EYE BOLT FAILURE IN RIGGING AND HOISTING Produced by: Professional and Specialized Services, Ministry of Labour, Alert 13/0795 ISSN 1195-5228 HAZARD SUMMARY: Two workers were injured, one fatally, when an eye bolt failed during an attempt to hoist a mould weighing about 65,000 lbs. Four shoulderless eye bolts, 2.5 inches in diameter, had been screwed in close to the four corners of the 7' x 7'6" x 6' mould. Four chains 6'10" long were hooked into the eye bolts and attached to the hook of a 40-ton overhead travelling crane. One eye bolt snapped before the mould lifted off the floor. The chain, with part of the eye bolt attached, swung up and struck the first worker, then hit the second worker as it came down. LOCATION AND SECTORS: Eye bolts are used in rigging and hoisting of heavy equipment and parts, for example, in automotive manufacturing, in tool and die shops, and in manufacturing and installing heavy equipment. RECOMMENDED PRECAUTIONS: 1. EYE BOLTS The manufacturer's identification and the safe load-lifting capacity must be stamped onto all eye bolts to ensure safe use, as required by the Regulations for Industrial Establishments (R.R.O. 851, section 51(1)(c), quoted below). Shoulderless eye bolts should be used only where the hoist chain or sling is aligned with the axis of the bolt, i.e. so that it pulls in exactly the same line as the length of the bolt, as in Figure 1. The bolt must be fully screwed into the load. Figure 1 - Shoulderless eye bolts, CORRECT use. 'P' (the direction of pull) is aligned with the axis of the bolt.** Figure 2 - Shoulderless eye bolts, INCORRECT use. If the chain or sling pulls at an angle to the axis of the bolt it may snap.** Figure 3 - Shouuldered eye bolt, CORRECT use. The chain or sling is in the plane of the eye.** **NOTE: Please see original copy for Figures 1, 2, and 3. Shouldered eye bolts (Figure 3) must be used whenever the chain or sling is rigged at an angle from the axis of the bolt. The following precautions must be taken: - When the eye bolt is screwed into the load, the shoulder must: - be at right angles to the axis of the hole tapped or drilled for the bolt and - fit flat against the surface of the load. - To make sure the eye bolt will not be bent sideways, the chain or sling must be in the plane of the eye (as in Figure 3). To ensure that the shoulder is firmly seated on the surface of the load when the eye has been correctly aligned with the chain or sling, a metal washer of suitable size and shape may be used under the shoulder. - As the angle between the chain or sling and the axis of the eye bolt increases, the available load-lifting capactity of the eye bolt is reduced from the stamped capacity. Degrees from eye bolt Percentage of stamped load- axis of chain or sling: lifting capacity available ======================================================== 15 degrees 55% 30 degrees 35% 45 degrees 25% 90 degrees 20% For example, if the chain or sling is at 30 degrees from the axis, the available load-lifting capacity of the shouldered eye bolt drops to only 35% of the stamped amount. When the chain or sling is at an angle greater than 45 degrees from the axis of the bolt, the use of shouldered eye bolts is not recommended. 2. SWIVEL HOIST RINGS In any situation where there is doubt about the safety of using eye bolts, it is recommended that swivel hoist rings be used instead. Follow manufacturers' recommendations in selecting and using these rings. Figure 4 - Swivel hoist ring.** **NOTE: Please see original copy for Figures 4. LEGAL REQUIREMENTS: The regulations for Industrial Establishments state (R.R.O. 851, section (51)(1)): "A lifting device shall: (a) be so constructed, of such strength and equipped with suitable ropes, chains, slings and other fittings so as to adequately ensure the safety of all workers; (b) be thoroughly examined by a competent person to determine its capability of handling the maximum load as rated, (i) prior to being used for the first time, and (ii) thereafter as often as necessary, but not less frequently than recommended by the manufacturer and in any case, at least once a year, and a permanent record shall be kept, signed by the competent person doing the examination (d) be plainly marked with sufficient information so as to enable the operator of the device to determine the maximum rated load that the device is capable of lifting under any operation;..." REFERENCES: For information on eye bolts and safe rigging practices, refer to: - Rigging Manual, Construction Safety Association of Ontario, 1975 - Craning and Rigging Handbook, Ontario Hydro, 1991 - Lifting with Eye Bolts, Safety Infogram B 16, Canadian Centre for Occupational Health and Safety (CCOHS) For more information, pleasse contact your nearest Ministry of Labour office.