Types of Gantry Cranes: Fixed, Adjustable, Portable — and What Each Is For
A gantry crane is an overhead lifting frame that carries its own legs — the bridge beam rides on uprights that roll on wheels, casters, or rails, instead of hanging from building steel. Types are classified four ways: by mobility (portable vs. rail-mounted), height (fixed vs. adjustable), structure (single vs. double girder, full vs. semi), and material (steel vs. aluminum). The right type follows from the work: what you lift, where, and how often the crane has to move.
Full gantry vs. semi-gantry
A full gantry carries the bridge on two legs — the whole structure stands on the floor, which is why it needs no building steel at all. A semi-gantry replaces one leg with an end truck riding on an elevated rail along a wall, saving floor space on one side but tying the crane permanently to that runway. Full gantries are by far the more common form, and the only form that can be genuinely portable.
Fixed-height vs. adjustable-height
Fixed-height gantries are welded or bolted to one geometry — simple and rigid, but the doorway they can’t pass under is a permanent fact. Adjustable gantries change height (and often span) in increments, so one crane clears a low mechanical-room door, then works at full height inside. For crews that work in more than one building, adjustability is usually the difference between one crane and several.
Portable vs. rail-mounted
Rail-mounted gantries travel a fixed runway — common at container ports and heavy steel yards. Portable gantry cranes roll on casters, break down into components, and move to the work: through doors, up freight elevators, onto service trucks. Some portable designs — including every eme gantry — are engineered to roll while fully loaded on level, prepared surfaces, which turns a lift into a lift-and-carry without rigging twice.
Single-girder vs. double-girder
The bridge can be one beam or two. Double-girder designs put the trolley on top of paired beams and suit very heavy permanent installations. Single-girder designs hang or surround one beam — lighter, faster to assemble, and the standard for portable cranes. Capacity in a well-engineered single-girder line grows by making the one beam deeper, not by doubling it up.
Steel vs. aluminum
Steel dominates fixed installations where weight doesn’t matter because the crane never moves. Aluminum changes the arithmetic for anything portable: a 1 ton aluminum gantry can weigh roughly 235 lb assembled, light enough for two people to set up with hand tools. Corrosion behavior differs too — the full comparison lives in aluminum vs. steel gantry cranes.
By capacity class
Portable gantry cranes are typically specified by short-ton class. The eme line spans six classes, every model rated in pounds above its metric equivalent:
| Class | Rated capacity | Series |
|---|---|---|
| 1/2 ton | 1,100 lb | 1100 Series |
| 1 ton | 2,200 lb | 2200 Series |
| 2 ton | 4,400 lb | 4400 Series |
| 3 & 4 ton | 6,600–8,800 lb | 6600/8800 Series |
| 5 ton | 11,000 lb | 11000 Series |
| 10 ton | 22,000 lb | 22000 Series |
Which type fits which work
| The work looks like… | The type that fits |
|---|---|
| One production line, same lift, decades of duty | Fixed steel gantry or overhead bridge crane |
| Maintenance lifts across a plant, multiple rooms and doorways | Portable, adjustable-height gantry |
| Service work at customer sites, crane travels in a truck | Portable aluminum gantry, light enough to hand-load |
| Load must move across the floor mid-lift | Portable gantry rated to roll under load |
| Heavy dedicated yard with rail infrastructure | Rail-mounted gantry |
Where eme sits in this taxonomy: portable, adjustable-height, single-girder, full-gantry cranes — all-aluminum, ½ ton to 10 ton, designed to roll while fully loaded. Browse the portable aluminum gantry crane line, or start from the selection guide if you’re matching a type to a lift.
Frequently asked questions
What are the main types of gantry cranes?
Four classification axes cover them: full vs. semi-gantry (two legs vs. one leg plus a wall rail), fixed vs. adjustable height, portable vs. rail-mounted, and single vs. double girder — plus the material split between steel and aluminum. Most portable cranes are full-gantry, single-girder, adjustable designs.
What is the difference between a gantry crane and an overhead crane?
An overhead (bridge) crane runs on rails attached to the building structure; a gantry crane carries its own legs to the floor. Same lifting job, different real estate — the deeper comparison is in gantry vs. overhead bridge cranes.
Can a portable gantry crane move while carrying a load?
Only if it’s designed and rated for it — check the manufacturer’s manual. Every eme gantry is engineered to roll fully loaded on level, prepared surfaces; how loaded travel works covers the conditions.
eme has been engineering lightweight and portable lifting equipment since 2003.