Bus crashes

[windtrader]

What is still missing is any rationale if tire age is such a critical safety issue why would the CHP inspection rules not have tire date code checking on their list? Also, it is fair to say the tire lobby has constantly pushed for the date code inspections as that would increase sales (not sure how much) by forcing aged tires off the road. Just does not add up guys.

[Nel]

I'm no tire expert but I still think from my experience and like I said in my reply earlier, I'm running 12r 22.5 old tires with like new tread and at the speeds I'm traveling and keeping an eye on tire pressure so far so good. I think tire companies do have an interest when giving tire advice, why wouldn't they to make a buck. Most of these casualty bus accidents are from commercial companies where time is money and I'm sure they are speeding towards the next job with full loads of people and cargo unlike most of us bus/rv owners . I also think these commercial type truck and bus tires we are running are made to take a lot more punishment than we might give them in the RV world, Just my opinion. Nelson

[Scott & Heather]

Interesting article discussing why the transportation board hasn't set an aging standard yet: http://www.tirebusiness.com/article/20140721/ISSUE/307219981/nhtsa-nixes-tire-age-safety-rule


Sent from my iPhone using Tapatalk

[daddysgirl]

To each their own . . .
I am amazed at the casual concern some have concerning tires.
As Scott has shown, tire failures can leave a significant impact.

Isn't the CHP is the enforcement arm of the litigation part of the government? So, when it comes to my tires, I am placing my trust in what the tire engineer has to say about tire life.

Cause of tire failure are many & complex. Some damage is cumulative, so the tire fails because of something seemingly small . . . . .

A very good friend recently had a steer tire blow. Tire was only 6 years old & always properly maintained/ inflated.

While I visually inspect my tires at every chance I get, I still can't see inside the sidewall. So, I will replace them based on position & age as I deem appropriate.

YMMV
Seems there is lots more to tire rubber compounding than most mortals can comprehend.

I don't suppose your friend was on I-95 outside of Charleston? There is/was an issue with 95 somewhere in the vicinity?  If so, we might share a friend.

[kyle4501]

I don't suppose your friend was on I-95 outside of Charleston? There is/was an issue with 95 somewhere in the vicinity?  If so, we might share a friend.

Nope, he was still in Florida, not too far from home, just starting out on his trip.

[eagle19952]

Just does not add up guys.

yeah it does, u just don't seem to want it too.

The DOT concentrates it's inspection $$'s on commercial operators.
News Flash... they don't take 7 years to wear out a tire.

[kyle4501]

What is still missing is any rationale if tire age is such a critical safety issue why would the CHP inspection rules not have tire date code checking on their list? Also, it is fair to say the tire lobby has constantly pushed for the date code inspections as that would increase sales (not sure how much) by forcing aged tires off the road. Just does not add up guys.

You are assuming the CHP knows what they are doing . . . . 
CHP doesn't make the laws, they just enforce some of them.

[Jon]

The beauty of being non-commercial operators is we are free to do anything we want and there is nobody to inspect us or regulate us. So if we are comfortable driving on old tires we are just as right as those of us that are uncomfortable doing the same thing.

But to use the previously mentioned Statesville church bus as an example there are now 7 or 8 people dead because it was known to have had a blowout. The driver was not an amateur. It was a commercial truck driver with a lot of driving experience so those that think they can take the risk because they know how to drive may be in denial. That bus went from the eastbound lanes of I-40, through a cable barrier, into the rear of a Tahoe killing the rear seat passenger, head on into a west bound semi killing the driver, and then laid over killing some of the people on the bus including the driver and his wife. There was never a mention in any of the reports I saw regarding tire age so it is anyone's guess as to what happened.

Yes new tires have blowouts, but new tires are driven at lower pressures than called for so to justify driving on old tires is like saying it is OK to drive without a seat belt because sometimes you can get trapped in a burning car.

I also think it is foolish to think police officers who do commercial inspections are not very smart. When I was in a Bendix Brake certification class there were not only mechanics in the class, but there were law enforcement officers and accident investigators. They were very well informed and had a deep understanding of commercial vehicles and took the class very seriously. I doubt if anyone could get past them with anything. They don't inspect tires for date code because there are no applicable regulations, but they do inspect for pressures, valve stem caps, tread depth and physical damage so they get it.

