Differences Between the CAT 951 and CAT 955 Track Loaders: A Comprehensive Comparison

[MikePhua]

Caterpillar’s track loaders have been indispensable machines on construction sites, mines, and heavy industry for decades. Among these, the CAT 951 and CAT 955 stand out as iconic models that shaped the evolution of tracked loaders. This article thoroughly explores the key differences between the CAT 951 and CAT 955, detailing their technical specifications, design improvements, operational characteristics, and historical context. It also provides relevant terminology explanations, industry anecdotes, and practical insights for users and collectors alike.
Key Terminology

• Track Loader: A heavy machine combining the features of a bulldozer and a loader, running on tracks for enhanced traction.
  
• Operating Weight: The total weight of the machine ready for operation, including fluids and attachments.
  
• Bucket Capacity: The volume of material the loader bucket can carry.
  
• Horsepower (HP): Engine power rating.
  
• Hydraulic System: Network of pumps and cylinders controlling the boom and bucket movements.
  
• Swing Frame: The pivoting frame allowing loader arms to move up and down.
  
• Transmission: System transferring engine power to the tracks.
  
• Undercarriage: The tracked system supporting and moving the machine.
  

Historical Context
The CAT 951 was introduced in the late 1960s and quickly gained popularity for its rugged design and versatility. The CAT 955 followed as an evolution, incorporating enhancements based on operational feedback and technological advances. These machines played a vital role during the transition era from pure bulldozers to more versatile track loaders capable of multiple earthmoving functions.
Technical and Design Differences

• Engine and Power
  • CAT 951: Equipped with a diesel engine producing approximately 130-140 HP.
    
  • CAT 955: Upgraded engine offering around 150-160 HP, providing better performance and fuel efficiency.
    
• Operating Weight
  • CAT 951: Weighs approximately 32,000 lbs.
    
  • CAT 955: Slightly heavier at about 36,000 lbs, contributing to increased stability.
    
• Bucket Capacity
  • CAT 951: Standard bucket capacity ranges from 2.5 to 3 cubic yards.
    
  • CAT 955: Larger bucket options up to 3.5 cubic yards, improving productivity.
    
• Hydraulic and Control Systems
  • CAT 951: Basic hydraulic controls with mechanical linkages.
    
  • CAT 955: Improved hydraulic system with better control sensitivity and reliability.
    
• Undercarriage and Tracks
  • CAT 951: Standard track design suitable for most terrains.
    
  • CAT 955: Reinforced undercarriage components for durability in tougher environments.
    
• Operator Comfort
  • CAT 951: More basic cab design with minimal ergonomics.
    
  • CAT 955: Enhanced operator station with improved visibility, seating, and control layout.
    

Operational Characteristics
The CAT 955 offers smoother and more responsive controls compared to the 951, resulting in more precise digging and loading. Its increased horsepower and bucket capacity allow operators to handle heavier loads and tougher materials efficiently. The heavier weight of the 955 contributes to better traction and stability on uneven or soft ground.
Maintenance and Parts Availability
Both models benefit from Caterpillar’s extensive parts network, though the older CAT 951 may face limited availability of some components. The CAT 955’s design improvements often result in reduced downtime and easier maintenance due to better component accessibility and enhanced system reliability.
Case Story
A mining company operating both CAT 951 and CAT 955 machines noted that the 955 significantly reduced cycle times during material handling, especially in rocky terrain. Operators favored the 955 for its smoother hydraulic response and greater lifting capacity, which translated into measurable productivity gains and lower fuel consumption over extended shifts.
Industry Impact and Legacy
The CAT 951 and 955 track loaders represent milestones in Caterpillar’s design philosophy, bridging traditional bulldozing with modern, versatile material handling. They influenced the development of later models that further integrated hydraulic sophistication and operator comfort, paving the way for today’s multi-functional tracked loaders.
Summary

• CAT 955 is an improved successor to the CAT 951 with more power, larger bucket capacity, and enhanced hydraulic controls.
  
• The 955 offers better operator comfort and machine stability due to increased weight and refined design.
  
• Both models have proven reliability but differ in performance, efficiency, and maintenance convenience.
  
• Real-world experience highlights the 955’s operational advantages in demanding environments.
  
• The evolution from 951 to 955 reflects Caterpillar’s response to industry needs and technological progress.
  

Understanding these differences aids operators, owners, and enthusiasts in machine selection, maintenance planning, and historical appreciation of Caterpillar’s track loader legacy.