The danger of using old tyres on our buses, especially on the front axle, has been discussed many times before but just to highlight the risks again here is a news report that I've just seen on the BBC website about the subject. It relates to a horsebox (ie. private truck conversion), which is about the nearest thing to a bus conversion that you commonly get here:
M5 crash that killed five 'unavoidable', inquest hears
A motorway crash in which five people died could not have been "reasonably" avoided, an inquest has heard.
The driver of the converted horsebox that veered off course after a blowout could not have done anything differently, an investigator said.
Avon Coroner's Court heard there was no legislation requiring a tyre to be replaced at a certain age and its poor condition would not have been obvious.
Richard and Elaine Evans, Audrey Hodge and Adrian Beaumont died at the scene.
Mr Beaumont's partner, Rebecca Mitchell, died in hospital seven months later
(https://ichef.bbci.co.uk/news/660/cpsprodpb/C7DB/production/_97836115_5cc10be4-1a80-4c1c-808b-566977624cd1.jpg)
The crash happened on 16 September 2017, when a tyre blowout caused the adapted Mercedes 1820 box van, driven by Michael Bakewell, to steer to the right and crash through the central reservation barrier.
He collided with two cars travelling in the opposite direction between junctions 14 near Falfield and 15 near Almondsbury.
Forensic collision investigator PC Sharon Little told the inquest the vehicle was "found to have no significant defects before the collision that could have been considered dangerous".
She said: "The great age of the tyres were a significant factor in how the tyre burst. There was nothing readily apparent that the tyre was close to bursting.
"It was not possible for Mr Bakewell to realise there was a problem that day. Mr Bakewell could not have done anything to avoid the tyre blowout or the steering."
She added that there was nothing the drivers of the other two cars could have done to avoid the collision, which was timed at less than a second after the van went through the metal barrier.
PC Little said the Subaru Forester, carrying driver Richard Evans, 66, his wife, Elaine Evans, 62, and her mother, Audrey Hodge, 84, was "torn apart" and left "almost unrecognisable" following the collision.
She said the Seat Leon carrying Adrian Beaumont, 46, his partner, Rebecca Mitchell, 42, and their 12 year-old son and 10-year-old daughter, from Bristol, was forced off the road by the van and overturned down an embankment.
Mr Beaumont died at the scene, while Ms Mitchell suffered serious brain injuries and died at Southmead Hospital seven months later. Their children are still recovering from their injuries.
The inquest continues.
https://www.bbc.co.uk/news/uk-england-bristol-47403571 (https://www.bbc.co.uk/news/uk-england-bristol-47403571)
Jeremy
(Image below is just to give an idea of the size of a Merc 1820 horsebox - it's not the actual vehicle involved in this accident)
(https://horseboxseller.com/images_product/large/x13-582-l1.jpg.pagespeed.ic.6RhW37cqQz.jpg)
How old?
Here's the reference to the age of the tyres.
https://www.bbc.com/news/uk-england-bristol-47387676 (https://www.bbc.com/news/uk-england-bristol-47387676)
Tire failure aside, I wonder how fast he was driving on that road?
Quote from: chessie4905 on February 28, 2019, 12:10:19 PM
Tire failure aside, I wonder how fast he was driving on that road?
A truck that size will (I think, although horses are heavy) be designed to fit within the 7.5 ton classification, which means that it can be driven on a standard car driving licence and at up to 70mph on dual carriageways and motorways. If it was more than 7.5 ton (or was articulated) then the max. legal speed would be 60mph
Jeremy
Front tire (tyre). I'm guessing it totally exploded but I've seen the Michelin videos showing that braking will increase the out-of-control factor while pressing the accelerator until the vehicle is stable will allow the driver to stop the vehicle safely. If the tire exploded and completely shredded, maybe there's nothing that could have been done, but maybe if the deflation was gentler, good training might have made a difference.
It's impossible to really know, of course.
A few years ago, it was recommended by the tire manufacturers to put the best tires on the front of the vehicle, then in the past few years they reversed themselves and are now telling people to but the best tires on the back. Illogical to me, so I still put the best tires on the front.
I thought that was just on cars, especially fwd ones.
At the Michelin test facility in Laurens SC they demonstrate on wet surfaces how the best tires when on the rear make a huge difference in preventing loss of control.
It applies to all vehicles, but that has nothing to do with loss of control from a sudden blowout or zipper failure which is an entirely different situation.
What do zippers have to do with this?
All I know is that it is not that bad if you forget to pull it up-- it's only a problem if you forget to pull it down...
It's all about when your 'gator gets loose.
Jim
Or Volkswagen with two flat tires
Quote from: Oonrahnjay on March 07, 2019, 07:57:51 AM
Front tire (tyre). I'm guessing it totally exploded but I've seen the Michelin videos showing that braking will increase the out-of-control factor while pressing the accelerator until the vehicle is stable will allow the driver to stop the vehicle safely. If the tire exploded and completely shredded, maybe there's nothing that could have been done, but maybe if the deflation was gentler, good training might have made a difference.
