Portable Van weighing solutions
Portable Van weighing solutions
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Discussion

PixelpeepS3

Original Poster:

9,016 posts

172 months

Wednesday 5th July 2017
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Hi all,

Working in compliance we have recently inherited the process of sample based auditing on various issues to do with fleet - one of them being vehicle weight.

I've had a look at writing a new process for this to be done and started down the route of 'where is there a list of public weigh bridges' but then stumbled across portable weighing solutions.

Problem is it seems a bit of a mindfield - how many do i need for an accurate overall weight of the whole van - do we buy two and weigh the front axle then the rear as an example?

anyone got any suggestions for a solution? it has to be portable as we have engineers all over the UK so an installed one in a single location would not work.

thanks in advance.

BMWBen

4,906 posts

231 months

Wednesday 5th July 2017
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Physics would suggest that if you weigh the front axle and the rear axle and then add the two together, you'll get the overall weight of the van.

chopper602

2,334 posts

253 months

Wednesday 5th July 2017
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I think you'd need a set of four, one for each wheel, which when added will give the total weight. Look at motorsport applications as they tend to use them.
I don't see how front and axle and back axle will give you the total weight. You find this with motorhomes, max weight for front axle plus rear axle often adds up to more than the permitted vehicle weight

Bristol spark

4,509 posts

213 months

Wednesday 5th July 2017
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Set of corner weighing scales?

rewc

2,187 posts

263 months

Wednesday 5th July 2017
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BMWBen said:
Physics would suggest that if you weigh the front axle and the rear axle and then add the two together, you'll get the overall weight of the van.
This is not true when applied to Brake Tester lanes which measure each axle when it is on the roller and add them together for total weight. The downward thrust on the roller throws weight forward or back depending on the axle and thus a non accurate total weight is computed. It is especially noticeable on longer vehicles such as motorhomes where the weight computed by the Brake Tester is perhaps 200 - 300kg more than the whole van measured on a weighbridge.
Reich have a tester which measures each wheel in turn as you drive over it on a level surface. I have found it to be accurate enough for my purposes.
https://www.ebay.co.uk/i/222066552208?chn=ps&d...

Edited by rewc on Wednesday 5th July 13:44

imagineifyeswill

1,250 posts

196 months

Wednesday 5th July 2017
quotequote all
rewc said:
This is not true when applied to Brake Tester lanes which measure each axle when it is on the roller and add them together for total weight. The downward thrust on the roller throws weight forward or back depending on the axle and thus a non accurate total weight is computed. It is especially noticeable on longer vehicles such as motorhomes where the weight computed by the Brake Tester is perhaps 200 - 300kg more than the whole van measured on a weighbridge.
Reich have a tester which measures each wheel in turn as you drive over it on a level surface. I have found it to be accurate enough for my purposes.
https://www.ebay.co.uk/i/222066552208?chn=ps&d...

Edited by rewc on Wednesday 5th July 13:44
Brake testing rollers measure braking force not vehicle or axle weights, the brake forces are added together and then worked out as percentage of the kerb weight for cars and vans upto 3000kg, heavier vans the percentage is worked out from gross vehicle weight. With load sensing valves which allow more pressure to the rear brakes as load increases it quite possible for a heavily laden upto 3000kg van to obtain a brake force totalling more than the kerb weight of the vehicle thus giving a braking efficiency reading off say 115% which wont be a true figure as the vehicle is probably overloaded.

Gavin0478

480 posts

171 months

Wednesday 5th July 2017
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We used a pair when we were being monitored for weight loading on our 7.5 ton vehicles and weighed axles then added total together.
I cant for the life of me remember what depot the scales are at now to find out who they are made by.

rewc

2,187 posts

263 months

Wednesday 5th July 2017
quotequote all
imagineifyeswill said:
Brake testing rollers measure braking force not vehicle or axle weights, the brake forces are added together and then worked out as percentage of the kerb weight for cars and vans upto 3000kg, heavier vans the percentage is worked out from gross vehicle weight. With load sensing valves which allow more pressure to the rear brakes as load increases it quite possible for a heavily laden upto 3000kg van to obtain a brake force totalling more than the kerb weight of the vehicle thus giving a braking efficiency reading off say 115% which wont be a true figure as the vehicle is probably overloaded.
On Automatic Test Lanes the rollers measure the weight of each axle and add them together to obtain the presented weight. This weight is than used to determine the braking efficiency.

BMWBen

4,906 posts

231 months

Thursday 6th July 2017
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There may be other ways of doing it that are used in certain circumstances to give more information - but if you weigh the using the front wheels and then using the rear wheels and add it together it's no different to driving onto a weighbridge that measures both front and back together. Maybe the OP's question wasn't phrased correctly, but if you want to know how much something large weighs that's absolutely a valid way of doing it.

