Spider Crane Outrigger Setup: Footprint, Ground Pressure and Safe Positioning
A spider crane is only as stable as the ground under its four pads. Here is how to read the footprint of each Risenmega model, calculate pad loads, and position the machine before the first lift.
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Quick answer: how do you set up spider crane outriggers?
- Check the ground first. Pad pressure must stay below the soil's allowable bearing capacity, with margin.
- Extend all four legs fully to the position your load chart assumes, then level the chassis.
- Use outrigger pads sized from the heaviest single-leg load, not from machine weight alone.
- Position the boom over the strongest ground and re-check level after the first lift.
1. Spider Crane Footprint: Folded Width vs. Outrigger Spread
The footprint changes completely between transport and work. Folded, a 1-ton Risenmega spider crane is 600 mm wide and fits a standard doorway. Deployed, its outriggers reach roughly 3.1 × 2.95 m. Always plan the working area from the extended figures below, not the folded size.
| Model | Capacity | Folded L × W × H (mm) | Outrigger extension (mm) | Weight | Track size (mm) |
|---|---|---|---|---|---|
| RM1.0 | 1 t | 2260 × 600 × 1470 | 3120 × 2950 | 1,200 kg | 1110 × 150 |
| RM2.0 | 2 t | 2450 × 750 × 1470 | 3120 × 3000 | 1,550 kg | 1110 × 150 |
| RM3.0 | 3 t | 3550 × 955 × 1700 | 4470 × 3940 | 2,700 kg | 1600 × 230 |
| RM5.0 | 5 t | 4650 × 1400 × 2160 | Side 5600 / Front 5560 / Rear 5000 | 6,800 kg | 2200 × 300 |
| RM8.0 | 8 t | 5010 × 1600 × 2200 | Side 6400 / Front 6500 / Rear 5400 | 7,800 kg | 2570 × 350 |
| RM10.0 | 10 t | 5550 × 1850 × 2300 | Side 7400 / Front 7000 / Rear 6000 | 9,300 kg | 2570 × 350 |
| RM12.0 | 12 t | 6050 × 1850 × 2300 | Side 7400 / Front 7000 / Rear 6000 | 11,500 kg | 2570 × 400 |
| RM14.0 | 14 t | 6300 × 2000 × 2400 | Side 7400 / Front 7000 / Rear 6000 | 14,500 kg | 3350 × 400 |
| RM16.0 | 16 t | 6800 × 2000 × 2400 | Side 7800 / Front 7900 / Rear 7200 | 15,500 kg | 3350 × 400 |
Every model uses four independently adjustable, manual-rotation outriggers with automatic support leveling. A one-key auto-leveling upgrade is available. Full parameter sheets are on the 1–16 ton spider crane page.
2. Ground Pressure: What the Soil Actually Feels
Two different pressures matter. Track pressure applies while the crane travels. Outrigger pad pressure applies while it lifts, and it is far higher because the whole load concentrates on four small areas.
Worked example: RM10.0 lifting 1 t
Machine 9,300 kg + load 1,000 kg = 10,300 kg. With the boom over one leg, assume that leg carries 60% (a conservative planning figure, not a manufacturer rating): 10,300 × 0.60 × 9.81 ≈ 60.6 kN.
On a 0.6 × 0.6 m pad (0.36 m²) that is about 168 kPa. On soil allowed only 100 kPa, you need roughly 0.61 m², so a pad near 0.8 × 0.8 m.
Typical allowable bearing (indicative only)
| Ground | Approx. kPa |
|---|---|
| Soft or wet clay | 25–75 |
| Firm clay, loose sand | 75–150 |
| Compacted gravel | 200–300 |
| Reinforced concrete slab | Check slab rating |
Values are broad industry ranges. Confirm site conditions with the person responsible for the ground.
For travel, Risenmega's 12-ton series lists a track ground pressure of 49 kPa (0.50 kgf/cm²). Wide rubber tracks keep that low, but they do nothing for the pad loads during a lift.
3. Step-by-Step Outrigger Setup
Survey the site
Look for soft ground, drains, voids, buried services, slopes and overhead lines. Mark the lift zone.
Plan the footprint
Use the extension figures above. Confirm all four legs can reach full spread without obstruction.
Drive into position
Use the wireless remote (100 m range) and track the machine in at low speed. Stop with the chassis square to the lift.
Place the pads
Set pads on firm, flat ground, centred under each foot. Add timber or custom aluminum pads on soft surfaces.
Deploy all four legs
Swing each leg out, then extend it to the spread the load chart assumes. Never lift on a partly extended leg.
Level the machine
Use the automatic support function. Check the level indicator and keep the tracks just clear or lightly loaded as the manual specifies.
Test before lifting
Check the load chart for the radius, then lift a few centimetres. Watch the pads and the level.
Re-check during work
Re-inspect after rain, after the first lift, and whenever the radius or load changes.
4. Safe Positioning: Do and Don't
Do
- Work within the radius and capacity on the load chart.
- Keep the boom over the strongest ground and the widest leg spread.
- Fit vacuum or basket attachments only after re-checking capacity at the radius.
- Use a signaller when the operator cannot see the load.
- Keep the crane within the 20° grade ability only while travelling, never while lifting.
Don't
- Don't lift with any leg short of full extension.
- Don't place pads on edges, trenches, backfill or covers.
- Don't override the torque limiter or the overload alarm.
- Don't slew over a lightly loaded leg with a heavy load.
- Don't work near unsupported slopes or fresh excavations.
Risenmega cranes include seven built-in safety devices: torque limiter, anti-rollover device, interlock, hook overwinding device, overload alarm limiter, tri-colour alarm light and emergency stop. They support good practice. They do not replace a correct setup. For ground conditions, see the US regulator's requirements in OSHA 1926.1402, and apply local rules and the machine manual. Our units are CE certified.
5. Choosing a Model by Site Footprint
Match tonnage to the load and the clear area you actually have. A small site often decides the model before the load does.
- Doorway and indoor jobs: 1 ton (600 mm) or 2 ton (750 mm), with battery-electric options for silent, zero-emission work.
- Rooftops and façades: 5 ton for up to 16 m, or 8 ton for 18.2 m.
- Heavy industrial lifts: 10 and 12 ton models, which need a clear area of about 8 m wide.
- Glass installation: pair any model with vacuum suction attachments.
See real results in our European customer cases, or read the complete spider crane buying guide.
Frequently Asked Questions
How far do spider crane outriggers extend?
It depends on the model. Risenmega's RM1.0 extends to about 3.1 × 2.95 m, the RM10.0 to 7.4 m side and 7.0 m front, and the RM16.0 to 7.8 m side and 7.9 m front.
Do I need outrigger pads on every job?
Use them on any soft, uneven or unknown surface. Pads spread the load and reduce pressure. Pad size should come from the heaviest single-leg load and the ground's allowable bearing capacity.
Can a spider crane work on a slope?
The tracks climb up to 20° when travelling, but lifting needs a levelled chassis. Level the machine with the legs and use packing, never a slope, to compensate.
How long does setup take?
Typical on-site setup is 15–30 minutes depending on conditions. The one-key auto-leveling option shortens the levelling step.
Can I use one indoors?
Yes. Battery-electric RM1.0–RM3.0 models are zero-emission and nearly silent. Confirm the floor's load rating first.
Not sure which spider crane fits your site?
Send us your load weight, lift height and available working area. We will recommend a model and confirm the outrigger footprint before you order.
