Lift capacity
The maximum load a crane can safely lift at a specified working radius and configuration, defined by the manufacturer’s load chart and never by a single headline number.
Lift capacity is the maximum mass a crane is rated to lift safely. The critical thing to understand is that a crane does not have one capacity — it has hundreds of capacities, one for each combination of boom length, working radius (the horizontal distance from the crane's centre of rotation to the load), counterweight configuration, outrigger extension, and slewing direction. The single number you see in marketing material (e.g. "350-tonne crane") is the maximum capacity at the shortest radius and fully extended counterweight — it falls off rapidly as the load moves away from the crane.
That's why load-chart literacy matters more than the headline tonnage when buying a crane. A 350-tonne all-terrain at 20 metres radius might lift 50 tonnes; the same crane at 60 metres radius might lift 5. If your job needs to place a 12-tonne wind-turbine component at 45 metres radius, you need a crane whose load chart shows ≥12 tonnes AT 45 m — not a crane with 350 tonnes in its name.
For a transaction on Kranly, the load chart is the single most important document the seller can share. Every active listing should include load chart values for at least the standard configuration. Capacity decreases as the boom is lengthened, as the load is moved away, as counterweight is reduced, and as the crane operates off-outrigger or on rubber. It increases with shorter radius, more counterweight, and luffing-jib or main-boom-only configurations within their rated ranges.
In Europe, capacity is quoted in metric tonnes (1,000 kg). In North America, capacity is quoted in US tons (2,000 lb = 0.907 metric tonnes) — be careful when comparing US and European specs.