Clean It Up

UK Window Cleaning Forum => Window Cleaning Forum => Topic started by: Lee Burbidge on April 28, 2012, 01:52:20 am

Title: FYI - ratchet straps
Post by: Lee Burbidge on April 28, 2012, 01:52:20 am
Do you know the tonnage your ratchet straps can take if you are using them to fix your wfp tank inside your van?

Just for your information to ensure you have got the right straps........

100L at 30mph = 5.2 ton of forward force

1000L at 30mph = 52 tonnes

Imagine what force is involved at 40, 50, 60mph
Title: Re: FYI - ratchet straps
Post by: Window Washers on April 28, 2012, 01:57:39 am
great post Lee ;)
Title: Re: FYI - ratchet straps
Post by: andyM on April 28, 2012, 07:04:35 am
Where did you get your formula from Lee?
Surely the answer should be in Newtons not Tonnes?
F = m x a  ;)
 
Title: Re: FYI - ratchet straps
Post by: Dave Willis on April 28, 2012, 08:01:58 am
52 tonnes  :o

Is that halved if you use two straps or does it remain the same? Can't see many lashing eyes standing up to half that.
Title: Re: FYI - ratchet straps
Post by: gary999 on April 28, 2012, 09:04:06 am
ratchet strapping from a reputable company is batch proof tested to destruction
and rated at 6:1 which is 6 times the safe working load of the strap the metal
fittings are the weak points they are only at a ratio of 2:1

if you buy ratchet straps from anywhere make sure they have a test cert or at least
a certificate of comformity at least you know you will be buying genuine gear
Title: Re: FYI - ratchet straps
Post by: Perfect Windows on April 28, 2012, 09:45:03 am
Do you know the tonnage your ratchet straps can take if you are using them to fix your wfp tank inside your van?

Just for your information to ensure you have got the right straps........

100L at 30mph = 5.2 ton of forward force

1000L at 30mph = 52 tonnes

Imagine what force is involved at 40, 50, 60mph

Very vague on the maths to get there...

Crash at http://www.youtube.com/watch?v=TMl-WQ5XkMI has a time from hitting wall to dead stop of around 70 milliseconds, so 0.07 seconds.

Bung that into Newtons equations for acceleration (see the three or four posts at: http://www.cleanitup.co.uk/smf/index.php?topic=148875.msg1230162#msg1230162 ) and you get an effective weight of a 650L tank during that deceleration of 140 tons.  Your 1000L would be about 215 tons.

Now the news is that that was an empty van in the test, so your full van will take more time to stop and increase the amount of the van that crumples, but the numbers are a good indication of the scale of the problem.

Vin
Title: Re: FYI - ratchet straps
Post by: Nathanael Jones on April 28, 2012, 10:23:36 am
Its worth mentioning that straps do degrade over time (especially when wet) and most manufacturers recommend re-testing or replacing on a regular basis.
Title: Re: FYI - ratchet straps
Post by: gary999 on April 28, 2012, 05:28:52 pm
Its worth mentioning that straps do degrade over time (especially when wet) and most manufacturers recommend re-testing or replacing on a regular basis.

when i used to test lifting gear on site the normal period for replacement was 6months
with wear and tear but that was with gear which was being used taken off thrown around
and stored in ridiculas places.

you should get away with checking your straps every twelve months check for fraying
movement of the stiching especially in the areas of where the restraint fittings ares seated
check for correct movement of the ratchet itself and any movement of the fittings
themselves all lifting equipment fittings are designed to give or stretch before fracturing
as most lifting a strapping tackle is subject to shock loading, any faults in these areas
replace straight away
Title: Re: FYI - ratchet straps
Post by: Lee Burbidge on April 29, 2012, 07:25:11 pm
52 tonnes  :o

Is that halved if you use two straps or does it remain the same? Can't see many lashing eyes standing up to half that.

