Turnout and crossing assembly — a scissors crossover comprises which combination of points and crossings?

Introduction / Context:
A scissors crossover allows simultaneous crossing and switching between two parallel tracks within a compact footprint. It combines two interlaced crossovers with a diamond crossing, resulting in a sophisticated assembly of points and crossings that must be correctly counted for design and maintenance purposes.

Given Data / Assumptions:

• The formation includes two interlaced crossovers between the same pair of tracks.
• A central diamond provides the intersecting geometry.
• Standard acute (V) and obtuse (K) crossings are used.

Concept / Approach:

Each crossover requires two pairs of points (right-hand and left-hand), so a scissors crossover includes four pairs of points in total. The diamond contributes two obtuse crossings, and the interlaced layout completes a total of four acute crossings. This is the standard count widely referenced in permanent way practice.

Step-by-Step Solution:

Verification / Alternative check (if short method exists):

Refer to a standard scissors crossover diagram and count the elements; tally matches the chosen option.

Why Other Options Are Wrong:

Options claiming six acute or four obtuse crossings inflate the crossing count and do not reflect the canonical layout of a scissors crossover.

Common Pitfalls (misconceptions, mistakes):

Confusing a simple crossover plus separate diamond with a true interlaced scissors; miscounting acute vs obtuse crossings in the central diamond.

Final Answer:

four pairs of points, four acute angle crossings and two obtuse angle crossings