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The Madill 071 and Its Winch Configuration
The Madill 071 Tower Yarder is a classic piece of forestry equipment designed for cable logging operations in steep terrain. Built by Madill Equipment, a Canadian company with deep roots in the Pacific Northwest logging industry, the 071 was engineered to handle complex rigging systems with multiple winches and line functions. Its five primary winches—Skyline, Mainline, Haulback, Strawline, and Tagline—each serve distinct roles in moving logs from the forest to the landing.
Madill yarders like the 071 were widely used across British Columbia, Washington, and Oregon, and many remain in service today due to their rugged design and adaptability. The machine also features three guyline winches for stabilizing the spar during operation.
Terminology Notes
The skyline runs over the top of the spar and is anchored at a distant tailhold. The carriage, which carries chokers for log attachment, rides along this cable. The mainline and haulback are attached to the carriage and control its movement along the skyline. The strawline is used during initial rigging to pull the haulback into position and is often broken into 200–250 ft sections called extensions or coils.
The tagline, slightly heavier than the strawline, was historically used with older carriages like the Berger dropline. Modern carriages often don’t require a tagline, but it remains useful for auxiliary tasks or as a backup strawline.
Guyline winches route their cables through sheaves atop the spar and anchor to stumps or deadmen opposite the yarding direction. Some operators add a fourth guyline for extra stability, especially in high-lead or long-span setups.
North Bend vs South Bend Systems
Two common rigging systems in cable logging are the North Bend and South Bend configurations:
Regional Variations and Terminology
In British Columbia, the strawline is called strawline, while Americans often refer to it as haywire. The tagline retains its name across borders but may serve different functions. In New Zealand, strawline sections are called coils, and the tagline is used to hold the carriage in North Bend systems. The haulback is often called the tailrope, especially in tower hauler setups.
The term “Dutchman” in New Zealand refers to a method of pulling the skyline sideways using a block and extension, not the tail tree jack. This technique is used when direct tailholds are unavailable.
Practical Advice and Setup Tips
Yarder rigging is a complex but elegant system of cables, winches, and blocks designed to move timber efficiently in steep terrain. Understanding the roles of each line and the differences between regional systems allows operators to rig safely and effectively. Whether building a model or running a full-scale yarder, mastering these fundamentals is key to successful cable logging.
The Madill 071 Tower Yarder is a classic piece of forestry equipment designed for cable logging operations in steep terrain. Built by Madill Equipment, a Canadian company with deep roots in the Pacific Northwest logging industry, the 071 was engineered to handle complex rigging systems with multiple winches and line functions. Its five primary winches—Skyline, Mainline, Haulback, Strawline, and Tagline—each serve distinct roles in moving logs from the forest to the landing.
Madill yarders like the 071 were widely used across British Columbia, Washington, and Oregon, and many remain in service today due to their rugged design and adaptability. The machine also features three guyline winches for stabilizing the spar during operation.
Terminology Notes
- Skyline: A stationary cable stretched between the yarder and a tailhold, supporting the carriage and chokers.
- Mainline: The inhaul cable that pulls the carriage and logs toward the yarder.
- Haulback: The outhaul cable that returns the carriage to the loading area.
- Strawline (Haywire in the U.S.): A lightweight line used to pull heavier lines during setup or road changes.
- Tagline: Originally used to operate dropline carriages; now often repurposed as an auxiliary strawline.
- Guyline: Anchoring cables that stabilize the spar against lateral and vertical forces.
- Dutchman: A rigging system or block used to redirect the skyline when direct tailholds are unavailable.
The skyline runs over the top of the spar and is anchored at a distant tailhold. The carriage, which carries chokers for log attachment, rides along this cable. The mainline and haulback are attached to the carriage and control its movement along the skyline. The strawline is used during initial rigging to pull the haulback into position and is often broken into 200–250 ft sections called extensions or coils.
The tagline, slightly heavier than the strawline, was historically used with older carriages like the Berger dropline. Modern carriages often don’t require a tagline, but it remains useful for auxiliary tasks or as a backup strawline.
Guyline winches route their cables through sheaves atop the spar and anchor to stumps or deadmen opposite the yarding direction. Some operators add a fourth guyline for extra stability, especially in high-lead or long-span setups.
North Bend vs South Bend Systems
Two common rigging systems in cable logging are the North Bend and South Bend configurations:
- North Bend System: Uses a fixed skyline with the mainline tailholted on the carriage. The mainline passes through a drop block with chokers and haulback, then down to the bull block and drum.
- South Bend System: Similar to North Bend, but the mainline passes through a sheave on the carriage and returns to the fall block. In some setups, a two-sheave drop block is used, and the mainline is tailholted back at the carriage.
Regional Variations and Terminology
In British Columbia, the strawline is called strawline, while Americans often refer to it as haywire. The tagline retains its name across borders but may serve different functions. In New Zealand, strawline sections are called coils, and the tagline is used to hold the carriage in North Bend systems. The haulback is often called the tailrope, especially in tower hauler setups.
The term “Dutchman” in New Zealand refers to a method of pulling the skyline sideways using a block and extension, not the tail tree jack. This technique is used when direct tailholds are unavailable.
Practical Advice and Setup Tips
- Use strawline coils for flexible rigging and easier handling.
- Anchor guylines to solid stumps or engineered deadmen, spaced to counteract spar forces.
- Inspect sheaves and blocks regularly for wear, especially in high-tension systems.
- Label winch drums clearly to avoid confusion during setup and teardown.
- Train rigging slingers in both North Bend and South Bend systems to adapt to terrain and timber layout.
Yarder rigging is a complex but elegant system of cables, winches, and blocks designed to move timber efficiently in steep terrain. Understanding the roles of each line and the differences between regional systems allows operators to rig safely and effectively. Whether building a model or running a full-scale yarder, mastering these fundamentals is key to successful cable logging.
