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From: (Bruce Hamilton)
Subject: Re: How do Air bags work?
Date: Fri, 18 Nov 1994 17:32:49 GMT

>Help! A question about sodium azide and car safety air bags

>   We have a need for a solid phase material which can be stored
>safely, and when needed in a rapid and controlled fashion, undergo
>a phase change and release a large amount of inert gas.  I heard that
>car air bags have a small amount of sodium azide, and when triggered
>the solid phase sodium azide can be turned into a gas in a rapid and
>controlled fashion.

If you believe sodium azide can be stored safely, and releases only
a large amount of inert gas, I've got news for you - and it's mostly bad.

Sodium azide is toxic, The airbag inflators are aluminum-encased units
that contain an ignitor ( squib), gas generant pellet or wafers of sodium
azide propellant and filters to screen out combustion products.
The electrical signal ignites a few milligrams of initiator pyrotechnic 
material.That then ignites several grams of booster material which then 
ignites 10s of grams of sodium azide that burns to produce nitrogen gas
and sodium.  

The sodium azide is pelletized to control the rate of gas generation by
controlling its surface area. The free sodium would form sodium
hydroxide when it contacts  the water in people's noses, mouths, and
eyes so, to prevent this, the manufacturers mix in chemicals that will
produce sodium salts ( silicates, aluminates, borates ) on combustion.

Inflator units also often have a layer of matted material of alumina and
silica called Fiberfrax in the particulate filter. The Fiberfrax mat reacts
with most of the remaining free sodium in the generated gas.

There is apparently also corn starch and talcum powder used as
lubricants in the bag, and if the bag explodes these are the powders
that contaminate people - not the toxic chemicals in the Inflator.  
>   I'd like to learn more about how air bags work.  Perhaps this
>system can be used to solve our problem.  Some questions I have:
>   1) how much solid phase sodium azide is in an air bag?

One article quotes 160 grams  of propellant for a drivers-side bag 
( 60 liters of gas) and 450 grams for a passengers-side bags 
( which are 3-5 times larger) . I suspect that may be all of the
above ingredients in the Ignitor, but not the bag lubricants. 
>   2) how much gas phase is generated?  at what pressure?

Assume the bag reaches atmospheric pressure, the manufacturers
now control the bag inflation speed to 90-200mph, less than the
early models.

>   3) how fast is the reaction?

Sequence is:-
0 - Impact
15-20milliseconds - sensors signal severe frontal collision.
18-23milliseconds - pyrotechnic squib fired
21-27 milliseconds -  nylon bag inflates
45-50 milliseconds  - the driver ( who has moved forward 5 inches)
                 slams into the fully inflated bag
85-100 milliseconds - the driver "rides the bag down" as the air
                 cushion deflates.
>I'd appreciate any help.  If there are any relevant journal articles,
>I'd like to know the citations.

"Automotive safety is in the bag" Steven Ashley
Mechanical Engineering January 1994 p58-64 
( best technical descriptions)

"Airbags : Education and Experience"
Automotive Engineering September 1993 p29-32

"Everything you need to know about airbags"
Autocar & Motor ( UK) 3 March 1993 p55-57

One article notes the following major airbag supplier:
Breed Automotive
Boonton Township, N.J.

                   Bruce Hamilton

From: (Bruce Hamilton)
Subject: Airbags - was Re: EV safety vs Gasoline burning vehicles
Date: Fri, 04 Apr 1997 21:14:57 GMT (DaveHatunen) wrote:

>In article <..>Will Stewart  <> wrote:
>>Daniel Stern wrote:
>>> On Sun, 30 Mar 1997, Will Stewart wrote:
>>> >   1.  EVs such as the EV-1 have a battery containment structure that
>>> > greatly reduces such a risk; GM even won a safety award for it.
>>> H'm.  Is that anything like the door-mounted 3-point safety belts for
>>> which GM won a safety award?  Those things killed and injured a lot of
>>> people...
>>And airbags have killed and injured a lot of people. So?
>You're losing track of your own argument. You said the EV design had
>won safety awards. The point is that safety awards do not always
>indicate a whole lot of increased safety. Especially when they are
>awarded before even a few million miles of experience has been logged.

Will hasn't yet confirmed the EV-1 battery case won a safety award,
nor has Daniel indicated the safety award, or the ratio of lives
saved v lives taken for the GM system.

People are losing perspective here. Wearing safety belts has been
responsible for saving far more lives than any bad belt designs may 
have taken. The same applies to airbags. As of late last year
the number of lives saved in the US alone was around 1500, with
about 88 saved by passenger side airbags, but the number of lives
taken by passenger side airbags was around 32. 

The airbag problem was solely caused by the failure of NHTSA 
to accept the evidence of the automakers that the high bag 
opening velocities ( required to prevent harm to unrestrained
passengers ) were likely to harm children or small, frail people
in accidents that would be otherwise survivable. People sometimes
forget that airbags are 200mph slaps in the face.

The automobile manufacturers provided evidence of relatively
high seat belt usage, and asked to be allowed to use restrained
passengers and slower deploying airbags, but NHTSA listened
to the consumer safety lobby groups and refused to permit them. 

The companies had formally notified government safety officials 
of their concerns that children too close to a deploying air 
could be " severely injured or killed " many times, starting with 
GM in 1969. The automobile safety lobby groups claimed that the 
companies were deliberately trying to avoid putting airbags in 
vehicles. It took a massive public outcry and 30+ children's deaths 
before NHTSA would accept the automakers evidence instead of the
advice of the consumer safety lobby groups. Many of the automakers
also put notes in the manuals stating that children should be
belted-up in the back seat - starting with Ford in October 1973,
for the Mercury Montereys equipped with passenger-side airbags.

However, they were obviously not prominent enough to stop people 
placing children in the front seat. One of the most strident
claims was that of retired Ford engineer Emil Greenier (who helped
develop safety systems ) - who said in March 1978 " Airbags are
more dangerous than a hangman's noose ". he also filed for a
patent for airbags under the category of "execution devices". 
In July 1979, GM and Volvo conduct crash tests with anesthetized
pigs to simulate unbelted children. Seven animals died. 
The list goes on and on...  

Now the family of the most tragic cases of all, Frances Ambrose 
( a 5-year-old properly belted in a Dodge Caravan involved in a
12-15mph accident on 11 Sept 1996 that was killed by the inflating
passenger side airbag - the first known belted child to be killed ),
have filled a $60 million lawsuit against Chrysler. I hope 
Chrysler drag out all the warnings, all the counterclaims by the
lobby groups, and the unwillingness of NHTSA to accept the studies
provided by the automakers - and the delay of NHTSA in permitting
deactivation or depowering. 

Naturally the lobby groups are now saying that the automakers didn't 
spend enough on "smart" airbags research, and that the two year delay 
to build the technology is too long - conveniently forgetting the 
minor detail that NHTSA still has not figured out what a smart airbag 
should do. The automakers know some of the problems - out of position
passengers, size of passenger, passengers not wearing seat belts, 
bulky or heavy parcels, passengers with parcels etc. etc. Current 
sensors can be confused by temperature, sunlight, passengers in
unusual positions, or even glittery clothing. 

