Front engine safer than rear?

[XJ Flyer]

Mave said:

But, as I said, its actually about distributing load through the crumple zone. Actually, while the engine playing the part of load distribution in the transverse layout, further longitudinally concentrates it's force. The engine is stiff, so to the point in question, the BMW penetrates the crumple zone, but the Volvo to the point in question defeats the opponent's crumple zone. Further, in the offset test in question, the 911 defeat's the BMW's bulkhead.

Firstly the photographic evidence of the BMW v 911 shows which car defeated which's bulkhead area to catastrophic degree at least in that case.

The video evidence shows that the offset head on,between the longitudinal layout Volvo and transverse layout shopping car,predictably resulted in the transverse layout defeating the crumple zone of the front wing structure and the exposed bulkhead of the Volvo.

As for the engine playing any part in spreading the load through the crumple zone of a transverse layout.It is more a case that transverse usually means trading less crumple zone in the form of less length of bodywork from bulkhead to bumper.In exchange for the engine acting as a barrier in front of,and spreading the impact load across ,the bulkhead area.Which translates as being more likely to be able to defeat both the crumple zone and exposed bulkhead of a longitudinal layout in an offset head on type collision.

The common link being that the engine really needs to play a part in optimising frontal,especially head on,type impact protection.Which of course is impossible with the rear engine layout.

[Mave]

XJ Flyer said:

Mave said:

But, as I said, its actually about distributing load through the crumple zone. Actually, while the engine playing the part of load distribution in the transverse layout, further longitudinally concentrates it's force. The engine is stiff, so to the point in question, the BMW penetrates the crumple zone, but the Volvo to the point in question defeats the opponent's crumple zone. Further, in the offset test in question, the 911 defeat's the BMW's bulkhead.

Firstly the photographic evidence of the BMW v 911 shows which car defeated which's bulkhead area to catastrophic degree at least in that case.

The video evidence shows that the offset head on,between the longitudinal layout Volvo and transverse layout shopping car,predictably resulted in the transverse layout defeating the crumple zone of the front wing structure and the exposed bulkhead of the Volvo.

As for the engine playing any part in spreading the load through the crumple zone of a transverse layout.It is more a case that transverse usually means trading less crumple zone in the form of less length of bodywork from bulkhead to bumper.In exchange for the engine acting as a barrier in front of,and spreading the impact load across ,the bulkhead area.Which translates as being more likely to be able to defeat both the crumple zone and exposed bulkhead of a longitudinal layout in an offset head on type collision.

As stated earlier, the key consideration is the length of crumple zone, and ability to effectively ustilise the energy absorbtion. The transverse layout results in significantly more efficient transfer of crumple zone, but the desire to indicate packaging efficiency results in shorter layout. Nevertheless, the transverse layout trades higher impact protection with regards to length than the in line layout, whereas inline typially has higher bonnet length

[XJ Flyer]

Mave said:

As stated earlier, the key consideration is the length of crumple zone, and ability to effectively ustilise the energy absorbtion. The transverse layout results in significantly more efficient transfer of crumple zone, but the desire to indicate packaging efficiency results in shorter layout. Nevertheless, the transverse layout trades higher impact protection with regards to length than the in line layout, whereas inline typially has higher bonnet length

I'd agree with that although obviously maybe for slightly different reasons.However the superiority of the transverse layout v longitudinal arguably reduces massively in the case of a square on head on collision as opposed to an offset one based on my reasoning.Let alone in the case of front engined v rear engined.Maybe the media like 5 th gear would like to prove me wrong with some relevant crash tests.

[Mave]

XJ Flyer said:

I'd agree with that although obviously maybe for slightly different reasons.However the superiority of the transverse layout v longitudinal arguably reduces massively in the case of a square on head on collision as opposed to an offset one based on my reasoning.

No, it doesn't. The longitudinal layout just reduces the total available crumple zone length for everyone.

[Foppo]

I have never thought about which car is safer or not regarding engine layout.

Some of my cars where VW Beetles nothing in front except a spare tyre.

