Hi and welcome, to Failurology; a podcast about engineering failures. I’m your host, Nicole, and I’m from Calgary, Alberta.
A little about me, since 2008 I have worked as a contract administrator for a mechanical engineering firm in the construction industry. What does that mean exactly? Well, I visit construction sites of various buildings throughout construction to ensure the plumbing, HVAC and fire protection systems are installed as per design and applicable codes. I also work with the contractors and other consultants to resolve conflicts and answer questions related to the mechanical design. It’s a stressful job, but I really love it.
As I’ve said before, starting a podcast has been a dream of mine for a long time. It’s been a steep learning curve, which I had somewhat expected.
And while I’m happy with the content to date, the delivery isn’t quite what I had in mind.
I underestimated how nervous I would get when recording. I have all these thoughts and ideas in my head, but when I hit the record button I start to stumble over my words. I also talk really fast when I get excited, which is sometimes hard to understand. So the episodes to date have been more scripted and monotone than I had intended.
But I am working on it, please bear with me.
I also wanted to talk about why I started this podcast in the first place. I was reading an engineering ethics text over the summer; I was studying for an exam, I don’t generally read textbooks for fun, although I’m not opposed to it if it’s interesting. Anyways, I found myself drawn to all of the failure case studies in each chapter. But I also realized that there is a lack of engineering failure content taught to young engineers. There is a lot of talk about what to do and what not to do, but how do you prevent failures and what happens when something goes wrong. My hope for this podcast is to help prevent future failures and show that shedding light on problems with a design before the failure occurs is way way better than waiting for the failure to happen. In the case of the Citicorp building in episode one, the engineer was actually hailed a hero for admitting to the design problems and helping to correct them before anything bad happened.
I have an exciting episode for you today, the Ford Pinto, which exploded when rear ended. But first, the news.
News – See underwater
This week in engineering news; engineers combine light and sound to see underwater.
Today, most underwater mapping is done by attaching sonar systems to ships. This technique is slow and expensive.
Sound or light waves cannot pass from one medium to another, in this case from air to water, or vice versa, without losing most of their energy.
In a mapping scenario from above the water surface, the wave would pass from air to water and back again, doubling the energy loss.
The Photoacoustic Airborne Sonar System, or PASS, was developed by researchers at Stanford School of Engineering this year.
PASS uses light in the air and sound in the water, where both travel well
They fire a laser from air to the water surface which generates ultrasound waves when it hits the water.
When the ultrasound waves reverberate back to the water’s surface, it still loses some energy, but it’s not double like it would be using traditional methods.
To date, the PASS system has only been tested in a lab in a container the size of a fish tank, but the researchers are optimistic that the concept can be transferred to open water settings.
Did you guys hear or read about the One Apus container ship that lost almost 2000 containers in early December? The ship hit a storm 3000 km northwest of Hawaii as it was travelling from China to California.
Because the containers are filled with air, they float just below the surface for a while before sinking. Making them super dangerous for other ships to run into.
The PASS system is something that would be very helpful to not only retrieve the containers, but also warn other ships of their location.
It also could have been used to help find Malaysia Airlines flight 370 that went missing mid-flight in 2014, which is such a sad story.
There are so many applications for this system.
Check out the link in the show notes if you want to read more on the Photoacoustic Airborne Sonar System
Now on to this week’s engineering failure; the Ford Pinto, the car that exploded when rear ended.
In order to accurately discuss the Pinto, we have to hop on our way back machine to the middle of the 20th century. It was a much much different time.
History on auto safety
Until the 1960s, automotive safety was not at the forefront of design, manufacturing, or even sales. Which is crazy, because safety is one of the biggest factors buyers look at today when purchasing a car.
But in the 60s, it was believed that accidents were caused by bad drivers and poor roads, not unsafe cars.
Cars were not expected to survive accident conditions; designed for normal use but not crashworthiness. Even though 1/3 to ¾ of all automobiles are involved in accidents.
One common argument from the automotive industry was that - Manufacturers know cars could be driven into a body of water, but that doesn’t mean they need to be equipped with flotation devices. I laughed when I read this the first time, it’s a bit ridiculous and short sighted.
