Environmental Engineering Reference
In-Depth Information
horizontal. bands. and. must. be. fastened. to. them.. Vertical. bars. must. be. spaced. at.
intervals.not.more.than.9
1
/
2
.inches,.measured.centerline.to.centerline.
The.bottom.of.the.cage.must.be.between.7.and.8.feet.above.the.point.of.access.to.
the.bottom.of.the.ladder..The.bottom.of.the.cage.must.be.lared.not.less.than.4.inches.
between.the.bottom.horizontal.band.and.the.next.higher.band..The.top.of.the.cage.
must.be.a.minimum.of.42.inches.above.the.top.of.the.platform.or.the.point.of.access.
at.the.top.of.the.ladder..Provisions.must.be.made.for.access.to.the.platform.or.other.
points.of.access.
Wells.must.completely.encircle.the.ladder.and.be.free.of.projections..The.inside.
face. of. the. well. on. the. climbing. side. of. the. ladder. must. extend. between. 27. and.
30 inches.from.the.centerline.of.the.step.or.rung..The.inside.width.of.the.well.must.
be.at.least.30.inches..The.bottom.of.the.well.above.the.point.of.access.to.the.bottom.
of.the.ladder.must.be.between.7.and.8.feet.
All.safety.devices.must.be.able.to.withstand,.without.failure,.a.drop.test.consist-
ing.of.a.500-pound.weight.dropping.18.inches..All.safety.devices.must.permit.the.
worker.to.ascend.or.descend.without.continually.having.to.hold,.push,.or.pull.any.
part.of.the.device,.leaving.both.hands.free.for.climbing..All.safety.devices.must.be.
activated.within.2.feet.after.a.fall.occurs,.and.limit.the.descending.velocity.of.an.
employee.to.7.feet.per.second.or.less..The.connection.between.the.carrier.or.lifeline.
and.the.point.of.attachment.to.the.body.harness.must.not.exceed.9.inches.in.length.
Mountings. for. rigid. carriers. must. be. attached. at. each. end. of. the. carrier,. with.
intermediate.mountings.spaced.along.the.entire.length.of.the.carrier,.to.provide.the.
necessary. strength. to. stop. workers'. falls.. Mountings. for. lexible. carriers. must. be.
attached.at.each.end.of.the.carrier..Cable.guides.for.lexible.carriers.must.be.installed.
with.spacing.between.25.and.40.feet.along.the.entire.length.of.the.carrier,.to.prevent.
wind. damage. to. the. system.. The. design. and. installation. of. mountings. and. cable.
guides.must.not.reduce.the.strength.of.the.ladder..Side-rails.and.steps.or.rungs.for.
side-step.ixed.ladders.must.be.continuous.in.extension.
Fixed.ladders.with.structural.defects.(such.as.broken.or.missing.rungs,.cleats,.or.
steps,.broken.or.split.rails,.or.corroded.components).must.be.withdrawn.from.service.
until.repaired..Defective.ixed.ladders.are.considered.withdrawn.from.use.when.they.
are.(1).immediately.tagged.with.“Do.Not.Use”.or.similar.language,.(2).marked.in.a.
manner.that.identiies.them.as.defective,.or.(3).blocked,.for.example,.with.a.plywood.
attachment.that.spans.several.rungs.
lAdders, PortABle (29 cFr 1910.25 And 1910.26)
Non-self-supporting. and. self-supporting. portable. ladders. must. support. at. least.
four. times. the. maximum. intended. load;. extra. heavy-duty. type.. The. ability. of. a.
self-supporting.ladder.to.sustain.loads.must.be.determined.by.applying.the.load.to.the.
ladder.in.a.downward.vertical.direction..The.ability.of.a.non-self-supporting.ladder.to.
sustain.loads.must.be.determined.by.applying.the.load.in.a.downward.vertical.direc-
tion.when.the.ladder.is.placed.at.a.horizontal.angle.of.75.5.degrees.(see.Figure 25.18).
When. portable. ladders. are. used. for. access. to. an. upper. landing. surface,. the.
side-rails.must.extend.at.least.3.feet.above.the.upper.landing.surface..When.such.an.
extension.is.not.possible,.the.ladder.must.be.secured,.and.a.grasping.device.such.as.a.
