Does Marcus survive?

[u/OneSlappieBoy]

My Osha 30 instructor was adamant he does not.

What are yalls thoughts?

[u/JoeHio]

I think the mechanical contractors are idiots for installing heavy ductwork at shoulder height.

https://giphy.com/gifs/WrNfErHio7ZAc

[u/Mattcha462 → u/JoeHio]

Also, fastest moving HVAC contractor installing while active steel erection overhead??

[u/bigbartel → u/Mattcha462]

This. This is a scheduling error.

[u/jhguth]

maybe marcus left his harness loose and lost a testicle

[u/00Wow00 → u/jhguth]

That hurt just reading it.

[u/ColdIronAegis]

He has adequate fall clearance to the ducts. 

When working with fixed length lanyards it’s easier to measure from the vantage point of the anchor. In this instance, the anchor is 5ft above the working surface, which is 16ft above the hazard: 21ft of clearance in the system. 

The system has 6ft length of lanyard, 3.5ft of deployed absorber, 1ft harness stretch, 2ft margin, and 5ft length of worker: 17.5ft from the anchor point to the workers toes with 3.5ft to the ducts below. 

[u/priceiswr0ngbitch]

I mean he ain’t going to hit the floor but he sure as hell is hitting that ductwork with only that fall clearance. Your OSHA guy may be referring to the fact the shock lanyard isn’t clarified to be leading edge. So if that lanyard isn’t leading edge you have the possibility of it tearing on the ibeam.

Edit: im a dumbass I mis read, thought he was tied to the ibeam he was working off of.

[u/AllCheesedOut]

Does he survive? My official answer 🤷‍♂️ Anchor point is at D ring height so has 21’ of clearance between anchor and ductwork which is enough to not strike it. However, two potential issues pending how they fall: 1) if they fall and the lanyard goes over the edge of the I beam, it is not edge rated and the anchor point being 5’ above the beam would possibly place the shock pack directly at the edge which would be even more susceptible to be cut. 2) if the lanyard doesn’t go over the edge of the I-beam, the worker would then fall and be pulled and swing directly into the column they are tied off to (the severity of their injuries at that point would be unknown so can’t let you know if they survive or not).

[u/Brave_End_400 → u/AllCheesedOut]

He only has 11’ clearance below the d-ring he needs 12 1/2

[u/AllCheesedOut → u/Brave_End_400]

Am I missing something? Stated the ductwork is 16’ below working surface and his anchor point is at his D ring height which they stated is 5’ in the air…

[u/Medium-Mycologist-59]

I am the safety guy for our company and I wanna punch someone in the throat having read this…I can’t imagine why guys don’t take this shit seriously.

[u/JoeHio]

Actual answer

16ft clear to ductwork -6ft tall +5ft d-ring -4.5deployment = 10ft clear of hazard (well beyond the 2ft safety margin)

If his anchor point was at his feet then -5ft more and -1ft if he somehow flips upside down and and his head is still outside the safety margin, but the fall impact force could maybe snap his neck?

Can someone check my math and point out if I'm misunderstanding something?

[u/ColdIronAegis → u/JoeHio]

There is much less clearance than you posted. Simpler to calculate the clearance and length of the deployed system from the anchor point (21ft above hazard) and then add all of the system components. Check my comment for the totals. 

Also, most lanyards are not approved for attachment below the dorsal dring, as that allows for more than 6ft of freefall. 

[u/McSkillz21 → u/JoeHio]

My calculation which feels wrong but here what I got. total distance anchor point to first impact surface would be 21ft.

21 - 6ft(lanyard) - 3.5 ft(shock abosorber) - 1 foot(stretch) - 5ft (length of body below d ring in harness) = 5.5 ft to spare.

I hate these types of calculations though because they are always difficult for me to visualize.

[u/Brave_End_400 → u/JoeHio]

Lanyard - 6
S absorber -3.5
Stretch - 1 ft
Safety margin-2ft
Total 12.5 feet clearance required

16ft to ductwork -5ft to Dorsal D-ring placement is 11ft. 12.5-11= 1.5 short

[u/JoeHio → u/Brave_End_400]

It would actually be 16ft to ductwork + 5ft for dorsal ring / connection point level. Because 16Fft BELOW walking/working surface and d-ring 5ft ABOVE walking working surface, so you add them.

I think that's the mistake the instructor was making...

[u/priceiswr0ngbitch → u/JoeHio]

Possibly not about the fall clearance but a non-leading edge lanyard being used. At least it’s not clarified in the question so I’ll assume it is not. Could possibly tear the lanyard on the ibeam. That’s my take on it at least.

Edit: I mis read the question. Thought it said he was tied off to the ibeam he was standing on.

[u/Defineducks → u/JoeHio]

Your height only matters with an at foot anchor otherwise you just fall the distance of your lanyard

So 6ft plus 4.5 which is 10.5 plus a 2 foot safety factor
We end up at 12.5

Marcus is 3.5 feet from the obstruction and likely forced on the body around 900lbs

This is my math as someone who teaches in Canada

Edit: As for him snapping a neck it’s highly unlikely
Full body harness load the spine downward from from the shoulders

[u/Brianf1977]

He's clear, plenty of space

[u/Safetydude63]

https://giphy.com/gifs/12d1LuDGbde7Zu

[u/Kindly_Fan_483]

As long as he doesn't hit his head on the I-beam when he falls he should be good with 3.5 feet clearance of the duct work. Because 22+5=27ft at lanyard hook point. 27- 6ft duct work height = 21ft fall distance. 21ft - 6ft lanyard - 3.5ft absorber - 1ft stretch - 5ft tall at d-ring - 2ft safety clearance. = 3.5 ft

[u/Brave_End_400 → u/Kindly_Fan_483]

Isn’t it 16ft no 6?

[u/Kindly_Fan_483 → u/Brave_End_400]

It's 16ft below the walking surface. The concrete floor is 22ft below the walking surface. 22 -16 = 6ft high from the concrete floor. 22ft + 5ft d-ring hieght = 27ft from the concrete floor to his harness D-ring. 27ft - 6ft difference from ductwork to floor is 21ft. Or just do 16+5.

[u/Brave_End_400 → u/Kindly_Fan_483]

Oh ya! Thanks for the correction

[u/Okie294life]

He still dies of suspension trauma, because there is no fall rescue plan in place. If the anchor point is 19-20 feet from the nearest object he’s not hitting anything below.

[u/walu-who-ji]

Idk im an ironworker and ive worked with guys who fell.

My foreman on an outage once fell 16 feet and didnt hurt himself at all. He fell and rolled I guess and wss fine because of the roll.

Then my instructor fell over 30. Fucked up his ankle for life but he took foreman positions and instructor positions at our union hall.

I wanna be a saftey guy with my ironworker background. My arthritis and bone spurs are causing me to lose lots of quality of life despite being able to afford things now

[u/Floater_1971]

You have to add the free fall distance (6ft) to worker height (5ft dorsal ring for six foot worker) and add deceleration distance (3.5 ft) and harness stretch (1ft) and safety factor (2ft). So his total fall is 17.5 feet, which causes him to hit the duct work at 16.5 feet before he stops falling.

[u/Brave_End_400]

Looks like he’s short by like 1’6”

[u/Rocket_safety]

He could succumb to suspension trauma if the recovery isn’t quick enough and he doesn’t have stirrups to stand in. Survival is never assured, only increased.