Travelling with the table in place?

[Nostrovia]

Hi all,

I have a (detachable) table on a dinette behind the driver, where my 2 kids sit. It is fastened to the wall, and has a single leg at the other end.

What do you all do when travelling? take it down and secure it somewhere? or leave it up?

I suppose that in an accident, it could become a projectile and dangerous(?). Then again, if it were just placed on the bed, then it's essentially the same.

What do you lot do?

Cheers!

 

[PP Bear]

 

[ambulancekidd]

you need to have a nosy at more MHs then as lots don't have any place to store them. Ours is meant to be left 'in use' mode all the time so never gets taken out.

Yes me thinks your right Mel, I have to confess that the only motorhomes I've had any experience of are UK built ones & most appear to have dedicated storage space for the table.
I don't care for any of the foreign motorhomes I've glanced at.

I must say that I wouldn't allow my granddaughter to travel sitting at the table in the motorhome.
Even wearing a seatbelt in any crash it'd be incredibly easy to sustain serious injury when a head hits a table.
Perhaps the law needs to be looked at to protect people from themselves in a similar way to crash helmets & seatbelts. You can lead a horse to water but....

Maybe I'm a bit paranoid as a result of my career

 

[mitzimad]

in the first clip above the table is the only thing that doesnt move

 

[Mrsambulancekidd]

in the first clip above the table is the only thing that doesnt move

The table slide out of it's wall slot and could have caused internal injury if the dummy had been a real person...…...now which funster could we test this on....hmmmm.

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[tonyidle]

The table slide out of it's wall slot and could have caused internal injury if the dummy had been a real person...…...now which funster could we test this on....hmmmm.

For the table to do any damage it has to develop sufficient momentum relative to the driver. Mounted further back it could certainly do so but if it is part of a dinette immediately behind the driver / passenger it would barely indent the back of a front seat. It's a bit like following another vehicle at 70mph: if you are determined to hit it when it stops it's better to be as close to the rear of it as possible - preferably less than a foot away. You will then stop with no more force and no more quickly than it does. (And if it stops because it hits something you'll have three crumple zones working for you). If however you hit it from twenty feet away it will be stationary and you'll still be travelling at 70mph. Better to stick with the two second rule of course but as I said, if you are determined ..............

 

[Mrsambulancekidd]

For the table to do any damage it has to develop sufficient momentum relative to the driver. Mounted further back it could certainly do so but if it is part of a dinette immediately behind the driver / passenger it would barely indent the back of a front seat. It's a bit like following another vehicle at 70mph: if you are determined to hit it when it stops it's better to be as close to the rear of it as possible - preferably less than a foot away. You will then stop with no more force and no more quickly than it does. (And if it stops because it hits something you'll have three crumple zones working for you). If however you hit it from twenty feet away it will be stationary and you'll still be travelling at 70mph. Better to stick with the two second rule of course but as I said, if you are determined ..............

That's ok then & if we all assume that it will always be a favourable outcome we'll be fine & dandy.

 

[tonyidle]

That's ok then & if we all assume that it will always be a favourable outcome we'll be fine & dandy.

I used a little 'poetic licence' there .

 

[Mrsambulancekidd]

I used a little 'poetic licence' there .

Give up on the poems, your rubbish at em….

 

[tonyidle]

Give up on the poems, your rubbish at em….

I will . But I was making a serious point about the table - or any other heavy object. If it's so close to the cab that it cannot move very far it will have considerably less energy than something that sets off from the rear.

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[Mrsambulancekidd]

I will . But I was making a serious point about the table - or any other heavy object. If it's so close to the cab that it cannot move very far it will have considerably less energy than something that sets off from the rear.

Listen I lack energy all the time, does that make me safe....
No really though, I do understand the physics, the problem is not all accidents are the same, so introducing a heavy object that could wreak havoc is best avoided.

 

[Barclaybasher]

I don't like the weight of some tables, they seem over engineered.

