Skip to content
flowss
Start freeChecking your session
Reliability block diagram templates

RBD — 25 kV Rail Traction Chain

Six-month traction availability for a regional line: grid supply point, paralleled feeder substations, overhead line, pantograph and a 3-of-4 traction converter group on the unit.

Reliability block diagramOperations & OpsReliability block diagram syntax docs
Template previewReliability block diagram
25 kV traction power chain — regional lineMission 4 380 h · 183 d · 11 blocks · 2 redundant arrangements · R 0.473608National grid supply pointR 0.844964 · A 0.99988parallel · R 0.996321Feeder substation AR 0.939346 · A 0.99989Feeder substation BR 0.939346 · A 0.99989Overhead line equipmentR 0.784010 · A 0.99967PantographR 0.864158 · A 0.999933 of 4 · R 0.944034Traction converter, bogie 1R 0.896282 · A 0.99970Traction converter, bogie 2R 0.896282 · A 0.99970Traction converter, bogie 3R 0.896282 · A 0.99970Traction converter, bogie 4R 0.896282 · A 0.99970Auxiliary power unitR 0.923452 · A 0.99989Train control and managementR 0.952499 · A 0.99996System reliability0.473608Unreliability0.5264System MTTF5 530 h · 230 dAvailability0.999331Reliability importance — Birnbaum ∂R/∂Rᵢ, with criticality share1Overhead line equipment0.604083crit 25%2National grid supply point0.560506crit 17%3Pantograph0.548057crit 14%4Auxiliary power unit0.512866crit 7.46%5Train control and management0.497226crit 4.49%6Traction converter, bogie 10.125399crit 2.47%7Traction converter, bogie 20.125399crit 2.47%8Traction converter, bogie 30.125399crit 2.47%+3 more blocks not shownWeakest link: Overhead line equipment — R 0.784010, Birnbaum 0.604083, 25% of system failure. Improving this one block moves the system number further than improving any other.Redundancy check: removing any one of the 6 branches makes its own group measurably more likely to fail — the least of them by 400%. Every one of them is earning its place.

Make it your own.

title "25 kV traction power chain — regional line"
mission 4380h

block grid  "National grid supply point"    mtbf: 26000h  mttr: 3h
block ssA   "Feeder substation A"           mtbf: 70000h  mttr: 8h
block ssB   "Feeder substation B"           mtbf: 70000h  mttr: 8h
block ohle  "Overhead line equipment"       mtbf: 18000h  mttr: 6h
block panto "Pantograph"                    mtbf: 30000h  mttr: 2h
block conv1 "Traction converter, bogie 1"   mtbf: 40000h  mttr: 12h
block conv2 "Traction converter, bogie 2"   mtbf: 40000h  mttr: 12h
block conv3 "Traction converter, bogie 3"   mtbf: 40000h  mttr: 12h
block conv4 "Traction converter, bogie 4"   mtbf: 40000h  mttr: 12h
block aux   "Auxiliary power unit"          mtbf: 55000h  mttr: 6h
block tcms  "Train control and management"  mtbf: 90000h  mttr: 4h

# 3-of-4 converters: the unit keeps timetable speed on three bogies, so
# losing one is a defect, not a failure.
series {
  grid
  parallel { ssA; ssB }
  ohle
  panto
  kofn 3 of 4 { conv1; conv2; conv3; conv4 }
  aux
  tcms
}