Seating Safety 'Protecting the Bumb's Bum'

[xcarguy]

As some of you here already know, since my accident at TWS back in Feb, I’ve had well-earned concerns about seating. I’ve been involved in some pretty good discussion on a couple of other forums, but nothing much here….so I figure I’d get the ball rolling for interested parties. To recap, I suffered a severe back injury at TWS from a vertical drop during an accident; four broken vertebrae put the ‘ball’ in motion for me regarding seat safety. :ack: When my accident occurred, I was fastened snugly into an aluminum shell with no padding except for the seat cover. :banghead: The shock from the impact transferred all the stored energy upward through my spinal column….not fun. :cuss: Much of my research has lead me to a type of seat foam known as Confor Foam. As I type, Janice at Hi-Tech Foams is sending me out samples of all densities offered:

 

http://www.seatfoam.com/index.html

 

Confor Foam is available from a handful of aviation supply companies; here are a couple more of them, and the kch site has a very informative table addressing the foam’s application based on individual weight:

 

http://www.aircraftspruce.com/catalog/cmpages/conForFoan.php

http://www.kch-inc.com/KCH_aviationsupplyonline/Information.php

 

Confor Foam may be familiar to several here, especially those who are involved with experimental (home built) aircraft. Personally, I had never learned of the foam (shame on me) until just recently; wish I had known about it four months ago. If you are running a race-shell type seat (as I did) and are currently sitting on nothing more than the seat bottom (as I was), I implore you to consider, at the very least, some type of seating material that has energy absorbing properties in the event of a verticle impact.

 

But don’t let this thread be simply about seat foam. I’d like to see/hear about what you are currently using; feedback regarding seating types, seating angles, thoughts on Hans use, seat belts, etc…anything of interest that may very well make all of us a little safer as we drive. I recently received a pm from a concerned forum member regarding seat belt (shoulder belt) mounting as well as the use of a Hans device during an accident such as mine; I do hope he will read this thread and perhaps put that information on the table for discussion.

 

Shane :cheers:

Edited June 22, 2015 by xcarguy

[DeanD3W]

Hi Shane,

I posted a thank you and wished you a speedy recovery on the thread in the locost racing portion of the locostusa site. Thank you again for providing all the help and information for others on both sites.

 

Unless seat mounting brackets are designed properly to deform vertically in a big impact, I wonder whether our cars might be better off without separate seats. It may be a better approach to reinforce the seat back and seat bottom areas with sheet metal attached on the front and back of the seat back structure and top and bottom of the seat bottom/floor structure, possibly with foam or end-grain balsa type material between the layers (to add stiffness and strength to the structure), then use all the vertical and horizontal space possible for a well designed one-piece foam pad and upholstery. This approach will also avoid "big bird syndrome" (heads too high for windshields or roll bars) and misaligned lap belt holes that might occur when adding Confor foam or other materials within a separate seat. An angled seat bottom panel panel attached to the floor may be helpful too, so stopping forward motion in a frontal impact wouldn't be all from the harness straps. A small contribution from compressing foam may help spread loads with the harness in a frontal impact. Either way the pad should be angled up under the person's legs to provide more surface area for absorbing vertical impacts, I believe.

 

Maybe others have experience with this approach in formula cars that will tell me that this isn't the best approach??

 

If I take this approach with the partially built Ultralite S2K that will be in my garage in a few weeks I may also add welded headrest loops into the seatback structure, so the one-piece upholstered pad could extend up to provide a built-in headrest area. Each loop would be welded on just inboard of the shoulder harness mounts for each side. Part of the attachment of the one-piece seat pad could be to slide the top of the headrest portion over the top of the welded on loops.

 

I did some searching on "optimal seat back angle for racing" and didn't find much useful information. I think foot room constraints in most 7s will make the built in angle of the seat back bulkhead the "good enough" angle to use.

 

Since I appreciate the the help that both sites provide I'll post this on locostusa as well.

 

Dean

[jlumba81]

+1 on the Confor foam. I put a piece on my seat bottom and seat back, makes bumpy highways more tolerable. Just 3M adhesive on the foam and the seat cover and slid them in.

[xcarguy]

. . . . . I wonder whether our cars might be better off without separate seats. It may be a better approach to reinforce the seat back and seat bottom areas with sheet metal attached on the front and back of the seat back structure and top and bottom of the seat bottom/floor structure, possibly with foam or end-grain balsa type material between the layers (to add stiffness and strength to the structure), then use all the vertical and horizontal space possible for a well designed one-piece foam pad and upholstery.

 

Dean

 

Dean,

 

Thanks for joining in. I think a molded bead seat (as suggested by Croc in my accident thread) would compliment your idea well.