Lower safety levels were more acceptable for smaller cheaper cars than they were for larger and more expensive cars. Safety devices were offered as optional. Small vehicle vulnerability was assumed to be an intrinsic part of their nature.
In 1956 Ford even sold a safety package. Sales were initially strong but dropped off, Ford cancelled the campaign ads halfway through the year. “Safety doesn’t sell” became the auto industry motto.
In the 1960s Lee Iacocca, known as the father of the mustang, urged Ford management to pursue compact car design, for fear German and Japanese manufacturers would capture the sub compact market. – Volkswagen (beetle) and Toyota
To get the car in the showroom with the 1971 line up, the conception to production schedule, normally 43 months, was shortened to 38 months.
Design started in June 1967
Tooling takes 18 months, meaning it began shortly after design.
Production began on aug 10 1970
The motto of the Pinto design, as stated by Iacocca was quote "The Pinto was not to weigh an ounce over 2000 lbs (or 900 kg) and not cost a cent over $2,000." – Iacocca. $2000 is equivalent to roughly $12,800 dollars today.
Due to styling, or aesthetic constraints, locating the gas tank over the rear axle, a location known to prevent fire in rear end collisions, was not desirable. To increase the luggage department or trunk, the gas tank was relocated to the car’s rear – right in front of the bumper. This resulted in the gas tank being outside the frame of the car.
Car was released on Sept 11, 1970 for $1919, competitive with the Beetle and Chevy Vega.
The 41 litre tank was sheet metal and attached with two metal straps.
The fill pipe was attached to the inner side of the driver's side rear quarter panel with a bracket. The other end slid through the top left side of the tank through a sealed opening. – in an accident, the fuel fill pipe was dislodged or the tank itself was punctured or torn. This resulted in fuel leaking onto the ground or into the passenger compartment and often led to a fire.
Since the 1980s, designers have located fuel tanks within the vehicle frame, outside the crumple zones of the car. Typically ahead of the rear axle.
Back in 1966, the motor vehicle safety act was passed, which allowed the US federal government to put safety standards in place for motor vehicles. This was following 5 years of significant increase in vehicle related deaths.
If the possibility of injury is foreseeable, car makers could be held liable for selling a reasonably dangerous product. Crashworthiness had to be considered.
My dad has a 1952 Oldsmobile, which he calls Ingrid, it doesn’t have any seatbelts. The first time I rode in it, I was very confused, though the belts were stuck in the seat. I think that was the first time I realized they used to make cars without seatbelts, which now seems insane, but at the time it was the norm. Lap belts were not mandatory in the US until 1968.
Lawsuits – highly publicized skewing public opinion
On May 28, 1972 Lily Gray driving 1972 Pinto on the California freeway. Car stalled and coasted to a halt in the middle lane (not “normal use” by the way). Hit from behind. Tank ruptured and leaked fuel, causing fire and engulfing the car in flames.
Lily Gray died in hospital.
Her 13 year old passenger, neighbor Richard Grimshaw, suffered horrible burns requiring over 90 surgeries and leaving him permanently disfigured. Their families sued Ford, in a highly publicized court case.
Feb 1978 Grimshaw was awarded $2,516,000 in compensatory damages and $125 million in punitive damages, later reduced to $3.5 million. Case was appealed, but the ruling stood. Court statement “”ford decided to defer correction of Pinto's shortcomings by engaging in a cost-benefit analysis balancing human lives and limbs against corporate profits. Ford’s institutional mentality was shown to be one of callous indifference to public safety. There was substantial evidence that Ford’s conduct constituted ‘conscious disregard’ of the probability of injury to members of the consuming public. The conduct of ford’s management was reprehensible in the extreme. It exhibited a conscious and callous disregard of public safety in order to maximize corporate profits.”
Two key witnesses
Byron Bloch – private consultant and very vocal on shortfalls of auto safety. Had testified on other fuel system fault lawsuits
Harley Copp – previous Ford employee, supporters believe he was forced to retire because he pushed too hard for auto safety.
