Four steel sections weighing over two tonnes must extend in sync and carry people twenty metres up.
Four sections in one. The sections nest inside each other with a clearance and run on nylon slide pads. One cylinder inside the boom extends them, and chains pull the two smaller sections: a 3 × 3500 mm stroke with at least a third of each section's length left in overlap when extended.
The basket always stays level. The boom angle runs from −25° to 80°, the basket floor must stay level. Levelling is hydraulic, no electronics: a master cylinder on the column and an identical slave at the basket, ±0.4° error against the five degrees EN 280 allows.
Boarding from the ground without extending. The boom lowers to −21°, the basket floor ends up 0.68 m above ground, with a fold-down two-rung step under the gate. The gate opens inwards: EN 280 does not allow one that folds down.
Travel over the cab. Folded, the basket is raised to the underside of the boom and sits over the cab without blocking the windscreen. Heights assume a slewing ring 1.3 m above ground; they will be refined once the truck is measured.
