2011 NMRA Convention - Sacramento, California logo
national train show

RP-2 Standards Gage

This GAGE, shown in two Types, checks the following STANDARDS:
 Dimensions G, C, S, F, H, and P STANDARD S-3
 Dimensions K B, N, and D STANDARD S-4
The Type I GAGE also checks the following:
 Dimensions A, B, C, D, E, F, G, H, and PSTANDARD S-7

Note: For Help with NMRA Gage letter definitions and the AAR Plate diagrams on which it's based see: Standard S-7 Clearances and the NMRA Gage

WARNING: This GAGE is intended only for checking STANDARD dimensions. Misuse as a tool may damage the accuracy of the GAGE.

(Gages)

Figures 3 and 4 below identify the different Components of a turnout for use with the Instructions on the reverse side.

(Turnout)

  1. TRACK marks the side of the gage used for checking Track Gage through all trackwork, including turnouts and other special work. Apply light pressure in the direction of the arrow. See figures A, B and C for interpretation of results. (Note that the prongs of the Gage must clear spikes.) (Track)
  2. FLANGEWAYS, spacing of Guard Rails, Wing Rails and Frogs are checked With this side of the Gage. Apply light side pressure toward the Frog and against the Guard Rail (see arrow). See figures A, B and C for interpretation of results. Gage prongs must clear all obstructions below the rail head as in figure D. Use NO-GO prong of Gage to check Flangeway width at the Frog in figures E and F.

    (Flangeways)

  3. POINTS are checked against excessive Spread by applying light side pressure against the Gage side of the closed switch point rail as shown by the arrow. The opposite prong on the GAGE dropping fully into the gap between the open switch point rail and the adjacent stock rail ensures adequate Electrical Spread, while dropping only to the step on the inside of the prong shows adequate Mechanical Spread. Clearance of the outside of the prong checks Track Gage. Make this check along the entire length of the switch point rail. (Points)
  4. WHEELS are checked by applying light side pressure in the direction of the arrow. Each wheel must be checked - reverse the direction of pressure and check the other wheel. See figures A, B, C and D for interpretation of results. Use the wide NO-GO slot to check Tire Width as in E and F. (Wheels)
  5. CLEARANCE may be checked only with the Type I GAGE in the position of 1.B., seeing that no obstruction interferes with passage of the GAGE along the track. CAUTION: This check is valid only for tangent track and curves of very wide radius. Refer to NMRA STANDARD S-8 for increased Clearances in sharper curvatures.
  6. COUPLER HEIGHT is checked by mounting a coupler of your choice in the center of the slot and matching all other couplers to this height when the GAGE is in the position of 1.B. above.

WARNING: WHILE THESE GAGES ARE VERY DURABLE, THEY ARE MEASURING DEVICES AND NOT METAL CUTTING TOOLS. THE USE OF THE GAGE TO REMOVE METAL (EVEN SOFT SOLDER) WILL CAUSE WEAR ON THE MEASURING SURFACES AND DESTROY THE DEVICE AS A MEASURING INSTRUMENT.