The so-called "smart" systems on some European cars aren't - they 
merely detect whether the seat belt is being worn and select one of 
two inflation speeds and change the airbag trigger threshold speed. 
The bare minimim for a "smart" system is to detect occupants size 
and position, whether seat belt is being worn, the seat belt 
pretensioner tightens the shoulder harness, a computer assesses the
force and rate of deployement, and a multi-stage bag inflation 
system complies with the computed requirements. The big three have
formed a consortium to speed development of such bags.   
NHTSA is culpable because it listened to the lobby groups rather
than the detailed studies provided by the automakers, and it still
has failed to devise appropriate performance specifications for 
smart airbags. However, there is clear evidence that both seatbelts
and airbags have saved far move lives than they have taken, and that
ratio should continue to improve now that NHTSA has finally decided
to permit 20-35% depowered airbags and disconnection ( and perhaps 
the automakers preferred choice of indicating cut-off switches ).

In both the airbag and seatbelt debates, the problems arise because
safety systems only work if used, and the automakers have continually
been frustrated by authorities failing to enforce seatbelt use, as
airbag and seltbelt systems can work most effectively when carefully
integrated. Deactivation of airbags in integrated systems will 
adversely affect protection in vehicles with such systems.

      Bruce Hamilton

From: (Bruce Hamilton)
Newsgroups: sci.environment,sci.chem,sci.physics,
Subject: Re: Airbags:  was: Global Warming Sweepstakes
Date: Sat, 29 Nov 1997 18:38:45 GMT

Talk.environment,, removed,
added. Followups set to (William R. Penrose) wrote:
>I really don't care what other people do, but the auto folks would not
>have developed airbags without being kicked in the butt by govt.

This is not true. The first air bag patent was in 1952, and GM first
tested an air bag in 1959 ( in the form of an inflabale dashboard ).
However, the problem was that insufficient information existed to
determine what was an acceptable design force for automotive components
necessary to improve occupant impact survivability. In 1960, GM installed
a crash decelerator sled at Wayne State University, and by 1963 embalmed
cadavers were being used to measure the deceleration forces that could be
tolerated. Higher speed data was also beginning to be produced from
aerospace industry tests.

The auto companies opposed the mandating of airbags because most
research had demonstated that mandating seat belts was more effective,
and they had already serious concerns about the safety of small and
out-of-position occupants. If three point seat belts were mandated,
then the companies could have slower-inflating airbags to supplement
the belts, and the air bags would not be the 200mph slap in the face
required to protect unbelted passengers. The automakers wanted to
wait until they had resolved all the safety concerns associated with
airbags. Even the 1984 NHTSA data supported their stance, but the safety
lobbyists prevailed, and in 1984 NHTSA issued its rule on air bags .

NHTSA Restraint System Effectiveness Estimates for Front Seat
Occupants of Cars (1984). ( The numbers indicate the % surviving
what would otherwise be a fatal crash, and the AIS levels represent
serious to moderade injury )
                                Injury Level
Restraint System             Fatal      AIS 2-5
Three-point belt             40-50%      45-55%
Automatic Belt               35-50       40-55
Air bag only                 20-40       45-55
Air bag with 3-point belt    45-55       50-60

A February 1996 NHTSA report indicated that a manual 3-point belt was
slightly more effective in reducing AIS 2+ injury than an air bag with
3-point belt. The US national average usage of seat belts has risen
from 11% in 1980, to 15% when the airbag law was mandated in 1984,
to 67% in 1994 ( partly as a result of the introduction of state
laws and automatic seat beat systems ), however the rate varied
from 32% in North Dakota to 84% in Hawaii.

[ The following is edited from some posts of mine last year, and
I can't be bothered updating the numbers ]

The problem with airbags is mainly the failure of the NHTSA to push for
mandatory seat belt laws, and then permit the design the airbags around
the restrained drivers and passengers. NHTSA should have been more
receptive to the data from the companies, but NHTSA even appeared to
be incapable of balancing the lobbyists information against their own
evidence of numbers "saved".

According to a 1996 NHTSA report, it estimated 88 lives of people 13
and over have been saved by passenger side airbags between 1986-95,
versus 28 children killed, and 8 others with nonfatal skull fractures
and brain damage. The NHTSA has also found airbags had saved 1,136 lives
from 1986-1995 ( 462 were saved in 1995 alone ), but did not provide a
significant benefit from drivers 70 and over. In May 1997, NHTSA calculated
that 65 people, including 35 children, had been killed by deploying
airbags since 1990.

They found fleets with driverside airbags had 11% fewer fatal accidents than
the same vehicle without airbags, and air bags cut the unbelted driver
fatality rate  by 34% for front impacts and by 13% for all crashes.

The problem is huge in the USA, because passenger side airbags are mandated
for all vehicles by 2000, and NHTSA has refused ( until September 1996,
after  Frances Ambrose's death ) to allow the vehicle manufacturers to use
slower deploying airbags, instead demanding they should send a letter to all
vehicle owners telling them to put all children under 12 in the back seat
and ensure they are properly belted in. In late 1996, after intense public
scrutiny, NHTSA said it will allow the companies to use slower-inflating
bags, but was still slow in changing the regulations - which could still
leave the companies facing major litigation. If NHTSA had accepted the
recommendations of the auto industry during the past decade, then the
slower-deploying airbags would have prevented many of the unnecessary
deaths from small people and children ( sitting closer to the air bag )
and out-of-position passengers.

In 1996 the automakers have introduced a family of different-sized crash
test dummies ( US$150,000 each ), rather than just the standard adult male
specified in the regulations. These are designed to help evaluate the
diverse array of restraint systems and vehicle design improvements
appearing on vehicles - from foot airbags to side curtains.

The obvious solution is smart airbags - using sensors on the seat and safety
belt to ascertain whether the passenger is a child and whether they are belted
up, and then partially/slowly deploying the bag. Intensive research has been
underway for several years, but the existing problem is of increasing
magnitude as newer cars appear, of the 28 children killed up to October 1996,
14 occurred in 1996.  It is estimated it will take several years to develop
a suitable "smart" system, and expedient measures - such as deactivation
and cut-off switches - have been proposed, although the automakers are
concerned about liability issues with such devices. Not surprisingly,
NHTSa doesn't seem concerned about the liability issues, and proposed
that servive facilities could deactivate the bags if customers wanted it.


The air bag is not intended to be deployed until a specific crash impact
velocity is reached. Ford uses 22km/h, and have a design " may deploy"
between 13 - 22km/h impact, and other manufacturers will have similar
criteria. There have been few reports of unwarranted inflations, and
the minor abrasions were a consequence of "bag slap" from the older
style bags that had a neoprene coating over the nylon. These days the
neoprene isn't present, and abrasions are much less. As always, there
is a tradeoff of superficial injuries versus serious internal injuries.

The following chronology is from several different sources...