[B_K]

OK first off OLD TIRES ARE DANGEROUS! PERIOD!
Yes I know some people have run tires that are 10-15 yrs old and had no problems.
But they are taking huge risks every time they turn the ignition on!

Now for the issue of DOT inspectors.
They are like anyone else and only as good as the training they have received and how well they apply it!

I have driven commercially for a living for 35+ yrs and I can tell you I have seen DOT officers that would make Barney Fife look like Albert Einstein and at the same time some that would make Albert Einstein look like Barney Fife!

I have personally seen a DOT officer miss blatant obvious violations on a truck while stubbornly concentrating on looking for simple and insignificant violations.

I once had found a cracked rim on a pre-trip inspection and had called and found a shop that had a new wheel in-stock and was on my way to get it replaced and got stop by a CHP DOT  officer that was doing roadside inspections less than a mile from where I was going on hwy 395.
He wrote me up for that tire being low on pressure but did not say a word about the obvious crack I was staring at.
When I pointed out that the rim was cracked and I was going to the tire shop right down the road to get it fixed and that was the only reason it was low, he threatened to put me out of service for the cracked rim if I didn't sign his ticket for the low tire. He never even went back to the tire/rim in question to look at it. He just wanted to get his citation signed showing he found a problem. It wasn't at all about safety as much as it was the $ for writing an out of stat trucker a ticket! I signed the ticket, took the truck to the tire shop, took pictures before and after they changed the wheel, got them to make duplicate copies of the ticket, and the receipt for the new wheel and labor.
Then I finished my trip and went home. Once home I wrote a letter explaining exactly what happened and sent the copies of the ticket and pictures along with it. Several days later I got a call from the assistant prosecutor for the court asking me what all of it meant.
I told him I was very upset that they wrote me a ticket for something a s minor as a low tire when I told the officer I was going just a mile up the road to get it fixed and had already made an appointment with the shop that he could call and verify if he wanted too. And that even WHEN I POINTED OUT THE CRACKED RIM ALL THE OFFICER CARED ABOUT WAS ME SIGNING THE TICKET HE ALREADY WROTE! 
The prosecutor asked so does that mean you intend to fight this ticket?
I told him if he was unwilling to dismiss the ticket and send me proof it was dismissed yes I intended to fight it!
He told me it seemed awful silly to waste all the time and $ to come out and go to court to fight such a little ticket! I told him I didn't care about the $ or the time it was the principal! He told me "See ya in court then, have a nice day!"
So I hired a local attorney who showed up in my behalf and got the judge to dismiss the ticket right away! It cost me $150 to fight a $35 ticket but I was happy!

Another time down on I-8 me and 4 other trucks rolled across the scales in Winterhaven, CA (just outside of Yuma, AZ) and out of the 5 I was the only one pulled in.
As I gathered my paperwork (log book, registration, and bills of lading) that I knew he would be asking for he walked out and told me it'll just be a minute, as he walked on by.
When he came back he had a 6' ladder, a flashlight, and an extendable mirror.
He told me I just want to make sure that you have mufflers in those stacks. (I had 10" stacks on the truck and trust me I bought and put them on the truck and there were no mufflers in them!) I started to admit there was not a muffler in there when he looked in with the mirror and  said "yup I see it, you can go, have a good night!"

So again they are only as bright as they wanna be!
  BK 

[Zephod]

I drive school busses for work. The dot code on the rear duals on some busses is 4007 indicating week 40 of 2007. Those tires are unlikely to be retreaded. In the view of the work mechanics, they're fine on duals. The steers are what need to be pristine.


Sent from my iPad using Tapatalk

[windtrader]

@Nelson - Although the tires on bus conversions and commercial trucks and trailers are the same, the usage pattern is very different. Surely, the tire manufacturers make commercial tires best support commercial use/abuse; busnuts driving old buses are not even on their radar. If busnuts perform regular tire checks before and during trips, I'd be a tire related issue is caused by something other than age.

@Scott - Great link, My followup to your post is in another post.

