Introduction
Most facilities researching overhead cranes encounter conflicting specifications, confusing terminology, and equipment that looks similar but performs very differently. The single girder crane is the most widely used overhead lifting system in light to medium industrial applications—but buyers regularly misjudge its capacity limits, duty ratings, and structural requirements, then pay for the mismatch over a 20-year service life. This guide defines the single girder crane clearly, breaks down every major component, covers the four main types, explains key specifications, and outlines exactly when single girder design is the right choice versus when you need something heavier.
What is a Single Girder Crane?
A single girder crane is an overhead lifting system built around one horizontal main beam—the girder—that spans between two runway rails. The hoist and trolley travel along this single beam, while the entire bridge assembly moves along the runway for full coverage of the working area below.
The single beam is the defining distinction from double girder cranes, which use two parallel beams. This structural difference affects headroom, capacity limits, hoist positioning, and total system weight.
Standard configurations handle 1-20 tons across spans of 7.5-31.5 metres—covering approximately 80% of light manufacturing material handling requirements.
Main Components
Every single girder crane consists of the same core assembly:
- Main girder: Single fabricated steel beam, typically box-section IS 2062 grade, spanning the full bay width
- End carriages: Steel assemblies at each girder end carrying wheel sets that travel along runway rails
- Electric hoist: Wire rope or chain hoist unit providing the vertical lifting mechanism
- Trolley: Wheeled frame carrying the hoist, traveling along the girder bottom flange
- Runway beams: Fixed structural members the crane travels on, supported by building columns
- Control system: Pendant, radio remote, or cabin controls for operator use
- Electrical system: Motors, VFD drives, busbar or festoon power supply, protection circuits
How It Works
Three independent motions combine to position loads anywhere within the crane’s working envelope.
The hoist raises and lowers the load vertically. Cross-travel moves the trolley and hoist left or right along the girder. Long-travel moves the entire bridge forward or backward along the runway.
These three axes—vertical, transverse, longitudinal—give complete three-dimensional coverage of the working area below without moving the load by hand.
Types of Single Girder Cranes
Top-Running Single Girder
The bridge girder sits on rails mounted on top of runway beams. This is the standard configuration for most factory and warehouse installations. It suits buildings with adequate headroom and provides spans up to 31.5 metres.
Underhung / Underslung Single Girder
The girder suspends from the bottom flange of ceiling beams rather than running on top. This suits low-headroom facilities under 4 metres, costs 40-60% less to install, and integrates into existing building structure without runway beam additions.
EOT Single Girder
Electric Overhead Travelling—the standard powered configuration for industrial use. All motions are electrically driven with variable frequency controls for smooth acceleration.
Gantry-Style Single Girder
The same single beam design mounted on freestanding legs instead of building structure. Suits outdoor yards, construction sites, and facilities without adequate roof support.
Technical Specifications
Standard single girder crane parameters:
- Capacity: 1-20 tons
- Span: 7.5-31.5 metres
- Lifting height: 3-30 metres
- Lifting speed: 0.5-12 metres per minute
- Bridge travel speed: 20-80 metres per minute
- Duty class: A3-A5 (light to moderate cycles)
- Operating temperature: -20°C to +40°C standard
Advantages
Single girder design delivers five concrete advantages over heavier configurations:
- Lower purchase cost: 30-40% below double girder at equivalent capacity
- Faster installation: 2-4 days versus 5-10 for double girder systems
- Lower building loads: 30-40% lighter structure reduces runway and column requirements
- Better headroom: Hoist runs on bottom flange, gaining 300-500mm of hook height versus top-running double girder
- Simpler maintenance: Fewer structural components mean fewer inspection points and lower annual service costs
Single Girder vs. Double Girder
The capacity threshold is the primary dividing line. Single girder handles up to 20 tons reliably. Beyond this, double girder construction provides the structural depth and rigidity heavy loads require.
The uncomfortable truth: most facilities that buy double girder cranes for 10-ton applications are overspecifying, spending 40% more than necessary for capacity they never use.
Span is the second determinant. Single girder becomes structurally marginal beyond 25 metres due to deflection. Double girder handles 40+ metre spans routinely.
Safety Features
A properly specified single girder crane includes these protection devices as standard:
- Overload protection relay cutting power at rated capacity
- Upper and lower hoist limit switches preventing over-travel
- Bridge and cross-travel end limit switches
- Electromagnetic brakes holding loads during power loss
- Emergency stop on pendant and remote controls
- Slack rope detection protecting wire rope integrity
Installation and Maintenance
Installation follows a defined sequence:
- Structural verification of building support for runway loads
- Runway beam installation and rail alignment
- Bridge girder assembly and end carriage fitting
- Hoist and electrical system installation
- Load testing at 100% and 125% rated capacity
- Operator training and documentation handover
Maintenance focuses on wire rope inspection every two weeks, monthly wheel and brake checks, and annual comprehensive structural and electrical review.
FAQs
What capacity is single girder crane best suited for?
Single girder cranes deliver best value between 1 and 15 tons. Capacities of 16-20 tons are achievable but require heavier girder sections. Beyond 20 tons, double girder design becomes structurally and economically preferable.
How long does a single girder crane last?
With proper maintenance and correct duty cycle matching, single girder cranes deliver 15-25 year service lives. Mismatched duty ratings are the leading cause of early failure—a light-duty A3 crane running A5 cycles fails in 5-8 years.
Can single girder cranes be used outdoors?
Yes, in gantry configuration with weatherproof electrical components, corrosion-resistant coatings, and rail anchoring for wind resistance. Standard indoor configurations require modification for outdoor use.
What’s the difference between wire rope and chain hoists on single girder cranes?
Wire rope hoists suit 1-ton+ capacities, longer lift heights, and higher speeds—standard for most industrial applications. Chain hoists work best under 5 tons in compact, low-height applications like maintenance bays and workshops.
Conclusion
Single girder cranes cover 1-20 ton capacities across the broadest range of light to moderate industrial applications. They install faster, cost less, and require simpler maintenance than heavier alternatives—provided the specification matches the actual duty requirement.
Contact us to specify a single girder crane matched precisely to your capacity, span, duty cycle, and building constraints.
Heben Cranes manufactures single girder crane systems from 1 to 20 tons in top-running, underslung, EOT, and gantry configurations. Our engineering team verifies your building structural capacity, selects hoist and control systems for your duty requirements, and manages complete installation including load testing and operator training. Every crane meets IS 3177 compliance standards with full material traceability and safety documentation. We back every installation with scheduled maintenance programmes and regional technical support for 15-25 year service lives. Visit hebencranes.com to discuss your lifting requirements and receive an engineered single girder crane specification for your facility.
