NMRA CURVED TRACK CENTER AND OBSTACLE CLEARANCE ASSISTANT

Author: Van S. Fehr
Version: 1.0 Date: July 2017
Copyright: July 2017 National Model Railroad Association

Instructions (these are reminders - see NMRA 7.6 for detailed instructions):

  1. Enter all input values in the yellow and blue boxes. Click or tap INPUT EXAMPLE to enter an example.
  2. Yellow boxes require decimal numbers in the same units (inches, feet, millimeters, etc.).
  3. Blue boxes require text (numbers and mixed-case letters).
  4. Output Units Format: Enter D for decimal output (any units), or F for fractional output (inches only).
  5. Click or tap CALCULATE to display results in the green boxes.
Click or tap to fill input boxes with an example.

TRACK PARAMETERS CLEARANCE DIAGRAM (from RP-7.1)
Tangent Track Centers Dimension A
Tangent Obstacle Clearance Dimension B
Curve Radius (inner) Dimension G
Superelevation Dimension P
Track Gauge Dimension Rc
Output Units Format
EQUIPMENT ENVELOPES Equipment 1 Equipment 2
Type Type
End Distance A End Distance A
Pivot Distance Pivot Distance
End Distance B End Distance B
Height Height

Click or tap to see results.

Curved Track Center Outer Curve Radius
for SINGLE-TRACK for DOUBLE-TRACK
OBSTACLE CLEARANCES
Inside Obstacle Clearance Inner Obstacle Clearance
Outside Obstacle Clearance Outer Obstacle Clearance
CLEARANCE DIMENSIONS
Dimension Aw Dimension Aw
Dimension Bw Dimension Bw
Dimension Gw Dimension Gw
Dimension Pw Dimension Pw
TUNNEL DIMENSIONS
Dimension Aw Dimension Aw
Dimension Bw Dimension Bw
Dimension Qw Dimension Qw
Dimension Rsw Dimension Rdw