Braking Questions - Approval of LL blocks in accordance with UIC Leaflet 541-4 in 2xBg configuration on vehicles with nominal wheel diameters of 840 mm and 760 / 730 mm

The existing UIC approval of composite LL blocks for standard applications is to be extended to include dual-sided brake applications in 2xBg block configuration on monobloc wheels with nominal diameters of 830 mm and 760 / 730 mm. The present report analyses the extension, on the basis of UIC Leaflet 541-4, 4^th edition, of the application range of approved LL blocks on wheelsets with different rolling circle diameters.

On the basis of the documents submitted and the observations contained in the present report, it is recommended that LL blocks be approved for use, under specific technical conditions, in 2xBg configuration on wheels with nominal diameters of 840 and 760 mm. It is recommended that LL blocks in 2xBg configuration be approved for use on wheels with a nominal diameter of 730 mm on condition that the axle load will be restricted. Should this limit be exceeded, further examination is required on a case by case basis.