The 2004 Burstner I owned and the 2001 Mobilvetta are ridiculous - steel sprung frames, heavy laminate tops.

I might even use the Mobilvetta one in a flat - works as a coffee table and dining table

The Burstner I fitted a smaller ply top to, the Mobilvetta table I store in the garage.

By contrast my 1991 Eriba (just passed another MOT) was supplied with a ply top table with a fold down leg that just clips into trim on the back wall and can be clipped to the bodywork for use outside - simple, lightweight, sensible - and I even cut that down!

 

[SpeedyDux]

I am fairly relaxed about travelling with the table in place because in its forward position it is in contact with the back of the passenger seat. I don't doubt that in a big crash it would come loose but so might the 2 hab batteries under the back seat, held only by fabric straps and separated from the cab by thin plywood. A lot more kinetic energy in those batteries.

Best policy is to hang back and leave big gaps in front when driving. Don't be in a hurry. Keep looking out for the ever increasing numbers of careless drivers and dangerous idiots. Happy and safe travels everybody!

 

[Minxy]

Hi all,

I have a (detachable) table on a dinette behind the driver, where my 2 kids sit. It is fastened to the wall, and has a single leg at the other end.

What do you all do when travelling? take it down and secure it somewhere? or leave it up?

I suppose that in an accident, it could become a projectile and dangerous(?). Then again, if it were just placed on the bed, then it's essentially the same.

What do you lot do?

Cheers!

Going back to the OP ... personally I would remove the table and store it safely elsewhere as it's not so much the table coming adrift but the kids making contact with it in an emergency stop.

 

[Rocking Rivet]

only 60mph were you going up hill?

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[Scudajoh]

We have a 4-berth Bailey Approach Autograph 745. DO NOT travel with table up it says in manual. This table is heavy and solid as it doubles up as base for second bed in dining area. Stowage is under rear bed in designated space above rest of locker space. It probably weighs 15-18 kgs. BRILLIANT idea to leave behind if only 2 of us travelling and use lightweight table instead. Thanks Tinks703

 

[Minxy]

We had a really, REALLY heavy table in our Rapido 709F ... I removed the top and put in my own lightweight one!

 

[thebriars]

I will . But I was making a serious point about the table - or any other heavy object. If it's so close to the cab that it cannot move very far it will have considerably less energy than something that sets off from the rear.

Actually no, two identical objects, one at the front and one at the rear will have exactly the same energy.

 

[mitzimad]

Actually no, two identical objects, one at the front and one at the rear will have exactly the same energy.

potential energy perhaps but i know if somethings going to hit me i dont want it getting to its full potential before it strikes

 

[thebriars]

Doesn't matter, it will strike you with the same energy whether close by or more distant. Its not potential energy in this case, its kinetic energy. If the motorhome is travelling at 60mph and brakes sharply, the object will fly forward at 60mph with the same kinetic energy whether at the front or the back. The amount of kinetic energy released when it hits you depends on how fast the motorhome (and you) decelerate, and of course the mass of the object.

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[Duck Truck]

We've always left tables up. Makes it easier to serve the meals and hot drinks cooked while travelling along the motorway..... I know, were probably not a good example

So do you set the cruise control and go and have something to eat

 

[tonyidle]

Actually no, two identical objects, one at the front and one at the rear will have exactly the same energy.

They won't. And with out any reference to science consider the following: the back of your seat has the same energy as a table touching the rear of the seat and will do no harm. The same cannot be said of an airborne object that left the rear of the van and is headed your way.

 

[thebriars]

I'm afraid your physics is rather lacking. For me, I'll rest on what I learned on my physics degree.

 

[g3cwi]

Autotrail Tracker has one

Accordo 125 has one too. Maybe it’s just those overpriced foreign van that don’t?

 

[Spriddler]

I'm afraid your physics is rather lacking. For me, I'll rest on what I learned on my physics degree.

