"Sam Payne" (sampayne)
10/30/2013 at 12:56 • Filed to: SAFETY
2
13|
"Sam Payne" (sampayne)
10/30/2013 at 12:56 • Filed to: SAFETY | 2
| 13 |
Check-out my lifted Jeep! Sorry about that. Let’s turn to the matter at hand: a lot of us work on our own cars. When we hear on the news that a car has fallen on someone, it’s easy to dismiss it as “unlikely to ever happen to me,” and then to simply move-on. When we fail to investigate what has actually happened, we miss-out on all of the valuable information we could use to significantly minimize the chance of another tragedy.
I have reviewed some of the literature, and provide my own suggestions below for the casual reader. My suggestions are informed by my own experience and the research performed by others. Those who are interested in the research should read-on for a brief discussion of a couple studies considered.
Buy four jack stands
They’re $30/pair. Just go do it. This post will be here when you get back.
Don’t assume anything about the proper way to support
your
car
My own car, a Miata, has a rather touchy and dainty pair of jack rails. They are easily bent, and are only suitable for changing a tire. A quick search of the Miata.net archives returned a guide to the various other jack points of which I had not been aware. Just inboard of the jack rails, the front sub-frame, and the rear differential itself are excellent jack-points to use for a 1990-97 MX-5. Do some research for your own car, because something that should be so obvious sometimes is not.
Assess your environment – particularly the surface
It may seem obvious not to work on a slope, but the slope itself may not be evident. Does anything roll down from one end of the surface to the other? Also, never work on anything other than pavement – earth tends to get soggy.
Never work alone
Let’s discuss the unthinkable. You won’t die simply because the car has “squashed” you – you’ll suffocate long before you die of any internal injuries. Your life is not necessarily going to be over if that car falls on top of you. Even if someone isn’t there to help you in your work, you need to get someone to sit nearby and casually pay attention as you work. MAKE SURE THEY KNOW WHAT TO DO IF SOMETHING HAPPENS, because you won’t be able to instruct them if you can’t breathe.
Think twice (or thrice) before using a ramp
Ramps are easy. You drive up onto them, jack-up the rear of the car, and place it on two jack stands. Using ramps is quicker than using four jack-stands. However, there is one major disadvantage to using ramps: they’re ramp-shaped. What makes for an easy drive onto the ramps sometimes means an easy slip back off of them. All that really stands between you and a rolling car is a little bump near the top of the sloped portion of the ramp.
Control your environment
Do any kids have access to your work area? What about dogs? How likely is it that someone would carelessly interrupt you? What’s the weather like today? Who else is using your workspace?
Never, ever get under a car supported partially or entirely by a jack or jacks
Jacks are used to get the car up; jack-stands are used to support it. Period.
Never use anything that wasn’t designed to support a vehicle
You should never describe your car support set-up with any of the following words: Board, block, cinderblock, brick, rock, stone, coil spring (yes, someone has tried that before – it didn’t end well), and/or “cantilevered.”
Consider how what you’re doing affects your set-up
Are you removing a major component of the driveline? How will that affect the operation of the driveline? How will the operation of the driveline affect your set-up? Will the weight distribution be significantly affected? To where will the weight of the car shift? Are you going to be pulling on something that will pull the entire car or any portion thereof?
The literature
Driscoll, T., & Healey, S. (1999). Fatalities whilst using jacks in Australia, 1989 to 1992. Retrieved from
!!!error: Indecipherable SUB-paragraph formatting!!!
An Australian study published in the late 90s was particularly helpful. From 1989 to 1992, researchers studied 27 fatalities resulting from a car having fallen on someone who was performing vehicle maintenance or repair. Relying on high-quality information sources such as police and coroners’ reports, the authors summarize the relevant characteristics of each situation and the contributing factors. In not one adequately-documented fatality was it the case that a perfectly reasonable endeavor or set-up led to the car somehow falling on the deceased. In all but one of the cases (for which there was limited information available), at least one of the following contributing factors was present: a car rolling off a ramp, the use of an improper support, and/or the use of an improper work surface.
Poindexter, K., & Hardie, K. (1998). Injuries associated with hazards involving motor vehicle “jack failures”. Retrieved from
!!!error: Indecipherable SUB-paragraph formatting!!!
It seems as though inquiries into vehicle maintenance-related deaths and injuries were
en vogue
during the Nineties. A 1998 DOT publication is less helpful, but represents the only other relevant research published. The researchers relied on self-description (substantially less reliable than police or coroners’ reports), and, from this smaller sample, project the incidence of injuries in the general population. Statistics are meaningless to the individual. Statistics tend to desensitize us to the real risks rather than inspire us to take proactive measures to minimize them.
