Hymer, which chassis ? (1 Viewer)

[StephDeLux]

You cannot use these videos as evidence, you are comparing an ambulance with a fixed cabin/bulkhead to a coachbuilt with no bulkhead. Also my Swedish isn't very good but there is no indication of the speeds in these tests - are they comparable?

This is not a scientific comparison, sure. You can choose to focus on what this is not and ignore what you see if is reassures you. But really, would you buy a car with crash-test results like the Swedish found with the Ducato?

A rigorous comparative study does not exist or is not available publicly. We still can look at what is there.

The behaviour of the Ducato cabin shows that at the time of design structural integrity of the driver and passenger space in case of a collision was not in the requirements. The Ducato is now a pretty old vehicle and it is what it is.

What we have about the Sprinter shows at least a better consideration for that aspect. It is also a more recent design.

The third video is in fact a comparison between a Sprinter and a Transit. There you can see a big difference in the cabin resistance for those panel vans. We can expect that difference to translate in a difference of safety with low-profile MH based on those chassis. The front cabin remains the same

I would expect A Class to be generally catastrophic regarding safety. I don't expect crash tests and resistance to collisions to be in the design process, it would be way too expensive for such low levels of production. I hope I'm wrong on this.

For sure, cars sold today by Fiat behave much better that the Ducato.

We are nearing the moment we will order our new MH and having seen that, it will be pretty hard for us to go with a Ducato.

 

[Paddywack]

This is not a scientific comparison, sure. You can choose to focus on what this is not and ignore what you see if is reassures you. But really, would you buy a car with crash-test results like the Swedish found with the Ducato?

A rigorous comparative study does not exist or is not available publicly. We still can look at what is there.

The behaviour of the Ducato cabin shows that at the time of design structural integrity of the driver and passenger space in case of a collision was not in the requirements. The Ducato is now a pretty old vehicle and it is what it is.

What we have about the Sprinter shows at least a better consideration for that aspect. It is also a more recent design.

The third video is in fact a comparison between a Sprinter and a Transit. There you can see a big difference in the cabin resistance for those panel vans. We can expect that difference to translate in a difference of safety with low-profile MH based on those chassis. The front cabin remains the same

I would expect A Class to be generally catastrophic regarding safety. I don't expect crash tests and resistance to collisions to be in the design process, it would be way too expensive for such low levels of production. I hope I'm wrong on this.

For sure, cars sold today by Fiat behave much better that the Ducato.

We are nearing the moment we will order our new MH and having seen that, it will be pretty hard for us to go with a Ducato.

But the Mercedes ambulance is a solid cab - the box on the back can be unbolted leaving a full cab and chassis - no motorhomes are made with this construction.

 

[KUSKUS]

Don't worry about the structural safety of the front end , the fridge or table will probably kill you in the event of a heavy collision.

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[StephDeLux]

But the Mercedes ambulance is a solid cab - the box on the back can be unbolted leaving a full cab and chassis - no motorhomes are made with this construction.

That does not change how the front of the cabin resists to a shock.

 

[StephDeLux]

Don't worry about the structural safety of the front end , the fridge or table will probably kill you in the event of a heavy collision.

The fridge and the table are potential concerns indeed.

In both cases in the Swedish test, the (big) fridge is dislodged but does not fly, so remains pretty harmless at the speed of the test. The people are dead anyway from getting crushed, not from the table. No doubt higher speeds would multiply the sources of harm.

I still think there is a difference of safety between older and newer cabin designs and I intend to take that into account.

I also think the general situation is appalling but I can't say I see a solution. A someone said, fatal frontal collisions involving motorhomes are rare and building them to get 5 stars at NCAP tests for 4 passengers would make them so expensive very little people would be able to buy them.

 

[Paddywack]

That does not change how the front of the cabin resists to a shock.

I can only guess that you know little about structural engineering. The full cab is a game changer as to how the front of the cabin performs - think coupe vs convertible.

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[KUSKUS]

Bailey Motorhome first tests 2011/2012 presumably Fiat x250
During the first test, both the fridge and the oven came free and flew out of the front of the motorhome.

 

[StephDeLux]

I'm not sure I understand well what you mean by the full cab (English is not my native language).

If you mean the whole vehicle including the whole body that is added by the conversion, I don't agree.

If you mean that cutting out the roof of the cabin can and will severely impact is structural behaviour, yes of course. But that roof is cut for the ambulance too.

We can also add the total weight of the vehicle. A heavier MH will impose stronger forces on the cabin.

And again, I agree these videos are not meant to be compared.

But I find the behaviour of the Ducato is alarming.

I find the behaviour of the Sprinter in the case of the ambulance is more encouraging.