To ensure non failure your straps will have to be that for each.
Title: Re: FYI - ratchet straps
Post by: Lee Burbidge on April 29, 2012, 07:28:04 pm
ratchet strapping from a reputable company is batch proof tested to destruction
and rated at 6:1 which is 6 times the safe working load of the strap the metal
fittings are the weak points they are only at a ratio of 2:1

if you buy ratchet straps from anywhere make sure they have a test cert or at least
a certificate of comformity at least you know you will be buying genuine gear

Can I just check, the numbers your quoting are in tons, right? so your talking about 6 ton load straps. Because they would not stop 52 tons of forward force.
Title: Re: FYI - ratchet straps
Post by: Lee Burbidge on April 29, 2012, 07:29:43 pm
ratchet strapping from a reputable company is batch proof tested to destruction
and rated at 6:1 which is 6 times the safe working load of the strap the metal
fittings are the weak points they are only at a ratio of 2:1

if you buy ratchet straps from anywhere make sure they have a test cert or at least
a certificate of comformity at least you know you will be buying genuine gear

Can I just check, the numbers your quoting are in tons, right? so your talking about 6 ton load straps. Because they would not stop 52 tons of forward force.

I just read your post again, does that mean a 5 ton strap will take 6 times 5 tons??
Title: Re: FYI - ratchet straps
Post by: CLEANCARE WC on April 29, 2012, 07:31:06 pm
Can i just ask why they use ratchet straps on lorrys for loads way heavier than 650kilo if they are so terrible?
Title: Re: FYI - ratchet straps
Post by: Lee Burbidge on April 29, 2012, 07:44:39 pm
Its worth mentioning that straps do degrade over time (especially when wet) and most manufacturers recommend re-testing or replacing on a regular basis.

My new employee told me he snapped one tightening it up once.
Title: Re: FYI - ratchet straps
Post by: Lee Burbidge on April 29, 2012, 07:50:38 pm
Have you seen the video of the crash test with a system bolted into the floor of a van. If that crash test dummy was a real human, he would look like a bad cheese and tomato pizza!!
Title: Re: FYI - ratchet straps
Post by: H S and Son on April 29, 2012, 08:27:32 pm
Can i just ask why they use ratchet straps on lorrys for loads way heavier than 650kilo if they are so terrible?

Ratchet straps don't stop moving loads on lorries necessarily if there's an accident. What makes you think they do?

http://alturl.com/z5d85
Title: Re: FYI - ratchet straps
Post by: mikecam on April 29, 2012, 08:34:27 pm
Have you seen the video of the crash test with a system bolted into the floor of a van. If that crash test dummy was a real human, he would look like a bad cheese and tomato pizza!!

I seen the video of the ionics tank bolted to the floor and its seemed fine. The Ionics test and accreditation was for the design of a tank frame that did not collapse. Not a method of securing a tank frame in a van.A lot of what they reproduce as saftey features are at best misrepresented as saftey features.
Title: Re: FYI - ratchet straps
Post by: stuart mc on April 29, 2012, 08:36:26 pm
Its worth mentioning that straps do degrade over time (especially when wet) and most manufacturers recommend re-testing or replacing on a regular basis.

My new employee told me he snapped one tightening it up once.

I have snapped one as well but it wasn't a 5 tonne heavy duty strap, it was a cheap rubbish one and I was using it as a engine hoist
Title: Re: FYI - ratchet straps
Post by: Perfect Windows on April 29, 2012, 08:51:32 pm
Have you seen the video of the crash test with a system bolted into the floor of a van. If that crash test dummy was a real human, he would look like a bad cheese and tomato pizza!!

I seen the video of the ionics tank bolted to the floor and its seemed fine. The Ionics test and accreditation was for the design of a tank frame that did not collapse. Not a method of securing a tank frame in a van.A lot of what they reproduce as saftey features are at best misrepresented as saftey features.

Not quite sure what you're saying - can you rephrase it?  I thought the fitting WAS part of their test, unless I've misunderstood what you're saying.

Vin
Title: Re: FYI - ratchet straps
Post by: mikecam on April 29, 2012, 09:47:55 pm
Have you seen the video of the crash test with a system bolted into the floor of a van. If that crash test dummy was a real human, he would look like a bad cheese and tomato pizza!!

I seen the video of the ionics tank bolted to the floor and its seemed fine. The Ionics test and accreditation was for the design of a tank frame that did not collapse. Not a method of securing a tank frame in a van.A lot of what they reproduce as saftey features are at best misrepresented as saftey features.

Not quite sure what you're saying - can you rephrase it?  I thought the fitting WAS part of their test, unless I've misunderstood what you're saying.

