Ballast tractors

[cheb]

The ones used for hauling very heavy loads. I understand the need to them to be weighted so as to have enough grip to haul the load, but how much ballast weight is needed? Or how little, there being no economic sense in moving unneeded weight.

In short, how is it calculated?

Edit: Typo corrected

 

[Agroshield]

I think in the UK, they come under the STGO regulations. For CAT3, it says maximum axle weight 16,500kg, so you would ballast up until that figure is reached. If there is not enough traction to move the load, you have to add more drive axles.

Edit:

This might be worth reading:

Pull Force

Pull Force is the force that a truck or prime mover can exert onto a transporter or any type of trailer. It has been a subject of much controversy and misu...

www.nbmcw.com

 

[8ob]

Normally get ballasted tractor units when they are pulling fifth wheel dollies under heavy trailers, without the ballast they wouldn't move an inch.

Bob

 

[Agrismith]

The ones used for hauling very heavy loads. I understand the need to them to be weighted so as to have enough grip to haul the load, but how much ballast weight is needed? Or how little, there being no economic sense in moving unneeded weight.

In sort, how is it calculated?

When you get the that much train weight, then what they actually ballast themselves with is insignificant. So as above go for the maximum you can.

 

[gaz1]

we should remember this post where ballasted wasnt used

https://www.mig-welding.co.uk/forum/threads/tractor-crash.124289/

 

[cheb]

Thanks, not nearly as complex as I thought it might, just lots of brute force. I've no need to know about this, just curiosity.