There are many ways in which a coach will crash and not cause fatalities - no fire being one of them. Train, plane and coach travel are all safer ways to travel than by private car or motorbike. When a fatal accident happens in public transport always many questions are asked and there’s a lot of analysis to find how to prevent it happening again.
But how can a coach crash and all of the seats rip away from the floor?
Are we talking about a specific incident or is this a hypothetical?
I would assume that if the structure of the coach was severely corroded, to the point that the seats were held in place by a small fraction of the original construction, then sudden deceleration could well cause the seats to rip from the floor.
Another possibility is that some nefarious character loosened the fixing bolts, or weakened the anchor points in some way.
But what if the bus/coach was a new vehicle, only two years old and in good condition and run by a reputed company, the passengers had no reason to be ‘sabotaged’ in any way, the accident was unforeseen but, crucially, predicted by other motorists in the vicinity. Still, the carnage seen does not relate to other coach/bus crashes. What, exactly, went wrong here?
You obviously have a particular incident in mind. Care to enlighten us?
I’m guessing maybe that bus crash in Switzerland a few days ago?
From the linked article:
If that’s the case, I’m pretty sure that ramming into a wall at 62mph would decelerate the vehicle suddenly enough to cause whatever is holding the seats to the floor to fail.
The tragic event in Switzerland, yes. I saw no threads on the subject which is why I was being obtuse. I don’t recall an event as this happening because of a crash, so I’m wondering as to whether all buses or coaches would react in this manner.
I thought that was possible, but the reports I’ve read do not indicate that all the seats came loose - indeed photographs indicates that the back ones are in situ.
But in the crash the floor is going to be crumpled which will weaken the fixings, and the seats are heavy and have massive objects (people) attached, and momentum is going to cause them to try to continue to travel forwards. They might well sheer free of the fixings.
I’m unfamiliar with the case, but it sounds like that’s the report of a (justifiably) scared young girl. I’ve been in only one bad accident, and it was quite disorienting. It felt from my perspective as if I was hanging in place, and the vehicle and things in it were moving all around me, and changing shape and distorting in space. Of course, it wasn’t really doing that; I was the one moving, in ways a body doesn’t normally move through a car.
The news report does state that suitcases were found scattered across the road. So we do know that some large objects were flung around.
The front seats, the report says, are “all smashed against each other,” but it’s not really clear from that if they were dislodged from the floor, or if the floor accordioned as the front end of the bus hit concrete, bringing the seats closer together because the floor space got smaller.
So lets back up a bit: Do we know, in fact, that the seats were dislodged during the accident?
Many years ago a similar accident occurred here in Australia in 1989. The coroner was scathing in his criticism of the lax attitude to safety on buses. In response the government instituted new design rules for buses (Australian Design Rule 68/00 - Occupant Impact Protection in Buses) that includes specific tests for seat mounting strength. It was only in 1994 that this standard became mandatory on all coaches. What is interesting is that the Australian standard was much stricter than the equivalent EU standard, and indeed it was determined that even if the buses had met the EU standard they would not have protected the occupants sufficiently. Since then the EU has updated its standards, to standards that look (to my non mech-eng eye) as if they are nearly as strict as the current Australians ones, and coming into force in 2001. But these are standards for new vehicles. Usually older vehicles are not required to be updated. Indeed in Australia coaches can be up to 25 years old. Those built before our new standards still drive the roads. In the EU the situation is likely similar. Individual countries enforce the standards, and without knowing a lot about the exact nature of the bus, its age, and country of registration, we don’t know that it wasn’t built to a standard much too low to allow this accident to be survivable. If the coach was built before 2001 it is possible it was never built to a standard that would have made the accident survivable. Also these standards apply to long distance coaches that travel at high speeds on highways. Minibuses and buses used for low speed commuting are built to lower standards. Some depressingly lower.