Also, bonus points to the best image annotations above
Image credit: Franklin D. Roosevelt Library (released under 17 U.S.C. § 105)
Sethersm
> Sam Payne
10/30/2013 at 13:06 |
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Also, never work on anything other than pavement
Hard to know if you're US or not, but over here, "pavement" is the black stuff they use to pave roads. It is an unsuitable work surface. A loaded jackstand will sink into it. Concrete is what you want.
davedave1111
> Sam Payne
10/30/2013 at 13:06 |
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Once the car's on jackstands, give it a good shove and shake to make sure everything's solid. You don't want to knock the car over when you're wanging on a breaker-bar or something.
Also, even if you take all sensible precautions, there's no reason not to shove other things under the car for additional support just in case - so if you take a wheel off, for example, you might as well put it under a chassis rail.
desertdog5051
> Sam Payne
10/30/2013 at 13:08 |
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Interesting post. Some of my friends would chuckle when I said I would not run a chain saw without someone there. Until one of them almost cut his leg halfway through and nearly bled to death.
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Sam Payne
> davedave1111
10/30/2013 at 13:13 |
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I was going to add-in a section about how I always put one of the wheels under the car - just in case. I removed it because I didn't want to give the impression that I thought a wheel was a proper support.
A lot of the Miata.net guys also advocate giving the car a "good shove." I suppose a dropped car is better than a dropped car on top of you.
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Sam Payne
> Sethersm
10/30/2013 at 13:14 |
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"Pavement" can refer to concrete in the U.S. As in "he hit the pavement running." So, yeah, to clarify, I only mean concrete. Of course, blacktop is better than any other surface besides concrete.
corvairsomeday2
> Sam Payne
10/30/2013 at 13:40 |
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Jeep: "Soon..."
Casper
> Sam Payne
10/30/2013 at 14:01 |
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Psh, I once changed a 300ZX transmission in a parking lot by lifting the front of the car with a come-along hurled over tree branches. Thinking about some of the stuff we did to fix cars makes me shocked we are alive.
Good advice. Being safe while under cars is a big deal that most people... especially guys, gloss over in favor of a speedy fix.
Bird
> Sam Payne
10/30/2013 at 14:19 |
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All that really stands between you and a rolling car is a little bump near the top of the sloped portion of the ramp.
This part seems a little strange to me. I use ramps occasionally, my ramps have a nice flat at that top and raised edges all around (sides, front, and back). I'm wondering if there is another ramp design I'm missing? It takes a good effort to drive the Miata off the ramps when I'm done (or two friends to push it off if its dead), so it's hard for me to picture it rolling off. I always use my parking break and chock the wheel as well if I'm not continuing to lift the rear.
And after writing this I realized I haven't really used ramps in a long time....none of my cars clear them anymore...
I would add the part about sticking a wheel under the car though. Just in case the worst happens, that wheel might create the air pocket you need to survive.
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Bird
> Sam Payne
10/30/2013 at 14:24 |
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I'll second dave's suggestion on giving it a shove. I had a 3rd gen Camaro when I was younger. If you've ridden in a 3rd gen you know the doors have a similar heft to a bank vault door. I remember gingerly opening and closing the door after i had it up on jackstands. Then I though to myself, if it falls off from shutting the door, I don't want to get under that! So I slammed it. Car didn't budge.
George McNally
> Sam Payne
10/30/2013 at 15:05 |
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Good post...my best friend is a trauma nurse and he is constantly amazed at the stupidity of the general public.
In specific, he tried (unsuccessfully) to revive someone who had used cinder blocks to support a truck while he worked underneath it.
Cinder blocks are kinda like carbon fiber- they give you absolutely no warning when they fail.
Zipppy, Mazdurp builder, Probeski owner and former ricerboy
> Sam Payne
10/30/2013 at 15:32 |
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I took these precautions when jacking up my father's BMW so we could do the brakes, I gave him advice to not keep it on the jack, and put the stands on a structural part of the car, so we decided to support the car via the subframe. Our driveway is too slanted to jack a car up safely, so we used the garage of a friend's old house, since he moved out a week before, It was perfect for our needs. The only issues we ran into were tools, cheap ones in fact (from an old toolset my grandfather had), since it was Thanksgiving (yes, Candians celebrate it early), stores were closed, and we couldn't get replacements at Canadian Tire until the next day.
He was a driveway mechanic when he was my age, so this experience jogged his memory a bit. He was thankful we also got a 6 tonne jack from Princess Auto beforehand, since our regular jack coudn't lift the car enough for the stands.
occamsrezr
> Sam Payne
11/01/2013 at 13:35 |
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They should print this post out at all of the DIY auto repair places and give it to every customer buying parts.
It's just common sense that could save your life.
Another thing to add: when under a a car, you're looking up, wear safety glasses.
I was replacing a starter on my old saturn and forgot to disconnect the battery cable. When disconnect the leads on the starter, I got a shower of sparks. in. my. face.
Sparks are cool when they're not in your eyes.
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Sam Payne
> occamsrezr
11/03/2013 at 00:48 |
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Good point! Yes, I suppose glasses are a necessity for certain repairs, but are also probably a good idea all the time!