In 1969, General Motors warned government safety officials that children
who are too close to an airbag when it deploys could be " severely injured
or killed ".

In 1971, Chryler's President, John.J.Ricardo wrote to John Volpe, head
of the Transportation department, noting that the air bag is " potentially
hazardous for an out-of-position adult or small child '.

In September 1971 Ford expressed concern that NHTSA was given the power to
mandate airbags when they may not provide as much protection as wearing seat
belts, and could be hazardous to small children.

In October 1972 Ford places instructions in manuals of vehicles with
passenger-side airbags stating that small children should never be allowed
to occupy the front seat " because the force of the deploying airbag may
impose dangerously high loads on them ".

In 1972, a GM study using baboons concluded that out-of-position children
may be at risk of serious or fatal injuries from air bags. A NHTSA brochure
dismissed these concerns, saying the agency had tested risks to
"out-of-position" occupants and found them not to be valid.

In 1974, tests by Volvo showed out-of-position children could be killed
or seriously injured by air bags. The tests used baby pigs, of which only
3 of the 24 test pigs survived.

In 1976, NHTSA stated that air bags caused " no significant injuries to
improperly positioned occupants ", however a GM study had indicated that
two people,( one adult and one child ), had been killed in low speed
crashes involving airbag deployments, and had concluded that the people
"may have been too close to the air cusion module at the time of
deployment '

In March 1978, retired Ford engineer Emil Grenier, who helped develop
systems, filed a patent for airbags under the category of "execution
devices", stating that "airbags are more dangerous than a hangman's noose".

In July 1979, GM and Volvo conduct crash tests with anesthetized pigs to
simulate unbelted children, seven animals die.

In 1979, GM states that it plans to delay the introduction of airbags
because of concerns about risks to out-of-position passengers and
drivers sitting close to the steering wheel. NHTSA head, Joan Claybrook,
publically attacks GM, and accuses them of depriving the public of life
saving technology.

In 1982, still another GM study found that test pigs positioned close to
the air bag were severely harmed or killed.

In 1984, NHTSA issued its rule on air bags.

1n 1990 and 1991, further tests show drivers to close to the sterring
wheel are likely to suffer severe to fatal injuries in lower speed
accidents they would be expected to survive if air bags had not deployed.

In 1991, NHTSA admitted to automakers that it was aware of cases where
the air bag caused death, but it did not want that information publicized
as it would harm the public's perception of airbags.

In 1993 the industry pushed for strongly-worded warning labels " An
Occupant who is to close to the inflating air bag can be seriously
injured ". NHTSA instead followed the advice of so-called consumer advocacy
groups - such as the Coalition for Consumer Health and Safety - which said
the automakers' proposed language " will inadvertently alarm motor vehicle
occupants ".

In 1995, NHTSA head Ricardo Martinez said " The safety agency is aware of
no air bag-induced injuries to infants ". Almost a year earlier, a
three-month-old suffered a skull fracture when an air bag hit the baby's
rear facing car seat.

Despite all those ( and many more ) warnings, NHTSA mandated test procedures
involving unbelted passengers - which required high speed airbag inflation
to meet the survivability criteria - all the while claiming there was no
problem, and that the automakers were being obstinate. Now that there is a
an obvious problem, NHTSA claim the automakers should have invented
"smart" airbags to sense the size of the occupant and inflate accordingly.
The minor detail that the automakers had invested large sums of money
trying to find systems that would cope with occupants who could be almost
anywhere - because of the lack of mandated seat belts - seems to have been
conveniently ignored.

All the while, NHTSA were portraying the airbag as a nice soft pillow
that gently protects occupants, when the reality is that it's a 200mph
slap in the face. A recent survey showed that, despite all the
instructions in vehicle manuals and brochures, and extensive media
commercials, 85% of the US respondents believed it was safe
to place children 12 and under in the front seat of cars, and 66%
believed it was safe for children under six.

The complexity of sensors ( have to cope with out of position passengers,
discriminate between children and parcels, with or without seat belts,
vibration and humidity  etc.) means that fairly sophisticated sensing and
inflation systems will be required for smart systems, and they are still
several years away for most vehicles. Some entrepeneur firms, with their
"solutions", have been quick to join the NHTSA - claiming that their
"inventions" could immediately solve the problems. The air bag and
automotive manufacturers have several systems already undergoing trials,
but consistency and reliability remain major technical issues.

On September 12th 1996, five-year old Frances Ambrose died, whilst
properly belted into the front seat, and in a low speed accident that
should not have hurt her, the first known properly-belted child to die.
As her father Albert Ambrose Jr said, " take care of your children, and
love 'em while you've got 'em - make sure the kids ride in the back seat
and are properly buckled".  Her family have filed a US$60 million lawsuit
against Chrysler, claiming that they knew airbags were dangerous to
children, and that their 1996 Dodge had them. Airbags are mandated in
all 1996 cars by the US Government.

So you see, the automakers had developed airbags, mostly prior to
the government involvement, but they understood that wearing seat belts
was an even more effective measure at reducing harm, and the automakers
did not want to introduce air bags until they had resolved all the
associated safety issues.

The following is from the sci.chem FAQ, and describes the airbag
deployment mechanisms..

31.5  What causes an automobile airbag to inflate?.

The final cause is the production of nitrogen from 10s of grams of sodium
azide, but there are some extra chemicals involved along the way.
Sodium azide is toxic, The airbag inflators are aluminium-encased units
that contain an igniter (squib), gas generating pellets ( or wafers of
sodium azide propellant ), and filters to screen out combustion products.
The electrical signal ignites a few milligrams of initiator pyrotechnic
material. The pyrotechnic material then ignites several grams of booster
material, which ignites the tens of grams of sodium azide, and the azide
burns very rapidly to produce nitrogen gas and sodium.

The sodium azide is pelletised to control the rate of gas generation by
controlling its surface area. The free sodium would form sodium
hydroxide when it contacts  the water in people's noses, mouths, and
eyes so, to prevent this, the manufacturers mix in chemicals that will
produce sodium salts ( silicates, aluminates, borates ) on combustion.

Inflator units also often have a layer of matted material of alumina and
silica called Fiberfrax in the particulate filter. The Fiberfrax mat reacts
with most of the remaining free sodium in the generated gas. A typical
reaction pathway is as follows [6];-

  2 NaN3  ------>  2 Na  +  3 N2
  10 Na  +  2 KNO3  ------>  K2O  +  5 Na20  +  N2
  K2O  +  Na2O  +  SiO2  ------>  alkaline silicate glass.

There are apparently also corn starch and talcum powder used as lubricants
in the bag, and if the bag explodes these are the powders that contaminate
people - not the toxic chemicals in the inflator.

One article quotes 160 grams  of propellant for a drivers-side bag
( 60 litres of gas) and 450 grams for a passengers-side bags
( which are 3-5 times larger) . I suspect that may include all of the
above ingredients in the igniter, but not the bag lubricants.

