Interoperability constituents

The GB Railways Interoperability Regulations (RIR) describe interoperability constituents as:

“Any elementary component, group of components, sub-assembly or complete assembly of equipment that is incorporated or intended to be incorporated into a subsystem upon which the interoperability of the rail system depends directly or indirectly”.

Interoperability constituents are defined in each of the GB National Technical Specification Notices (NTSNs), along with the permissible assessment methodologies (assessment modules). The assessment methodologies range from design and construction conformance, to quality management system assessment and verification – we’re here to assist with all of them.

As a fully accredited GB Approved Body (ApBo) with the scope of accreditation covering all subsystems, we at NCB can assess and certificate the full range of interoperability constituents from all corresponding NTSNs:

Control Command and Signalling (CCS)

ETCS Onboard

Odometry Equipment

Interface of external STM

GSM-R Voice
Cab Radio

GSM-R ETCS Data only Radio



Radio in-fill unit



LEU Eurobalise

LEU Euroloop

Axle Counter

Infrastructure (INF):


Rail fastening system

Track sleepers

Energy (ENE):

Overhead contact line

Persons with Reduced Mobility (PRM):


Platform ramps and platform lifts

Interface of door control device

Toilet modules

Baby nappy changing table

Call for aid devices

Internal and external displays

Boarding devices

Rolling Stock – Locomotive and Passenger (LOC and PAS):

Automatic centre buffer coupler

Manual end coupling

Towing coupler for rescue


Automatic variable gauge systems

Wheel slide protection system

Head lamp

Marker lamp

Tail lamp



Pantograph contact strips

Main circuit breaker

Driver’s seat

Toilet discharge connection

Inlet connection for water tanks

Rolling Stock – Freight Wagons (WAG):

Running Gear




Automatic variable gauge systems

Friction element for wheel tread brakes

Rear-end signal

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