Definitions

 

overhead contact line system (OCS)

supporting network for supplying electrical energy to electromotive power units

NOTE The system may include all overhead wiring, including the catenaries, the grooved contact wires and return wires, earthwires, lightning protection wires, line feeders and reinforcing feeders mounted on the supports, overhead conductor rails, foundationsand supporting structures and components, terminating, supporting, registering or insulating the conductor equipment and switching,detecting or protecting equipment.

 

overhead contact line

contact line placed above (or beside) the upper limit of the vehicle gauge and supplying vehicles withelectric energy through roof-mounted current collection equipment

 

contact line

conductor system for supplying electric energy to vehicles through current-collecting equipment

 

overhead line

an electric line whose conductors are supported above ground, generally by means of insulators andappropriate supports.

NOTE Certain overhead lines may also be constructed with insulated conductors

 

overhead contact line with catenary suspension

overhead contact line where the grooved contact wire or wires are suspended from one or morelongitudinal catenariesNOTE Longitudinal suspension is an equivalent term to catenary suspension.

 

load gauge, static

maximum cross-sectional profile of the vehicles using the railway line

 

kinematic load gauge

static load gauge enlarged to allow for dynamic movements of the vehicle, e.g. suspension travel andbounce

 

kinematic envelope

kinematic load gauge further enlarged to allow for possible tolerances in the position of the track

 

swept envelope

kinematic envelope enlarged to allow for centre and end throw of the vehicles on horizontal andvertical curves

 

neutral section

section of a contact line provided with a sectioning point at each end, to prevent successive electricalsections, differing in voltage or phase, being connected together by the passage of current collectors

 

insulated overlap

sectioning point formed by overlapping the ends of adjacent sections of contact lines, allowing parallelrunning, insulation being provided by a suitable air gap between the two sets of equipment

 

contact wire

electric conductor of an overhead contact line with which the current collectors make contact

 

catenary

longitudinal wire supporting the grooved contact wire or wires either directly or indirectly

 

main catenary

catenary supporting an auxiliary catenary by means of droppers

 

auxiliary catenary

catenary suspended from the main catenary and supporting the grooved contact wire or wires directlyby means of droppers

 

stitch catenary suspension

catenary suspension in which the contact wire is suspended by one or more droppers from a shortcontinuos auxiliary wire, attached to the main catenary at one point on each side of the main catenarysupport

 

feeder

electrical connection between the contact line and the substation or switching station

 

line feeder

overhead conductor mounted on the same structure as the overhead contact line to supplysuccessive feeding points

 

reinforcing feeder

overhead conductor mounted adjacent to the overhead contact line, and directly connected to it atfrequent intervals, in order to increase the effective cross-sectional area

 

return circuit

all conductors which form the intended path for the traction return current

NOTE The conductors may be e.g. running rails, return conductor rails, return conductor earth wires, return cables.

 

return conductor

any part of the return circuit

 

return conductor rail

conductor rail used instead of the running rails for the traction return currents

 

return cable

insulated return conductor forming part of the return circuit and connecting the rest of the returncircuit of the substation

 

conductor

a metal wire or cable, either solid or stranded, designed to carry electrical energy and forming part ofthe overhead contact line system

 

earth wire

wire connecting supports collectively to earth or the running rails to protect people and installations incase of insulation fault and which may also be used as a return conductor

 

nominal voltage

voltage by which an installation or part of an installation is designated

NOTE The voltage of the contact line may differ from the nominal voltage by a quantity within permitted tolerances given in EN 50163.

 

feeding section

electrical section of the route fed by individual track feeder circuit breakers within the area supplied bythe substation

 

earth

conductive mass of the earth, whose electric potential at any point is conventionally taken as equal tozero

 

fault current

maximum current passed through the overhead contact line under fault conditions, within a shortdefined time period, between live equipment and earth

 

short circuit

accidental or intentional conductive path between two or more points in a circuit forcing the voltagesbetween these points to be relatively low. Any such conductive path whether between conductors orbetween conductor and earth is regarded as a short circuit

 

short circuit current

electric current flowing through the short-circuit

 

continuous current rating

nominal rating capacity of the overhead contact line within the system operating parameters

 

stray current

current which follows paths other than the return circuit

 

feeding point

point at which the feeding system supply is connected to the contact line

 

isolation

disconnection of a section of overhead contact line from the source of electrical energy, either in anemergency or to facilitate maintenance

 

span

the overhead contact line from one support or suspension point to the next

 

tension length

length of overhead contact line between two anchoring points

 

gradient

ratio of the difference in height of the overhead contact line above rail level at two successivesupports to the length of the span

 

stagger

displacement of the contact wire to opposite sides of the track centre at successive supports to avoidlocalised wear of the pantograph wearing strips

 

encumbrance

vertical distance from the lower face of the grooved contact wire to the middle of the catenary,measured at the support

NOTE System height is an equivalent term for encumbrance.

 

contact wire height

distance from the top of the rail to the lower face of the contact wire, measured perpendicular to the track

 

minimum contact wire height

a minimum value of the contact wire height in the span in order to avoid the arcing between one ormore contact wires and the vehicles in all conditions

 

minimum design contact wire height

theoretical contact wire height including tolerances, designed to ensure that the minimum contact wireheight is always achieved

 

nominal contact wire height

a nominal value of the contact wire height at a support in the normal conditions

 

maximum design contact wire height

theoretical contact wire height including tolerances and uplift, which the pantograph is required to reach

 

contact wire uplift

vertical upward movement of the grooved contact wire due to the force produced from the pantograph

 

support structure

parts which support the conductors and the associated insulators of an overhead contact line

 

mast

mainly vertical structure to provide for support, tensioning and registration of the overhead contact line

 

cantilever

support consisting of one or more transverse members projecting from a mast

 

cross-span, span wire

wire or cable, normally electrically insulated, placed across the track and used either to support one ormore overhead contact lines (headspan), or to carry lateral registration force (cross-span registration)

 

foundation

construction, usually of concrete or steel, completely or partly buried in the ground on which thesupport is mounted. The foundation shall provide stability to all loads carried by the support

 

section insulator

sectioning point formed by insulators inserted in a continuous run of a contact line with skids or similardevices to maintain continuous current collection

 

dropper

component used to suspend a cross-span registration, an auxiliary catenary or a contact wire from aheadspan or a longitudinal catenary

 

tensioning device

arrangement enabling the mechanical tension of the conductors to be adjustedNOTE Tensioning equipment and tensioner are equivalent terms for tensioning device.

 

automatic tensioning device

device used in tensioning equipment to automatically maintain constant the mechanical tension in theconductors within certain temperature limits

 

pull-off

form of supporting structure or registration assembly which only fixes the horizontal position (stagger)of the contact and catenary wires, and does not support their vertical load

 

current collector

equipment fitted to the vehicle and intended to collect current from a contact wire or conductor rail

 

pantograph

apparatus for collecting current from one or more contact wires, formed of a hinged device designedto allow vertical movement of the pantograph head

 

trolley

apparatus for collecting current from a contact wire by means of a grooved wheel or contact slippermounted on a pole which is movable in any direction

 

Source from EN-50119