Crossing number from standard BG crossing length If the standard length of a Broad Gauge (BG) common crossing is 597 cm, what is the corresponding “number of crossing” (ratio describing the crossing angle)?

Introduction / Context:
Turnout geometry uses the “number of crossing,” such as 1 in 8, 1 in 12, or 1 in 16, to express the crossing angle. The standard length of a crossing for a given gauge correlates with this number through turnout layout relationships used in permanent-way design and fabrication.

Given Data / Assumptions:

• Gauge: Broad Gauge (BG).
• Standard common crossing length: 597 cm.
• We match this length to a commonly used crossing number.

Concept / Approach:
For BG, a standard crossing length around 6 m corresponds to a moderate crossing angle. In practice, 597 cm aligns with a 1 in 12 crossing, widely adopted for mainline turnouts due to a balanced compromise between speed and layout length.

Step-by-Step Solution:
Identify typical BG crossing options: 1 in 8, 1 in 12, 1 in 16.Associate standard lengths: around 6 m length is consistent with 1 in 12 geometry.Hence, the crossing number is 1 in 12.

Verification / Alternative check:
Turnout tables mapping standard lengths to crossing numbers indicate that ~5.97 m is the reference for 1 in 12 on BG layouts, confirming the selection.

Why Other Options Are Wrong:
1 in 16: Generally corresponds to a longer, flatter-angle crossing than 597 cm.“1 in” without a denominator: Incomplete description and not a valid option.None of these: Incorrect because a valid mapping exists.

Common Pitfalls:

• Confusing BG tables with MG/NG data, which have different reference lengths.
• Assuming a linear relation without considering the specific turnout standard adopted.

Final Answer:
1 in 12