On Aug 10, 1978 three teenage girls died in a fire caused by their 73 Pinto being rear ended by a van. They stopped to pick up the gas cap, but there was no breakdown lane so they stopped in traffic. They were hit by a van going 80 kph – driver was looking for a cigarette he dropped. The doors were jammed shut from the crash and the occupants were trapped inside. Two of the girls died instantly and the driver died in hospital
A grand jury indicted Ford on charges of reckless homicide and criminal recklessness. First time a corporation was tried for criminal behavior.
In order to prevent legal precedent, Ford assembled a defense at trial, convincing the jury that the Pinto was stopped when it was hit, therefore no low speed collision occurred and deaths were not reckless homicide.
Byron Bloch and Harley Copp testified in this trial as well
Harold MacDonald – engineer in charge of Pinto’s design, testified on behalf of Ford.
MacDonald’s father died in a fire when his Model A burst into flames after a front end collision with a tree. The Model A’s gas tank was in the front of the vehicle, close to the driver.
MacDonald felt very strongly it should be as far away from the passenger compartment as possible
He thought that placing the tank above the rear axle was closer to the passenger compartment and more likely to be punctured by items in the trunk.
Placing the tank above or straddling the axle would be more vulnerable to side impacts which were over twice as common as read end collisions.
Placing the tank above axle would raise centre of gravity, affecting handling properties
Increasing the length and angle of filler pipe would make it more susceptible to damage
Relocating the fuel tank would reduce trunk capacity, make servicing more difficult and a station wagon or hatchback model would not possible
Almost all American made cars of the time had a tank behind the rear axle, not just the Pinto. This represented acceptable engineering practice of the time.
Ford was found not guilty of failure to warn, but the reputation was harmed forever.
11 crash tests of 1971-76 model Pinto’s were tested with speeds between 48 kph and 56 kph
Of four tested at 56 kph, two caught fire and two leaked fuel.
Chevy Vega’s were also tested as a control car – leaked smaller amounts than the Pinto at all speeds and did not catch fire.
Ford argued the test was unfair because all subcompacts had similar risks, although maybe not to the same extent as the Pinto. Everyone else seemed to be able to deflect criticism, except Ford.
The investigation found that rear end collisions of Pintos can result in puncture and other damage to the fuel tank and fuel fill pipe, creating substantial fuel leakage.
When rear ended by a full-size vehicle, the fire threshold is 48-56 kph per hour; residential neighborhood speeds.
In 1972 NHTSA (National Highway Traffic Safety Administration) had set a cost of $200,725/human life. And President Gerald Ford issued an executive order in 1974 to provide numerical estimates of cost and benefits associated with any rules. Numerical values had to be placed on human life in order to provide this data.
Based on a cost of $11/car to strengthen the gas tank integrity, Ford did a cost benefit analysis and determined it was not feasible to make the repair - $49.5 million lost due to burn death, burn injury and burned vehicles vs $137 million to repair 11 million cars and 1.5 million light trucks. But one month after the 1978 report was issued, under immense public and federal government pressure, Ford initiated a recall to replace the filler pipe and add two polyethylene shields to protect the tank.
Recall was estimated at 20 million after taxes. 20% the cost of the death and burn related costs, and 14% of the initial recall estimate. Largest automotive recall campaign at that time.
Formulating rationale of company profit had become a way for engineering teams to communicate effectively with non-engineers in the company. Although engineers amongst themselves understood acceptable risk. You have to find a way to help non technical people understand how and why certain decisions are made.
Many modifications exist; implementing them all is cost prohibitive. Cost benefit analysis is a widely accepted selection method. Although I wish that corporations would be more responsible in designing safer products, but I don’t expect to see this in my lifetime. I would recommend voting with your dollars where you can. If you disagree with a corporation’s decisions, don’t buy their products. Money seems to be the only thing some of them understand.
Ford had done some testing of their own and was aware of the fire risks as early as 1968 and that a relatively inexpensive solution was available. Partially financed a UCLA study that recommended the gas tank be placed above the axle and not adjacent to the rear bumper.
In 1969, three Ford engineers modified Ford Capris to move the gas tank to the rear.