It's impossible to really know, of course.
I've had a couple of blowouts ( the second one made me a believer in date codes ) that were complete sudden catastrophic failures. Applying the accelerator definitely improves stability.
Still a good idea to not yank the steering wheel back & forth. :P
I did not see where the age of the tyres was mentioned. Does this apply to tires also?
Quote from: Lin on March 08, 2019, 08:54:56 AM
I did not see where the age of the tyres was mentioned. Does this apply to tires also?
From the first post -
Forensic collision investigator PC Sharon Little told the inquest the vehicle was "found to have no significant defects before the collision that could have been considered dangerous".
She said: "The great age of the tyres were a significant factor in how the tyre burst. There was nothing readily apparent that the tyre was close to bursting.
Stating that the age of the tires was the cause is not helpful without mentioning the age. Was it 9 years or 19 years? Inflation could have also been a critical factor that is unverifiable now. If they were improperly inflated to begin with, or if there was a leak, that could have even been a greater issue. Hence, many choose to use TPM's. I understand that PC Little is doing the best she can with what information she has, but it may not be the whole story.
For those asking about the specific age of the tyres....see the first reply to the original post
Jeremy
Yeah, 18 years is pretty questionable.
Jim
" sure my tires are old, but they look like new." The years sneak by when you age and twenty years seem more like 5 or 6.
I'm no advocate for new laws and regulations but it does seem that at a good start at least would be to require tyre manufacturers to state the production date on the sidewall in large and easily-read text
Jeremy
You think they should put an expiration date?
Jim
Possibly, if some formula could be agreed that took all the variables into account - although expiration dates might then replace common sense:-
"I don't care if it's got a crack in the sidewall right through to the belting - it's within date so it's legal and I'm going to use it!".
Better perhaps for the public to become more educated so that "tyre age" becomes as important as "tyre wear" in their consciousness. How you achieve that I have no idea.
Jeremy
It would be nice if some type of UV exposure meter could be built into the sidewall - enough UV hits the sidewall, and suddenly a warning emerges and comes into view. Of course, that would require a determination to be made which establishes a safe amount of UV exposure is safe for a tire and over what period of time. Same could be done for other environmental dangers.
Or, we could do a better job of teaching about this in basic drivers ed classes. I don't remember anything about tire safety being taught other than checking air pressure and tread depth.
They could put flashing lights and a siren on tires to indicate when they reach a certain age and there would remain the same number of RV owners that will continue to use tires so old the rubber is as hard as a rock. It is almost like a blue ribbon to be able to brag about driving cross country on 20 year old ties.
Think I'm kidding? Go back and read some of the posts on here.
The DOT in most jurisdictions does not care about the age of tires. They look for their condition: tread wear, cuts, cracks, etc. I have tires that are cracked at 4 to 5 years old. Others that look great at 15 years old and would satisfy a DOT officer.
JC
Since there was no thorough analysis of just what caused the tire to explode. Was it age, underinflation, or impact with a foreign object, brand of tire, overload, etc? Overall, still good info to, at least to maintain reasonably fresh front tires.
Maybe that vehicle has a high percentage of weight on the front wheels or some other factor.
The easiest way to understand clearly that the experts who design, build, and recap the tires consider age a factor is to see if any tire will be accepted for recapping if it is older than 6 years, regardless of how it looks.
They won't recap an old tire.
Tire makers could come up with an indicator if they wanted to. Hardness of the rubber is a standard metric. All tires are rated for the hardness of the tread. Tread hardness is inversely related to the volume of solvents, plasticizers, and other liquids in the rubber, which "outgas" or evaporate over time, making the compound harder. That's always been known. For any given compound, the ratio of liquids to hardness is also well known, as is the point at which cracking, cord separation, and other failures will begin to occur. So all that is needed is some type of detector to measure the remaining non-solid components in the rubber.
Maybe they could include a dye that creates a loud contrast when the rubber gets too brittle. Then, "Hey! You got pinwheel tires! Time for new ones.
Jim
The entire conversation about old tires is contained within we RV, busnunts, etc., that drive minimal miles in a non-commercial setting. 99% plus miles of truck tire sizes are put on in commercial use. As long we we fall through gaps and loopholes, that portion of unaccounted "shrinkage", nothing is going to change with respect to regulations, leaving we busnuts to decide when to retire old but unused tires.
We need to get some made up out of the rubber they use in tractor tires. Ever notice how they can sit out for decades in the weather and never so much as a crack anywhere until they're near the half century mark or beyond it?
Jim
my old 1998 kubota tractor tires never had any cracks on them and it sits outside for 7 mths of the year in the sun . 21 years young and no reason to change them
dave
I have some Firestone lease tires on my other 4905 parts coach. Been sitting out in the weather for 25 years. Just last year starting to develop small cracks on sidewall near rim.