Clean It Up
UK Window Cleaning Forum => Window Cleaning Forum => Topic started by: Davew on December 27, 2006, 03:45:49 pm
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I see various sized tanks available of different shapes and sizes - would it be safe to strap them to the van floor (say 650ltr) or is this method just not safe enough?
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hi i am no expert though i would say that size of tank i would bolt it down through floor. Though you can get straps to strap it down too it will weigh when full approx 700kgs also got to factor in breaking strains as your moving around hope this is of help.
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make sure the tank you fit is baffled
it can be fitted using metal straps and plates
then drilling through the floor and fixing using strong bolts
and plate it top and bottom.
Get your dimensions and get your local steeel fabricator to knock them up in his lunch break for a nice drink.
I personally would not even consider using material straps-
they just do not seem strong enough if the worst was to happen.
Just my personal opinion
Russ
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i use a 400ltr tank strapped down which is fine but i wouldnt go any bigger as obviously the more water the heavier the load can move
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Just bolting through the floor isn't good enough. Most van floors are thin steel plate spot welded to the chassis members, they will rip like tissue paper in the event of a crash - you need to spread the load across as many under floor chassis members as possible - I have a 4"x2" channel section under the floor across the width of the van with the tank retaining bolts through it, so the whole floor and chassis will have to be torn up before the tank comes up and hits me in the back of the head.
Just think of this: You're travelling at 50 mph and have a smash. the van stops (almost ) dead - 700kg of deadweight continues to travel forward at 50mph - are your bolts through the thin van floor going to stop it?
Cheers,
Ian
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Just bolting through the floor isn't good enough. Most van floors are thin steel plate spot welded to the chassis members, they will rip like tissue paper in the event of a crash - you need to spread the load across as many under floor chassis members as possible - I have a 4"x2" channel section under the floor across the width of the van with the tank retaining bolts through it, so the whole floor and chassis will have to be torn up before the tank comes up and hits me in the back of the head.
Just think of this: You're travelling at 50 mph and have a smash. the van stops (almost ) dead - 700kg of deadweight continues to travel forward at 50mph - are your bolts through the thin van floor going to stop it?
yes they are i was involved in a head on crash just before xmas with a 700ltr tank full up when i was hit at 70mph.... the tank nor the bolts moved so i have to dissagree here
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Do you need to strap a tank down in a lidded trailer?
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I have an upright 400 litre baffled tank in my Vauxhall combi. The legnth and height of the tank is slightly bigger than the entrance to the cab from the back. Also I have a full steel bulkhead. What I have done is fitted the tank against the bulkhead and used 4 x 350kg rachet straps to secure the tank to the bulkhead and stop the tank from falling over into the back of the van as I pull away.
I showed this to my friend who is an engineer and he said it would be fine. As he pointed out, the tank is slightly bigger than the cab so an accident bad enough to make the tank come through the bulkhead would probably kill the driver outright.
Hope I never have to find out. :o
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Colin just curious, what have you clamped the straps to, I have a few sets of ratchet staps, used to tie harrier jump jets to the deck of a carrier and was going to use these to strap my tank down with, but realise the fixings have to be reliable.
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I've been visiting several sites on the net and some suppliers show their tanks with metal bands around them one was banded across the vehicle and it looked as if the tank might just slide through in a crash. Other tanks offered are laying flatter in the van offering a lower center of gravity maybe they would be safer. There seems to be many diy offerings and I just wonder how safe they are as most would be untested. A couple of vans I looked at only have a flimsy ladder type bulkhead that would only stop parcels flying into the cab. The bigger manufacturers offer a proper cradle - at a price. I'll keep looking and decide later.
I wonder if health and safety comes into this or insurance cover?
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fabric straps are more than good enough, (provided you use the correct ones) ;) you would need to be hit by a airbus-A380 to break them!
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There does seem to be an industry generated negative press towards good old fabric ratchet straps.
Every other industry is quite happy to use them extensively and for almost all requirements. Just because something is made of steel does not guarantee its integrity, at what point will a weld burst apart?
Cars on transporters rely on just fabric straps to hold them onto the back of the lorry (around their tyres), I had my 2 ton vehicle shipped down from up country this way, and the transporter had 8 other vehicles all held down the same way.
As has been said 'Jump-jets' rely on them. Every time we take a car journey we strap ourselves in with them (seat-belts).
Take a look at what RSJ's are held down with on the back of lorries. Glass panels on the side of vans are held down with them.
The key is what the rating on them is and how they are anchored, which is the same issues for bolted down frames and straps.
Just my thoughts on the issue,
Alex
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I worked in the metal industry for 16 years and all the lorrys that came to us used the fabric ratchet straps and i used to deliver RSJs to customers using the same thing but one day i lost an RSJ off the back of my van and it wasnt the strap that broke it was the hook it was hooked on which was a 10mm steel hook welded to the side of the van.
So like Alex said its how its bolted down that makes the difference..
Bazz...
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All these things that are strapped down are all being moved temporally not permanent.
Only one way to find out though eh?
DO IT PROPERLEY DO IT ONCE!
