Upright Tiger Manlift Restoration and Operational Reliability

[MikePhua]

The Upright Legacy in Aerial Access Equipment
The Upright Tiger manlift was part of a generation of compact vertical lifts produced by Upright Powered Access, a company that gained prominence in the 1980s and 1990s for its durable, mechanically simple aerial platforms. Upright specialized in scissor lifts, mast lifts, and boom lifts designed for indoor maintenance, warehouse operations, and light construction. The Tiger series, known for its narrow footprint and telescoping mast, was often used in schools, retail stores, and industrial plants where maneuverability and reach were essential.
Upright eventually merged into Snorkel, and many of its older models—including the Tiger—were discontinued. However, thousands remain in service, especially in facilities that value mechanical simplicity over electronic sophistication.
Terminology Note

• Manlift: A powered aerial platform designed to lift personnel vertically or laterally for access to elevated work areas.
  
• Telescoping Mast: A vertical column composed of nested sections that extend hydraulically or mechanically.
  
• Limit Switch: An electrical device that stops movement when a component reaches a preset position.
  
• Ground Control Station: The base-level interface used to operate the lift from the ground.
  

Common Issues in Aging Tiger Units
Owners of Upright Tiger manlifts often encounter the following problems:

• Platform fails to raise or lower consistently
  
• Limit switches malfunction, preventing full extension
  
• Hydraulic fluid leaks from mast base or cylinder seals
  
• Electrical controls become intermittent due to corroded connectors
  
• Ground control override fails to engage
  

These issues typically stem from age-related wear, lack of documentation, and obsolete parts. In one case, a maintenance crew in Ohio inherited a Tiger lift with no manual and a non-functioning platform. After tracing wires and cleaning contacts, they discovered a faulty limit switch and a bypassed safety interlock. Replacing the switch and restoring the interlock returned the lift to safe operation.
Electrical System and Control Logic
The Tiger manlift uses a 12V or 24V DC electrical system, depending on model year. Controls are routed through relays and limit switches, with safety interlocks preventing movement unless conditions are met. Common faults include:

• Corroded battery terminals reducing voltage
  
• Broken wires at pivot points due to repeated flexing
  
• Stuck relays causing continuous current draw
  
• Failed joystick potentiometers or toggle switches
  

To troubleshoot:

• Test voltage at the control panel and actuator terminals
  
• Inspect all ground connections and clean with contact cleaner
  
• Replace relays with identical amperage ratings
  
• Verify continuity through limit switches using a multimeter
  

Upgrading to sealed connectors and adding inline fuses can improve reliability in damp environments.
Hydraulic System and Mast Extension
The Tiger’s mast is extended via a hydraulic cylinder mounted within the base. The cylinder pushes nested aluminum or steel sections upward, guided by rollers or bushings. Common hydraulic issues include:

• Leaking cylinder seals
  
• Air in the hydraulic lines causing jerky movement
  
• Contaminated fluid reducing pump efficiency
  
• Worn mast rollers causing misalignment
  

Maintenance steps:

• Replace hydraulic fluid every 1,000 hours or annually
  
• Bleed air from the system using manufacturer-recommended procedures
  
• Inspect mast rollers and bushings for wear
  
• Use ISO 32 hydraulic oil for indoor applications
  

Operators should avoid overloading the platform, as excess weight can strain the mast and cause premature wear.
Safety Systems and Interlocks
Upright Tiger lifts include multiple safety features:

• Tilt sensor to prevent operation on uneven surfaces
  
• Platform overload sensor
  
• Emergency lowering valve
  
• Keyed ground control override
  

If any of these systems fail or are bypassed, the lift may become unsafe. Technicians should verify that all interlocks are functional and not overridden. In one incident, a bypassed tilt sensor allowed a lift to operate on a sloped warehouse floor, resulting in a tip-over. No injuries occurred, but the unit was retired.
Anecdote from the Field
In 2023, a school district in Arizona refurbished three Upright Tiger lifts for gymnasium lighting maintenance. The units had sat unused for over a decade. After replacing batteries, cleaning electrical contacts, and rebuilding the hydraulic cylinders, the lifts were returned to service. The district now performs monthly inspections and logs all maintenance, extending the life of these legacy machines.
Manufacturer History and Equipment Evolution
Upright Powered Access was founded in the UK and became a global player in aerial lift manufacturing. Its Tiger series was designed for simplicity, with minimal electronics and robust mechanical components. After merging with Snorkel, many Upright models were phased out or rebranded. Today, Snorkel continues to produce vertical lifts, but the Tiger remains a symbol of minimalist engineering.
Sales of Upright lifts peaked in the late 1990s, with thousands deployed across North America, Europe, and Asia. Many are still in use, especially in facilities with low lift frequency and good maintenance practices.
Recommendations for Owners and Restorers

• Source manuals from online archives or manufacturer support
  
• Replace all hydraulic seals and electrical connectors during restoration
  
• Test limit switches and interlocks before each use
  
• Use battery maintainers to prevent sulfation during storage
  
• Keep a log of repairs and modifications for future troubleshooting
  

Conclusion
The Upright Tiger manlift may be a relic of a previous generation, but its mechanical simplicity and compact design make it a valuable tool when properly maintained. With careful restoration, attention to safety systems, and disciplined upkeep, these lifts can continue serving in schools, warehouses, and industrial plants for years to come. Their legacy is not just in steel and hydraulics—but in the quiet reliability of well-built machines.