Vin

Sorry, i got it completley arse about face. It is the method of securing the tank that is accredited
Title: Re: FYI - ratchet straps
Post by: gary999 on April 30, 2012, 12:25:09 am
ratchet strapping from a reputable company is batch proof tested to destruction
and rated at 6:1 which is 6 times the safe working load of the strap the metal
fittings are the weak points they are only at a ratio of 2:1

if you buy ratchet straps from anywhere make sure they have a test cert or at least
a certificate of comformity at least you know you will be buying genuine gear

Can I just check, the numbers your quoting are in tons, right? so your talking about 6 ton load straps. Because they would not stop 52 tons of forward force.

I just read your post again, does that mean a 5 ton strap will take 6 times 5 tons??

depends on the quality of strap wher you have bought them from,the swedish lifting
tackle and strapping company i worked for used to batch test their ratchetsstraps
roundslings webslings etc at the depot where i was based we had a 100tonne ram
where we proof tested gear to destruction we often proof tested 5tonne and 10 tonne
ratchet strapping for customer wanted more than just conformity of our parent
companies batch testing.

not once did the strapping fail before 6 times its safe woprking load or swl
which is normally on the printed label this is not to be confused with strap labels
which have mbl on the label which stands for minimum breaking load which would
normally be on a lower quality strap.

so yes on a correctly supplied good quality strap of 5 tonne should only
break under load at 6x its safeworking load.

the thing is and i apologise for waffling that these slings are only certified
to their swl which well within their capacity because of euro and british standards
to keep items used well within safety margins.

the real problem though isnt the strap itself but the fittings attached they are
made out of poorer quality material because they are only for restraint and not
shock loading at best these are rated at only twice the safe working load so
these would fail first.

their are ways round this but you would have to go to a lifting tackle company for
the supply of strapping and the correct grade t steel fittings that at least would
give you a ratio of 4:1

sorry for waffling ;D
Title: Re: FYI - ratchet straps
Post by: Rogue Trader on April 30, 2012, 03:02:05 pm
i wish i had a swede lifting my tackle :)
Title: Re: FYI - ratchet straps
Post by: AuRavelling79 on April 30, 2012, 05:02:28 pm
My 650L (flat) is secured thus:-

It sits in a frame the main part of which is 90 mm angle along the back edge of the tank. It is secured through the floor with 14 separate 16 mm high tensile bolts into more angle placed across and underneath the longitudinal box sections of the van.

The tank is strapped underneath the 90 mm angle (but inside the van so kept dry) with 4 winds of 5 tonne ratchet strap through each of the 2 baffles of the tank.

The tank is also against the manufacturers bulkhead which has as standard a box section strengthener across it inside the cab section.

It'll have to do because I subscribe to the cozy notion that the van will rip apart before the tank becomes an issue.

I also think there is a huge fuss about tank fixings out of all proportion to the number of injuries ever recorded.

I mean - compare the risk of injury compared with ladder and step ladder usage.
Title: Re: FYI - ratchet straps
Post by: Mike #1 on April 30, 2012, 05:15:27 pm
Gold how have you put your straps through the baffles . thanks mike
Title: Re: FYI - ratchet straps
Post by: AuRavelling79 on April 30, 2012, 05:28:45 pm
Gold how have you put your straps through the baffles . thanks mike

Wound them round the tank (through the baffles) and under the 90mm angle four times and then ratcheted them up.
Title: Re: FYI - ratchet straps
Post by: Mike #1 on April 30, 2012, 06:02:41 pm
Thanks gold might do that with my flat tank at the moment i have just got tank straps over tank from left to right corners in the back of my pickup.

And at the sides and back of tank i have placed some good quality lengths of wood to help prevent sideways movement and backwards and forwards movement of tank in load area .

I am getting some rubber matting this week to place under tank as well . Mike
Title: Re: FYI - ratchet straps
Post by: scud on April 30, 2012, 07:18:08 pm
  As I am of Italian decendancy I refuse to bet against myself and think I may crash, so my straps will do ;D

  my tank is well strapped in and hasn't moved for 4 years, if I was to have an impact bad enough for it to come forward and crush me, chances are I really wouldn't be in a good state without the whack from the tank, so it may well do me a favour and give me the final push.