Outrigger pads (outrigger pads) are load-bearing pads used at the bottom of the outriggers of heavy equipment (such as cranes, pump trucks, cranes, lifting platforms, etc.). Their main functions are to disperse the load, protect the ground, increase stability, and ensure operational safety.

Core uses of outrigger pads:

1. Disperse the outrigger load to prevent it from sinking into the ground

Outrigger pads can disperse the pressure concentrated on the outriggers by heavy machinery to a larger area to prevent ground collapse or equipment tilting.

Particularly suitable for soft ground such as grass, soil, gravel, asphalt, etc.

2. Protect the ground from damage

Hard ground (such as floor tiles, concrete floors, asphalt) is easily cracked when directly contacted by the outriggers of the equipment;

Using pads can prevent the equipment from directly “piercing” the ground or leaving pits.

3. Improve equipment stability and safety

Provide a solid and flat bearing surface to reduce the risk of shaking or outrigger slippage during operation;

It is an important safety device to prevent rollover accidents.

4. Compensate for uneven ground and keep the height of the outriggers consistent
   The pad can be used with wedges or adjusted in thickness to balance the forces on the four outriggers and improve overall stability.
5. Extend the service life of the equipment outriggers
   Reduce direct friction and wear between the outrigger base and the ground;

Prevent rust or damage to the bottom of the outriggers.

Applicable equipment scenarios:
Equipment type Is it recommended to use outrigger pads? Reasons
Crane Strongly recommended Anti-rollover, anti-sinking, and in compliance with construction specifications
Concrete pump truck Strongly recommended The outriggers are heavily loaded and the ground is prone to collapse
Lifting platform/aerial work vehicle Recommended to increase stability and prevent outriggers from sliding
RV/camper Optional to keep the ground stable and prevent subsidence
Small mechanical equipment Can be used according to the ground conditions Better when the ground is soft or there is a protective layer

Outrigger pads (English: Outrigger Pad) are high-strength load-bearing pads placed under the outriggers of heavy equipment such as cranes, concrete pump trucks, and aerial work vehicles. Their purpose is to:

Basic definition of outrigger pads:
Outrigger pads are structural components used to disperse outrigger pressure, enhance stability, and protect the ground. They are usually made of polymer plastics (such as UHMWPE, HDPE) or steel or wood.

Function of outrigger pads:
Function Description
Disperse pressure Distribute the point pressure of the outrigger evenly over a larger area to prevent the ground from sinking or cracking
Provide stable support Increase the friction between the outrigger and the ground to prevent sliding
Keep the whole machine level Prevent equipment from tilting and unbalanced, and improve hoisting safety
Protect the ground Prevent the outrigger from directly damaging fine surfaces such as grass, asphalt, and floor tiles
Easy to carry Most outrigger pads are equipped with handle holes or ropes for easy carrying

Common materials and features of outrigger pads:
Material Features
UHMWPE (ultra-high molecular weight polyethylene) is the most commonly used high-end material with strong pressure resistance, wear resistance, weather resistance, non-absorbent, and light weight
HDPE is low in cost and moderate in performance, suitable for light load operations
Wood is low in cost, but easy to absorb water and rot, and not durable
Steel plate is very strong but heavy, easy to rust, and not suitable for frequent handling

Common size examples (unit: mm)
Crane tonnage Recommended size
5–10 tons 400×400×30–40mm
25 tons 500×500×50mm
50 tons 600×600×60mm
100 tons 800×800×80mm or larger

When the ground is uneven, it is very necessary to use additional pads or adjust the structure of the outriggers to ensure that the crane remains level, stable and evenly stressed.
Why is it necessary to use additional pads for uneven ground?
Risk Consequences
Outriggers are suspended in the air and cannot be effectively stressed, which makes it easy to lose balance or overturn during lifting
Outriggers are unevenly stressed. One leg is overloaded, resulting in cracks in the pad, bending of the outriggers and even collapse of the ground
Crane is not level. The swing of the hoisting arm is limited, the shaking of the heavy objects increases, and the operation is extremely unsafe
How to deal with uneven ground? (Recommended practice)

1. Use additional pads for leveling
   Use wood blocks, rubber pads, thick steel plates, composite plastic pads and other materials to add pads under the outrigger pads and adjust them to the same level for each leg;
   A common practice is to use a large outrigger pad + several layers of small leveling blocks;
2. Ground pretreatment
   If construction is possible, it is recommended to use sand, concrete or steel plates to simply level the soft ground or potholes in advance;
   If necessary, lay a ground protection mat to form a temporary leveling platform.
3. Use an automatic leveling system (limited to high-end equipment)
   Some modern cranes have electronic level detection + hydraulic automatic leveling functions, but they still require the cooperation of a foundation pad.
   Recommended configuration example
   Component Purpose
   Main leg pad Large size for pressure bearing, placed at the bottom layer
   Leveling pads (small pads) 1 to 3 layers stacked on the main pad to adjust the local height
   Block box/leg tool box Carry spare leveling blocks for quick on-site adjustment
   Practical suggestions
   When the ground height difference is large: a combination of pads of different thicknesses may be used under each leg;
   The pads must be made of strong, non-slip, and crack-resistant materials, and cannot be made of fragile wood or bricks;
   The leg must be fully in contact with the center of the pad, and cannot be suspended or skewed;
   All legs must land at the same time and the force must be balanced, and one side cannot land first.