Don't know about crash test but I would think that a engine in front in a head on crash would give you some protection.

Crumple zones and airbags obviously help but anything above a certain speed and depends if a lorry runs into you.You are in the hands of the Gods me thinks.

[XJ Flyer]

Mave said:

XJ Flyer said:

I'd agree with that although obviously maybe for slightly different reasons.However the superiority of the transverse layout v longitudinal arguably reduces massively in the case of a square on head on collision as opposed to an offset one based on my reasoning.

No, it doesn't. The longitudinal layout just reduces the total available crumple zone length for everyone.

The longitudinal layout is actually just another variation on the same advantages which the tranvserse one has in that crumple zone alone won't save anyone.That is because it is actually all the about the 'combination' of ,and resulting interaction between,the ability of the crumple zone to absorb energy and the ability of the engine and bulkhead combination to transfer energy into the opposing car's structure by way of penetration/intrusion while resisting same vice versa.

Which is why I'd prefer to be sitting in something like an E or S class than a 911 or a transverse engined shopping trolley/rep mobile in a severe square on head on.That 'might',possibly,be different in the case of the transverse shopping car in the event of an offset head on.

[Finlandia]

Forget about the square head on, the majority of crashes are offset in some way (trying to avoid a crash) or only cover a small part of the width of the car (crashing into a tree or road furniture/structure).

[XJ Flyer]

Foppo said:

I have never thought about which car is safer or not regarding engine layout.

Some of my cars where VW Beetles nothing in front except a spare tyre.

Don't know about crash test but I would think that a engine in front in a head on crash would give you some protection.

Crumple zones and airbags obviously help but anything above a certain speed and depends if a lorry runs into you.You are in the hands of the Gods me thinks.

^ This.Although having more metal in front can only help.Not car v car head on but shows that there is a point where having no engine and/or just not enough metal in front in the form of both engine and crumple zones are more or less as bad as each other.

www.youtube.com/watch?v=YRbwTutw-Hk

www.youtube.com/watch?v=029nFGSzZZY

[Finlandia]

XJ Flyer said:

^ This.Although having more metal in front can only help.Not car v car head on but shows that there is a point where having no engine and/or just not enough metal in front in the form of both engine and crumple zones are more or less as bad as each other.

www.youtube.com/watch?v=YRbwTutw-Hk

www.youtube.com/watch?v=029nFGSzZZY

You can't compare offset (VW) with full head on (Volvo) crash tests.

[XJ Flyer]

Finlandia said:

Forget about the square head on, the majority of crashes are offset in some way (trying to avoid a crash) or only cover a small part of the width of the car (crashing into a tree or road furniture/structure).

On that note it would have at least been interesting to find out 'if' the Volvo 140 might have performed better in the offset head on v the transverse engined test than the Volvo 7 series.It is my guess that the 140 seems to have been built like a tank by comparison with the later car.

However all the reasons as to why the longitudinal layout is flawed in that specific case are the same reasons as to why the rear engined layout won't perform in either in the case of the square on or offset scenarios.

[XJ Flyer]

Finlandia said:

XJ Flyer said:

^ This.Although having more metal in front can only help.Not car v car head on but shows that there is a point where having no engine and/or just not enough metal in front in the form of both engine and crumple zones are more or less as bad as each other.

www.youtube.com/watch?v=YRbwTutw-Hk

www.youtube.com/watch?v=029nFGSzZZY

You can't compare offset (VW) with full head on (Volvo) crash tests.

It is my guess that there wouldn't have been a big difference in either case.Firstly the Beetle didn't have an engine at all to contribute to the resistance to intrusion offset or square on and the Golf obviously had the benefit of a transverse layout.

Which worked in the case of the 740 v shopping trolley offset head on test.Therefore like choosing the offset scenario to make the shopping car look good I'm guessing that they also chose the obviously inferior impact resistance of the 7 series Volvo instead of the 140 series for the same reason.IE the longitudinal layout can still work even in the offset scenario but it needs to be a good one to do it.While even the transverse layout can't always compensate for just too much lack of metal to crumple and resist intrusion.

