A "55 ton" crane lifts 55 tonnes only at its shortest radius. Move the load a few metres out and the capacity can fall to a small fraction of that figure. Hirers who choose a crane by the number in its name often find it can't handle the load at the real lifting point.
This guide helps you size a crane from three figures you can measure yourself, then check them against the load chart.
What size crane do you need?
Gather three figures:
- Total load weight, including slings, shackles, spreader bar and hook block.
- Working radius, the horizontal distance from the crane's slewing centre to the pick-up point and the set-down point.
- Lift height, from the ground to the load's highest position.
With those three numbers, check the crane's load chart at the radius and boom length you will use. Choose a crane whose capacity at that radius is still above the total load weight.
Count the total weight, not just the item
The crane carries the item plus everything below the boom. On heavy lifts, slings, shackles, a spreader bar and the hook block can add hundreds of kilograms. Put all of it in the calculation from the start.
Capacity drops as radius grows
A crane's maximum capacity applies at its shortest radius. The further out the load goes, the less the crane can safely lift. Plan the lift from the furthest radius the load will pass through, including set-down, and keep a margin below the chart limit.
How to read a crane load chart
A load chart is the manufacturer's capacity table. Every unit has its own, and the figures change with each configuration.
- Pick the chart that matches the set-up on site. Manufacturers publish separate tables for outrigger spread (full or partial), counterweight and working area. A full-outrigger chart doesn't apply if the site only allows a partial spread.
- Find the row for the boom length needed to reach the lift height.
- Find the column for the working radius. If your radius falls between two columns, use the larger radius.
- Read the figure where they meet. That is the gross capacity.
- Subtract the hook block and rigging. The result is the heaviest item you can lift.
- Read the chart's footnotes. The manufacturer lists deductions there, such as for a stowed jib, and other conditions you must meet.
Example (illustrative figures): the chart shows 8.5 tonnes at 25 m of boom and a 12 m radius. The hook block and rigging weigh 400 kg. The heaviest item you can lift in that position is 8.1 tonnes.
Loader cranes: reading t·m
Loader cranes (knuckle-boom cranes mounted on a truck, such as PALFINGER) are rated by lifting moment, in t·m: weight multiplied by reach. As a rough guide:
- A 38.2 t·m crane lifts about 3.8 tonnes at 10 m reach, or about 7.6 tonnes at 5 m.
Treat this as an estimate. Check the unit's load chart for each boom position.
Choose the crane type
| Type | Best for | Notes |
|---|---|---|
| Loader crane (truck-mounted) | Loading and unloading material, installing light to medium equipment | Carries and lifts, moves between sites quickly |
| Mobile crane | Heavy lifts on sites reachable by road | Fast to mobilise, no long assembly |
| Rough terrain crane | Uneven project ground | 4×4 drive for off-road sites |
| Crawler crane | Very heavy, long-running lifts in one area | Travels on tracks, needs transport and assembly |
Cranes you can hire in Batam:
- PALFINGER loader cranes, 17.4–42.3 t·m, for hire or purchase
- SANY 55 ton mobile crane and SANY 70 ton rough terrain crane
- XCMG and SANY crawler cranes, 55–100 tonnes
Check the ground and the work area
A crane stands on outriggers or tracks, so the ground underneath has to carry that pressure. Check fill ground, covered drains and quay edges, and lay crane mats where needed. Look for overhead power lines and leave room for the boom and counterweight to swing.
Safety documents
In Indonesia, cranes are lifting equipment regulated under Minister of Manpower Regulation No. 8 of 2020. The unit needs a valid inspection and test certificate (riksa uji), the operator needs a K3 licence, and a competent rigger should handle the rigging. Our rental cranes come with a certified operator and inspection documents.
Send us your lift details
Send the item's weight and dimensions, the radius and lift height, and photos of the site on WhatsApp. Our team checks them against the load charts of the units available and prepares a rental quote. If forks can move the load, compare a 10–25 ton forklift as well.
