RCDD · Question #267
You have the responsibility of designing a railroad track crossing for an outside plant OSP cable. There are three separate railroad tracks to be crossed. The measurement between the center of the…
The correct answer is C. 31 m (102 ft). Railroad crossing conduit length is calculated by adding required right-of-way extensions on each side to the measured track span, totaling 31 m (102 ft) for this three-track crossing.
Question
You have the responsibility of designing a railroad track crossing for an outside plant OSP cable. There are three separate railroad tracks to be crossed. The measurement between the center of the two outer tracks is 16 m (52 ft). Using the standard track width of 1435 mm (4 ft 8.5 in), what is the length of the rigid steel conduit required to facilitate the crossing?
Options
- A20 m (66 ft)
- B25 m (82 ft)
- C31 m (102 ft)
- D35 m (115 ft)
- E40 m (130 ft)
How the community answered
(28 responses)- A7% (2)
- B11% (3)
- C75% (21)
- D4% (1)
- E4% (1)
Why each option
Railroad crossing conduit length is calculated by adding required right-of-way extensions on each side to the measured track span, totaling 31 m (102 ft) for this three-track crossing.
20 m (66 ft) does not provide adequate extension beyond the outer tracks to clear the railroad right-of-way boundaries and ballast embankments on both sides.
25 m (82 ft) falls short of the required per-side extension, leaving the conduit endpoints within the ballasted zone rather than beyond the right-of-way boundary.
The 31 m (102 ft) total is derived by taking the 16 m (52 ft) center-to-center span of the outer tracks and adding the standard required extension of approximately 7.5 m (25 ft) past each outer track center - 16 + 7.5 + 7.5 = 31 m. This 25 ft per-side extension corresponds to the standard railroad right-of-way boundary measured from each outer track centerline, ensuring the rigid steel conduit exits the disturbed ballast and embankment zone with sufficient burial depth and mechanical protection on both approaches.
35 m (115 ft) exceeds the calculated requirement, representing unnecessary conduit length and cost beyond what the standard crossing calculation specifies.
40 m (130 ft) significantly over-extends the crossing, adding approximately 9 m of excess conduit beyond the properly calculated length.
Concept tested: OSP railroad crossing rigid conduit length calculation
Source: https://www.bicsi.org/standards-and-practices/standards/bicsi-standards/outside-plant
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