Switch type for Bull-Head (BH) stock rails When the stock rails used are Bull-Head (BH) rails seated in chairs, which type of switch is generally provided for the turnout?

Introduction / Context:
Turnout design must match the rail section and seating system. For Bull-Head rails carried in chairs, the switch and its heel/planing style are chosen to provide proper fit and clearance while maintaining strength at the thin switch tip.

Given Data / Assumptions:

• Stock rails are Bull-Head rails (BH) with chair and key fittings.
• Conventional chairing and planing practices apply.
• We seek the common switch type used with BH stock rails.

Concept / Approach:
BH turnouts traditionally use undercut switches, where the underside of the switch rail is planed so that the head can close against the stock rail while clearing the chair and keys. This planing geometry is compatible with BH chair seats and ensures the required running clearance and flangeway.

Step-by-Step Solution:
Identify rail form: BH section in chairs with keys.Match with compatible switch design: undercut planing is standard for BH practice.Conclude “undercut” as the generally provided switch type.

Verification / Alternative check:
Traditional turnout drawings in BH practice specify undercut switch geometry to suit chair spacing and keying; this has been standard for decades in BH territories.

Why Other Options Are Wrong:
Articulated/over riding/straight cut: These do not reflect the specific planing and seating needs for BH rail in chairs.

Common Pitfalls:

• Confusing BH practices with modern flat-bottom rail turnouts that often use different switch planing and baseplate systems.

Final Answer:
undercut