Every year, buyers make two opposite mistakes when sizing a mini crane: they pick a machine that's too big — paying for tonnage and boom length they'll never use — or they pick one that's too small, only to find it can't hold rated capacity at the radius their job actually needs. Both mistakes are preventable, and the tool that prevents them is sitting in every manufacturer's spec sheet: the load chart.
This guide breaks down exactly what a spider crane load chart tells you, how to use it to shortlist the correct model before you buy, and how the same chart — paired with an onboard load moment indicator (LMI) — keeps every lift safe once the crane is on site.
What a Spider Crane Load Chart Actually Tells You
A load chart (also called a rated capacity chart) is a table published by the manufacturer that shows the maximum weight a crane can safely lift at every combination of boom length and working radius. It's not a marketing number — it's the machine's legal and mechanical safety limit, tested and certified by the manufacturer.
Unlike a single "max capacity" spec on a data sheet, the load chart shows that capacity drops as the boom extends outward. A crane rated for 3,000 kg close to the base might only lift 600–700 kg at full reach. Reading the chart correctly — not just the headline tonnage — is what separates a correct crane selection from a costly guess.
The 4 Variables Every Load Chart Is Built From
Before comparing spider crane models, you need to understand the four inputs that make up every row of a load chart. Together, they answer three questions: how much you can lift, how far you can reach, and at what angle it's still safe to work.
01 · RATED LOAD
Capacity (kg)
The exact weight the crane can lift at a specific radius — not the machine's absolute maximum. This is the number to match against your heaviest actual load, plus rigging weight.
02 · BOOM LENGTH
Arm Length (m)
How far the telescopic boom extends. Risenmega spider cranes range from roughly 8 m to 25 m, determining how high and how far a load can travel from the base.
03 · WORKING RADIUS
Radius (m)
The horizontal distance from the crane's center of rotation to the load. As radius increases, rated capacity decreases — this is the core trade-off every load chart visualizes.
04 · OUTRIGGER SPREAD
Support Base
Spider cranes stabilize on four independently adjustable outrigger legs. Full spread unlocks the chart's maximum figures; a narrowed stance (for confined access) always lowers rated capacity.
Put together, these four variables let you answer the questions that actually decide whether a crane fits your job: how much you can lift, how far you can extend safely, and under what outrigger configuration. A model that looks "big enough" on paper can still fail your job if its outriggers can't fully deploy in your access space — the load chart is what tells you the real, site-specific number.
Real Example: Risenmega 3-Ton Spider Crane Load Chart
Below is the actual rated capacity diagram for the Risenmega 3-ton spider crane. The horizontal axis is working radius (m), the vertical axis is lifting height (m), the radiating straight lines are boom angle (10°–80°), and each curved line traces a constant rated capacity (0.6T–3T) as the boom telescopes and pivots through that range.
Official Risenmega 3-ton spider crane load chart
Reading it in practice: pick your required working radius on the bottom axis, follow it upward to where it meets the boom-angle line you plan to work at, and read off the nearest rated capacity curve — that intersection is the maximum safe load for that exact configuration. As the chart shows, capacity drops sharply from 3T near the base (short radius, low angle) down to just 0.6T at the crane's maximum reach and height — exactly the trade-off every buyer needs to plan around before purchase.
Figures apply to the standard 3-ton Risenmega spider crane on full outrigger spread. Always confirm against the exact chart shipped with your unit before planning a lift.
How to Choose the Right Tonnage Using the Chart
Follow this sequence before shortlisting a model:
- Identify your heaviest realistic load — not the average, the peak. Include slings, spreader bars, and rigging hardware in the total.
- Measure the maximum working radius your job requires — the horizontal distance from where the crane can be positioned to where the load must land.
- Cross-reference load vs. radius on the chart — find the row where the rated capacity at your required radius meets or exceeds your load weight.
- Check outrigger space — confirm the crane's full outrigger spread physically fits your access point; a narrowed stance lowers every number on the chart.
- Build in a safety margin — professional practice is to select a model that keeps you comfortably under 100% of rated capacity at your working radius, not right at the limit.
