Double Girder
Semi-Gantry
Heavy-duty lifting capacity where only one side has structural support. Twin box girders, one gantry rail, one floor rail — the right choice when you need strength up to 500 T without a full portal structure.
Double Girder
Semi-Gantry
Double Girder Strength, Semi-Gantry Footprint
Two parallel box-section beams deliver the hook height, torsional rigidity, and capacity of a full double girder overhead crane — while only one side requires a ground rail. The other end carriage rides on an existing building runway beam, wall bracket, or elevated structure, cutting civil works cost and installation time significantly.
Secondary Zone Under Existing EOT
One of the most common deployments: install the double girder semi-gantry beneath an existing overhead crane on an intermediate-level runway, creating an independent lower work zone without occupying any floor space. The ground remains completely free for personnel and material movement.
Built for Outdoor & Harsh Environments
High-quality carbon steel (Q235B / Q345B) main beams, automatic submerged arc welding on all primary joints, anti-derailment devices, and full environment-specific sandblast and paint systems. Canopy, anemometer, and IP65 protection available for exposed outdoor sites.
Heavy Capacity Where Full Gantry Isn't an Option
The Double Girder Semi-Gantry crane is the structural answer when a facility needs genuine heavy-lifting performance — capacities up to 500 tonnes, spans from 3 to 60 metres, and lifting heights to 25 metres — but a full portal structure on both sides is either impossible, impractical, or unnecessarily expensive. One end carriage travels on a floor-level ground rail; the opposite end carriage uses an existing overhead runway, building column, or wall bracket, leveraging the structure that is already there.
The twin box-girder bridge means the hoist trolley sits on top of the girders rather than below them, maximising available hook height within the same structural envelope. A full-length maintenance walkway platform runs along both girders as standard, giving safe, unrestricted access to every hoisting and travel mechanism without the need for additional scaffolding or access equipment.
Crane control is via pendant push-button, radio remote, or fixed and travelling operator cabins — with dual-speed buttons on all axes as standard. All motion drives are VFD-controlled for smooth, jerk-free operation. Power supply via shrouded DSL conductor rail, cable reeling drum, or diesel generator for remote or outdoor sites without fixed electrical infrastructure.
- Double girder capacity and hook height — one side independent of ground
- More economical than a full portal gantry — uses existing building structure
- Installs below an existing EOT crane — second independent work zone at no floor cost
- Ground remains completely free — no obstructions to personnel or material flow
- Maintenance walkway platform along full girder length — standard inclusion
- Automatic submerged arc welding + NDT testing on all primary structural welds
- Anti-derailment devices and buffer systems standard on all ground beams
Key Specifications
Every unit is custom-engineered to span, capacity, duty class, and site conditions.
Full Specifications
| Parameter | Value / Range | Notes |
|---|---|---|
| Lifting capacity | 3.2 T — 500 T | Higher capacity engineered on request |
| Span | 3 m — 60 m | Custom span on request |
| Height of lift | 6 m — 25 m | Extended range up to 100 m on request |
| Working class | A5, A6, A7, A8 | FEM duty classification |
| Location | Indoor & Outdoor | Canopy available for outdoor units |
| Ambient temperature | −20 °C to +60 °C | Molten metal / extreme ranges on request |
| Main hoist speed | 1 – 10 m/min | Single or dual speed; VFD option |
| Cross travel speed | 5 – 60 m/min | VFD-controlled |
| Long travel speed | 5 – 60 m/min | VFD-controlled |
| Crane control | Pendant / Radio Remote / Cabin | Dual-speed buttons on all axes |
| Operator cabin | Open / Closed / AC | Fixed or travelling independently |
| Power source | DSL / Cable Reel / Diesel Gen. | 380V 50Hz 3-phase or custom |
| Protection grade | IP54 – IP65 | IP65 / Ex-proof on request |
| Main beam material | Q235B / Q345B carbon steel | Box-type main beam |
| Primary welding | Automatic submerged arc | Non-destructive testing (NDT) applied |
| Spreader options | Hook / Grab / Electromagnet / C-hook | Lifting beam and tong on request |
| Design standards | FEM / DIN / VDI / CE | Full CE documentation supplied |
Why Choose Semi-Gantry Over Full Gantry?
Double Girder Semi-Gantry
This ProductDouble Girder Full Gantry
AlternativeStandard & Optional Features
Standard Features
- VFD — Variable Frequency Drive on all motions
- End limit switches + emergency limit switch
- Hooter + flasher (travel motion indicators)
- Under-bridge lighting
- Crane anti-collision system
- Anemometer (outdoor cranes)
- Drag chain for cross-traverse motions
- Sealed bearings — lubricated for life
- Energy-efficient motors, IP54 protection
- Steel core wire rope
- Anti-derailment device on ground beam
- Buffer and rail cleaning device on ground beam
- Maintenance walkway platform along both girders
- Canopy — weather protection for outdoor units
- Human sensors
Optional Features
- EMote remote crane monitoring
- Load indicator with or without display
- Load summation for multi-hoist systems
- Crane synchronisation for tandem operation
- Two or more hoists on same girder
- Overhang on either side with auxiliary hoist
- Anti-sway / sway control system
- Automation for target positioning
- Zone protection + slack rope protection
- Container grab / electromagnet / C-hook / spreader bar
- Ex-proof / ATEX certification
- Adjustable span and adjustable height
- Access ladders and staircases to cabin
- Special floor wheels — no guide rail obstruction
- Enhanced speed range on all axes
Typical Applications
Mechanical Processing
Heavy component lifting and positioning in machining workshops where floor space must remain clear.
Steel & Metal Processing
Coil, slab, and structural steel handling in mills and yards — continuous duty, high capacity.
Below Existing EOT Cranes
Creates a fully independent secondary lifting zone beneath an existing overhead crane — floor stays free.
Outdoor Assembly Zones
One side tied to a building or portal frame; the other on a ground rail for open-air heavy assembly work.
Oil, Gas & Energy
Heavy equipment handling in refineries, power stations, and energy plants with asymmetric structural support.
Warehouses & Logistics
Heavy pallet, coil, and container handling in facilities with one-sided runway support infrastructure.
Automotive & Manufacturing
Body panel, press tooling, and heavy sub-assembly handling in production facilities with existing structure.
Paper & Timber Industry
Roll, reel, and heavy timber handling requiring high capacity and reliable long-cycle operation.
Need Heavy Capacity Without the Full Portal?
Tell us your capacity, span, lift height, and what structure you have available on each side. Our engineering team will specify the right configuration and send a full technical proposal — typically within 48 hours.