The bag fills until it reaches slightly above atmospheric pressure, and
the manufacturers now control the bag inflation speed to 90-200mph, which
is less than the early models - because they were too violent and could
harm occupants. The actual sequence goes something like:-

0  - Impact
15 - 20 milliseconds - sensors signal severe frontal collision.
18 - 23 milliseconds - pyrotechnic squib fired
21 - 27 milliseconds - nylon bag inflates
45 - 50 milliseconds - the driver ( who has moved forward 5 inches)
                       slams into the fully inflated bag
85 -100 milliseconds - the driver "rides the bag down" as the air
                       cushion deflates.

Recently, there have been calls to change the crash testing procedures to
allow the test dummy to be belted in, as seat belt usage is now about 67%.
Having a belted dummy would permit the use of slower inflating airbags, as
the deaths of 30 children ( up to Dec. 1996 ) have been attributed to the
speed of inflation of the larger passenger-side bag. Early in 1997, the
US NHTSA finally permitted depowering and/or disabling of passenger-side
airbags. A major airbag supplier is Breed Automotive, Boonton Township, N.J.

More details can be found in specialist articles [7-9], and research is
continuing into alternative inflation mechanisms, such as compressed gases.
There has been extensive work over the last decade on "hybrid" airbag
systems. These two-stage systems often use cylinders of compressed gas,
which can be released at ambient temperatures for situations where low-speed
deployment is appropriate, or the gas can be rapidly heated for high-speed

     Bruce Hamilton

From: (Bruce Hamilton)
Subject: Re: New Air Bags
Date: Tue, 15 Sep 1998 18:27:08 GMT (JCWCONSULT) wrote:

>For everyone's information, NHTSA intends to try to:

Surely a typo?, you obviously meant "misinformation".

>- return to 200 mph air bags, the first generation style of deployment
>  speeds that immediately kill children and smaller adults
>- eliminate switches as a protection
>- return to 30 mph barrier crash UNbelted testing
>- refuse to adopt the better set of rules in Europe, based upon
>  belted occupants, and MUCH safer air bag equipment.

Oh, it' s the usual paranoid drivel from JCWConsult, for people curious
about the current status of NHTSA's plans for advanced airbags ( which
are not the uncontrolled explosive, 200mph, sodium azide-driven first
generation models - automakers aren't that techically stupid ),
visit the NHTSA WWW site and review the proposals.
If you want alternative perceptions, try the Insurance Industry for
Highway Safety WWW site.

I'm no friend of the NHTSA, and I've long posted the sad history of
NHTSA ignoring the advice of industry experts about mandating airbags
without mandating seatbeat usage and NHTSA prefering to listen to
safety lobbyists instead. NHTSA was still requiring unbelted large
dummy testing when seat belt usage statistics were suggesting that
seat belts were being used much more, and the industry was expressing
concerns about small and out-of-position passengers that were not,
and could not, be protected whilst complying with the unbelted test.

However, after the outrageously-slow response to the increasingly-
obvious problems, NHTSA has embarked of a programme of at least
listening to industry experts, and begun to recognise the complexity
of the issues. Recent recalls because some new airbag sensors were
affected by wet seats from rain entering open windows is an example
of how making haste slowly is sometimes better. Imagine the system
designer's check list of stupid owner actions that they have to
allow for.

Smarter airbags are already replacing the older systems,
and they require much more controlled deployment than can be
provided by sodium azide, and so it's projected that 40% of airbags
sold in 2000 will use alternative propellants. There are still
major problems for truly "smart" airbags,  ( eg glittery clothing
or wrapping can affect optical sensors, mass sensors can't
discriminate between out of position passengers, parcels, or
children ). There are no serious plans to return to the
explosive 200mph slap-in-face first generation airbags.

People that want to review what is planned for airbags can obtain some
indications from past issues of Automotive News. Unlike JCWConsult,
I've no intention of selectively extracting comments that match my
perception, as the articles are fairly well balanced discussions
of the technical, economic and political issues they briefly cover.

The problem of identifying accidental deployments is covered in:-
" Airbags trigger new fears " August 24, 1998 p1, 50-52.
A new design using traditional inflators is covered in:-
" New airbag is safer, Autoliv says " May 5, 1997 p38.
The new crash testing dummies are discussed in :-
" smaller dummies provide big edge in safety " January 22, 1996 p33.
" New crash test dummies are stronger, smarter " March 9, 1998 p3.
Problems of designing the new smart systems are covered in :-
" Smart-airbag software poses challenging riddles " March 9, 1998 p26.
" Automakers, suppliers rush to offer smart airbag systems "
  December 2, 1996 p47.
" Big 3 form group to speed "smart" bag development " December 23, 1996 p4
" Smart airbags lack savy sensors" May 26, 1997 p33C
" Don't expect airbags to get "smart" for 2 years" November 4, 1996 p50-51

The are also more specialised articles about sensor development and
problems in journals such as Sensor Review ( " Vehicle Sensing gets an
inflated image " v16 n4 p31-36 1996.

There is no intent to return to first generation systems, and
JCWConsult's self-serving attempt at panic-mongering should be
treated with the contempt it deserves.

           Bruce Hamilton

From: John De Armond
Subject: Re: Air Bag Disconnection?
Date: Sun, 25 Jun 2000 02:47:11 -0400

Some Girl wrote:

>   I'm working on getting legal papers to get my air bag disconnected and
> so far I've only found one place who will be willing to do this after I
> get the papers and I was wondering what a average cost of this would be.
> They wanted $375 which seems like a whole lot and I'll look around more
> if it is way too much...

Wow!  What Thievery.  Why don't you look at your fuse panel and
remove the fuse labeled "airbag"?  No fuss, no muss and you can take
hubby out for a FINE night on the town with the $375.

If I found myself in the unfortunate situation of having to drive a
car with an exploding steering wheel, I'd want the explosive yanked
out in addition to powering down the system.  Even with the system
powered down, static and other events can detonate the thing.  I
have an aunt who was blinded by an "accidental discharge" of the
airbag in her Lincoln.  yeah, she got a lot of money from Ford but
she's still blind.  I doubt that you'll find anyone who will yank
the airbag for you so it will be a do-it-yourself project. Pretty
simple job but you need to read the service manual (check the
library) to learn what steps to take to make sure the thing doesn't
explode in the process of removal.

From: John De Armond
Subject: Re: Air Bag Disconnection?
Date: Mon, 26 Jun 2000 05:13:12 -0400

Some Girl wrote:

>     So does that mean if I take it to a mechanic and get it disconnected
> it could still go off??.

NO!  The "aux energy source" mentioned by others  is simply a
capacitor built into the air bag controller.  It stores enough
energy to make sure the steering wheel explodes even if the battery
connection is severed early in the crash.  The cap discharges fairly
rapidly after the fuse is removed.  Thirty minutes after pulling the
fuse, the system is dead.


From: (Bruce Hamilton)
Newsgroups: sci.chem
Subject: Re: air bags
Date: Fri, 03 Apr 1998 20:00:56 GMT (Lloyd R. Parker) wrote:

>Here's the true data:

No. Here are some data. There is considerable debate about how
to separate airbag-caused fatalities from other causes. Not
surprisingly, the NHTSA have adopted a conservative approach.

