Rediscovering the Koehring Bantam 450 and Its Forgotten Legacy

[MikePhua]

The Koehring Company and Its Excavator Heritage
Koehring was founded in Milwaukee in 1886 and became a major player in the crane and excavator industry by the mid-20th century. Known for its rugged lattice boom cranes and hydraulic excavators, the company introduced the Bantam line to serve the growing demand for compact, mobile digging machines. Bantam excavators were often mounted on truck chassis or crawler bases and used in utility work, road building, and small-scale construction.
The Bantam 450, though not widely documented, appears to be one of the lesser-known models from Koehring’s transitional period in the 1960s and 1970s, when hydraulic systems were replacing cable-operated mechanisms. These machines were often custom-configured, making serial number tracking and parts sourcing a challenge today.
Identifying the Bantam 450 in the Field
When encountering a machine believed to be a Bantam 450, visual cues and mechanical layout are essential for identification. Key features may include:

• A mid-size crawler base with steel tracks
  
• A single boom cylinder with auxiliary hydraulic lines
  
• A cab mounted on a rotating turntable with manual levers
  
• Diesel engine, often sourced from Detroit Diesel or Cummins
  
• Mechanical swing gear with chain or gear drive
  

Terminology annotation:

• Turntable: The rotating platform on which the cab and boom are mounted.
  
• Swing gear: The mechanism that allows the upper structure to rotate.
  
• Auxiliary hydraulics: Additional hydraulic circuits used for attachments or secondary functions.
  

In one case from Ohio, a retired operator inspected a presumed Bantam 450 and noted the presence of a Koehring data plate partially obscured by rust. The machine had been parked for over a decade, yet the boom and stick showed minimal wear, suggesting limited use.
Challenges in Documentation and Parts Sourcing
Unlike modern excavators with digital manuals and VIN-based parts catalogs, older Koehring machines often lack centralized documentation. Many Bantam 450 units were sold through regional dealers who customized configurations based on customer needs. As a result:

• Service manuals may be incomplete or missing
  
• Part numbers may vary across identical models
  
• Hydraulic fittings and seals may be obsolete
  
• Electrical systems may use non-standard wiring
  

Solutions include:

• Contacting vintage equipment clubs and archives
  
• Cross-referencing parts with similar Bantam or Koehring models
  
• Fabricating bushings, pins, and seals using machine shop resources
  
• Replacing hydraulic hoses with modern equivalents using thread adapters
  

In British Columbia, a restoration team rebuilt a Bantam 350 using a combination of salvaged parts and custom-machined components. They documented the process and shared it with a regional museum, helping preserve the machine’s legacy.
Operational Characteristics and Field Behavior
The Bantam 450, like its siblings, was designed for simplicity and durability. Its hydraulic system operated at moderate pressure (typically 2,000 psi), and its controls were mechanical, offering direct feedback to the operator. Common operational traits include:

• Slow but deliberate boom movement
  
• High torque swing with limited speed
  
• Manual throttle and gear control
  
• No onboard diagnostics or electronic sensors
  

These machines were often used in rural drainage projects, small quarry operations, and municipal trenching. In Iowa, a Bantam 450 was used for culvert installation until the early 2000s, outlasting newer machines due to its straightforward design and ease of repair.
Preservation and Restoration Advice
For those acquiring or restoring a Bantam 450:

• Begin with a full fluid flush and filter replacement
  
• Inspect hydraulic cylinders for pitting and seal degradation
  
• Test swing gear backlash and lubricate turntable bearings
  
• Replace fuel lines and clean injectors if diesel-powered
  
• Rewire electrical circuits with modern insulation and fuses
  

Recommendations:

• Use ISO VG 46 hydraulic oil for moderate climates
  
• Replace track pads with bolt-on aftermarket equivalents
  
• Install LED work lights for improved visibility
  
• Document all modifications and part substitutions for future reference
  

In Texas, a collector restored a Bantam 450 for display at a county fair, adding safety railings and a plexiglass cab window. The machine became a local attraction, drawing attention to the region’s construction history.
Conclusion
The Koehring Bantam 450 represents a transitional era in excavator design—bridging cable-operated cranes and modern hydraulic diggers. Though documentation is scarce, the machine’s mechanical simplicity and rugged build make it a viable candidate for restoration and light-duty use.
By combining field observation, historical research, and practical ingenuity, operators and enthusiasts can bring these forgotten machines back to life. In doing so, they preserve not just steel and hydraulics, but the legacy of American innovation in earthmoving history.