AS A FIREFIGHTER, YOU MAY be called to a building collapse or other type of rescue that will necessitate the use of an oxygen/acetylene cutting torch to cut and remove metal I-beams to gain access to victims (photo 1).
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I-beams include the web and top and bottom flanges. The web is the vertical section between the two horizontal flanges that run along the top and bottom of the web. Keep in mind that metal I-beams are very heavy, weighing from five pounds per foot for a three-inch I-beam to as much as 23 pounds per foot for an eight-inch I-beam that is ½ inch thick. Also, it is common to find beams in larger sizes; 18- and 24-inch beams may weigh more than 60 pounds per foot (photo 2). During cutting and removal operations, maintain control of the I-beam at all times, so it will not shift as it is cut apart and fall on personnel. You may need cranes, blocks, slings, chains, or webbing to stabilize the I-beam.
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1 Marking the I-beam. Mark the area to be cut on the I-beam. Using soapstone, mark the outline of the cut on the beam (photo 3).
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2 Flange access hole cut. If two or more I-beams are close together or if you are otherwise unable to access the other side of the I-beam, you will not be able to cut the flange on the other side (photo 4). You will have to make a circular cut first to remove a piece of the web so that you can reach through with a torch and cut the other side of the flange.
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Using the torch, heat the web to a cherry-red color (photo 5). Begin the cut by slightly raising the cutting tip flame off the metal as you press down gradually on the oxygen handle. This will help reduce the spatter from bubbles of molten metal popping and clogging the torch tip. When cutting, maintain a slight angle to aid in directing the hot slag and sparks away from you. Once you have cut through the web, move the cutting flame close to the metal once again to continue the cut (photos 5, 6).
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3 Bottom flange cut. Starting at the edge of the bottom flange, preheat the metal to a cherry-red color with the torch. Then start cutting the flange with the torch, moving it away from you and using it to push the hot metal and sparks away from the cut (photos 7, 8, 9).
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Alternatively, cut from the outer edge of the bottom flange, work inward toward the web, lift the torch as it nears the web, and cut the flange access circle.
4 Cutting web. To cut the web, start at the top and cut downward toward the hole that has already been cut. If you didn’t need to cut the flange access hole, continue cutting to the flange that was cut. Cutting down the web, preheat the metal as you move the torch down; it will blow the melted metal away from the cut (photos 10, 11).
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5 Top flange cut. Starting at the edge of the top flange, preheat the metal to a cherry-red color with the torch. Start cutting the flange with the torch so that it will blow the hot metal sparks away from the cut and you. Depending on the I-beam’s position, it may be possible to cut the top flange first, which sometimes is easier. Using a piece of scrap as a guide will make the cut go smoothly and sometimes prevents the torch tip from dropping or dipping into the metal (photos 12, 13).
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6 Cutting completed. The I-beam is now cut completely and can be moved (photos 14, 15).
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SAFETY PRECAUTIONS
- Wear personal protective equipment: Helmet, leather gloves, long-sleeve shirt (cotton), and cutting goggles or glasses (shade 5), safety boots, and kneepads are a must.
- The welding kit must include a torch tip cleaner (to keep holes in the torch tip clean) and a spark lighter (to ignite the acetylene gas).
- Always have a staffed fire extinguisher or charged hoseline standing by during cutting operations.
- Cool the metal with water if a victim is close to the cutting operation (e.g., a victim impaled on a fence); also protect the victim from the cutting operation (flying sparks and so on).
- Whenever possible, cut away from yourself to move slag and stray sparks away and prevent injury.
- Secure torch cylinders to a cart to prevent them from falling.
- Never use oil or grease on any inlet/outlet connections or cylinder valves.
- Examine the torch hoses for cuts or burns.
- Always use a detector to check for possible leaks. Never test for leaks with a flame.
- Keep working pressure on the acetylene regulator at no more that 15 psi; normal cutting operations require between seven and eight psi.
- Open an acetylene cylinder’s valve one turn (the threads on the valve are left-handed). The oxygen cylinder valve should be opened fully (40 psi for normal cutting operations).
- Welding kits have three combination wrench sizes: 1 1/16 inch for the hose connector, 5/8 inch for the regulator’s outlet connection, and 1 1/8 inch for the regulator’s cylinder connection. Flashback arrestors on the outlet hose connection at the regulator prevent a reverse flow of ignited mixed gas from reaching the regulator and cylinders when cutting.
Using a cutting torch without clogging the cutting tip and making a complete cut through metal take practice. Personnel must be knowledgeable about and proficient in using all fire department tools and equipment safely.
DON FRANK retired from the fire service after 29 years. He provides contract fire services. He served as a firefighter with the Defense Distribution Depot, San Joaquin, California (DDJC), and the Fire Department of the Defense Logistics Agency, Tracy, California; as a rescue firefighter with the Robins Air Force Base Fire Department in Georgia; and as a rescue/EMT at McClellan Air Force Base in Sacramento, California, and the Springlake (CA) Fire Protection District. He is an instructor in aircraft emergency firefighting, confined space, high-angle rescue, and building collapse. He is a nationally certified fire instructor III and a California- and U.S. Department of Defense-certified fire officer.
