STABILIZING TOOLS

DEFINITION:TOOLS USED TO ASSIST IN MAKING AN OBJECT RESISTANT TO A SUDDEN CHANGE OF POSITION OR CONDITION.

During rescue operations, anytime a load is lifted, a method for temporary support is needed to insure the safety of the rescuer and the trapped persons. One quick and simple method of temporary support is known as “CRIBBING”.

Cribbing is the construction of a stable platform utilizing wooden blocks. Ideally, the blocks for cribbing are usually made from construction grade framing lumber and are two sizes – 2” x 4” x 18” and 4” x 4” x 18”.

However, at the scene of a disaster, there is usually ample material with a hard, flat surface that can be utilized. The requirement for improvised cribbing are:

  1. The material must be flat on both surfaces and
  2. The material must be able to withstand the weight it will have to support. Furniture, bricks, concrete blocks, and tire rims are all acceptable alternatives to pre-cut wooden blocks.

Cribbing provides the safety necessary when a load is being lifted by preventing the load from falling due to tool failure or slippage. As the load is raised, the crib should be built up accordingly. No rescue personnel should be allowed under a raised or unstable load without the proper safety precaution- cribbing.

There are two ( 2) basic methods of constructing cribs:

  1. Crosstie Crib
  2. Box Crib.

Cribbing allows the rescuer to utilize rescue tools more efficiently. If mechanical jacks, hydraulic rams, etc., have to be reset, the load can be cribbed, then the lifting tools reset. By utilizing cribbing, tools can also be freed for other uses.

An effective method of building a fulcrum during prying operations is to use cribbing techniques to increase the height of the fulcrum.

Wedges 4” x 4” x 12” cut diagonally, are used to ‘snug-up’ or tighten a load supported by cribbing, Wedges are also used to change the angle of weight thrust. Wedges are needed in tunneling, shoring and strutted operations. A single wedge used to simply take up space is referred to as a shim.

SHORING, CRIBBING & EXTRICATION

  1. INTRODUCTION TO CRIBBING AND WEDGES
  2. Cribbing is composed of wooden blocks used to construct a stable platform (crib).
  3. Two (2) types of platforms or cribs are commonly used.
  4. Cross Crib - is constructed by placing blocks in layers, with each layer 90 degrees to the last.
  5. Box Crib - is constructed by placing two (2) blocks parallel to each other with two blocks 90 degrees to these and top of the first two.
  6. Wedges are pieces of wood cut at an angle.
  7. Shims are single wedges used to take up space.