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The ratchets i used were there when i started and 16 years later are still as good and used every day so i dont call that Temporary..
Bazz...
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coming from a design engineering background I can honestly say there are pro's and cons to each method of securing a tank.
Straps are cheap, if used correctly (ie high enough rating and fastened down to a secure anchor) they are safe. However, straps need to be well maintained (any small cuts in the material will seriously weaken them).
Cages (again if built and fastened securely) are also very efficient.
The main rule of thumb in engineering is 49%. That is, the maximum anticipated load should never be any greater than 49% of the calculated strength.
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fabric for me every time, unless your talking aerospace spec' - steel has many flaws, especially the standard we're talking about. the metal hooks at each end though do let the side down as these are usually the weekest point that's why slingers have done away with them in favour of just a fabric loop. :P
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we only use grade 430 steel and above.
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JM123 i know what you mean im just saying in my opion, the anchor point is just as important as the strap you use metal or fabric and ive used fabric for years and had no problems with them but i have had problems with metal ones before as theres not much play in them.
Bazz...
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The ratchets i used were there when i started and 16 years later are still as good and used every day so i dont call that Temporary..
Bazz...
i was talking about the past threads lorrys carrying cars etc
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All these things that are strapped down are all being moved temporally not permanent.
Only one way to find out though eh?
DO IT PROPERLEY DO IT ONCE!
Yeah. And if you don't do it properly you may end up only doing it once as well >:(
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Those of you going down the strapping solution, what are you securing the hooks to the floor with? Is there a proper bolt and plate available with a strengthened eye to strap to?
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mine is strapped down i use the eyelets in the back of my pickup it has places to strap to all the down the load bed.
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Someone mentioned insurance on this topic, how do you get on if you have a crash and they see the tank is a "permanent fixture" ie bolted down, has anyone mentioned this to their insurance company? and are there gonna be any problems with the drilling of holes through the chassis itself thereby weakening it. You know how they will use anything they can these days to get from of paying out
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Someone mentioned insurance on this topic, how do you get on if you have a crash and they see the tank is a "permanent fixture" ie bolted down, has anyone mentioned this to their insurance company? and are there gonna be any problems with the drilling of holes through the chassis itself thereby weakening it. You know how they will use anything they can these days to get from of paying out
I told my insurance company and they would not renew the cover. I went elsewhere and they were OK with it.
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Those of you going down the strapping solution, what are you securing the hooks to the floor with? Is there a proper bolt and plate available with a strengthened eye to strap to?
I have a trailer mount and have the strap going all the way under the trailer chassis, up the sides and then across the tanks ( 2 x 175L uprights ) and then attached to itself, so the only thing the strap is strapped to is itself.
Tim
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dave
there is (or should be) anchor points in every van.you could add more but that would be up to you.
to be honest all i was trying to stress is that metal is not always stronger or a better solution in all cases. i'm sure a steel cage would be more than good enough if designed & constructed properly. me personaly, i use fabric straps. :D
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I still think the anchor point is more important than the strap...(metal or fabric).
Bazz...
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Hi Baz
What I have been saying is that the strap/cage is just as important as the anchor point. A chain is only as strong as its weakest link. One of my honours projects for uni was studying and developing different types of seatbelt materials and fixings, if we could synthesise and manufacture spider silk then that would be the strongest tensile material in the world (by calculation a strand of spider silk .62inch in diameter would be strong enough to halt a boeing 737 at over 500mph, but without a secure anchorage it couldn't stop a crow.
Our cages are secured to the underside of the chassis by a secure secondary chassis, the tank cannot go anywhere, likewise if you use straps be sure to anchor them securely, its cheap and effective to have anchor eyes fitted to 8mm steel plates which can be welded to the underside of the van floor and have the eyes showing through the floor. The plates should be made as big as possible to distribute as much of the energy as possible.
This is only intended as a guide and should by no means be used as a precise definition by anyone.
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Colin just curious, what have you clamped the straps to, I have a few sets of ratchet staps, used to tie harrier jump jets to the deck of a carrier and was going to use these to strap my tank down with, but realise the fixings have to be reliable.
Hi Jeff.
My straps are attached to the brackets that hold the bulkhead to the chassis of the cab. There are five of them 1/4 inch thick and one side is bolted to the frame of the cab with a factory fitted thread and a 13 mm bolt the other side is attached to the bulkhead with a 13mm nut and bolt.
The hooks of one strap are attached to the bottom two brackets either side. I have two straps attached to the other two brackets at the top on either side and I have the fourth attached to the fith bracket which is in the center at the top. This one is slightly looser than the rest as it is only a back up. As I said the straps are only there to stop the tank falling over backwards as I pull away or go up hill.
Being upright it is bigger than the entrance to the cab as I mentioned. If it were a flat tank I would be worried because a flat tank could easily slide into the cab in a accident;
I don't have a ladder type bulkhead, it is full steel. The bottom half is sheet steel rolled to a tube at the top which runs the width of the cab at about shoulder height to the drivers seat, the top half is a steel grill made of sheet steel with small square holes pressed out to give a grill effect. The whole bulk head is also slightly bigger than the entrance to the cab.
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