>94 people have been killed by air bags in the past 8 years.
>41 children -- 33 were unbelted, 4 were only wearing a lap belt.
>36 adult drivers -- 19 were unbelted, 3 were improperly belted, 3 were
>   slumped over the steering wheel
>13 infants -- 3 were being held on laps, 10 were in rear-facing child
>   seats in the front seat
>4 adult passengers -- 1 98-year old woman and 3 unbelted
>So we have 4 children and 11 adults whose death remains unexplained.
>That doesn't mean air bags killed them despite their doing everything
>right.  It may mean information is lacking -- their status prior to the
>accident couldn't be determined.

Do you actually understand the data you post?. The basic definition
for the 94 deaths is that they died *because* the airbag inflated.
End of "cause of death" story.

Virtually all of those people died because the airbag inflated
in a low-speed ( 12-18 mph ) accident that the assessors
believe they would have otherwise survived. The fact that some
people were ignorant of the serious consequences of having
children on the front seat, sitting too close to the steering
wheel, not wearing seatbelts etc. is a separate issue. All
of those 94 deaths have been attributed to the fact that if
the airbag had not inflated, the victims should have survived.

The comment about the few cases where they "did everything
right" is just drivel. The assessors could not determine
exactly why the victims died, but they have determined that
the low speed of the accident was usually survivable, thus
the injuries caused by airbag deployment caused the deaths.

There are known actions that can be taken to reduce the
adverse effects of deployment, but often less-severe injuries
are still sustained.
>Keep in mind, too, that we don't know if the 94 people would have
>survived the accident had air bags not deployed either.

Of course we don't know for sure, but in all the cases, the
initial assessors, and the followup reviewers, all determined
that the accident was of such a minor nature that the victims
would have been expected to survive in non-airbag equipped
vehicles. What is so difficult to understand?.

I also dislike the implication that many of the victims deaths
were due to there own wrong actions. I've been posting about
tthe potential hazards of airbags for several years, and some
posters accused me of mouthing the automotive company line.

The gift of 1998 20/20 hindsight is severely tainted when the
history of warnings to the public is considered. As my earlier
post in the "Airbag gas" thread noted, the companies have been
placing rather muted warnings about the hazards of airbags in
vehicle manuals for decades.

NHTSA listened to the safety lobbyists and discouraged the
industry from using more warnings and more extensive publicity
campaigns because they believed such publicity would create
fear and apprehension about airbags. The safety lobbyists also
opposed both the use of slower-deflating airbags, and the
industry line that seat-belt use was sufficient to justify
changes in regulattions to permit the use of slower-inflation
airbags that would cause less injury.

It has only been in the last couple of years, as the high-speed
inflation passenger-side airbags have become more prevalent,
and injuries have caused concern, that the public have become
more aware of the hazards. As a 1996 post of mine noted...

  All the while, NHTSA were portraying the airbag as a nice soft pillow
  that gently protects occupants, when the reality is that it's a 200mph
  slap in the face. A recent survey showed that, despite all the
  instructions in vehicle manuals and brochures, and extensive media
  commercials, 85% of the US respondents believed it was safe
  to place children 12 and under  in the front seat of cars, and 66%
  believed it was safe for children under six.

  On September 12th this year, five-year old Frances Ambrose died,
  whilst properly belted into the front seat, and in a low speed
  accident that should not have hurt her, the first properly-belted
  child to die. As her father Albert Ambrose Jr said, " take care of
  your children, and love 'em while you've got 'em - make sure the
  kids ride in the back seat and are properly buckled".

NHTSA also maintains that airbags have saved 1136 lives between 1986
and 1995. When the injury/fatality data was reviewed by experts, it
was also concluded that if NHTSA had considered airbags as supplements
to seatbelts, rather than passive restraints, then the trigger point
would have been nearly 20mph, rather than the 12-14 mph, and that
change alone would have eliminated most of the known fatalities.

The tragic reality is that the refusal of NHTSA to firstly listen
to the industry experts rather than the safety lobbyists, and
secondly to act with any urgency when the problem became apparent
makes them culpable. Unfortunately, the victims relatives will sue
the vehicle makers, not NHTSA.

Airbags have saved around 1600 lives ( not "thousands" as claimed
elsewhere in the Airbag gas thread ), and continue to save lives
in many medium and high energy accidents. The tragedy is that a
period of unnecessary death and injury will now occur, solely
because the regulatory authority listened to the wrong group, and
was very tardy about changing regulations.

I would always prefer to be in an airbag-equipped vehicle in an
accident, as all the evidence is that they still save far more
lives than they take. But if you want to contribute to informed
debate, please try to understand the data you provide.

       Bruce Hamilton

From: John De Armond
Subject: Re: Air bag retrofit?
Date: Fri, 26 Jan 2001 15:54:40 -0500 wrote:
[airbomb incidents snipped]

> I parked the car and haven't driven it again .
> I bought an 89 cavalier to get away from the air bags. I contemplated
> asking on this list if there was a way to remove the airbag in my car.
> I would consider everything before making this decision. Its pretty
> expensive to have it re-packed . I don't recall the exact cost but it
> was roughly 350.00 parts and labor . Plus the cost of a broken wrist.

Removing the system is pretty easy, though you may have to do some
of it yourself because mechanics tend to be frightened of liability
issues.  I did a similar project on my parents' late model Lincoln.
The steering wheel can be restored by cutting away the bag, filling
the cavity with foam and covering the opening with new vinyl.  This
will provide you with a cosmetically acceptable wheel but with no
bomb inside.  An alternative but much more dangerous and expensive
solution is to get an intact airbomb from a junk yard and remove the
explosive cartridge.

This leave a very unhappy control system to be dealt with.  Usually
you can shut off the system completely by finding the air bag fuse
and removing it.  You might want to consider removing the air bomb
control box because it has value on the used parts market.

> I am all for improving vehicles and making them safer but the airbags
> deploy with a great deal of force and it seems to me that if they can
> malfunction and deploy without cause in that case they are more of a
> danger than a lifesaving device .

Airbombs have not improved safety and NTSHA is cooking the numbers
to prove otherwise.  The fix is this.  When traffic accident
investigators report accidents using the uniform reporting codes, if
the airbomb deployed, the system automatically gives the bag credit
for the save.  This is even if the deployment was spurious or if the
accident was inherently survivable (low speed.)  The fact is, the
human body can only sustain a certain G force before suffering fatal
trauma.  The restraint system, regardless of the design, has only
the distance between the seated position and the steering wheel to
control the deceleration force.  A well-designed seat belt system
does it better than an airbomb and does it passively without any
electronics to malfunction.  I was working as a volunteer training
officer with our local PD when the NTSHA guidelines were handed down
from on high.  I recall the displeasure among our accident
investigators at the obvious books cooking.

