OK, where do I get 8 tons from then?

[ToughButterCup]

This here piling mat that I'm sorting out needs to be tested with a plate test. And to do that I need an 8 ton reaction load.

 

Following the by now normal steeeeep learning curve I learn from some that it is common to use a loaded 20 tonner's back axle, from others that I need a dead weight, like a 10 ton digger (no suspension).

 

• Where do I get a 'dead weight' 8 ton reaction load? (Keep it clean, please @Nickfromwales @ProDave)
• If I have 32 tons of lorry parked on my piling mat, and the test plate and hydraulic ram is put under the back axle, won't the test rig merely tend to jack the lorry back off it's suspension system? And  thus invalidate the test?

Here's an example of it done with a wagon  (sprung)

And here with a digger (unsprung)

 

What I want is Vorsprung durch Technik, fellas! And it'd be good if I knew the right Technik.

[IanR]

11 minutes ago, recoveringacademic said:

• If I have 32 tons of lorry parked on my piling mat, and the test plate and hydraulic ram is put under the back axle, won't the test rig merely tend to jack the lorry back off it's suspension system? And  thus invalidate the test?

 

 

Nope, it will just require the jack to lift further until the entire axle weight is taken by the plate (and the suspension is at full extension and tires lift off ground)

 

Edited to add: If you're jacking under the Axle and not the Chassis, then it makes no difference to what you are calling the Unsprung scenario

 

Edited January 13, 2017 by IanR

[ToughButterCup]

1 minute ago, IanR said:

 

Nope, [...]

 

Well now, @IanR, have a leedle look at this then

[Ferdinand]

Can you pay a delivery company an extra hour to hire it e.g. If you have gravel delivered?

 

Or get a hire company to fit you in when someone returns a big digger early?

 

Or it is 2mx2mx2m of water in a tank which you subsequently send back under the Distance Selling Regs.

 

Or borrow 2 elephants.

 

Or about 50 strapping friends - BuildHub AGM.

Edited January 13, 2017 by Ferdinand

[ragg987]

Water. I noticed they used large plastic containers filled with water to anchor the temporary stairs and walkway across a railway line at our local railway station. Each plastic containers seemd to be about 1m each side, so probably 1 ton each. You prpbably need a solid platform to support these so may be more complex than a digger or lorry option.

[IanR]

1 minute ago, recoveringacademic said:

 

Well now, @IanR, have a leedle look at this then

 

I edited my note just as you posted this

[ToughButterCup]

Yes but in this video, the wheels stay firmly on the ground:  Another case of  'Tinternet a place of shared ignorance' eh?

[IanR]

Yes, because it only has to get to xKg or xkN at the plate, not the entire axle weight, so doesn't need to lift the back of the vehicle entirely off the ground. ie. some of the weight is still taken by the suspension/wheels

Edited January 13, 2017 by IanR

[Triassic]

Your load cell will indicate the load, if the dead weight is too light, you just add more and redo the test. Maybe a local farmers plant trailer loaded with his / your digger, the full water butt and the .....

Edited January 13, 2017 by Triassic

[ToughButterCup]

Yo, just as I thought (suspected - logical thinking doesn't work on Fridays) if the mass of the counterweight is so large that it greatly exceeds the required 8 tons (in my case), then it doesn't matter.

 

[ToughButterCup]

Just now, Triassic said:

[...]  Maybe a local farmers plant trailer loaded with his / your digger,[...] (out of respect for SWMBO)

 

That's what I've come up with: maybe a water bowser or grain wagon - I'll just need to check the plated mass I suppose. Hmmm.

Thanks

Ian

[IanR]

Does it have to be a plate of a certain size? Could you use a plate of 1/2 or 1/4 the area and therefore use 1/2 or 1/4 the load?

[ToughButterCup]

@IanR, not sure I need to come up with a properly specified request. Off to t' pilers again.

[Triassic]

The wife bit was tongue in cheek, but I have seen load tests done where addition weight was required and after throwing on everything heavy that was to hand, it ended up with four of the big lads sat on top of the test weights! Every little helps.

Edited January 13, 2017 by Triassic

[ToughButterCup]