Piling rig
Heavy plant used to install piled foundations, typically imposing very high, concentrated ground loads through tracks or outriggers, often on ground that has not yet been fully engineered. Piling rigs commonly require substantial ground protection, particularly where they need to track across a site between pile positions.
In practice
A piling rig is the hardest ground bearing case on most sites and the earliest, which is an unhelpful combination. It works before the permanent works exist, on whatever the site was to start with, and it is tall, heavy and dynamic — loads shift as the mast moves and as the rig tracks between positions. This is the plant a working platform is usually designed for.
Where this comes from: Standard piling practice; rig loadings and platform requirements come from the rig manufacturer’s data and the working platform design.
Where it matters on site
The governing case is often travelling rather than piling: a rig at rest over a designed platform position, then tracking across ground between positions where the platform is thinner or absent. Where a certified working platform exists, the platform certificate defines what may go on it — and a rig substituted for a heavier one after the platform was designed is a change to the temporary works, not a plant swap.