based logging. Yarding causes less ground disturbance, particularly around environmentally-sensitive areas such near rivers, creeks, or in a riparian management zone.

As with ground-based equipment, yarders can be used in roadside or landing operations, and many of the factors that apply to ground-based systems also apply to cable systems. The ability to separate the yarding and loading phases results in increased efficiency, and the safety aspects are improved because of decreased congestion around the landing.

Roadside operations for cable systems are often limited to swing yarders because of their ability to pile the logs away from the immediate landing area.

Unlike ground-based systems, swing yarders can be used for roadside operations even on steep ground. Processing is usually done manually, and the side slope must only be low enough to allow the logs to be decked without sliding back into the cut block.

For yarding to landings, towers may be paired with an auxiliary machine, (e.g., a loader, skidder, or stroke delimber) to remove the logs after unhooking. In very steep locations, the loader may be required to hold the logs as they are unhooked, or the landing must provide a flat surface large enough to land the logs.

Custom solutions

Since there were only a few 78SLs ever built, Wheeler Equipment can modernize your existing machine, or convert your 78-40, or 78-A to a Wheeler 78Super SL. They are also able to build a Wheeler 78SL from scratch.

Source: Article & photos by Stuart Wheeler, Wheeler Equipment
For more information on the Washington 78SL, contact Wheeler Equipment at 604-882-9995.