[Finlandia]

XJ Flyer said:

On that note it would have at least been interesting to find out 'if' the Volvo 140 might have performed better in the offset head on v the transverse engined test than the Volvo 7 series.It is my guess that the 140 seems to have been built like a tank by comparison with the later car.

However all the reasons as to why the longitudinal layout is flawed in that specific case are the same reasons as to why the rear engined layout won't perform in either in the case of the square on or offset scenarios.

The problem is when cars were built as tanks, the occupants take the full hit, the driver of this sl 230 died but the car doesn't look too badly damaged.



When cars crumple like the 911 and BMW shown here you stand a chance to survive, both drivers did but sadly the passenger of the BMW died.

https://www.youtube.com/watch?v=bDyvOGW_80o

[DonkeyApple]

Finlandia said:

Forget about the square head on, the majority of crashes are offset in some way (trying to avoid a crash) or only cover a small part of the width of the car (crashing into a tree or road furniture/structure).

This is why it's important to ensure you steer into a head on collision than try to avoid it. It's also best done with a car designed in the early 50s as this was the pinnacle of safety cell design.

[XJ Flyer]

Finlandia said:

XJ Flyer said:

On that note it would have at least been interesting to find out 'if' the Volvo 140 might have performed better in the offset head on v the transverse engined test than the Volvo 7 series.It is my guess that the 140 seems to have been built like a tank by comparison with the later car.

However all the reasons as to why the longitudinal layout is flawed in that specific case are the same reasons as to why the rear engined layout won't perform in either in the case of the square on or offset scenarios.

The problem is when cars were built as tanks, the occupants take the full hit, the driver of this sl 230 died but the car doesn't look too badly damaged.



When cars crumple like the 911 and BMW shown here you stand a chance to survive, both drivers did but sadly the passenger of the BMW died.

https://www.youtube.com/watch?v=bDyvOGW_80o

There are lots of variations and possibilities which make certain scenarios survivable and others not in addition to a large amount of luck.

In general impact resistance and survivability is all about getting the balance between crumple to cushion the impact 'and' resistance to intrusion right,bearing in mind that the two are contradictory to each other.While the ability to transmit more energy into the opposing car while resisting same can help to shift that balance.

I'd still say that known legendary abilities of certain cars in banger racing over others provides a reasonable guide to that balance.

On that basis I really wouldn't want to meet most front engined cars of most types,but especially something like an old school Westminster,Volvo 140,XJ,or Granada, head on with a Beetle or a 911.Nor for that matter would it be a walk in the park to get involved with those specific types in many other types of front engined car either.

As for transverse v longitudinal front engined impacts,the possible scenarios and variables are probably endless and too many to make any real conclusions.

[Mave]

XJ Flyer said:

Which is why I'd prefer to be sitting in something like an E or S class than a 911 or a transverse engined shopping trolley/rep mobile in a severe square on head on.

How about a mk1/2 escort? Something similar size and era?

[Foppo]

Mave said:

XJ Flyer said:

Which is why I'd prefer to be sitting in something like an E or S class than a 911 or a transverse engined shopping trolley/rep mobile in a severe square on head on.

How about a mk1/2 escort? Something similar size and era?

Didn't save Princess Diana she died in a Mercedes S 280.

How that accident happened I don't follow.It isn't even a decent tunnel more of a underpass.The driver must have done a hell of a speed to cause her death.

[Finlandia]

XJ Flyer said:

There are lots of variations and possibilities which make certain scenarios survivable and others not in addition to a large amount of luck.

In general impact resistance and survivability is all about getting the balance between crumple to cushion the impact 'and' resistance to intrusion right,bearing in mind that the two are contradictory to each other.While the ability to transmit more energy into the opposing car while resisting same can help to shift that balance.

I'd still say that known legendary abilities of certain cars in banger racing over others provides a reasonable guide to that balance.

