Ladder Safety - United States Mine Rescue Association：梯子安全-美国矿山救援协会.ppt

MSHA standards do not require stepladders to be fully open, or prohibit the use of a leaning, folded stepladder, but ladders must be placed securely and prevented from slipping down or to the side. If an MSHA inspector observes a folded stepladder and believes it is not placed securely, the inspector must determine and document how the ladder is not placed securely when used. The left photo shows a leaning, folded stepladder that projects several feet above the point where it rests against the wall. The feet are not secured in any way. A person climbing above the support point will cause the ladder base to lift off the floor, and the ladder to rotate about the support point / fulcrum and become unstable. A ladder in this condition would not be considered securely placed. The right photo shows a folded stepladder resting against a large tire. Whether the ladder is placed securely depends on the condition of the floor, the ladder base, the angle of the ladder, where it is supported, and how high a person climbs when using it. The ladder in this photo appears not to be equipped with non-slip feet. Such a condition increases the likelihood the ladder could slip when used. * The photos show ladders that are not maintained in good condition and/or are not placed securely on suitable bases, as required by 30 CFR §§ 56/57.11003 and §§ 56/57.11004. The left photo shows a ladder on which rungs are missing and there are no bases to prevent it from slipping on the hard, smooth surface. The upper right photo shows a noncompliant ladder that has been cut off at the bottom. It has no bases to prevent it from slipping on the smooth, muddy surface. This a violation of §§ 56/57.11004 – Portable rigid ladders. The lower right photo shows a noncompliant ladder. The bases have been rotated so the non-slip cleats do not contact the surface on which the ladder is placed. This ladder is not placed securely on suitable bases, as required under 30 CFR §§ 56/57.11004 – Portable ri