Cribbing

Cribbing is essential in many extrication operations.  Its most common use is to stabilize objects.  Wood selected for cribbing should be solid, straight and free of major flaws such as large knots or splits.  Cribbing surfaces should be free of any paint or finish because this can make the wood slippery, especially when it is wet.  Cribbing can be made out of pieces of timber found in the debris and cut to size.  Pieces of 2X2 (5 cm X 5 cm) and 4X4 (10 cm X 10 cm) as well as wedges cut in this size timber are very useful.

Cribbing involves multiple pieces of wood laid on the side and crossed.  It spreads the load well and has many load transfer surfaces.  It also has lateral stability depending on the ratio of width to height.  The height should not be more that three times the width.  (Note:  pieces should not be more that two feed (60 cm) long.)

The overhand at corners should be no less than 4 inches.

4X4 crib capacity = 24,000 lb. (10,886 kg).


6X6 crib capacity = 60,000 lb. (27,215.5 kg).

Note:  using 3 pieces per layer as in 3X3 (7.5 cm X 7.5 cm) cross tie will double the capacity