In 1975 I was hit head-on by a drunk driver while driving a brand
new datsun 280Z.  I was doing around 60 mph at the time.  So was the
other guy.  The cars halted less than 50 ft from the point of
collision so the impact forces were brutal.  My engine was under my
seat and the front end of my car was gone.  My arms folded the
steering wheel around the column and my seat/shoulder belt was stiff
from partial melting from the frictional heat of the fibers rubbing
together during the impact.  Yet when I woke up a few seconds after
impact, I unhooked the belt, opened the door, got out and was able
to walk over to see what remained of the drunk.   He was NOT belted
in, was ejected while his car tumbled in the air and was smeared in
the pavement as the car came down on top of him.  I had a nasty
blister and bruise across my chest and was sore as a boil for a week
or so.  But the seatbelt did its job and saved my butt.  No cooked
books necessary.


From: John De Armond
Subject: Re: Air bag retrofit?
Date: Fri, 26 Jan 2001 14:06:18 -0500

Roger Blake wrote:

> On 25 Jan 2001 23:22:05 GMT, Alex Rodriguez <> wrote:
> >Not as simple as you think.  Also, why would you want one of those explosive
> >devices in your car?  If you use a seatbelt properly they don't do much
> >for you and can harm you.
> I have a friend whose father-in-law was blinded by an airbag after a
> moderate fender-bender set it off. He spent 3 years blind until
> a talented doctor managed to repair the damage with laser surgery.

Add my aunt to the casualty list.  She was in a side impact wreck in
her Lincoln.  The airbomb spuriously deployed.  The caustic
discharge (the sodium azide "propellant" discharges nitrogen and
sodium oxide which combines with moisture to make sodium hydroxide -
lye) chemically burned her eyes.  She can see light and dark but
that's about it.  She got lots of money from Ford but somehow
neither the lawyers nor Ford could get her eyes back.

> I'm with you, I wouldn't buy a car with air bags. (Since I prefer
> older vehicles anyway, this isn't a problem.)

Same here.  I won't even ride in a car with an air bomb.


From: John De Armond
Newsgroups: rec.outdoors.rv-travel
Subject: Re: Air bag question
Message-ID: <>
Date: Wed, 05 Jun 2002 03:11:07 -0400

On Wed, 05 Jun 2002 04:24:37 GMT, "Madeleine" <>

>When I got my estimate today (almost $3500 in damage) the man asked if
>the air bag deployed.  I hadn't even thought about it.  This is my first
>vehicle (99 VW Eurovan Winnebago Class B Camper) with air bags.  Does a
>collision have to be on the bumper for the air bags to explode?  I'm
>glad they didn't of course.  I had my seat belt on and wasn't injured so
>there was no need for the air bags, but I'm just wondering....

There's almost always a sticker under the hood somewhere to show the mechanic
where the air bag accelerometers, control box, etc are located.  Most of the
time there's an accelerometer on each side of the front bumper or just behind
it.  There may also be one in the dash or perhaps in the center console.

<soapbox on>

Of course, you can do what you want but me, I have the air bomb disconnected
in my one vehicle that has one.  I've seen too many people severely injured,
including an aunt who was blinded, by spuriously deploying air bombs.  Just
this week I saw another one.  The local AutoZone delivery guy hit something in
their pickup.  Maybe a fireplug, maybe a bridge abutment.  Whatever, it pushed
in the passenger side headlight up to about the tire.  The kind of minor toof
that just pisses you off but does little damage.  Only this time the air bomb
went off.  It blew his hands off the wheel, spraining both wrists and giving
him rather nasty burns on the insides of both arms.  If he hadn't been a
fairly large guy, it would probably have broken his arms.

My aunt was t-boned in the passenger side door by a drunk driver.  It was a
severe wreck and she suffered other injuries.  In a side impact the air bomb
isn't supposed to go off but it did.  She was close enough to the wheel that
the deploying bag abraded her cornea and the lye dust formed by the bag
propellant chemically burned them.

I'd rather have a loaded gun pointed to my face than to have an air bomb in my
steering wheel.  I know from experience (Personally, a head-on collision with
a drunk plus experience in rescue.) that a properly worn seatbelt will provide
all the protection needed.

My recommendation is to find someone who knows how to disarm that weapon
before it hurts you.

<soapbox off>


From: John De Armond
Newsgroups: rec.outdoors.rv-travel
Subject: Re: Air bag question
Message-ID: <>
Date: Wed, 05 Jun 2002 20:39:48 -0400

The way you disable the bag properly is to locate the wiring to the actual
bag.  it almost always is yellow wire with a bright yellow warning sticker on
it.  After removing the battery wire and waiting 30 mins for the internal
power storage cap to discharge, you unhook the airbomb connector and
substitute a suitable resistor across the connector.  The proper value for the
various brands are on the net.  Then short the pins of the connector going to
the airbomb to prevent static from firing it.  The resistor keeps the computer
and everyone else happy while completely disabling the airbomb.

Unfortunately, because of the state of things these days, you'll probably have
to do this yourself.  Seems everyone is running around scared shitless of
being sued if they unhook someone else's air bomb.


From: John De Armond
Newsgroups: rec.outdoors.rv-travel
Subject: Re: Your Tow Vehicle May Already Have a 'Black Box'
Message-ID: <>
Date: Thu, 10 Jul 2003 00:04:08 -0400

On Mon, 30 Jun 2003 19:43:31 -0400, Sandy A. Nicolaysen <>

>Here's an article that describes how lawyers have used data from a
>truck's on board computer to win court cases:
>Now, the thing that bothers me is that all of the facts in this story
>are true.  I can use my laptop computer to retrieve maximum speed,
>emission limits, seat belt use, etc.  Maybe Alan King can clarify us
>about the capabilities.  I do know that the last few 'events' are
>recorded in RAM and can be uploaded to a computer.

Actually that article was quite misleading.  Speaking only for GM products
which I am familiar with, the "Sensing and Diagnostic Module" feature is well
known among informed mechanics and is extensively documented in the service
manual.  This functionality is actually part of the air bomb control module.
In general, all the inputs to the air bomb module are sampled at high speed
and written to a circular buffer.  When the bomb is triggered, the contents of
the buffer are flashed to flash RAM using the remainder of energy stored in
the internal energy storage unit (capacitor).  This ensures that the data gets
written even if the crash has severed power to the module.

What gets recorded and for how long is vehicle-dependent.  In my 94 caprice,
the buffer length is 17 seconds.  I can't recall all of the inputs but ones I
remember include throttle position, RPM, VSS (speed), brake light status
(on/off), ABS status and several other things.

As that article mentioned, this facility was designed into the air bomb
control module for post-deployment diagnostics.  The data stream was encrypted
but the encryption was so weak that it was quickly broken.  The Big Two
decided to make some money on the situation by licensing the readout
technology to Vetronix and other companies.

The way to defeat this logging function is the same as the way to remove the
potential of severe injury from the air bomb - remove the fuse to the air bomb

>Lawyers are going high tech.  God save us!

The major problem with the scumbag lawyers being allowed to use this data is
that it is a perfect example of GIGO - Garbage in, Garbage out.  The SDM was
not designed to log data with any degree of absolute accuracy.  For the
intended purpose, only reasonable accuracy and linearity does the job.  Trends
are more important than absolute values in most instances.  That's the first
major problem.