If the table is in contact with the back of the seat in a say, 60mph collision, it will decelerate 'gradually' at the same rate as my seat/body/head. An unsecured table on the other hand will fly forward at 60mph until it impacts the back of my seat/body/head. It's the impact speed that I would be concerned about. That's why I hammer a nail into wood rather than push it.

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[Puddleduck]

Most motorhomes that I know of have a dedicated storage position for the table or tables.

Ours doesn't. But we have taken it out anyway and use a folding table that is put into a box and clipped in place when we travel.

We only use the table that came with the van if we need the fifth and sixth berths as it forms part of the bed base.

 

[gus-lopez]

Ours stays stored in its positions as bed base. Held down usually ,by the wife asleep on it

 

[tonyidle]

I'm afraid your physics is rather lacking. For me, I'll rest on what I learned on my physics degree.

The calculations in part are here. The force on the seatback (as an example) is reduced the closer the object is to it. I don't have a degree in anything but your suggestion that the force on the back of a seat is unaffected by the distance the object is behind it flies in the face of common sense (and my limited grasp of the physics involved).

https://books.google.co.uk/books?id...epage&q=energy of loose object in car&f=false

 

[thebriars]

The calculations in part are here. The force on the seatback (as an example) is reduced the closer the object is to it. I don't have a degree in anything but your suggestion that the force on the back of a seat is unaffected by the distance the object is behind it flies in the face of common sense (and my limited grasp of the physics involved).

https://books.google.co.uk/books?id=09vsCgAAQBAJ&pg=PA119&lpg=PA119&dq=energy+of+loose+object+in+car&source=bl&ots=cpapBL5ELH&sig=P47IfIqeK-hJTkiB4vO8UCP6Ulg&hl=en&sa=X&ved=2ahUKEwizkbmZmsreAhUMLcAKHdfaB4YQ6AEwAHoECAgQAQ#v=onepage&q=energy of loose object in car&f=false

I think you are muddling two separate things. Earlier you said "For the table to do any damage it has to develop sufficient momentum relative to the driver". Now you are saying the force on the seatback is reduced the closer an object is to it.

There are two separate issues here. Firstly the table whether at the back or the front will have exactly the same kinetic energy. This is half of the mass times the velocity squared. Same table, same mass, same speed therefore same kinetic energy. In a crash that kinetic energy is dissipated whether directly behind the seat or not. In a crash the extra force on the back of the seat caused by the table will certainly have an effect as it decelerates to zero. In a vehicle decelerating at 30g, as a rough approximation a table weighing 5kg will weigh 30 times that weight, ie 150kg. That weight will be pressing on the back of the seat, forcing it forward. That's an awful lot of weight on the back of the seat, and possibly the occupant! To argue Spriddler's point, you don't just have to hammer a nail in, you can press a nail into wood, essentially as a nail gun does.

Next consider the deceleration. This is given by the equation force = mass times acceleration, (or deceleration). This is far more difficult to equate, because now we also have to factor in the difference between the speed of the table flying forward and the speed of the occupant when it hits them. Clearly the occupant will slow down more than the table during that fraction of a second at impact, as you rightly point out.

However, the salient point is that even if the table is behind the seat and not secured to something substantial, it can still do a lot of damage in an accident.

 

[Spriddler]

That reminds me of the party puzzler of a fly flying towards a tunnel entrance when a train comes out. When the fly impacts on the front of the train its direction changes (reverses) by 180 degrees. Since it is then is travelling in the same direction as the train and at the same speed as the train at some point one might say that it must have stopped before reversing its direction by 180 degrees.............Or not

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[thebriars]

Yes it does stop, and then reverses direction. Simple really.

A more interesting (?) example is a light car (e.g. a Smart car) hitting a far heavier car head on. The heavier car will decelerate slower than the light car, which will in fact slow down, stop and then be bounced backwards. The car might survive but the passengers in the light car will experience a far greater deceleration than those in the heavier car. Its that high deceleration (high g force) which can cause severe internal damage to ones organs.