Spacing and position engine (the spacing limit is entered from your standard), in-pavement/elevated/mixed fixture configuration, taxiway-centreline and holding-position relationship checks, control/monitoring/circuit framework, serviceability calculation, and existing-installation inspection.
Built as a safety-critical intersection calculator, not a simple quantity tool. It keeps three items strictly separate — the runway holding-position marking (a surface marking), the Stop Bar (a lighting system), and taxiway centreline lights (a separate guidance system) — and never counts a marking as a light.
Spacing is never reused from the taxiway-centreline calculator (#09) — Stop Bar spacing has its own standard-specific database.
Used only as the default basis for the calculated Stop Bar coverage width below — not automatically assumed equal to it.
The two configurations are not treated as interchangeable — each records its own fixture-specific fields below.
Selecting CAT II/III changes the applicable configuration but does not, in this build, pull an exact figure-level database — the detailed CAT II/III configuration is not incorporated (project-verified).
Affects fixture selection, orientation and circuit arrangement — documented, not silently assumed.
LSB ≈ Wtaxiway subject to the applicable standard and approved layout — reported as a calculated coverage width, never silently assumed equal to pavement width without being shown.
ΔD = DHP − DSB is reported explicitly rather than assuming the Stop Bar location from taxiway length — enter the approved-layout chainages for both reference points.
Default reproduces the 23 m / 3 m illustrative example (8 intervals, 9 lights, Sactual = 2.875 m). The actual value must come from the selected standard.
Never reused from taxiway centreline or edge-light spacing — the exact ICAO/FAA/DGCA Stop Bar spacing database is not hard-coded here. For reference, ICAO Annex 14 5.3.20.6 requires lights at uniform intervals of no more than 3 m across the taxiway; confirm the value in your own copy and in the FAA and DGCA documents.
Used for symmetry/centring check against the taxiway-centreline intersection point and duplicate-fixture detection.
Checked against the expected centred position (LSB/2) within tolerance T — confirms PCL−SB lands where intended.
No generic percentage is hard-coded — the applicable limit must come from the governing standard or project specification.
Generated positions are auto-checked pairwise against tolerance T. Add any further known duplicates here.
| Item | Quantity |
|---|---|
| Stop Bar in-pavement lights | — |
| Stop Bar elevated lights | — |
| Stop Bar control equipment | — |
| Circuit/control interface | — |
| Monitoring equipment | — |
| Total light fixtures | — |
Light fixtures are kept distinct from control equipment — control/circuit/monitoring units are BOQ line items, not additional light positions.
Spacing, alignment and colour are checked against the design Stop Bar generated on the Calculate tab.
Quick answers on stop bar spacing, positions, configuration and serviceability.
It is a safety-critical intersection calculator. It runs a spacing and position engine, supports in-pavement, elevated and mixed configurations, checks the relationship to the taxiway centreline and holding position, and covers the control, monitoring and circuit framework, serviceability, and an inspection of an existing installation. It keeps the runway holding-position marking, the Stop Bar and the taxiway centreline lights strictly separate, and never counts a marking as a light.
The number of intervals is the coverage width divided by the design spacing, rounded up, and the number of lights is that plus one. The actual spacing is the coverage width divided by the number of intervals, and it must not exceed the maximum spacing. For example, a 23 m width at 3 m design spacing gives 8 intervals, 9 lights and an actual spacing of 2.875 m, uniformly distributed instead of leaving one oversized final gap.
It is entered by you from your standard. Stop Bar spacing is never reused from the taxiway-centreline calculator (#09), and no figure is assumed by default for ICAO, FAA or DGCA. For reference, ICAO Annex 14 5.3.20.6 requires lights at uniform intervals of no more than 3 m across the taxiway, but confirm the value in your own copy and in the FAA and DGCA documents.
The coverage width can be set automatically equal to the taxiway width, or entered as a custom value, and it is reported as a calculated width. You enter the holding-position chainage and the stop bar chainage from the approved layout, and the difference is reported explicitly. If you enter a measured centreline crossing position, it is checked against the expected centred position of half the coverage width, within your tolerance.
