Stability, Load Charts, Safe Working Loads and Load-Handling Principles
A telehandler's stability is governed by its centre of gravity and the machine's stability triangle or longitudinal/transverse stability limits. The load chart is the authoritative source: it gives the rated capacity at each combination of boom length (or radius/reach) and boom angle or height, for a defined configuration (on wheels or on stabilisers, with a specified attachment). The rated capacity already includes the machine's design safety factor - the operator must not add or subtract from it. The safe working load is the rated capacity for the actual configuration, minus any allowance the chart specifies for attachments or load-handling devices. Loads must be kept as low and as close to the machine as practicable; the boom should be retracted before raising or lowering, and the machine should be level.
Principles to understand: the load's centre of gravity must be known and controlled; a load that shifts (e.g. a suspended or loose load) changes the effective radius and can overload the machine; side loads and dragging loads are dangerous; the machine must not travel with the boom raised beyond the manufacturer's limits; and the load chart must be visible and legible in the cab. Question traps include assuming a higher boom angle always increases capacity (it depends on radius), confusing rated capacity with the load's actual weight, and ignoring that the chart is configuration-specific. Another trap: a load within capacity at one radius becomes an overload the moment the boom is extended.
Worked example: chart shows 2,000 kg at 4 m reach and 1,200 kg at 6 m reach. A 1,500 kg load is safe at 4 m but overloads at 6 m - extend only within the chart.
Rule of thumb: read the chart for the exact configuration, keep the load low and close, and never exceed the rated capacity.