FORCIBLE-ENTRY TOOLS

To do an effective job when fire fighting, you must gain access to the fire. If the normal means of access are blocked, or locked, you will need to use forcible-entry tools to gain access into the area so that you can fight the fire.

The tools most frequently used for forcible entry are the sledge hammer, axe, crowbar, wrecking bar, claw tool, hacksaw, bolt cutter, and oxyacetylene cutting torch. It is important to know how to use these tools. Some of them, such as the sledge hammer, axe, crowbar, wrecking bar, and claw tool, require no special skills or knowledge. Therefore, we will discuss only the hacksaw, bolt cutters, and oxyacetylene cutting torch.

To use a HACKSAW properly, mount the blade with the teeth pointed away from the handle. Tighten the blade until it hums when plucked. Keep the blade tight or you may break it. Use long, steady, even strokes, about 40 or 50 strokes per minute. Do not try to work faster than this. Apply pressure on the forward stroke and then release the pressure on the return stroke. If the blade breaks during a cut, install another blade in the frame and start a new cut. A new blade has more set than an old one; if a new blade is used to finish a cut started by an old blade, the new blade is likely to bind and break.

BOLT CUTTERS may be used to cut mild steel stock up to one-half inch in diameter. Do not twist the bolt cutters when using them. If

YOU do, you might break the jaws or blades. Emergencies may arise in which it will be necessary to cut electrical cables with a bolt cutter. NEVER attempt to cut electrical cables unless you are SURE that the cables have been de-energized.

The portable pack-type OXYACETYLENE CUTTING OUTFIT (fig. 6-40) may be used to cut holes in decks or bulkheads so that nozzles and applicators equipped with fog heads may be

Figure 6-40.-Portable pack-type oxyacetylene cutting outfit.

inserted to fight a fire. The outfit may also be used to cut away debris that would hinder fire fighters or rescue workers. These cutting outfits are to be used for emergencies only; never for routine cutting jobs.

The cutting outfit shown in figure 6-40 consists of two oxygen cylinders, one acetylene cylinder, an oxygen cylinder manifold, preset regulators, hoses, torch, tip, gloves, igniter, wrenches, and goggles. The unit weighs 56 pounds. The oxygen cylinders have a capacity of 22 cubic feet. Each oxygen cylinder is charged to 1,800 psi. The acetylene cylinder has a capacity of 10 cubic feet and is charged to 250 psi. The preset regulators give a controlled ratio of 25 psi for oxygen and 5 psi for acetylene. Since the pressure cannot be regulated, gas welding cannot be performed with this outfit.

The hoses of the pack-type cutting outfit are 5 feet long. The acetylene hose is always red in color and always has left-hand threads. The oxygen hose is always green or black in color and always has right-hand threads. The torch is a medium cutting torch with a number 2 tip. The unit will cut ferrous metals up to 1 inch thick. When the unit is fully charged, it can be used for 30 minutes.

Before using the portable cutting unit, open both oxygen valves slowly to prevent damage to the regulator. Then open the valves all the way. Next, open the acetylene valve one-half of a turn, using the key provided. The unit is now ready to be strapped on your back.

To light the torch, open the acetylene needle valve a quarter turn and immediately ignite the fuel with the igniter. Do not delay, since this would allow a buildup of acetylene gas in the torch area. Next, open the oxygen needle valve a quarter turn and adjust the flame until you have a good neutral preheating flame. When the adjustment is correct, you should have a preheating flame that is a clear, blue-white cone about one-fourth of an inch long.

To cut metal with the oxyacetylene cutting torch, adjust the preheating flames to neutral. Hold the torch perpendicular to the work, with the inner cones of the preheating flames about one-sixteenth inch above the end of the line to be cut. Hold the torch in this position until the spot you are heating is a bright red. Introduce the cutting oxygen by depressing the oxygen lever slowly but steadily until it is fully depressed.

If you start the cut correctly, a shower of sparks will fall from the opposite side of the work, indicating that the cut is going all the way through. Move the cutting torch forward along the line just fast enough for the cut to continue to penetrate the work completely. If you have made the cut properly, you will get a clean, narrow cut which looks somewhat like one made by sawing. When cutting round bars or heavy sections, you can save time and gas if you raise a small burr with a chisel where the cut is to start. This small raised portion will heat quickly, and cutting can be started immediately.

If you start a cut from the center on some portion of metal other than the edge, use the following method: Preheat the spot on the surface where the cut is to start until it is bright red. Tilt the torch at an angle of about 450 from the perpendicular, in line with the direction of the cut. Press the cutting oxygen lever very slowly. As the ^{torch begins to cut,} start righting it to a perpendicular position to the surface of the plate. Continue to right the position of the torch gradually as it cuts until it is 900 to the surface of the place and is cutting all the way through. Move it forward along the line of cut as fast as you can get complete penetration. If you do not follow this procedure, you are likely to blow the slag back on the cutting tip. This will clog the orifices or otherwise damage the equipment.

When you have started a cut, move the torch slowly along the cutting mark or guide. As you move the torch along, watch the cut so you can tell how it is progressing. Make torch adjustments

if necessary. You must move the torch along at the right speed. If you go too slowly, the preheating flame will melt the edges along the cut and may even weld them back together at the top surface. If you go too fast, the oxygen will not penetrate completely through the metal, and the cut will be incomplete. If that happens, you will have to release the cutting oxygen lever and start the entire operation over again at the beginning of the partially cut area.

To secure the portable pack-type cutting outfit, use the following procedures:

1. Close the acetylene valve on the torch.

2. Close the oxygen valve on the torch.

3. Close the acetylene cylinder valve.

4. Close the oxygen cylinder valves.

5. Open the torch acetylene valve to drain the acetylene line. Do this with the torch oxygen valve still closed. After the acetylene line has drained, close the torch acetylene valve immediately.

6. Open the torch oxygen valve to drain the oxygen line. Do this with the torch acetylene valve closed. After the oxygen line has drained, close the torch oxygen valve immediately.

If this procedure is followed, acetylene will not get into the oxygen line, nor will oxygen get into the acetylene line while you are lighting or securing the portable oxyacetylene cutting outfit. It is important to keep these gases from mixing; flashbacks result from mixed gases in either the oxygen line or the acetylene line. Flashbacks also result when the torch flame is not properly adjusted and maintained with the correct pressures, and when the tip orifices are not kept free of obstructions. Make sure that all valves are tightly closed before storing the unit. Check the oxygen pressure by removing the oxygen regulator and attaching a test gauge. If the oxygen pressure reading is below 500 psi, replace all three of the cylinders. This way you can maintain the 5-to-1 ratio of oxygen pressure to acetylene pressure. When using the portable oxyacetylene cutting out fit, follow these safety precautions:

. Always wear protective gear, including goggles and gloves.

. Be sure that the space or area is safe for cutting before you begin. Always check to see what is on the other side of the deck or bulkhead before you start cutting.

. Station a fire watch.

. Never allow oil or grease to come in contact with oxygen cylinders, valves, regulators, hoses, or fittings. Do not handle any oxygen equipment with oily hands or oily gloves. Grease or oil in the presence of oxygen under pressure is violently explosive.

. Use and store the cylinders in an upright position. This is particularly important for acetylene cylinders. It prevents acetone from being discharged with the acetylene when the cylinder is in use.

. Never use an acetylene working pressure in excess of 15 psi. There is danger of an explosion above this pressure.

. Take the unit to a clear area topside if leakage is suspected. With your back to the wind, expend the acetylene gas slowly. Use only a mild soap and water solution to test for leakage.

. Be sure that all cylinder valves are tightly closed when the unit is not in use.