Increase tractor speed limit proposal

[s.varty]

I thought that fastracs were not allowed to exceed 20mph. They were capable of exceeding 20, but registered as agg were limitted to 20 by law. If you wanted to run faster you needed to register them as HGV with all the associated etc etc. That was my interpretation of the law when I was looking into what vehicle to buy.

 

Seems to me that if a vehicle is agg registered there are no laws, not until theres an accident that is

[Billhook]

I'd be interested to see how you work that out, the trailer cannot gross more than 18.29 tonnes so payload cannot lawfully exceed 15.29, even then it's problematic because not many balanced trailers weighing 3 tonne can carry that and the maximum drawbar load of an unbalanced one cannot exceed 6.4 tonnes. The tractor would have to have to have coupled service brakes and I suspect the 8210 is limited to a gross train weight of 18.25 tonnes by virtue of the road traffic act power requirement, which I do not think AMVs are exempt from.

 

Now whilst no policeman will be expected to realise that it's only after an accident that a barrister will check on all these things.

 

I bow to your superior knowledge here and admit I have not looked too closely at the 8210 position as I would not dare to use it.

I may be wrong about the trailer weight which is an AS Marston and they are much lighter than Bailey/Larrington, but the three ton figure sticks in my mind.

 

Is there not also another law about the GTW not being greater than four times the weight of the tractor.

 

I could pull a five ton trailer with my Little Grey Fergie in theory but that would be in another league of potential disaster! (even at max speed of 14 mph the hills around here make it even more dangerous.)

[agrimog]

the 20mph isnt only applicable to tractors, it applies to various classes of vehicles, the common factor is not having suspension on all wheels, the fastrac, unimog and trantor, get by this by having suspension on all wheels, this allows then to travel at higher speeds, unfortunatly jcb boloxed this on the larger models by fitting hydraulic steering, thus limiting them to 20 again, no mechanical linkage=20, it looks like some of the new "fancy" cars that have "fly by wire" systems could also fall foul of this, will prove interesting to see how they get round this

[openspaceman]

I

Is there not also another law about the GTW not being greater than four times the weight of the tractor.

 

This relates to tractors that do not have the trailer brake operating off the service brake, most mainstream full sized tractors post 1986 should operate the trailer brakes proportionally when the service brake is pressed.

 

Earlier tractors with separately operated trailer brakes are limited to 14230 kg and the tractor must weigh 25% of the trailer(s) being pulled, this is slightly different from the figure you posted.

 

I'm still not sure if the 4.4kW/tonne (6hp/ton) rules apply, they do not apply to solo tractors but I believe they probably apply to post 1986 trailers which I believe have to be plated. This is in the 1986 construction and use act, not the road traffic act and seems to apply to all goods vehicles that are plated.

 

Once your trailer grosses more than 14230 kg complying becomes complicated as the rules talk about distances between axles so reaching the allowed 24390kg GTW needs some thought and the tractor has to weigh at least 6 tonnes (and probably have 150hp)

[gensetsteve]

so reaching the allowed 24390kg GTW needs some thought and the tractor has to weigh at least 6 tonnes (and probably have 150hp)

 

And I think you need air brakes on tractor and trailer although I am not sure if you need it legally its a good idea with 24 tonnes.