Appendix 1
United Kingdom
Symbols
The following symbols are used in Appendices 2, 3 and 4:
| FMnd and FMd in case of two-axled power-driven vehicles: these symbols may be simplified to corresponding Fi-symbols. | |
| Symbol | Notes |
|---|---|
| E | wheelbase |
| ER | distance between coupling point and centre of axle(s) of rigid drawbar towed vehicle (or distance between coupling point and centre of axle(s) of centre-axle towed vehicle) |
| ε | the adhesion utilised by the vehicle: quotient of the maximum braking rate with the anti-lock braking system operative (zAL) and the coefficient of adhesion (k) |
| εi | the ε-value measured on axle i (in the case of a tractor with a category 3 anti-lock braking system) |
| εΗ | the ε-value on the high-friction surface |
| εL | the ε-value on the low-friction surface |
| F | force [N] |
| FbR | braking force of the towed vehicle with the anti-lock braking system inoperative |
| FbRmax | maximum value of FbR |
| FbRmaxi | value of FbRmax with only axle i of the towed vehicle braked |
| FbRAL | braking force of the towed vehicle with the anti-lock braking system operative |
| FCnd | total normal reaction of road surface on the un-braked and non-driven axles of the vehicle combination under static conditions |
| FCd | total normal reaction of road surface on the un-braked and driven axles of the vehicle combination under static conditions |
| Fdyn | normal reaction of road under dynamic conditions with the anti-lock braking system operative |
| Fidyn | Fdyn on axle i in case of tractors or drawbar towed vehicle |
| Fi | normal reaction of road surface on axle i under static conditions |
| FM | total normal static reaction of road surface on all wheels of the tractor |
| FMnd f1 | total normal static reaction of road surface on the un-braked and non-driven axles of the tractor |
| FMd | total normal static reaction of road surface on the un-braked and driven axles of the power-driven vehicle |
| FR | total normal static reaction of road surface on all wheels of towed vehicle |
| FRdyn | total normal dynamic reaction of road surface on the axle(s) of rigid drawbar towed vehicle or centre-axle towed vehicle |
| FwM | 0,01 FMnd + 0,015 FMd |
| g | acceleration due to gravity (9,81 m/s2) |
| h | height of centre of gravity specified by the manufacturer and agreed by the technical service conducting the approval test |
| hD | height of drawbar (hinge point on towed vehicle) |
| hK | height of fifth wheel coupling (king pin) |
| hR | height of centre of gravity of the towed vehicle |
| k | coefficient of adhesion between tyre and road |
| kf | k-factor of one front axle |
| kH | k-value determined on the high-friction surface |
| ki | k-value determined on axle i for a vehicle with a category 3 anti-lock braking system |
| kL | k-value determined on the low-friction surface |
| klock | value of adhesion for 100 % slip |
| kM | k-factor of the tractor |
| kpeak | maximum value of the curve ‘adhesion versus slip’ |
| kr | k-factor of one rear axle |
| kR | k-factor of the towed vehicle |
| P | mass of individual vehicle [kg] |
| R | ratio of kpeak to klock |
| t | time interval [s] |
| tm | mean value of t |
| tmin | minimum value of t |
| z | braking rate [m/s2] |
| zAL | braking rate z of the vehicle with the anti-lock braking system operative |
| zC | braking rate z of the vehicle combination, with the towed vehicle only braked and the anti-lock braking system inoperative |
| zCAL | braking rate z of the vehicle combination, with the towed vehicle only braked and the anti-lock braking system operative |
| zCmax | maximum value of zC |
| zCmaxi | maximum value of zC, with only axle i of the towed vehicle braked |
| zm | mean braking rate |
| zmax | maximum value of z |
| zMALS | zAL of the tractor on a ‘split surface’ |
| zR | braking rate z of the towed vehicle with the anti-lock braking system inoperative |
| zRAL | zAL of the towed vehicle obtained by braking all the axles, the tractor un-braked and its engine disconnected |
| zRALH | zRAL on the surface with the high coefficient of adhesion |
| zRALL | zRAL on the surface with the low coefficient of adhesion |
| zRALS | zRAL on the split surface |
| zRH | zR on the surface with the high coefficient of adhesion |
| zRL | zR on the surface with the low coefficient of adhesion |
| zRHmax | maximum value of zRH |
| zRLmax | maximum value of zRL |
| zRmax | maximum value of zR |
Annotations
Footnotes
- f1
-
FMnd and FMd in case of two-axled power-driven vehicles: these symbols may be simplified to corresponding Fi-symbols.