The second major problem is that the data sources are not reliable.  Having a
lot of experience with race car data logging, I understand just how hard it is
to get accurate and repeatable data using systems designed for the purpose.
Example:  The vehicle speed input is actually the drive shaft RPM as signaled
by the Vehicle Speed Sensor (VSS).  This is fine within the envelope of normal
operation.  It produces garbage during an accident sequence when the drive
wheel(s) may be off the ground and the throttle position uncontrolled.

Consider a situation where the driver drifts to the median, loses control,
hops the berm and collides with someone traveling in the other direction.  The
impact with the berm will likely result in at least some of the wheels being
airborne.  Simultaneously the impact may G-load the driver's foot and leg
enough to press on the accelerator.  This causes an open throttle signal to be
recorded.  And with no load on the airborne wheels, the engine speed and drive
shaft speed accelerate rapidly.  At the same time the G-loading of the brake
pedal will move the pedal far enough to engage the brake light.

The readout will show the driver suddenly accelerating and braking at the same
time followed by the impact and air bomb deployment, ending data logging.
Since there are no inputs for actual vehicle speed, pitch, yaw or attitude,
there is nothing to indicate to the person looking at the data that the car
had been airborne and that the data is meaningless.  Toss in a lawyer to
intentionally obfuscate the data and the end result is a horrible mess.

As I see it, the real problem is not that the data is being logged.  The
problem is that judges are allowing such garbage anywhere near the courtroom.
Unfortunately most judges are lawyers who couldn't hack it in private practice
and are about as technology savvy as my cat so the "computer data" dazzles


From: John De Armond
Newsgroups: rec.outdoors.rv-travel
Subject: Re: Airbag Control Module in van
Date: Tue, 22 May 2007 10:09:07 -0400
Message-ID: <>

On Mon, 21 May 2007 23:27:35 -0400, "Flo Cala" <>

>Problem with 2000 Plymouth Grand Voyager (same as Dodge
>Caravan/Chrysler Town and Country): Airbag light comes on and stays on
>(engine going of course). Two testers were tried on it (one from
>Harbor Freight) with no resulting codes.

Those testers can only read the EPA-mandated emission-related OBD2 codes.  They can
not read the manufacturer's proprietary extended codes from other devices on the
network such as air bags, transmission controller, etc.  This requires either a very
expensive handheld unit or a PC solution.  This is the one I use:

Once you buy the network interface cable (what connects your PC to the OBD2
connector), the software updates are free for life.

About 2 to 3 years ago the EPA finally won a decades-long running battle with the car
manufacturers and forced them to disclose ALL their extended proprietary codes.  This
was under the guise (correctly) of fair trade, to enable independent shops to have
the same diagnostic access as dealers.  The OEMs have been VERY slow to comply so
software updates are still frequent as he adds new codes.

>From the _Haynes Repair Manual_ , the problem appears to be with the
>Airbag Control Module (ACM). The book says "If the AIRBAG light does
>go on and stay on, the vehicle should be taken to your dealer
>immediately for service."

About the only thing the Haynes manual is good for is starting campfires.

>I survived two wrecks before airbags came into being but do strongly
>believe in their usefulness. For example, I witnessed a T-bone
>accident when a pickup hit a BMW. The side airbag deployed, and the
>driver received no injuries. For this van, however, we are willing to
>forego the safety factor of its driver-side airbag.

I can't imagine having a loaded and cocked air bomb staring me in the face.  I have
an aunt who was blinded by a spurious airbag explosion.  In my youth I survived
without a scratch a head-on collision with a drunk driver at 60 mph.  My seat belt
did everything that needed to be done.  I was in a brand new 75 Datsun Z so I didn't
have mass on my side either.

If you dig under the covers of the government's claim that airbags save so many lies
you learn that like most things the government says, this house is built on a
foundation of sand.  To the feds, a "life saved" involves any accident in which the
airbag deployed and a few other conditions were met (speed, etc.)  If that steering
wheel condom is hanging limp, the cop checks off a block on the uniform accident
report and another life is 'saved'.  Of course, the feds don't report the people
who've been injured or killed by the airbombs.  A few make the news, as when a kid is
involved, but otherwise the truth machine marches onward.

>Can anybody shed some light on allowing a van with a not-working
>airbag situation to continue operating normally without going to a
>$$$repair shop$$$? Or how much cost to expect if we do take van to

Well, I'd find the fuse box and pull the fuse to the air bomb system and if
necessary, remove the bulb from the warning light.  I suspect that this isn't the
advice you want so...

The dealer's gonna clip you about $100 bucks (which would buy you the network
interface cable from the source above) to hook his diagnostic computer to your van.
Then the mechanic, who's incented to change parts and clear the job as rapidly as
possible, will change the black box or maybe the airbomb itself and you'll get a bill
for several hundred bux.

If you don't want to get your own network interface cable then I suggest finding a
reputable independent mechanic who won't charge you a "diagnostic fee" if you let him
do the repairs.  It may be a dirty connector so something else simple like that, or
it may be that the airbomb controller simply needs resetting.  You can try the
resetting route yourself by lifting a battery lead, leaving it off for 10 or 15
minutes, then reconnecting it.  That may or may not reset the box, as some store
codes in non-volatile memory and require resetting over the OBD2 network.

One thing you should not do is go poking around the air bomb wiring without reading
the factory service manual.  The FSM has very explicit instructions on how to go
about things to avoid accidentally triggering the air bomb.  Spurious triggering is
fairly easy and if you do that while inside the car, you'll probably mess yourself.
Ask me how I know....

All air bomb-related wiring must be tagged with something yellow (tag, tracer on the
jacket, etc) to warn one away.  There's a reason for that!


From: John De Armond
Newsgroups: rec.outdoors.rv-travel
Subject: Re: Your Next Toad?
Date: Thu, 17 Jul 2008 07:25:10 -0400
Message-ID: <>

On Wed, 16 Jul 2008 19:42:57 GMT, "RAMĀ³" <> wrote:

>> It matters because I don't have a death wish. While I don't plan on
>> driving into a concrete wall, I can't take the actions of others for
>> granted and it's good to have a car that will protect my DW and I.
>I don't depend upon any mechanical device or regulation to provide
>After all, they can all fail.
>I depend upon my Brain which, so far, has kept me from getting into
>situations whereby I might be forced to rely upon either the regulations or
>the devices.
>Far too many people are hopelessly deluded by the concept that "safety",
>per se, is conceivable as an absolute.
>They're the ones who insist upon buying and operating personal tanks.
>They're also the ones most likely to be involved in a multi-fatalaty crash.

Thanks for saying what I was thinking.

If we rewind a few years, let's recall that this whole passive restraint line
of bullsh*t came about when nannygov decided that it had to protect those who
wouldn't bother to wear a seatbelt.  Interfering with Darwin again.