 

 

https://www.kirkeyracing.com/category/MOLDED%20FOAM%20INS/molded-foam-seat-insert-kit

 

https://www.pegasusautoracing.com/productselection.asp?Product=4525

 

. . . . As for seats why not do what I do - standard road seats? Or what about a self moulded foam bead seat in a softer mix to provide some cellular impact protection?

[coffee break]

FWIW. The guy that does seasonal service on my HVAC had an off road experience that resulted in crushed vertebra injury. He was driving a full size Ford wagon and left the road and was airborne, one of those N. GA roads where the road is higher than the pavement. Since it was a normal 'merican car the seat had some give to it. I guess I'm saying, there's only so much you can do to prepare for bad situations, but you can't make it foolproof.

Its good that Shane and my HVAC guy are around to tell their experiences, I'll take luck any day of the week.

For instance, Saturday a crew was removing some trees for me. The trunk section of a tree, about 12 ft tall fell badly and pinned the sawman. fortunately they had a log loader and were able to lift the 1500 lb trunk and free Les. He was transported to a local ER, no internal injuries, but a broken hip/pelvis. It could have been worse.

[xcarguy]

coffee,

 

Thanks for sharinig. And you're right; we can't make it foolproof. When I was in the Air Force (Security Police), we security guys had a saying; expect the worst and hope for the best. I think the true 'lesser of two evils' would be to not try at all. :cheers:

[TheDingo8MyBaby]

An angled seat bottom panel panel attached to the floor may be helpful too, so stopping forward motion in a frontal impact wouldn't be all from the harness straps. A small contribution from compressing foam may help spread loads with the harness in a frontal impact. Either way the pad should be angled up under the person's legs to provide more surface area for absorbing vertical impacts, I believe.

 

Maybe others have experience with this approach in formula cars that will tell me that this isn't the best approach??

 

My experience here is with Formula Fords, but the majority of them sit on the belly pan. In a 7, you're in a much more upright position than a formula car, so the loads on the sub-straps should not nearly be as high. I still run a Formula style harness in my car, though, due to my seating position.

 

Most of the FF guys are looking for a low CG, so sitting on something is not desirable. Most use Bead seats, confor foam or SFI Molded Foam Seats. I shudder to think what your accident would have been like in a FF. Best of luck on your recovery, Shane.

 

You can find Confor foam on Mcmaster as well. I have some of the Blue Foam. I plan to use it in conjunction with some Green as I think it may be a little bit too soft for my taste.

[xcarguy]

. . . . You can find Confor foam on Mcmaster as well. I have some of the Blue Foam. I plan to use it in conjunction with some Green as I think it may be a little bit too soft for my taste.

 

Thanks for the tip. I'll take a look.

[DeanD3W]

Around 3:35 in this video is interesting... No mention or appearance of any padding of the sort that we're talking about. Not pleasant to think of much of a vertical impact with what is seen here.

 

 

I agree that nothing will will be perfect or foolproof. An inch or better yet two for thickness of the Confor foam sounds like a very good idea to me.

 

Dean

[kayentaut]

Guys,

I am not expert in this area, but in 2000, in my first Caterham, I threw away the driver seat and replaced it with a fully, foam in place material made by this company (http://www.sunmatecushions.com/pages/racing-sports-impact-absorbing-foam-applications ). The material completely filled the driver’s side tub; my butt sat on a 1 inch thick piece of medium density material. I used a four belt harness to secure me in place. I did this primarily for comfort, but the energy absorption is described in Sunmate’s sales material. Now that I am a Caterham owner again, I intend to once again build a similar seat. I will be interested to see what additional information is forthcoming related to other seating materials.

Jim

[Kitcat]

To the extent any foam or other padding compresses, doesn't that add corresponding slack in the seat belt harnesses?

FWIW, I have added a 3/4'' foam pad to my seat bottom.

It is a hard fiberglass racing seat, with helmet wings on each side of the upper seat back that keep my head from moving sideways. HANS + 6 pt belt system and arm restraints finish it up. FuelSafe gas tank hopefully adds a bit of protection as well.

Also, just bought a racing suit, and use fire resistant gloves/racing shoes & bought a new, updated helmet as well.

*** Further thought: I have a pair of cycle shorts with thick foam padding in the butt, designed to make long rides on the small hard bicycle seat more tolerable. I will try them out under my driving suit. I know they are not fire resistant but all this is something of a compromise.

###Yet another thought: Since you were sitting pretty erect when you had the abrupt landing your vertebrae and discs were perfectly lined up to be damaged. Think of 13 pool balls all in a straight line: hit one, they all get hammered. If you had been significantly reclined, then the vertical load would have been distributed somewhat from the side, not end to end. Seems like that would have helped???

Edited June 23, 2015 by Kitcat

[Off Road SHO]

I wonder if the suspension seats that they put in off road race cars would be any help? They are very "large" though so might not fit. You sit on a piece of canvas supported by parachute cord from a tubular metal frame. Just a thought.