@Kyle - Tire science and failure analysis are complex subjects, far far beyond my abilities. I can research the work of other reputable organizations and make sense of their findings. Read the following post. California Highway Patrol does enforcement of laws including laws related to safety of commercial trucks. They do not legislate the laws, business, lobbyists, DOT, etc and legislators do. I have zero experience as a professional trucker so I have no idea how long commercial tires keep rolling. I do know commercial tires are engineered to be recapped multiple times, keeping that original casing on the road longer. I do see many stored and dusty trailers and wonder how old those tires may be and whether a trucker hired to haul that trailer will refuse the load due to aged out tires. I'm kind of thinking the trucker will ensure the tires have tread and sidewalls look fine and defect free, then hop in and go.  Please see the following post.

@Jon - It is not just busnuts who can drive old tires. As you state, there are age requirements for safety inspections so commercial truckers drive them too. From multiple chats with the CHP and commercial vehicle inspection team, they take safety extremely seriously and are very knowledgeable what a safe truck looks like. A tour operator who I spoke with told me two guys show up and spend all day on ONE coach performing the required inspection. I asked who pays for that, he said it comes out of the various governmental fees and licenses they pay.

It is difficult to make a case giving a specific tire related accident. Please read the full report in the following post. Even the experts and I do mean experts are often unable to identify the true cause of failure.

@BK - With 35+ years of commercial truck driving, I'd argue they did an excellent job as the hundreds of other times, I'm guessing they did not miss a cracked rim.

@Zephod - After all the hoopla I create around here, this time on aged tires, I'm thinking the best compromise solution is to have two current newer steers and keep old (aged) tires on the duals and tag, checking them every trip and monitored by TPMS for pressure and temp.

[windtrader]

I researched Scott's link. Good start. I contacted the author, Dan Zielinski, Sr VP at the Rubber Manufacturers Association (RMA), the national trade association for tire manufacturers. As their address is K st in DC, obviously a paid lobby group.

From the original article
"The RMA and its members have commented extensively to NHTSA during the long process of tire-aging tests, Mr. Zielinski said during a July 11 conference call on the NHTSA report and other issues. The agency has conducted five separate phases of tire-aging tests since 2002.

"Over time, the agency was not able to articulate, at least to us, what the benefits of a tire-aging rule would be," he said. "They believe tires are performing better than ever, because of the new safety standards.

"I would add that the evolution of tire technology has also played a role, as manufacturers strive to improve tire performance," Mr. Zielinski said.

Meanwhile, the RMA succeeded in getting language added to the newly passed Colorado scrap tire management bill that makes it illegal to sell an "unsafe used tire" in the state, according to Mr. Zielinski. Colorado defines an unsafe used tire as whatever would cause a tire to fail a state safety inspection, he said. "

NHTSA's research on tire aging concluded with a report issued in 2014.
https://www.regulations.gov/document?D=NHTSA-2005-21276-0073

Please read it full, it is not that long. Following is a portion for those who do not.

The case for TPMS
Tire aging failures tend to appear in the high heat states, in the summer months,
during the day, while the vehicle is being driven at highway speeds. All of these factors make it
more difficult for the tire to dissipate heat, and heat build-up is the main factor in these types of
failures

The results of this research indicated that there are two mechanisms operating to produce
changes in tire properties. First is degradation of the rubber compound and material interfaces
due to the effects of heat and reaction with oxygen (thermo-oxidative aging). The second is the
effect of cyclic fatigue during tire deformation, which can initiate and propagate cracks and
separations.

