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Big Trailers - Blue slip / Weigh bridge etc

Posted: Sun Sep 07, 2008 3:38 pm
by thehanko
Hi guys,

For my business i bought an old caravan chassis which I have modified in length and replaced the draw bar etc.

It is now 24 foot by 8 foot, dual axel, electric brakes etc and I want to get it registered to a gvm of about 1990KG.

So this will be under the break away brakes requirment etc.

I know it is small enough to pass road rules etc, but only just started to wonder if I should have had an engineer specify materials etc before I built it.

Initially I was told by a number of people that what i was doing was fine.

I have added a longer draw bar which is 100 x 50 4mm RHS and added 50 x 75mm 3mm RHS right down the length of the chassis to allow we to extend the flat top from 21 foot to about 24 foot.

apart from that the old chassis is still all the same, just beefed up a bit.

Does anyone have any experience from modifying trailers, or from building a new one?

thanks
ben

Posted: Sun Sep 07, 2008 6:16 pm
by mkpatrol
Have it weighed at a weigh bridge for the tare weight.

You can then calculate the ATM (GVM is different, look at VSB1, it will come up with a google) with the axle and tyre ratings from there. Remember you must exceed the ATM with this calculation to have a measure of safety.

You shouldnt need an engineer to do this for you.

You will also need to measure your ball weight to get the ATM, once you have done this you should be away.

If I were you i would take a copy of VSB1 with you & tell the inspector that you performed the calculations as per that publication.

Posted: Wed Sep 10, 2008 10:05 am
by thehanko
gold thanks
ben