I know what this is but I have forgotten how this is calculated. I used to have saved on the computer a very detailed internet file about calibrating roller brake testers which went into great detail about VoSA’s brake performance cards, what the numbers in the DtP number meant, how brake imbalance is calculated and several other aspects including PSV criteria and of course front wheel allowance. The last few pages had examples of RBT print outs with detailed explanations of the relevance of the figures.
FWA is a percentage added to the front axle figures if both lock based on IIRC the vehicle GVW. What I can’t recall is how that is calculated without access to the manufacturer’s brake performance details. Trawling through a pile of RBT test results I am not coming up with an answer. Can anyone help please? If anyone has a link to my lost file I would be very grateful.
On steered axle, every locked wheel gives a 25% allowance, this count for every steered axle. (And only steered axle)
The DTP no for trucks are computer generated and actually have no meaning on their own.
The DTP no for trailers there is a formula for Digits 2,3, and 4, but cannot find them neither in my memory or in my computer.
The first digit is the amount of axles
The 6th digit shows ABS / EBS or nothing and what type.
The 5th digit is the important one: 3 means parking on axle 1&2
5 means parking on axle 1 & 3
6 means parking on axles 2 & 3
7 means parking on all 3 axles
It’s similar to 2 axles with 3 being both axles.
For PSV, there is a DTP no, but doesn’t get used, instead they use a simplified brake code, the first 3 digits are vehicle weight, the 4th digit is the amount of axles, the fifth split or progressive secondary, the 6th what axle the parking is on.
That is as far as I can remember, must have a better description somewhere, will have a look for it and update.