Safety Harnesses & Spinal Compression
I have been having a bit of a browse though various pics on this forum and it amazes me the number of examples of incorrectly mounted Safety Harness set ups I can see. I won't single any individuals out.
Many moons ago when I was a young rev-head (as opposed to being a slightly older and wiser rev-head) I had the misfortune to put my highly modified 55 Chevy through a fence (I was young, stupid and lucky). This was still in the pre seat belt days but I was about to go drag racing and figured I would need a 4 point safety harness. How wrong and lucky I was!
Not being any the wiser I mounted the rear attachments of the harness to the floor behind me. Luckily I only used some less than suitable mounting plates and when I impacted the whole harness just pulled out of the floor. I ended up on the non collapsible steering column somewhat winded but luckily not im-pailed.
Getting the car recovered by some more knowledgeable rev heads the mistakes of my 4 point set up were pointed out to me and I then was given a lesson in spinal compression and discovered that had I mounted the harness to the floor and the mounts had not broken I would likely have become a quadriplegic.
Over the years I have been involved in many forms of motor sport and scrutineered many vehicles and I thought it was nowadays a common understanding of spinal compression and incorrectly mounted 4 (and 6) point safety harnesses? A quick look through any 4x4 forum this one included and you do not have to search many pics to see incorrectly mounted harnesses.
I am sure there will be many who will defend their setups and some may have even passed some form of scrutineering but I am only trying to help.
The bottom line is you can not mount the rear attachment points below the shoulder line. FULL STOP NO CORRESPONDENCE! (Yes I know there is a formula that will be acceptable for some types of vehicles but the distance required behind the seat to the rear of the vehicle would generally not be practical for most vehicles).
Have I opened a can of worms? Or is there someone else out there who can assist with explaining the issues involved. I can not find any simple links to explain spinal compression.
RoverLord
do the bag of flour explination.
That usualy works well enough.
take a paper bag of flour, suspend it in a 6mm rope sling and hold both side of the sling at one point drop your arm suddenly then stop it... the bag will split open
do the same thing with the bag slung but holding your arms apart parallel. drop your arms the same distance and stop. it wont break open as badly...
why?
Dave
"In a Landrover the other vehicle is your crumple zone."
For spelling call Rogets, for mechanicing call me.
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Archaeoptersix 1990 6x6 dual cab(This things staying)
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Super Moderator
Yes it is a can of worms!
Given that most of our vehicles don't compete in motorsport, the argument can be raised that in the absence of an adequate B pillar, even an incorrectly positioned rear anchorage point is better than a two point harness or no restraint at all.
You won't find me on: faceplant; Scipe; Infragam; LumpedIn; ShapCnat or Twitting. I'm just not that interesting.
And the can is open, I would say a correctly mounted but somewhat rudimentary lap belt will not result in spinal compression (possibly some mid torso bruising and leaving your head to hit the dash or wheel) but should you survive you at least will not be a quadriplegic.Originally Posted by Lotz-A-Landies
I have seen (but can not find) a video of what happens with low mounted harnesses and believe me it will have people going out and re positioning their harnesses.
Wizard
I'm interested in the concept, but a couple of reds have me slightly befuddled. Got a diagram or pic?
Cheers,
Adam
Wizard
SubscriberHere this explains how to mount seatbelts. Its from the Simpson website.
http://simpsonraceproducts.com/pdf/S...t_Mounting.pdf
Hope it works
Gary
Super Moderator
Actually the risk of a 2 point harness is major baro trauma including rupture of the diaphragm, rupture of the great vessels, tearing of the liver and spleen and migration of the bowel into the thoracic cavity. For the driver, the restraint of pelvic girdle acellerates the upper body in an arc, so that the head hits the steering wheel decellerating the forehead as the remains of the upper body continue forward onto the steering column resulting in a fracture in the region of C1 through C3 which in the extreme are tetraplegic or fatal injuries.
I don't need the video thanks.
You won't find me on: faceplant; Scipe; Infragam; LumpedIn; ShapCnat or Twitting. I'm just not that interesting.
Master
Another important point is ....do not fit a harness unless you have a roll cage. Held firmly upright in your seat by a 4 point harness with the roof crushed in on your head in a rollover will ruin your day
Master
SubscriberFloor mounted harnesses are fine, but if the cage builder didn't put a harness bar between the (
Roughly) b pillars then that is just bad design
In my state there is a vicroads handout showing the allowable placement to get rego
Mind you any serious drivers side t bone in a defer and the last thing to go through your mind will be the seat belt anchorage
Dc
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