[Steven Biggs]

Which would have the biggest chance of moving the tank , . If you were travelling at say 30 mph and hit a stationery vehicle . Or if you were stationery and a vehicle hit you from behind at 30 mph . Regardless of whether the tank is bolted in with a cage or strapped in .

[Stoots]

Daftest question of the year?

I'm sure someone will be along shortly with a physics degree and a calculator and some long algebraic equation of force, mass, velocity and such.

Meanwhile why don't you go ask on the science forum what brush to clean a window with.

[Spruce]

Which would have the biggest chance of moving the tank , . If you were travelling at say 30 mph and hit a stationery vehicle . Or if you were stationery and a vehicle hit you from behind at 30 mph . Regardless of whether the tank is bolted in with a cage or strapped in .

NCAP crash testing is the reality. Everything else is theory.

Formula 1 teams design and manufacturer their own drivers monohull or cockpit but the finished product is crash tested by the FIA to ensure it meets safety standards. These designers are some of the best in the world.

In view of this,  I would doubt there is anyone in the window cleaning field able to give you a definitive answer.

I tried to be a little more diplomatic than Adam Thompson   

.

[Steven Biggs]

Daftest question of the year?

I'm sure someone will be along shortly with a physics degree and a calculator and some long algebraic equation of force, mass, velocity and such.

Meanwhile why don't you go ask on the science forum what brush to clean a window with.

well I know it wouldn't be a 2 year old cill brush .

[Steven Biggs]

Just interested as I was chatting to a mate last night regarding fitting my new van out . I didn't think there would be any difference . But I thought I would just ask on here for any opinions .

[Jonny 87]

I reckon it’s a pointless question really,

Only reason is that if you were hit from behind by a car traveling 30mph then the tank will only move backwards if anything. So no danger to the driver. whereas if you hit something else at the front then it’s the worry of being crushed by the tank.

Head on is all You should worry about really.

[Slacky]

It’s not  a stupid question.

Newton’s First Law Of Motion applies IMO.

[Ian Sheppard]

Which would have the biggest chance of moving the tank , . If you were travelling at say 30 mph and hit a stationery vehicle . Or if you were stationery and a vehicle hit you from behind at 30 mph . Regardless of whether the tank is bolted in with a cage or strapped in .

In my opinion it would come down to Mass - Inertia - acceleration and deceleration . If the vehicle is travelling forward at 30MPH the mass is increased so at the point of impact the larger mass caused by sudden deceleration would be greater then If the vehicle is stationary in this instance how much mass is transferred would depend on the size of the vehicle that hit you. In the case of you being stationary the inertia created would push the vehicle and tank forward first then back in a whiplash action.  But have to agree with Spruce that NCAP and Road transport lab would be good places to start to find the answer

[Plankton]

You didn't mention if it had baffle balls! If it did it wouldn't move at all and there would be no damage to the vehicle either 

[nathankaye]

I reckon this chap knows the answer,

[Steven Biggs]

Some good answers . So what most are saying is . The tank as got more chance moving forward in a head oncrash . Less chance hitting a stationary vehicle . And even less chance when stationary but hit from behind .

[Marc Stock]

If your traveling at 30mph and your payload is 600kg and you decelerate crash in 0.2 seconds. The force is approx 8 tons.

If your traveling at 60mph that force is 16 tons.

If your carrying 800kg payload at 60mph it's 21 tons or 30mph  10 tons

And that's a slow 20th second crash. Hit something harder perhaps a tree or a concrete wall then of course those numbers will go up.

http://calculator.tutorvista.com/impact-force-calculator.html?view=simple