They are not treated as interchangeable. In-pavement and elevated configurations each record their own fields, namely circuit grouping and obstruction clearance. For a mixed layout, no standard formula governs the split, so you enter the approved layout's split directly, and the calculator flags a mismatch if the two counts do not sum to the generated total. Control, circuit and monitoring units are BOQ line items and are not counted as light positions.
The number of failed fixtures is the total minus the working ones, and the failure rate is failed divided by total, times 100. Serviceability is 100 percent minus the failure rate. No generic limit is hard-coded, so the applicable limit must come from the governing standard or project specification.
Enter one measured fixture per line with its x and y position, type (in-pavement or elevated), direction (unidirectional or bidirectional), status (working or failed) and colour. The tool checks spacing, perpendicular alignment to the design Stop Bar line and colour against the expected value, and compiles working and failed counts. This is checked against the design Stop Bar generated on the Calculate tab.
It does not maintain the exact ICAO, FAA or DGCA Stop Bar spacing and configuration database, does not resolve the detailed CAT II and CAT III configuration, and does not do a true 2D match against a separately run taxiway-centreline calculation. Stop Bar geometry and operational control are safety-critical, so calculated positions and quantities must be verified against the applicable requirements and the approved aerodrome lighting layout.
Standard → geometry → spacing engine → position engine → colour/centreline/control → quantity → compliance. A marking, a Stop Bar, and a centreline light are never treated as the same thing.
The runway holding-position marking is a surface marking. The Stop Bar is a lighting system associated with a controlled holding position. Taxiway centreline lights are a separate guidance system. This calculator never counts a holding-position marking as a light, and never reuses Calculator #09's centreline spacing for the Stop Bar.
Worked example: LSB = 23 m, Sdesign = 3 m → N = ⌈23/3⌉ = 8 → Sactual = 23/8 = 2.875 m, uniformly distributed rather than leaving one oversized final gap. That is 8 intervals and 9 lights, one at each end of the coverage width. This is illustrative only — the real spacing value must come from the selected standard.
Both chainages are entered explicitly rather than the Stop Bar location being assumed from taxiway length. Where a measured centreline-crossing position is entered, it is checked against the expected centred position LSB/2 within tolerance T — confirming the Stop Bar is centred on the taxiway and the centreline passes through the intended reference point PCL−SB.
These are not treated as interchangeable. In-pavement and elevated configurations record their own fields (circuit grouping vs. obstruction clearance), and a mixed layout is captured via an explicit manual split of the generated positions — no standard formula predicts how a real mixed layout is arranged, so this calculator asks rather than assumes.
Serviceability is reported as 100% − Failure Rate. No generic operational limit is hard-coded — the applicable serviceability threshold must come from the governing standard or project specification, entered explicitly.
Measured fixtures are checked for spacing, perpendicular alignment to the design Stop Bar line, colour against the standard-derived expected colour, and compiled into working/failed counts — separately from the design-position engine above.
| Standard | Stop Bar Spacing |
|---|---|
| ICAO Annex 14 | Project-entered |
| FAA AC 150/5340-30J | Project-entered |
| DGCA / Indian implementation | Project-entered |
No figure is assumed by default — the exact ICAO/FAA/DGCA spacing and configuration database, and the detailed CAT II/III configuration, are not incorporated in this build and must be confirmed against the applicable document.
Colour is derived from Standard → Function → Colour rather than being a free engineering input. Stop Bar lights are internationally red; this calculator reports that as the standard-derived value and flags it for verification against the project's governing document rather than letting the user pick an arbitrary colour.
Generated positions are automatically checked pairwise against tolerance T, consistent with the duplicate-control approach used in Calculators #08 and #09. Any two positions closer than T are flagged rather than silently counted twice.
The calculator reports the physical fixture count (e.g. 9 individual light units) distinctly from the functional description ("one Stop Bar") — both are shown, since procurement and maintenance need the fixture count, not just the functional name.
It does not maintain the exact ICAO/FAA/DGCA Stop Bar spacing and configuration database, does not resolve the detailed CAT II/III configuration, and does not perform true 2D matching against a separately-run taxiway-centreline calculation — the centreline-crossing check relies on a manually entered measured position. Spacing engine, position generation, and the holding-position/centreline relationship checks are fully calculated; exact figure-level configuration must be confirmed against the approved layout.
Please read before relying on any content on this page or on any result or record produced by it.