BristolRich

545 posts

163 months

Thursday 6th July 2017
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PixelpeepS3 said:
how many do i need for an accurate overall weight of the whole van - do we buy two and weigh the front axle then the rear as an example?[...] it has to be portable as we have engineers all over the UK so an installed one in a single location would not work.
Depending on how accurate you want/need it to be, you may also need to consider how you will maintain accuracy, calibration and control of the scales.

Notwithstanding specific operating procedures, being mobile there is every chance that they will get bashed, dropped or exceed their maximum weight.




23

49 posts

258 months

Thursday 6th July 2017
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BMWBen said:
There may be other ways of doing it that are used in certain circumstances to give more information - but if you weigh the using the front wheels and then using the rear wheels and add it together it's no different to driving onto a weighbridge that measures both front and back together. Maybe the OP's question wasn't phrased correctly, but if you want to know how much something large weighs that's absolutely a valid way of doing it.
Yes. If you're on a weighbridge you'd weigh the whole vehicle and that weight will be equal to the sum of the axles providing certain criteria. Approach to the weighbridge has to be level and at the same height. Roll front axle on...brakes off wait for a stable reading on the scales. Repeat for all axles. The sum of the axles should equal the the whole within the stated accuracy of the system. If not. Repeat. You can weigh the sides too and calculate wheel station weights. OP if you're asking local weighbridge operators for prices..ask them for their procedures and calibration history too. Scrap yards council operators and vosa all have them and are required to operate with procedures and regular calibration. Portable pad scales will allow you to do this without visiting the weighbridge but there's the cost to buy, training and calibration and the admin.

23



grumpy52

6,074 posts

196 months

Thursday 6th July 2017
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Some of the weighbridges used by DVSA (VOSA) are the type that you drive over slowly and they measure each axles weight .
They are a pain in the a#rse to use .

23

49 posts

258 months

Thursday 6th July 2017
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How big are they? Are they just for one axle and it records the peaks as each axle passes. Quicker I suppose providing it works!

S11Steve

6,389 posts

214 months

Friday 7th July 2017
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A few years ago when I was running a rental branch, we got a couple of new vehicle transporters - both a 7.5t and 13t GVW.

We got a guy out from http://www.autoscales.co.uk/ in Blackburn with a set of pads to weigh the trucks, the various cars and vans we had on fleet, and also many various loaded combinations of cars and vans on the trucks.
He used a pad under each wheel, and their system added up the total weights and axle weights - depending on how the 7.5t vehicle was loaded, it was easy to overload one of the axles..

What I do remember is that when only a pair of pads was used, and the vehicles driven over them to add up the total weight, it gave a slightly different to using 4 pads. It was not much difference, but was explained as the vehicle not being level when it was weighed - if the back weheels were on the 4inch high pads, there was slightly more weight on the front axle - only 15-20kg from memory, but it was enough to overload the front axle when two vehicles were on the 7.5t truck.


grumpy52

6,074 posts

196 months

Friday 7th July 2017
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Many now use the axle weight type machines as overweight axles are the common problem that is harder to spot on the large platform type scales .
Having to run over the scales 5 times and still be legal does not put a smile on VOSA officials faces !

James_B

12,642 posts

287 months

Saturday 8th July 2017
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BMWBen said:
Physics would suggest that if you weigh the front axle and the rear axle and then add the two together, you'll get the overall weight of the van.
Physics would suggest that if you do that then you will always get less than the overall weight.

Not by enough that I'd worry, but definitely less.

RA500

251 posts

226 months

Saturday 8th July 2017
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Ive Just bought a van with an Axtec onboard axle load indicator, not too sure on the cost though but the company looks to be at the top of the field in vehicle weighing systems.

BMWBen

4,906 posts

231 months

Saturday 8th July 2017
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James_B said:
BMWBen said:
Physics would suggest that if you weigh the front axle and the rear axle and then add the two together, you'll get the overall weight of the van.
Physics would suggest that if you do that then you will always get less than the overall weight.

Not by enough that I'd worry, but definitely less.
Do explain?

S11Steve

6,389 posts

214 months

Saturday 8th July 2017
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BMWBen said:
James_B said:
BMWBen said:
Physics would suggest that if you weigh the front axle and the rear axle and then add the two together, you'll get the overall weight of the van.
Physics would suggest that if you do that then you will always get less than the overall weight.

Not by enough that I'd worry, but definitely less.
Do explain?
From my post above...


What I do remember is that when only a pair of pads was used, and the vehicles driven over them to add up the total weight, it gave a slightly different reading to using 4 pads. It was not much difference, but was explained as the vehicle not being level when it was weighed - if the back weheels were on the 4inch high pads, there was slightly more weight on the front axle - only 15-20kg from memory, but it was enough to overload the front axle when two vehicles were on the 7.5t truck.