Backed into a wall at 28 kph – welds on gas tank split open, tank was damaged when it hit the axle, fuel fill pipe pulled out, tank fell out of the car. Gas spilled into the interior of the car when the welds split open.
Rear ended at 33 kph – gas leaked from fuel fill pipe or from punctured tank
A 1970 test, Pinto backed into the wall at 33 kph – 18 inch crush of rear end, fuel fill pipe pulled out of tank causing spillage, puncture in upper right front surface caused by contact between tank and bolt on housing, tank was punctured twice by nearby metal objects. Also, both passenger doors jammed shut, prevented escape or rescue.
Ideas proposed in an effort to correct – starting in 1971
There were several ideas looked at by Ford to improve the fuel tank issues, such as a heavy bladder lining the tank, reinforcing the tank walls, shielding of the tank, additional brackets to keep the tank in place, and a flexible fuel fill pipe. The cost of these changes ranged from 22 cents per car to $6/car.
Information, crash test results, etc were pushed all the way up the chain of command, and still no changes were made. Changes required sign off from several levels of management.
Tests were not seen as sufficiently convincing at the time. Ford thought similar test with competitor’s vehicles yielded similar or worse results. Iacocca’s perceived lack of approachability and self-censorship due to a perceived lack of power to change the design or initiate a recall allowed several concerns to go unnoted.
Pinto Memo – gross misrepresentation
Here are some important things to know about the memo.
Written by Ford employees Earnest Grush and Carol Saunby
Unknown to Ford employees responsible for technical design and safety decisions
Intended to influence National Highway Traffic Safety Administration regulators
Not intended to be circulated internally at Ford
Not provided to Ford design engineers or recall personnel
Written in 1973, Pinto was designed in 67-70; couldn’t have impacted design
Written in relation to rollover accidents as a cost-benefit analysis associated with design changes - Didn’t deal with, or mention, the pinto
Related to all new cars, not just Ford’s – 12.5 million sold annually in US
Didn’t estimate a lawsuit cost of $200,000 per death
Aftermath and later reviews
Ford engineers didn’t consider they were “taking calculated risks with consumers’ lives”, the didn’t worry about lawsuits when designing, and “they did not refuse to correct perceived problems because settling lawsuits would be cheaper”
This simply came down to a preference of the devil you know to the devil you don’t – too many unknowns with a new design
Between windshield retention, fuel leakage on front impact, lack of safety glass, and fuel tank placement, there was a lack of consensus that the Pinto was unsafe. Meaning, yes the tank but also this other stuff is unsafe. It seems like everyone just assumed compact cars were less safe.
There was a really interesting comparison in 1975/1976 of all-cause fatalities per million vehicles. Rear end collisions made up about ~15%of the accidents – Pinto ranked fourth in least fatalities out of eight vehicles reviewed and better than average. Datsun 1200/210 was the worst both years
National Highway Traffic Safety Administration finding – 1971-1977 – 38 collisions for Pintos resulting in tank leakage or fire – 27 deaths – same number allegedly caused by Pinto transmission problem (no recall issued)
When I started researching this episode, I was expecting to find a number of flaws with the Pinto design; as well as a conspiracy of bureaucratic and capitalist cover-ups. But that isn’t quite what I found.
There was no conspiracy – “things just happened in a normal way a large technocratic bureaucracy proceeds”
It seems like everyone’s compact cars had one safety issue or another, and that while several Pinto accidents resulted in death, the Pinto was not the deadliest vehicle on the road. I’ve got to say, my thoughts on the Pinto have changed.
Former NSHSA Head Douglas Toms even said that the Pinto was “a very conventional automobile and was designed and constructed comparably with most other cars of its type at the time”
Check out the podcast page, link in show notes, for photos from this week’s episode. And if you want to chat with me, my twitter handle is @failurology. Thanks everyone for listening. If you’re enjoying what you’re hearing; please rate, review and subscribe to the podcast so more people can find it. And don’t forget to tune in next week to hear about the Quebec Bridge, the bridge that collapsed twice. But more on that next week. Bye everyone, talk soon.