Walking and Working Surfaces

Walking and Working Surfaces INSY 3020/7976 & ENH 670 Spring 2008

What kinds of Walking/Working Surfaces? • Floors and Aisles • Openings, Holes, Vats and Pits • Runways (Catwalks) • Stairs • Ladders • Scaffolding

An Unfortunate Accident • A Florida maintenance worker at a warehouse was asked to repair a leaking roof • The worker was allowed to hire a temp assistant • He asked his 15 yr old neighbor to help • They climbed onto this roof using this fixed ladder

An Unfortunate Accident (cont’d) • Spent 6 hours repairing the roof • Worked around these skylights • The roof is nearly 24 feet from the warehouse floor

An Unfortunate Accident (cont’d) • The 15 yr old neighbor fell through this skylight • He died from his injuries • This skylight was not guarded or protected by railings of any kind

An Unfortunate Accident (cont’d)

What can we do to prevent this kind of terrible tragedy? What role should an Engineer play?

Injury Potential • Falls from height: • Walking surface failure - planking, scaffolding, etc. • Accidental stepping where no walking surface exists. • Descending stairs and thinking your are at floor level when you still have one step left.

Injury Potential (Cont’d) • Stepping into openings, people holes, etc. • Stepping off loading docks and other elevated surfaces - balconies, landings, etc., w/o guards. • Deliberate stepping or jumping where no walking surface exists, i.e. suicide. • Failures of guardrails and other restraining devices, such as safety harnesses.

Injury Potential (Cont’d) • Falls from ladders: • Improper use of ladders for purposes for which they were not designed, i.e. braces, platforms, hoist supports, etc. • Improper foot wear - cowboy boots, loafers, sandals, etc. • Improper mounting or dismounting the ladder, including jumping off ladder and too rapid ascent, and descent. Keep hips between rails.

Injury Potential (Cont’d) • Placing ladder on an unstable base - soft, muddy, greasy, uneven, etc. • Hands-full climbing. • Failure to use safety belts.

Housekeeping • Did you know this was the LAW? • “All places of employment, passageways, storerooms, and service rooms shall be kept clean and orderly and in a sanitary condition.” • Why does OSHA care if your workplace is cluttered, dusty or non-orderly?

Aisles • Permanent aisles and walkways should be clearly marked • Must be kept clear of obstacles • Must be designed with adequate space for the tasks they are used for • Forklift operation • People traffic • Emergency Egress (Life Safety Code)

Floor Loading • The rated load limits for a floor, mezzanine, platform, roof, etc. must be… • Determined by a structural professional • indicated on a permanent plate affixed in an obvious place for that working surface • You must not allow loads above capacity, under any circumstances.

Floor & Wall Openings • Hatchways, ladderways, stairways, skylights, pits, manholes, chutes • Must prevent people and materials from falling through • Even if people can’t fit through the opening, tools/materials still might • Can have no more than 1 inch of open space without some kind of cover/railing/etc. • In lieu of a railing/cover, a permanent attendant to ensure no one or nothing falls through is required

Stairs • Fixed stairs are required… • If regular travel from one level to another is required • If daily travel is required to other levels that contain harmful substances • If the daily carrying of equipment, materials or tools is required • Ladders can be used instead if the destination is not another level but a tank, crane, platform, etc.

Stairs (cont’d) • Stairs must be designed according to strict guidelines • Rise / Tread Run (must have angle 30 - 50°) • Width • Treads on stairs/steps • Platforms / landings • Railings • Vertical Clearance • Shape (spiral, winding, etc.)

Ladders • Types of Ladders • Portable • Stepladders • Extension Ladders • Straight Ladders • Wood, fiberglass, or metal – different rules • Fixed

Ladders (cont’d) • Requirements • Rungs (12” apart and 16” wide) • Ladder must reach 3 ft above the surface • Extension ladder sections must overlap 3 ft (more if more than 36 ft long) • No stepladders can exceed 20 ft. high • If ladder tips over, it must be inspected • Must ascend and descend facing the ladder • If fixed ladders exceed 20 ft, must have a landing or platform every 20 ft. (every 30 ft if a cage is present)

Ladders (cont’d) • Pitch of a ladder: • 75-90 degrees for portable and fixed ladders. • Portable - 4:1 ratio, one foot out at the base for every four feet up. • Fixed Ladders: • 75-90 degrees. • Clearance between the ladder and the wall - seven inches. • Rear clearance - 30 inches. • Broken Ladders: • Never used • Immediately taken out of service until repaired or replaced.

Scaffolding • Definition • “Any temporary elevated platform and its supporting structure used for supporting workmen or materials or both. “ • Very detailed regulations (33 pages) • Designed for 4x the intended load • May not exceed 1x that load • May not work during storms or high winds • Must remove from use and inspect/repair if there is any reason to suspect damage • Must be kept clean and free of clutter

Railings • Standard Railing • Top rail + mid rail + posts • 42” high (mid rail = 21” high) • Must withstand 200 lb of horizontal force • Used to guard openings or other places where people may fall • Posts can be no more than 8 ft apart (depending on situation, may need to be 6 ft apart) • Standard Toeboard • ¼” from floor • 4” high • Keeps material from falling on people below and people from sliding under mid rail and falling

Railings (cont’d) • Standard Stair Railing • Used when there is no wall next to the stairs • Similar to standard railing except in height • Only 30-34” high • Standard Handrail • Used when there is a wall next to the stairs • 3” from a wall, bracketed to wall every 8 ft • 30-34” high • When to use a standard rail or handrail… • If there are 4 or more risers • At least one handrail on right side of enclosed stairs • A rail on each side of a stairway that is open • If stair width greater than 44 in., need a handrail on each enclosed side and a rail on each open side • If stair width greater than 88 in., need an intermediate rail in the middle

Can you identify what is wrong in the following pictures?

Questions & Comments

Walking and Working Surfaces