The rated capacity is the first number in any gantry crane enquiry. It is also the number that is most often chosen too quickly.
This guide explains what the capacity must cover, which other factors change the design and how to give your supplier the right information.
What rated capacity means
Rated capacity is the heaviest load the crane is designed to lift at the hook under normal conditions. CESAN builds gantry cranes up to 500 t.
The load at the hook includes more than the product. Lifting beams, spreaders, magnets, grabs and slings all count, because the crane carries their weight too.
Work out the real load
- The heaviest single item you will ever lift.
- The weight of every attachment used with it.
- Any future product that may be heavier than today's.
- Whether two hoists will share one load.
Do not size for one lift only
A crane that lifts its full rating once a month needs a different design from one that lifts half its rating every few minutes. Capacity alone does not describe this.
The duty class, set to FEM or ISO 4301, describes how often and how heavily the crane works. Send the number of lifts per hour, the typical load and the hours of operation per day, as well as the maximum load.
Span, cantilever and lifting height
- Span: the distance between the rails. A wider span means a longer, heavier girder for the same capacity.
- Cantilever: if the crane must reach beyond the rails, the structure changes.
- Lifting height: the height from the ground to the hook at its highest point.
Single girder or double girder gantry
Lighter gantry cranes often use a single girder. Heavy loads and long spans usually call for a double girder gantry. Your capacity, span and duty decide which one is right, and our engineers will recommend it.
What the ground must carry
A heavy gantry crane puts its weight and its load onto a few wheels. The rails and the foundation underneath must take those wheel loads without settling.
- Check the soil and the foundation design with your civil engineer.
- Ask us for the wheel loads at maximum capacity.
- Plan the rail length with room for the crane to travel to both ends of the yard.
Outdoor conditions
A gantry crane works in the open. Tell us the site location, the wind conditions, the temperature range and whether the site is near the sea, because the design and the protective coating depend on them.
Where gantry cranes are used
- Steel and material stockyards.
- Precast concrete plants.
- Shipyards and ports.
- Construction and project sites.
What to send for a quotation
- Maximum load and the attachments used.
- Duty: lifts per hour and hours per day.
- Span, cantilever and lifting height.
- Site layout, rail length and ground conditions.
- Power supply and control method.
- Installation and commissioning: required or not.
Send us your requirements
To prepare an accurate offer, we need the load, duty, span, lifting height and site details listed above. Send them through the enquiry form and our engineers will reply with a technical and budgetary assessment.
See our gantry cranes and the comparison gantry crane vs overhead crane.