At first there were those awful automatic seatbelts.  Then the air bomb came
along.  One of those blinded my mom's sister.  She got T-boned in the
passenger side door.  Air bomb detonation was completely spurious but that
didn't stop the coarse fabric of the bomb from abrading her corneas nor did it
stop the lye that is formed from the propellant from burning them.  But I
digress.  Cadillac paid her a nice settlement because of the spurious
detonation.  Still, it would be nice if she could see the money.

As Detroit Inc has done on several other occasions, after fighting off the air
bombs and other passive restrains for a few years, they gave in and accepted
the government meddling.  Then their PR people figured out how to turn a large
liability - the cost of the air bomb system - into a marketing asset.  Sell
"safety" as an abstract concept.

One air bomb is some safety.  Two air bombs is more safety.  15 air bombs is
safety nirvana.  The PR types did the same thing with crash testing.  It was
forced in the industry so the industry made lemonade out of lemons.

I guess that I shouldn't be surprised that people bought off on this crap.
After all, they buy the National Enquirer and believe in UFOs and think that
politicians are here to help them.

In the virtual blink of an eye, that $8000 car became an $18,000 car and then
a $28,000 car.  The major difference?  Lots and lots of "safety".  To pay for
it, the car companies came up with mortgage-like car loans.  Put half the rest
of your life into hock for "safety".  Bah.

Meanwhile even nannygov itself admits that the major cause for the continuing
reduction of driving fatalities is the combination of highway design
improvements and fewer teenage drivers.

I've yet to see anything more sophisticated than good belts, a sturdy chassis
and engineered crumple zones in race cars where crashing is part of daily
life.  Duh, I wonder why?

Those three features saved my life in 1975 when the drunk hit me head-on at 60
mph.  I didn't need air bombs and star ratings back then and I don't now.


From: John De Armond
Newsgroups: rec.outdoors.rv-travel
Subject: Re: Your Next Toad?
Date: Thu, 17 Jul 2008 10:51:25 -0400
Message-ID: <>

On 17 Jul 2008 13:43:30 GMT, Wes Dukes <>

>Back in the early 60's the first use of seat belts that caught my eye
>was a classmate a few grades ahead.  He was the first to put seatbelts
>in a 1953 Chevy that his grandmother gave him.  He was the son of the
>funeral home owner.  That funeral home in the days before rescue squads
>WAS the responder for traffic accidents.  He helped his dad and
>eventually became an undertaker himself.  I think he saw one traffic
>accident too many where people were ejected and decided it was wiser to
>add something that kept you in the car.

My first seatbelt experience was when Mom ordered them special for her new '64
Olds F85.  The car didn't move down the driveway without the belts being on.
I'm glad she did that, as I now feel naked without a belt.  That presents a
horrible dilemma.  On one hand I'm quite uncomfortable without the seat belt.
On the other hand, I feel a strong moral obligation to defy the federal
nannygov by not using it.  Maybe if I made a sleeve to match my clothes so
that it LOOKS like I'm not wearing it.

>I have come  across an  interesting  book that came out this year that
>seems interesting:
>Nudge: Improving Decisions About Health, Wealth, and Happiness by
>Richard H. Thaler and Cass R. Sunstein

I have a feeling that I could write an accurate book review without reading
it.  That's because I predict that I'll agree with everything in it.

Could it be that society crept right up to the tipping point of lunacy but is
now drawing back a little?  It seems that rationality is breaking out here and
there.  Just look at the news from yesterday


From: John De Armond
Newsgroups: rec.outdoors.rv-travel
Subject: Re: Your Next Toad?
Date: Fri, 18 Jul 2008 01:31:31 -0400
Message-ID: <>

On Thu, 17 Jul 2008 21:16:53 -0500, "Bill" <> wrote:

>"Neon John" <> wrote:
>> I've yet to see anything more sophisticated than good belts, a sturdy
>> chassis
>> and engineered crumple zones in race cars where crashing is part of daily
>> life.  Duh, I wonder why?
>I've never flown an aircraft with anything more than a 5-point harness (some
>have four, and some three, but a five point harness is necessary if you plan
>on encountering some "unusual attitudes"). If it's good enough to keep me in
>my seat at 9 negative gees, it's good enough for just about anything. In
>fact, I used to wear two complete sets, one over the other, just in case one
>failed. Not an airbag in sight. And one would certainly not have been
>considerd a welcome "safety feature".

I used to have a 5 point harness in my street/track car.  I'd tuck the crotch
strap back down behind the seat for street driving.  Just too much hassle.  I
really liked the 4 point harness, though if I had one today I'd redesign it to
be a single-operation hookup just like a regular 3 point belt.

That head-on collision that I wrote about showed me just how well the 3 point
system works so I've never bothered with anything more.  The aftermath was
quite interesting.  The shoulder strap was semi-rigid and could support its
weight when held horizontally.  It absorbed so much energy that the friction
between the nylon fibers momentarily melted them and the fused together.

I think that I still have the strap around here somewhere.  I used to have it
stapled to the wall of my office as a conversation piece.

>Now, however, several aircraft manufacturers are talking about installing
>airbag systems.

Just when you thought the world might be having a shortage of stupid....

>Can you imagine one of these things going off in your face
>because a few drops of 300-knot water leaked through the windshield seal and
>shorted out some contacts? Now imagine that happening at night, at weather
>minimums, during a white-knucke mid-winter approach to Jackson Hole. I
>promise you the results would not be pretty. Any perceived increase in
>"safety" is not worth the added risk.

That HAS to be an April fool joke.  Doesn't it?

The section on my Caprice's factory service manual on air bomb disposal is
interesting.  In pictures and text it shows how GM wants you to do it.  Anchor
the bomb to the ground.  Build up a berm of dirt around it.  Run a 20 ft cord
to a place of shelter, making sure one end of the cord is shorted to protect
against static.  Get behind the shelter and sound an audible warning before
detonating the thing.

I'm reading that and I'm thinking "That same bomb is in my car sitting not 3
feet from my face."  Hmmmm.  I haven't yet figured out how to get the bomb out
of my car without defacing the steering wheel.  At least the wires are
unhooked, twisted together and firmly grounded to the steering column.  Still,
I don't like looking at that bomb there in my face.  I'm funny about that.

Air bombs are fun to play with.  They make a helluva racket when detonated.
It's illegal to reuse used air bombs so salvage yards have to collect them and
dispose of them.  Many are happy to give you a bucket-full if you promise not
to sell them or otherwise use them in a car.

A bomb, er, propellant capsule laid face-down on the pavement blasts probably
50 ft into the air when detonated.  One detonated in an open-top 55 gallon
makes a thunderous roar, as does one detonated inside a plastic 5 gallon pail
with the snap-on lid.  Flip the pail over and it'll be blasted to the

Just be careful of the white residue.  It is sodium oxide which turns to lye
when it attracts some moisture out of the air.  It's OK after a day or so, as
the CO2 in the air neutralizes it to washing soda.

>The best solution is almost always the simplest. In this case, that's a few
>fabric straps and some steel buckles.

You betcha.  And passive protection is always better than active.


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