Commission Decision of 28 July 2006 concerning the technical specification of interoperability relating to the subsystem ‘rolling stock — freight wagons’ of the trans-European conventional rail system (notified under document number C(2006) 3345) (Text with EEA relevance) (2006/861/EC) (repealed)

I.9. BRAKE PAD U.K.

I.9.1. Purpose U.K.

The pad is to be used as part of the friction brake of a vehicle, which is capable of providing pre-defined retardation levels as specified by the purchaser, by being applied to a brake disc friction face. The pad shall fulfil the following requirements:

• Permit a braking moment or torque to be generated

• Permit, by frictional engagement with a brake disc friction face, the conversion into heat of the kinetic and potential energy involved in retarding the vehicle or vehicles, which is attributed to the use of the disc brake.

• Act as part of a holding or parking brake by frictional engagement with a brake disc friction face.

I.9.2. Operational U.K.

The design and manufacture of the pad shall, for all intended operating conditions, take into account the following criteria.

Performance

• The maximum specified retardation to be achieved in full service and emergency braking conditions

• The rotational speed range of the brake disc

• The specified requirements for any holding or parking brake facility.

• The range of specific pressure of the pad friction surface on the disc friction face

• The type of material used in the manufacture of the brake disc friction face.

• The quantity of brake energy to be converted and its rate of conversion and dissipation

• The temperature of the brake disc friction face

Service and life cycle costs

• The integrity and wear rate of the pad friction material and brake disc friction face

• The need to prevent the detachment of any part of the friction material from the pad throughout its useable thickness.

• The need to prevent deformation of the pad backplane in any plane throughout the useable thickness of the friction material.

I.9.3. Pad design U.K.

The interface dimensions for the Interoperability Constituent brake pad shall conform to figures I.9.3.1 and I.9.3.2 for 200 cm² and 175 cm² brake pads.

Figure 9.3.1

Figure 9.3.2

I.9.4. Frictional Performance U.K.

General requirements U.K.

Pads of the same size, with the same nominal friction coefficient and used in the same application, may produce different frictional characteristics depending on the pad material type and formulation.

As far as possible, the friction coefficient must be independent of the initial braking speed, the specific pressure on the brake disc friction face, the temperature of the friction face and atmospheric conditions. The friction coefficient should also be independent of the degree of bedding of the pad friction surface on the brake disc friction face

Specific requirements

The purchaser shall supply details of the range of duty level (maximum speed/braked load per disc/deceleration/disc type and material/any other specific requirements) that the pad should be capable of meeting.