On that basis I really wouldn't want to meet most front engined cars of most types,but especially something like an old school Westminster,Volvo 140,XJ,or Granada, head on with a Beetle or a 911.Nor for that matter would it be a walk in the park to get involved with those specific types in many other types of front engined car either.

As for transverse v longitudinal front engined impacts,the possible scenarios and variables are probably endless and too many to make any real conclusions.

There are many factors to a survivable crash, one of the biggest is to be in a modern car.

The cars that "defeat" the other car in a crash are good until you crash them into something bigger or something solid, all of the sudden they can't use the other part as a crash cushion, see the sl in the pic.

The crash safety of a Volvo 140 as explained by Anders Kullgren, head of research at Folksam Sweden:
"Skulle vi kört en Volvo 140 mot en modern småbil hade skillnaden varit enormt stor till småbilens fördel" Should we crash a Volvo 140 with a small modern car, there had been an enormous difference to the advantage of the small car.


In a modern car there probably isn't much to it, if the engine is longitudinal or transverse.

[kambites]

Foppo said:

Didn't save Princess Diana she died in a Mercedes S 280.

How that accident happened I don't follow.It isn't even a decent tunnel more of a underpass.The driver must have done a hell of a speed to cause her death.

IIRC everyone in the car who was wearing a seat belt survived. Everyone who wasn't died.

[XJ Flyer]

Finlandia said:

XJ Flyer said:

There are lots of variations and possibilities which make certain scenarios survivable and others not in addition to a large amount of luck.

In general impact resistance and survivability is all about getting the balance between crumple to cushion the impact 'and' resistance to intrusion right,bearing in mind that the two are contradictory to each other.While the ability to transmit more energy into the opposing car while resisting same can help to shift that balance.

I'd still say that known legendary abilities of certain cars in banger racing over others provides a reasonable guide to that balance.

On that basis I really wouldn't want to meet most front engined cars of most types,but especially something like an old school Westminster,Volvo 140,XJ,or Granada, head on with a Beetle or a 911.Nor for that matter would it be a walk in the park to get involved with those specific types in many other types of front engined car either.

As for transverse v longitudinal front engined impacts,the possible scenarios and variables are probably endless and too many to make any real conclusions.

There are many factors to a survivable crash, one of the biggest is to be in a modern car.

The cars that "defeat" the other car in a crash are good until you crash them into something bigger or something solid, all of the sudden they can't use the other part as a crash cushion, see the sl in the pic.

The crash safety of a Volvo 140 as explained by Anders Kullgren, head of research at Folksam Sweden:
"Skulle vi kört en Volvo 140 mot en modern småbil hade skillnaden varit enormt stor till småbilens fördel" Should we crash a Volvo 140 with a small modern car, there had been an enormous difference to the advantage of the small car.


In a modern car there probably isn't much to it, if the engine is longitudinal or transverse.

I think there is often too much emphasis on old v modern as opposed to just sufficient amounts of metal to combine all the required different jobs of crumpling to cushion the impact,resisting intrusion,and transferring as much energy as possible into the opposing car.

From at least the point of view of the old 140,amongst some other notables such as the examples I've listed,it is the ability,to combine all those different,often contradictory,requirements,that matters.

IE the Volvo showed that it can do the job of cushioning the impact with a solid object 'in addition' to having massive reserves of resistance to intrusion of the bulkhead.With the ability to transfer energy into a weaker structure being an obvious by product of the combination of the former two abilities.The same would apply in the case of modern cars.In general the more metal that has been used in the construction the more chance there is.

[XJ Flyer]

kambites said:

Foppo said:

Didn't save Princess Diana she died in a Mercedes S 280.

How that accident happened I don't follow.It isn't even a decent tunnel more of a underpass.The driver must have done a hell of a speed to cause her death.

IIRC everyone in the car who was wearing a seat belt survived. Everyone who wasn't died.

While to be fair it was also a case of speed combined with hitting an object which was never going to allow any transfer of energy.I'd guess that the Merc arguably more or less did the best possible job in the circumstances that case.