EN
8.9.2023
Official Journal of the European Union
L 222/209
— for units assessed in fixed or predefined formation(s) having 20 axles or more the calculated wheel/rail adhesion for the load case ‘minimum load’ is permitted to be higher than 0,15, but shall not be higher than 0,17.
Note:
for the load case ‘normal load’, there is no exception; the limit value of 0,15 applies.
This minimum number of axles may be reduced to 16 axles if the test required in point 4.2.4.6.2 related to the efficiency of the WSP system is performed for the load case ‘minimum load’, and provides positive result.
In the speed range > 250 km/h and < = 350 km/h, the three limit values above shall decline linearly in order to be reduced by 0,05 at 350 km/h.
(2)
The above requirement shall also apply for a direct brake command described in point 4.2.4.4.3.
(3)
The design of a unit shall not assume wheel/rail adhesion higher than 0,12 when calculating the parking brake performance.
(4)
These limits of wheel rail adhesion shall be verified by calculation with the smallest wheel diameter, and with the 3 load conditions considered in point 4.2.4.5.2.
All values of adhesion shall be rounded to two decimal places.’.;
(50)
point 4.2.4.6.2 is replaced by the following: ‘4.2.4.6.2.
Wheel Slide Protection (WSP) system (1)
A wheel slide protection system (WSP) is a system designed to make the best use of available adhesion by a controlled reduction and restoration of the brake force to prevent wheelsets from locking and uncontrolled sliding, thereby minimising the extension of stopping distances and possible wheel damage.
Requirements on the presence and use of a WSP system on the unit: (2)
Units designed for maximum service speed higher than 150 km/h shall be fitted with a wheel slide protection system.
(3)
Units equipped with wheel tread brakes with a brake performance which assumes in the speed range > 30 km/h a calculated wheel/rail adhesion higher than 0.12 shall be fitted with a wheel slide protection system.
Units not equipped with wheel tread brakes with a brake performance which assumes in the speed range > 30 km/h a calculated wheel/rail adhesion higher than 0,11 shall be fitted with a wheel slide protection system.
(4)
The requirement on the wheel slide protection system above shall apply to the two brake modes: emergency brake and service brake.
It shall also apply to the dynamic brake system, which is part of the service brake, and can be part of the emergency brake (see point 4.2.4.7).
Requirements on the WSP system performance: (5)
For units equipped with a dynamic braking system, a WSP system (if present according to the point above) shall control the dynamic brake force; when this WSP system is not available, the dynamic brake force shall be inhibited, or limited in order not to lead a wheel/rail adhesion demand higher than 0.15.
(6)
The wheel slide protection system shall be designed according to the specification referenced in Appendix J-1, index [15]; the conformity assessment procedure is specified in point 6.1.3.2.
(7)
Requirements on performance at unit level: If a unit is equipped with a WSP, a test shall be done to verify the efficiency of the WSP system (maximum extension of the stopping distance compared to stopping distance on dry rail) when integrated in the unit; the conformity assessment procedure is specified in point 6.2.3.10.
The relevant components of the wheel slide protection system shall be considered in the safety analysis of the emergency brake function required in point 4.2.4.2.2.