This is exactly the logic behind our own 1–16 ton spider crane range — each model publishes its full chart so you can match capacity and radius to your job before ever requesting a quote.
After Purchase: Using the Load Chart to Plan Each Lift
Sizing the crane correctly is only step one. Once the machine is on site, the same load chart tells your team, before every lift, whether a specific piece of cargo can be raised safely to the height and position the job requires.
Before each new task, operators should re-check three things against the chart: the load's actual weight, the radius at which it needs to be placed, and the boom angle/length required to reach that height. If any combination pushes past the rated line, the fix is straightforward — reduce the radius, shorten the boom, redistribute the load, or reposition the crane base — rather than attempting the lift as planned.
Beyond the Chart
Load Moment Indicator: Real-Time Overload Protection
A paper load chart tells you the limits before the job starts. A load moment indicator (LMI) does the same job in real time, during the lift itself. It continuously reads the crane's current boom length, angle, and radius, cross-references that against the onboard load chart, and displays how the current lifted weight compares to the rated capacity at that exact position.
Live Load Matching
Continuously compares actual suspended weight against the chart's rated capacity for the current radius and boom angle.
Early Overload Warning
Audible and visual alerts trigger before the crane reaches its rated limit — giving the operator time to stop, adjust radius, or reposition.
Fewer Misjudged Lifts
Removes guesswork from reading a static chart under time pressure, reducing the chance of an incorrect judgment call on-site.
Pairing a correctly sized spider crane with a load moment indicator is the practical way to carry the load chart's logic from the buying decision into daily operations — protecting both the equipment and the crew from overload-related incidents and unplanned downtime.
Risenmega Spider Crane Specifications: Which Model Is Right for You?
Risenmega manufactures spider cranes from 1 to 12 tons, with boom lengths from 8 to 25 meters. Use the table below as a starting reference, then request the full load chart for your shortlisted model before ordering.
| Model | Max Lift | Max Height | Dimensions (mm) | IP Grade | Engine | Power |
|---|---|---|---|---|---|---|
| 1 Ton | 1,000 kg | 5.7+3 m | 2260×600×1470 | IP-67 | Honda GX390 | 9.6 kW |
| 2 Ton | 2,000 kg | 7+3 m | 2780×710×1620 | IP-67 | Honda 390CC | 10 kW |
| 3 Ton | 3,000 kg | 14.5+1.5 m | 3450×950×1700 | IP-67 | Changchai EV80 | 12.0 kW |
| 5 Ton | 5,000 kg | 17+3 m | 4650×1400×2160 | IP-67 | YN 25GB | 37 kW |
| 8 Ton | 8,000 kg | 22+3 m | 5010×1600×2200 | IP-67 | YN 27GBZ | 58 kW |
| 10 Ton | 10,000 kg | 25+3 m | 5550×1850×2300 | IP-67 | YN 27GBZ | 58 kW |
| 12 Ton | 12,000 kg | 25+3 m | 6050×1850×2300 | IP-67 | Changchai | 65 kW |
Frequently Asked Questions
What's the difference between a crane's "max capacity" and its load chart rating?
Max capacity is the single highest weight the crane can lift, typically at its shortest radius. The load chart shows how that capacity changes across every boom length and radius — the number you actually need for planning a specific lift.
Do outriggers really change how much I can lift?
Yes. Rated capacities on a load chart typically assume full outrigger spread. A narrowed stance — often necessary in tight indoor spaces — lowers the safe capacity at every radius, so always check the chart's outrigger configuration column.
Is a load moment indicator required, or optional?
It varies by region and jobsite policy, but it's widely considered a best practice — and often mandatory on commercial and industrial sites. Risenmega spider cranes can be configured with an LMI for real-time overload monitoring.
How do I get the exact load chart for a Risenmega spider crane model?
Every Risenmega spider crane ships with its full, tested load chart. Contact our team with your required capacity and working radius, and we'll send the exact chart plus a model recommendation before you order.
Not Sure Which Ton Fits Your Job?
Send us your required lifting capacity and working radius — our team will match you to the correct Risenmega spider crane model and provide its full load chart before you commit to a purchase.
Request Your Load Chart & Quote →
