Parkour block 1500 × 1000 × 500, finger-jointed plywood

Timber-free version in the long 1500 × 1000 × 500 size, on the same principle as the finger-jointed 1000 block: six 18 mm plywood panels at the outer size meet with box joints on all twelve edges, fifteen equal 100 mm cells along the 1500 mm edges, nine 111 mm cells along the 1000 mm edges and five 93 mm cells along each vertical edge, with the top and bottom owning the corners; every finger has a 2.5 mm pilot bore for a screw into the edge of the neighbouring panel. Inside there are four ribs: three cross ribs at 375, 750 and 1125 mm from the end brace the long walls every 375 mm, the middle one running between the carry slots as on the 1000 block, and one lengthwise rib at mid-depth crosses them in half-lap notches (the cross ribs notched from the top, the lengthwise one from the bottom). Each cross rib carries four 120 mm tabs through slots in the top and bottom; the lengthwise rib carries one 120 mm tab per bay, four in all, with a pilot bore either side of each tab; every rib end has two 100 mm tabs through slots in the walls, with 0.2 mm slot clearance. The two-hand carry slots match the other blocks. The drawings show the ribs in teal. Estimated mass about 85 kg; the parts fit on four 1525 × 1525 mm sheets. Tabs and slots are nominal: a test cut on the actual plywood thickness is required.

The 2.5 mm pilot bores and the 130 × 45 mm carry slots are concepts, not certified lifting points. The cube's estimated mass is 221 kg: do not plan a four-person manual lift without a risk assessment and handle testing. Engineering analysis and full-scale testing are needed before children use these obstacles; cover the slots during use to prevent entrapment.