Fall protection system for the short fall clearance 2

[TracyStruc]

I am working on a project that requires to provide a horizontal fall protection system along the top of the retaining wall. The distance from the top of the retaining wall to the bottom of the pit is 10-ft or so. I specified ShockFusion Horizontal Lifeline System, but the manufacturer reviewed the drawing and said that their system does not compatible with my applicable due to insufficient available fall clearance. Could anyone suggest a fall protection system that applies to the 10-ft fall distance?
Thanks.

 

[CANPRO]

A flexible horizontal line is not the way to go with such a short fall distance. You're like going to experience at least a couple of feet of sag in the line during a fall (unless you have extremely high pre-tension, which requires large anchorage forces at the end of the cable).

The best form of fall protection is to eliminate the hazard (who remembers their fall arrest training??). Is it possible to put a 5'-6' high scaffold along the low side of the retaining wall to reduce the fall and eliminate the need for fall arrest? That, or a temporary guardrail would be my first preference. Otherwise, you may need a more rigid tie-off point and self-retracting lanyards.

Keep in mind that most safety regulations require a safety factor of a couple feet (can't remember the exact number off hand) between the low point of the worker and the ground in the event of a fall. During a fall, the D-ring on the harness ends up by your head, so if you're 6' tall and want a 2'-3' factor of safety at the bottom of the fall, that means you can't have any movement in your tie-off point and you can't have a shock absorbing lanyard lanyard. Designing for fall arrest at this height is difficult. You're probably better off with a travel restraint system instead of fall arrest (if scaffold or guardrails aren't an option).

 

[XR250]

I was thinking a pile of mulch at the base of the wall

 

[TracyStruc]

CANPRO and XR250, thanks!

 

[dik]

XR250: or mattresses... I think you have to provide an anchorage behind the wall... deadmen or screwpiles. 6' is about the shortest lanyard you can get and for a 10' height, it may not work. else, you may have to provide a guardrail.

About 45 years back the foundation contractor on one of my projects had a fellow cleaning the bottom of caissons... bedrock was about 40' down... the fellow had a safety harness, but his tie off was the end of an 80' rope... no shock absorbing lanyards, or whatever... I told him he should shorten his safety rope so that he wouldn't hit bedrock... not realising that being stopped by a 30' rope would likely kill him anyway.

Dik

 

[canwesteng]

Self retracting lifeline attached to a trolley on a monorail above, or something equivalent.

 

[PEinc]

What kind of retaining wall is it? Can you core fence post holes into the top of the retaining wall, install vertical (pipe?) posts, and then run horizontal rails or fencing between posts?
Also, will the retaining wall remain stable when you dig the pit in front of the wall? Check sliding and overturning.

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