In summary, NHTSA's main findings with regard to tire aging can be listed as follows:
• The aging mechanisms that are most likely to affect the relative safety of a tire are
chemical and mechanical in nature. Chemical aging occurs due to the combined
effect of heat and oxygen on the rubber compound and mechanical aging results from
the stresses and strains that a tire incurs during its normal use.
• In the warmer parts of the United States where we have data, including Arizona,
Florida, Texas and Southern California, there appears to be a relationship between the
age of the tire and the propensity of the tire to fail.
• Tire aging failures tend to appear in the high heat states, in the summer months,
during the day, while the vehicle is being driven at highway speeds. All of these
factors make it more difficult for the tire to dissipate heat, and heat build-up is the
main factor in these types of failures.
29
• Artificially aging a tire in a laboratory oven is a scientifically valid method to
accelerate the tire aging process and to simulate a naturally aged tire in service on a
vehicle.
• Our current oven-aging protocol approximates the aging experienced by a tire with
four years of service in Phoenix, Arizona.
• Oven-aged FMVSS No.139-compliant tires developed less severe failure modes
(mostly cracks) than oven-aged pre-FMVSS No.139 tires after endurance and low
pressure test.
VII. CONCLUSIONS
When Congress suggested the idea of a tire aging test requirement, passenger car tires and
light truck tires were regulated under FMVSS No. 109 and FMVSS No. 119 respectively. It was
believed at the time that a tire aging standard would make tires more resistant to degradation.
The agency believes that an improved roadwheel performance of oven-aged FMVSS No. 139-
compliant tires when compared to oven-aged pre-FMVSS No. 139 tires and an overall reduction
of tire-related crashes have lessened the tire aging concerns since the TREAD Act was enacted.
At this time, the agency does not believe it is necessary for motor vehicle safety to add a tire
aging requirement to its light vehicle tire standard due to the following reasons: First, FMVSS
No.139 has contributed to an increased robustness of oven-aged light vehicle tires. Our research
has shown that oven-aged FMVSS No. 139-compliant tires are more resistant to degradation than
oven-aged pre-FMVSS No. 139 tires. Second, light vehicle tires are performing better on the
road as reflected in our most recent crash data. Third, a mandatory TPMS on light vehicle tires
30
since 2007 has helped alert consumers to under-inflation, which is also known to degrade tires
faster.
Tire aging is still a concern for the Sun Belt states, during the summer months when heat
build-up can cause a failure. Spare tires remain a concern as well, since they are not replaced
regularly and may still show enough tread, even though the structural integrity of the tire may be
compromised by aging. Adding to this concern, spare tires are often rotated into use and are sold
as used tires.
For the reasons stated above, the agency is coordinating a promotional and educational
campaign to raise consumer awareness about tire aging issues and how to prevent these types of
failures. Campaign initiatives and outreach efforts to consumers, partners and the automotive
service industry will include social media messages, fact sheets, infographics, and other web
content.

[Jon]

The apparent theme is it is required to have relatively new tires on the steers, but OK to run aged tires on the drives.

I am not familiar with any coaches other than a Prevost, but I know for certain if a drive axle tire lets go the driver still has to exercise good control over the coach. Even if only one of the duals fails the remaining tire also has been ruined because it is now carrying more weight than its air pressure will safely carry. The lucky drivers will retain control and no damage other than a couple of tires will occur. But more often than not a blowout on the drives is going to deeply affect a wallet. It is common for body damage to be a result as the tread begins slapping around before it departs the vehicle. It can and has resulted in the loss of body panels, "fenders", muffler, and side engine doors.

If an inner drive tire comes apart it is not unusual to have air bags or brake chambers or both damaged along with other significant damage to the coach.

It all comes down to a risk versus reward calculation and owner considers when evaluating the risk of running on old possibly dangerous tires. BK has much more experience in this and I hope he offers an opinion.

[Nel]

Thanks for that article Don, I feel better about running older tires now, but I wasn't too worried about it before and like I said running them on my 55 - 60 mph  speed demon 4104 helped.

[windtrader]

@Nelson - Your welcome.

I'm glad to have gotten pulled down this rat hole, hey, I  don't even have the bus to worry about. LOL But most used coaches are running less than new tires, many getting toward that "aged" timezone. This has a bearing on the value of the coach, so that is why it's important for bus buyers to understand this topic and know what you face when buying that coach with "used" tires' Makes a big difference if you can run for some time on 7 year old tires that look nearly brand new vs some 50% tires that are a decade older or more.

Each person forms their own opinion based on different criteria and factors. Anecdotal stories, first person experiences, science based reports, group think, etc. all weigh in on how one forms their own opinion. Obviously, I am fact and expertise based and my opinion is based on industry science tests and reports, conversations with government agencies that make and enforce rules regulating tire usage, and NGO that lobby between government and private sector business related to rubber tires.