- Join the NMRA
- About the NMRA
- Education
- Resources
- Community
Search NMRA.org
RP-12.7 Turnout Dimensions
Look here for a larger printable copy of this diagram.
Jump to Frog Numbers 8, 9, & 10.
| (1) | FROG NUMBERS | 4 | 5 | 6 | 7 |
|---|---|---|---|---|---|
| PROPERTIES OF CURVED SWITCHES | |||||
| (2) | Rail Length | 28(1.088) | 28(1.088) | 28(1.088) | 44.5(1.744) |
| (3) | Point Angle * | 2d 01' | 2d 01' | 2d 01' | 1d 20' |
| (4) | Heel Spread [+] | 1.65(0.065) | 1.65(0.065) | 1.65(0.065) | 1.65(0.065) |
| (5) | Heel Angle * | 4d 50' | 4d 50' | 4d 50' | 2d 56' |
| (6) | Switch Radius | 562(22) | 562(22) | 562(22) | 1577(62) |
| (7) | Mid-Ordinate | 0.2(0.007) | 0.2(0.007) | 0.2(0.007) | 0.15(0.006) |
| LEAD TO THEORETICAL POINT OF FROG | |||||
| (8) | Lead | 67.5(2.657) | 75.5(2.971) | 83(3.256) | 115(4.514) |
| CLOSURE DISTANCE | |||||
| (9) | Straight Length | 32(1.269) | 39.5(1.546) | 45.5(1.793) | 59.6(2.339) |
| (10) | Curved Rail Length | 33(1.300) | 40(1.572) | 46(1.816) | 60(2.357) |
| (11) | Curved Rail Radius | 201(8) | 348(13.75) | 562(22) | 656(25.75) |
| GAGE LINE OFFSETS ON CURVED CLOSURE RAIL | |||||
| (12) | 1st Point Y1 [+] | 3(0.118) | |||
| (13) | 1st Point X1 | 64(2.520) | |||
| (14) | Mid-Point Y2 [+] | 4(0.157) | 4(0.157) | 4(0.157) | |
| (15) | Mid-Point X2 | 46(1.811) | 47.5(1.870) | 50.5(1.988) | |
| (16) | 3rd Point Y3 [+] | 5(0.197) | |||
| (17) | 3rd Point X3 | 84(3.307) | |||
| PROPERTIES OF FROGS | |||||
| (18) | Frog Angle * | 14d 15' | 11d 25' | 9d 32' | 8d 10' |
| (19) | Overall Length | 20.5(0.812) | 23.5(0.918) | 26(1.019) | 28.5(1.125) |
| (20) | Toe Length | 7.5(0.300) | 8.5(0.337) | 9.5(0.375) | 11(0.431) |
| (21) | Heel Length | 13(0.512) | 15(0.581) | 16.5(0.644) | 17.5(0.694) |
| (22) | Toe Spread | 1.9(0.074) | 1.7(0.067) | 1.6(0.062) | 1.6(0.062) |
| (23) | Heel Spread | 3.2(0.126) | 2.9(0.115) | 2.7(0.107) | 2.5(0.100) |
| POINT OF FROG TO INTERSECTION OF CENTER LINES | |||||
| (24) | PF to ICL | 36(1.416) | 45(1.771) | 54(2.123) | 63(2.479) |
| DATA FOR CROSSOVERS -- PF to PF ON PARALLEL TRACKS | |||||
| Distance for 1-1/16" Track Centers Along: | |||||
| (25) | Straight Track | 34.5(1.351) | 43.5(1.718) | 53(2.078) | 62(2.439) |
| (26) | Crossover Track | 38(1.483) | 46.5(1.824) | 55(2.166) | 64(2.515) |
| Increment for 1/16" change in track centers along: | |||||
| (27) | Straight Track | 6(0.246) | 8(0.310) | 9.5(0.372) | 11(0.436) |
| (28) | Crossover Track | 6.5(0.254) | 8(0.316) | 9.5(0.377) | 11.5(0.440) |
Return to Frog Numbers 4, 5, 6, 7
| (1) | FROG NUMBERS | 8 | 9 | 10 |
|---|---|---|---|---|
| PROPERTIES OF CURVED SWITCHES | ||||
| (2) | Rail Length | 44.5(1.744) | 44.5(1.744) | 44.5(1.744) |
| (3) | Point Angle * | 1d 20' | 1d 20' | 1d 20' |
| (4) | Heel Spread [+] | 1.65 (0.065mm) | 1.65 (0.065mm) | 1.65 0.065mm) |
| (5) | Heel Angle * | 2d 56' | 2d 56' | 2d 56' |
| (6) | Switch Radius | 1577(62) | 1577(62) | 1577(62) |
| (7) | Mid-Ordinate | 0.15(0.006) | 0.15(0.006) | 0.15(0.006) |
| LEAD TO THEORETICAL POINT OF FROG | ||||
| (8) | Lead | 122(4.814) | 129(5.084) | 136(5.361) |
| CLOSURE DISTANCE | ||||
| (9) | Straight Length | 65.5(2.577) | 70.5(2.783) | 76(2.998) |
| (10) | Curved Rail Length | 66(2.593) | 71(2.797) | 76.5(3.007) |
| (11) | Curved Rail Radius | 897(35.25) | 1189(46.75) | 1577(62) |
| GAGE LINE OFFSETS ON CURVED CLOSURE RAIL | ||||
| (12) | 1st Point Y1 [+] | 3(0.118) | 3(0.118) | 3(0.118) |
| (13) | 1st Point X1 | 64(2.520) | 66(2.598) | 67(2.638) |
| (14) | Mid-Point Y2 [+] | |||
| (15) | Mid-Point X2 | |||
| (16) | 3rd Point Y3 [+] | 5(0.197) | 5(0.197) | 5(0.197) |
| (17) | 3rd Point X3 | 88(3.465) | 91.5(3.602) | 96(3.742) |
| PROPERTIES OF FROGS | ||||
| (18) | Frog Angle * | 7d 09' | 6d 22' | 5d 43' |
| (19) | Overall Length | 33(1.294) | 37(1.463) | 41.5(1.631) |
| (20) | Toe Length | 12.5(0.493) | 14(0.557) | 15.5(0.619) |
| (21) | Heel Length | 20.5(0.801) | 23(0.906) | 26(1.012) |
| (22) | Toe Spread | 1.6(0.062) | 1.6(0.062) | 1.6(0.062) |
| (23) | Heel Spread | 2.5(0.100) | 2.5(0.100) | 2.5(0.100) |
| POINT OF FROG TO INTERSECTION OF CENTER LINES | ||||
| (24) | PF to ICL | 72(2.833) | 81(3.182) | 90(3.545) |
| DATA FOR CROSSOVERS -- PF to PF ON PARALLEL TRACKS | ||||
| Distance for 1-1/16" Track Centers Along: | ||||
| (25) | Straight Track | 71(2.798) | 80(3.155) | 89.5(3.516) |
| (26) | Crossover Track | 73(2.864) | 81.5(3.213) | 91(3.569) |
| Increment for 1/16" change in track centers along: | ||||
| (27) | Straight Track | 12.5(0.498) | 14.5(0.560) | 16(0.624) |
| (28) | Crossover Track | 13(0.502) | 14.5(0.564) | 16(0.627) |
* the d stands for degrees (2d 01' is 2 degrees 01 minutes)
NOTE: Calculations made in inches and converted to millimeters. Inches shown in parentheses.
Return to Frog Numbers 4, 5, 6, 7 or 8, 9, & 10.