 

Tom

[DeanD3W]

To the extent any foam or other padding compresses, doesn't that add corresponding slack in the seat belt harnesses?

 

A very good point. To do this right, there would be just enough "normal" foam to provide comfort, then layer(s) of other foam that would be stiff enough that it compresses only for a large enough impact to cause injury. The amount of compression sounds like possibly a delicate compromise. In an accident that violent too much compression of the foam would loosen the harness belts too much. Not enough compression of the foam wouldn't be effective in absorbing enough energy to prevent injury. Belt tensioners and other thoughts violate "KISS".

 

I wonder if a crushable sheet metal structure, maybe including some stiff foam or honeycomb material in a pair of "plates" on the bottom of the car would be a better approach than only making changes to the seat itself. Crush zones on all other sides (and even the top, when it comes to Outlaw Sprint Car wings) are normal. Why not add maybe 1.5" to the bottom of the car, adding vertical drop protection, and also adding oil pan clearance for the typical 7-type car? Maybe two 18" X 18" X about 1.5" crush structures under the floorpan with side skirts/bellypan added to integrate them into the design of the car? A higher CG is unfortunate, but I'd be willing to give up some performance in order to address this apparent hole in safety practices. The performance hit would be very small and the addition to safety could be a very big deal. Any solution will have associated design compromises.

 

Dean

[xcarguy]

A friend of mine, though not a 7 guy, but 70+ year old car guy, and a fabricating/car building genius in his own right, came up with the idea of mounting the seat on engine valve springs. Thoughts? :rofl:

[toedrag]

A friend of mine, though not a 7 guy, but 70+ year old car guy, and a fabricating/car building genius in his own right, came up with the idea of mounting the seat on engine valve springs. Thoughts? :rofl:

 

Just don't roll over: as they say, "solve one problem and create another".

http://i01.i.aliimg.com/photo/v1/543935991/driver_bus_seats_for_sale_LXSJ03.jpg_220x220.jpg

[DeanD3W]

A friend of mine, though not a 7 guy, but 70+ year old car guy, and a fabricating/car building genius in his own right, came up with the idea of mounting the seat on engine valve springs. Thoughts? :rofl:

 

I'm still thinking just a bit of extra seat foam of the right type and a crushable plate(s) under the seating location, under the floorpan, is best. As Kitcat pointed out, building much compliance into the seat mounting would lead to harness tension being released mid-wreck which doesn't seem good.

 

Dean

[bball7754]

Shane - I think a bare seat (Kirkey, Sparco, whatever) with an SFI foam insert would be a good way to go.

 

This company builds them, and you can see some examples on their photo page.

 

http://www.speedseatfactory.com/Full_Circle_Formula/Speed_Seat_Photos.html

 

My Mallock had nothing but a bare seat bottom on the floorpan, and used the rear bulkhead as the seat upright. I purchased an SFI foam kit, and created a custom seat.

 

Steve

[WestTexasS2K]

I have the 2" foam they sell in the Aircraft spruce catalog and had it made into seat cushins more so I can see over the dash of the Ultralite. It may give a bit of protection on compression but it does tend to compress to 1" in short order. It helped with monkey butt syndrom during the One Lap events.

[xcarguy]

I'm still thinking just a bit of extra seat foam of the right type and a crushable plate(s) under the seating location, under the floorpan, is best.

 

Dean

 

Shane - I think a bare seat (Kirkey, Sparco, whatever) with an SFI foam insert would be a good way to go.

 

Steve

 

 

I have the 2" foam they sell in the Aircraft spruce catalog and had it made into seat cushins more so I can see over the dash of the Ultralite. It may give a bit of protection on compression but it does tend to compress to 1" in short order. It helped with monkey butt syndrom during the One Lap events.

 

 

Foam in the seat bottom will be a 'must' for me. Loren, your 2" foam compressing a full 1" is in line with what Hi-Tech told me; compresses to about 50% when sat upon. And I have to say I've been toying with the idea of putting something underneath the seat.

[jimrankin]

There are some "Gel" seat cushions made for wheelchairs that don't compress very much under normal seating weights but having pressed on them know they will deflect under load, in fact they will probably split one of the seams and spill out if loaded too much. Since it is a gel this will happen at a slow enough rate that the impact will be of less duration than the leak down. What makes these cushions good for our cars is the "cut out" that is supposed to be in the "back" works as a pass through for the lower strap on a 5 point belt system when it's installed towards the front. They come in different sizes and a youths seat size will fit in a typical racing seat. My wife is too short to see over the dash in the S2K without the added pad. The rest of the seat, side bolsters etc. seem to line up better when she is raised up, probably because the seats are designed around an "average height" body.