I find in the third video the Sprinter has a better behaviour than the Transit.

 

[StephDeLux]

Bailey Motorhome first tests 2011/2012 presumably Fiat x250
During the first test, both the fridge and the oven came free and flew out of the front of the motorhome.

Did they correct that situation?

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[KUSKUS]

Bailey now anchors ovens and the fridges in all of its motorhomes to the floor.

The furniture also needed significant modification and dedicated storage was made for the table after three of the four rear seat passengers were hit by the flying table after it came loose. The table leg also broke and the table’s rail broke free and flew out of the window. The manufacturer has also now relocated its under-locker lighting after it was found the lights could injure the passengers.

 

[KUSKUS]

However, it was the motorhome’s bulkhead, which separates the rear passenger seats from the cab, that proved the toughest nut to crack and took a further three tests to get right.

In a motorhome built using Bailey’s Alu-Tech, the bulkhead is already a structural component of the shell, making it much more solid than a standard furniture panel used in some other motorhomes. However, even this required extra strengthening with a steel frame support and a steel brace mounted through the floor before it met the final test targets.

The bulkhead protects the rear-facing passengers and supports their backs. If it gives way, the passenger’s body can twist and he can be thrown free from the seatbelts. Indeed, during the first of the Bailey tests, the rear-facing passenger closest to the aisle ended up in the cab.

Despite its importance in protecting rear passengers, some motorhome manufacturers currently only use a standard furniture panel for the bulkhead.

Following the completion of its crash tests, Bailey has now made its findings and the engineering changes it has made as a result of the crash tests available free and without patent protection to other motorhome manufacturers through the National Caravan Council (NCC). It is hoped that other manufacturers will adapt their own production processes to make their motorhomes safer using Bailey’s findings.

 

[Paddywack]

I'm not sure I understand well what you mean by the full cab (English is not my native language).

If you mean the whole vehicle including the whole body that is added by the conversion, I don't agree.

If you mean that cutting out the roof of the cabin can and will severely impact is structural behaviour, yes of course. But that roof is cut for the ambulance too.

I find the behaviour of the Sprinter in the case of the ambulance is more encouraging.

If you look at the ambulance video again at about 2:24 they do a schematic that shows the ambulance box is just bolted onto the back of a cab and chassis, all coachbuilt motorhomes have that rear part of the cabin removed. That's where the additional strength comes from.

PS don't worry English isn't my native language either - I'm from Middlesbrough!

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[StephDeLux]

If you look at the ambulance video again at about 2:24 they do a schematic that shows the ambulance box is just bolted onto the back of a cab and chassis, all coachbuilt motorhomes have that rear part of the cabin removed. That's where the additional strength comes from.
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PS don't worry English isn't my native language either - I'm from Middlesbrough!

I checked, you're right. Not sure if that explains why the front wheel of the Ducato ends up under the driver but OK. I still find the video with the Ducato very frightening and this won't help to make me buy a Ducato if I find an alternative otherwise as good on a Sprinter You can call me stubborn or misinformed (both likely true).

Still, in the third video it is clear the Sprinter is better than the Transit and they are both panel vans.

 

[jongood]

I would expect A Class to be generally catastrophic regarding safety. I don't expect crash tests and resistance to collisions to be in the design process, it would be way too expensive for such low levels of production. I hope I'm wrong on this.

Really!!

 

[jongood]

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[KUSKUS]

don't think you can compare the tests above with previous tests , previous tests are using offset block test and would appear to be done at a much higher speed.
you can see the back wheels feet off the ground .
In the previous test it looks like an old style transit , would be interesting to see a comparable test involving a new style one.

 

[StephDeLux]

The Hymer and N+B videos are impressive. Good to see things are quite good for those brands. Nothing like the A Class the Swedish tested. The tests are indeed less demanding because they use the whole front to absorb the energy and they might be done at slower speed, as Kuskus says. But still, not a catastrophy.

The Hymer is Mercedes-based, by the way and the N+B Iveco.

 

[jongood]

It seems to me that a rollover is a more usual event for a motorhome, high winds, slippery roads, poor driving skills etc.
This is what happens to a coachbuilt in a rollover

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[jongood]

In a motorhome built using Bailey’s Alu-Tech, the bulkhead is already a structural component of the shell, making it much more solid than a standard furniture panel used in some other motorhomes. However, even this required extra strengthening with a steel frame support and a steel brace mounted through the floor before it met the final test targets.

Hmmm yes Bailey Alutech, what a misleading term that is, note the impressive technology ho ho ho.

 

[KUSKUS]

looked like building a garden shed, couldn't believe they were fitting the windows with the side frame being totally unsupported.