LeTourneau Equipment Teardown and Restoration

[MikePhua]

The Legacy of R.G. LeTourneau
Robert Gilmour LeTourneau, born in 1888, was a pioneering force in the development of earthmoving machinery. Dropping out of school at 14, he began working in iron foundries and machine shops, eventually becoming a prolific inventor with over 299 patents to his name. His innovations transformed the construction and mining industries, especially during World War II, when nearly 75% of the earthmoving equipment used by Allied forces came from his factories.
LeTourneau’s company, originally focused on contracting, shifted to full-time manufacturing in the 1930s. By 1935, his factories were producing equipment at scale, including scrapers, dozers, and cranes. His most revolutionary design was the Tournapull—a rubber-tired prime mover that defied convention and reshaped how heavy equipment was powered and mobilized.
Understanding the Equipment Lineup
LeTourneau machines were known for their electric drive systems, massive frames, and modular construction. Key models included:

• Tournapull: A self-propelled scraper with a front-mounted diesel engine and electric wheel motors.
  
• Tournacrane: A mobile crane used by military and industrial sectors, often seen in airfield recovery operations.
  
• Tournatractor: A rubber-tired tractor designed for high-torque applications.
  
• Tournadozer: A bulldozer variant with electric drive and articulated steering.
  

Terminology notes:

• Electric drive: A propulsion system where a diesel engine powers a generator, which then drives electric motors at the wheels.
  
• Articulated steering: A steering method where the machine bends at a central pivot point, improving maneuverability.
  
• Modular frame: A chassis design that allows components to be swapped or serviced independently.
  

The Challenge of Teardown
Disassembling a LeTourneau machine is a formidable task. These machines were built for durability, not ease of access. Bolts are often oversized, components are heavy, and many parts are custom-machined. A typical teardown involves:

• Removing the electric wheel motors, which can weigh over 800 pounds each.
  
• Disconnecting the generator and control systems, often buried beneath layers of shielding.
  
• Extracting hydraulic cylinders, some exceeding 6 feet in length.
  
• Separating the frame into transportable sections using oxy-acetylene torches and hydraulic jacks.
  

One technician described the process of dismantling a Tournapull as “like reverse-engineering a battleship.” The teardown required a 50-ton crane, a team of six, and nearly two weeks of labor.
Preservation and Restoration Strategies
Restoring LeTourneau equipment requires a blend of mechanical skill, historical research, and creative problem-solving. Many original parts are no longer available, so restorers often fabricate replacements or adapt components from other machines.
Recommended strategies include:

• Using reverse engineering to replicate missing parts, especially electrical components.
  
• Consulting archived manuals and blueprints, often found in university libraries or private collections.
  
• Upgrading wiring and insulation to modern standards while preserving original schematics.
  
• Applying rust inhibitors and epoxy coatings to protect aged steel frames.
  

For electric drive systems, restorers often replace the original DC motors with modern AC equivalents, paired with programmable controllers to simulate the original performance curve.
Stories from the Field
In 2012, a retired engineer in Texas began restoring a Navy Model B-70 Tournacrane found abandoned behind a scrapyard. The cab had been stripped, and the engine was missing. He sourced a Cummins diesel from a retired generator, rebuilt the boom using salvaged steel, and rewired the entire control system. After three years, the crane was operational and now serves in a local museum’s outdoor exhibit.
Another story comes from a mining site in Western Australia, where a Tournapull was unearthed during excavation. The machine had been buried under tailings for decades. A restoration crew recovered it, cleaned the frame with high-pressure steam, and documented the teardown process for educational use.
Historical Impact and Market Reach
By the 1950s, LeTourneau equipment had reached over 60 countries. Sales peaked during post-war reconstruction, with thousands of units deployed in infrastructure projects across North America, Africa, and Asia. The company’s influence extended to military logistics, with specialized models used for airfield recovery, bridge construction, and port operations.
In 1970, LeTourneau’s manufacturing assets were acquired by Marathon Manufacturing, and later divided among various industrial firms. Despite corporate changes, the legacy of LeTourneau’s designs persists in modern equipment, especially in electric drive systems now common in mining trucks and port cranes.
Technical Recommendations for Teardown Projects
For those undertaking a LeTourneau teardown, consider the following:

• Document every step with photos and notes—many assemblies are unique and lack modern references.
  
• Use hydraulic spreaders and torque multipliers for stubborn fasteners.
  
• Test electrical components before removal to identify faults.
  
• Label wiring harnesses meticulously; many use non-standard color codes.
  
• Partner with local machine shops for custom fabrication.
  

Safety is paramount. Always use rated lifting equipment, wear protective gear, and consult structural engineers when cutting frame sections.
Final Reflections
LeTourneau machines are more than mechanical giants—they are artifacts of industrial ingenuity. Each teardown is a journey into the past, revealing the craftsmanship and vision of a man who reshaped the earthmoving industry. Whether restored for display or repurposed for modern use, these machines continue to inspire engineers, historians, and operators alike. Their enduring presence is a tribute to R.G. LeTourneau’s belief that “the impossible just takes a little longer.”