The piling rig you choose directly affects the required working platform thickness. Understanding track pressures and EN 996 data is essential for efficient platform design and cost control.
Why Track Pressures Matter
The track pressure of a piling rig is the single most influential parameter in a BRE470 working platform design. Higher track pressures require thicker platforms, which means more material, more cost, and more time to construct.
Track pressure is expressed in kilopascals (kPa) and represents the ground pressure exerted by the rig's tracks on the working surface. Two values are critical:
Maximum track pressure (q1k): This is the highest ground pressure the rig exerts, typically during outrigger operations or when the mast is at maximum reach. This value governs the platform design in most cases.
Slewing track pressure (q2k): This is the ground pressure during slewing (rotating) operations. For some rig configurations, particularly those with short loaded track lengths, the slewing case can be more onerous than the outrigger case.
The relationship between track pressure and platform thickness is not linear — a 20% increase in track pressure can require a 30-40% increase in platform thickness, depending on the subgrade conditions. This means that selecting a rig with lower track pressures can significantly reduce platform costs.
EN 996 and Standardised Track Data
EN 996 is the European standard that specifies safety requirements for piling equipment. It includes standardised track pressure data for common piling rigs, which is used as the basis for BRE470 platform design.
The key parameters from EN 996 for each rig are:
Track width (W): The width of one track shoe, typically 0.6-1.0 m. Wider tracks spread the load over a larger area, reducing ground pressure.
Overall track length (L1): The full length of the track in contact with the ground. Longer tracks spread the load longitudinally.
Loaded track length (L2): The effective loaded length under slewing conditions. This is typically shorter than L1 as the load concentrates under the mast.
Maximum track pressure (q1k): The peak ground pressure under the most onerous operating condition.
Slewing track pressure (q2k): The ground pressure during slewing operations.
Our design tool includes EN 996 data for 23 piling rigs from three major manufacturers, so you don't need to look up these values manually.
Liebherr Piling Rigs
Liebherr is one of the world's leading manufacturers of piling equipment. Their LB series of rotary drilling rigs is widely used in the UK and internationally.
The LB range spans from the compact LB 16 (suitable for restricted access sites) to the large LB 44 (for deep, large-diameter piles). Key characteristics:
LB 16: The smallest in the range, with track pressures around 90-120 kPa. Ideal for restricted access sites and lighter piling works. Requires relatively thin working platforms.
LB 28: A mid-range rig commonly used for CFA and rotary bored piling. Track pressures typically 140-190 kPa. This is one of the most popular rigs in the UK market.
LB 36 and LB 44: Larger rigs for deep foundations and heavy-duty piling. Track pressures can exceed 200 kPa, requiring substantial working platforms on weak ground.
LRB 155 and LRB 255: Liebherr's leader rig range for driven piling and sheet piling. These have different track configurations and pressure distributions compared to the LB rotary rigs.
Our tool includes all major Liebherr models with EN 996 data pre-loaded, making it easy to generate a platform design for any Liebherr rig in the fleet.
Bauer and Soilmec Rigs
Bauer BG Series: Bauer's BG range is another mainstay of the UK piling market. The range spans from the BG 15 H to the BG 46, covering the full spectrum of rotary drilling applications.
The BG 15 H and BG 20 H are compact rigs suitable for restricted sites, with moderate track pressures. The BG 28 H and BG 30 are popular mid-range rigs, while the BG 39 and BG 46 are heavy-duty machines for large-diameter, deep piles.
Bauer rigs generally have similar track pressure characteristics to equivalent Liebherr models, though the specific values vary by model and configuration.
Soilmec SR Series: Soilmec's SR range includes the SR-30, SR-40, SR-50, SR-65, SR-75, SR-80, and SR-100. These Italian-manufactured rigs are widely used in the UK, particularly for CFA piling.
The SR-30 and SR-40 are compact rigs with relatively low track pressures, making them suitable for sites with weak ground conditions. The SR-75 and SR-100 are large rigs with higher track pressures that require more substantial platforms.
All 23 rigs across these three manufacturers are pre-loaded in our design tool, with EN 996 track dimensions and pressures auto-filled when you select a rig model.
Optimising Platform Design Through Rig Selection
Understanding the relationship between rig selection and platform requirements can lead to significant cost savings:
Consider the platform cost in rig selection: When choosing a rig for a project, the platform cost should be factored into the overall cost comparison. A larger rig with higher track pressures may be faster at installing piles, but if it requires a 900 mm platform instead of a 500 mm platform, the additional material and construction cost may outweigh the production benefit.
Run multiple scenarios: Our design tool makes it economical to run platform designs for different rigs and compare the results. At £299.99 per design, running 2-3 scenarios to optimise the rig/platform combination is a worthwhile investment.
Consider ground improvement: On sites with very weak subgrade, it may be more economical to improve the ground (e.g., with lime stabilisation or preloading) rather than constructing an excessively thick platform. Our tool helps quantify the platform requirement so you can make an informed comparison.
Use geosynthetic reinforcement: Including a geogrid at the base of the platform can reduce the required thickness by 20-30%, depending on the subgrade conditions. Our tool includes the option to design with geosynthetic reinforcement.
The key message is that platform design should not be an afterthought — it should be considered alongside rig selection and ground conditions as part of the overall project planning process.
