I don’t normally respond to these types of thread once they get to this point, but AuRav made some interesting points so I will. No disrespect meant to anyone here, just my honest responses.
My home fitted system has had a crash with me in it with a full tank and nothing moved or was distorted.
I estimate point of contact was 20 mph and the vehicle I hit had pulled out in front of me and got pushed about half a metre by the impact staving in its passenger side front door, front wing and side pillar.
My van front was smashed back to the radiators (punctured) and bonnet creased.
My tank (which is strapped with 2 x 5 tonne lorry straps triple wound to a welded frame, the back of which is a 6" L shaped girder bolted through the floor with plates underneath) is a Wyedale 650L.
The tank is against the factory fitted bulkhead.
After the crash the tank had not visibly moved and there was no distortion evident.
When I put the van back on the road the insurer (who had written it off on value) said it needed to have a brand new MOT before being allowed on the road.
It passed and is still being used by me.
Interesting, but (with respect) largely irrelevant.
Firstly the crash was only 20mph, and into another car that moved, thereby absorbing some of the energy. (By means of conservation of momentum). A 20mph crash into an immovable object, like a bridge support, would be far more severe. Unfortunately we can’t choose what we crash into when it happens.
Secondly, your 2x5 tonne lorry straps will (by definition) hold 10 tonnes. Sounds like a lot, but in a previous post I calculated that the force exerted by a 650kg mass in a 30mph crash will be 17.8 tonnes.
Then there’s how they are secured. Bolted through the floor, with spreader plates underneath. The vehicle floor is not designed with structural strength, and you can see ample demonstration of that in Ionic’s sled videos. Even lower speed impacts show them tearing through the floor like it was tissue paper.
Now ... looking at Pete Thompson's post highlighting the HSE and the poor lad crushed by his tank.
Looking at the registrations of Teeside window cleaners vans served prohibition notice they were all vans in the 10/20 year old range. I would opine that a commercial operator running eight vans all of this age would be 'on the radar.'
I don’t think you understand what happened here. The HSE didn’t issue prohibitions because they were ‘on the radar’, it was because one of their employees was killed, which of course prompted an investigation. The age of the vans is irrelevant.
(Nowhere in the prohibition notices is there any reference to vehicle age)
It was that the tanks were unsafely being used - there is no detail as to whether there was an attempt to secure them and if so what and by whom.
Yes we don’t know how they were secured (if at all) other than it was inadequate as evidenced by the fact that a man is dead. For all we know, it might have been with
2 x 5 tonne lorry straps triple wound to a welded frame…Do you see my point? Just because you think it looks safe, doesn’t mean it is.
I know of others where the owner has had gone to great care to get a cage made and fitted and then bolted in by a local garage with keeper plates.
Again, so what? How would you know if that was safe or not? How would you know that your cage or way of securing it will withstand 17.8 tonnes?
“Because it looks beefy and doesn’t move when I drive” is not an answer.
The fact that in twenty years of window cleaning with wfp that tank crush deaths are incredibly small in number means to me that it is a vanishingly small issue.
We don’t know how rare they are, because statistics like this are not collected anywhere. Vehicle fatalities occur all the time, they don’t all make the newspapers. Even when they do, they don’t always mention the occupation of the injured person.
(But I would throw the book at cavalier business owners who put lives at risk by not risk assessing how their tanks are installed and going for the cheapest option.)
Again, with respect, would you not put yourself in this category? The “cheapest option” is a DIY installation isn’t it? (As opposed to a professionally manufactured, crash-tested system such as Ionic/pure2o etc?)
If self installing take care to remember that half a tonne of water needs properly securing. The forces in a crash are exponential to the speed and weight.
This does not mean a conscientious owner cannot do a secure job. Even more so if they have staff.
I’m interested to know how a conscientious owner would know that they had done a secure DIY job? Just because it looks beefy enough?
In your own case, for example, (and again, I mean no disrespect) how do you know the way you have secured your tank is safe?
Do you know how much force the angle iron that the straps are attached to can withstand? Do you know what the shearing force the securing bolts can withstand is? Do you know how much force it takes to rip the spreader plates through the floor?
Sorry, but you don’t know, because you
can’t know unless you properly test these things in controlled conditions.
The last time this topic was raised on here, most DIYers had the attitude of “it’s safe because I want it to be safe”. It looks like not much has changed.
And anyway, all of this discussion of
DiY is it safe / unsafe will be irrelevant if you can’t get insurance. I personally think, as someone else said, the game is up for DIY tanks.
If I had a DIY setup, I’d be getting rid of it and get a proper system installed fast, before my renewal came due.
