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RP-12.4 Turnout Dimensions
OO & On3 Scales
Look here for a larger printable copy of this diagram.
Designed by Clarence H. Hill
Jump to Frog Numbers 8, 9, & 10.
| (1) | FROG NUMBERS | 4 | 5 | 6 | 7 |
|---|---|---|---|---|---|
| PROPERTIES OF CURVED SWITCHES | |||||
| (2) | Rail Length | 2-5/16" | 2-5/16" | 2-5/16" | 3-9/16" |
| (3) | Point Angle * | 2d 01' | 2d 01' | 2d 01' | 1d 20' |
| (4) | Heel Spread [+] | 9/64" | 9/64" | 9/64" | 9/64" |
| (5) | Heel Angle * | 4d 43' | 4d 43' | 4d 43' | 2d 51' |
| (6) | Switch Radius | 49" | 49" | 49" | 135" |
| (7) | Mid-Ordinate | .014" | .014" | .014" | .012" |
| LEAD TO THEORETICAL POINT OF FROG | |||||
| (8) | Lead | 5-7/8" | 6-1/2" | 7-1/8" | 9-11/16" |
| CLOSURE DISTANCE | |||||
| (9) | Straight Rail | 2-15/16" | 3-1/2" | 4-1/16" | 5-1/4" |
| (10) | Curved (Length) | 3" | 3-17/32" | 4-3/32" | 5-9/32" |
| (11) | Rail (Radius) | 18" | 30" | 49" | 57" |
| GAGE LINE OFFSETS ON CURVED CLOSURE RAIL | |||||
| (12) | 1st Point Y1 [+] | 17/64" | |||
| (13) | 1st Point X1 | 5-1/2" | |||
| (14) | Mid-Point Y2 [+] | 11/32" | 11/32" | 11/32" | |
| (15) | Mid-Point X2 | 3-15/16" | 4-1/8" | 4-1/4" | |
| (16) | 3rd Point Y3 [+] | 7/16" | |||
| (17) | 3rd Point X3 | 7-1/4" | |||
| PROPERTIES OF FROGS | |||||
| (18) | Frog Angle * | 14d 15' | 11d 25' | 9d 32' | 8d 10' |
| (19) | Overall Length | 1-11/16" | 1-7/8" | 2-1/16" | 2-5/16" |
| (20) | Toe Length | 5/8" | 11/16" | 3/4" | 7/8" |
| (21) | Heel Length | 1-1/16" | 1-3/16" | 1-5/16" | 1-7/16" |
| (22) | Toe Spread | 5/32" | 9/64" | 1/8" | 1/8" |
| (23) | Heel Spread | 17/64" | 15/64" | 7/32" | 13/64" |
| POINT OF FROG TO INTERSECTION OF CENTER LINES | |||||
| (24) | PF to ICL | 3" | 3-3/4" | 4-1/2" | 5-1/4" |
| DATA FOR CROSSOVERS -- PF to PF ON PARALLEL TRACKS | |||||
| OO--Distance for 2-1/4" Track Centers Along: | |||||
| (25) | Straight Track | 2-7/8" | 3-5/8" | 4-3/8" | 5-1/8" |
| (26) | Crossover Track | 3-1/8" | 3-7/8" | 4-5/8" | 5-5/16" |
| On 3--Distance for 3" Track Centers Along: | |||||
| (25) | Straight Track | 5-13/16" | 7-3/8" | 8-15/16" | 10-3/8" |
| (26) | Crossover Track | 6-3/16" | 7-5/8" | 9-3/16" | 10-5/8" |
| Increment For 1/8" Change In Track Centers Along: | |||||
| Straight Track | 1/2" | 5/8" | 3/4" | 7/8" | |
| Crossover Track | 1/2" | 5/8" | 3/4" | 7/8" | |
| (1) | FROG NUMBERS | 8 | 9 | 10 | |
|---|---|---|---|---|---|
| PROPERTIES OF CURVED SWITCHES | |||||
| (2) | Rail Length | 3-9/16" | 3-9/16" | 3-9/16" | |
| (3) | Point Angle * | 1d 20' | 1d 20' | 1d 20' | |
| (4) | Heel Spread [+] | 9/64" | 9/64" | 9/64" | |
| (5) | Heel Angle * | 2d 51' | 2d 51' | 2d 51' | |
| (6) | Switch Radius | 135" | 135" | 135" | |
| (7) | Mid-Ordinate | .012" | .012" | .012" | |
| LEAD TO THEORETICAL POINT OF FROG | |||||
| (8) | Lead | 10-5/16" | 10-15/16" | 11-9/16" | |
| CLOSURE DISTANCE | |||||
| (9) | Straight Rail | 5-3/4" | 6-1/4" | 6-3/4" | |
| (10) | Curved (Length) | 5-25/32" | 6-9/32" | 6-25/32" | |
| (11) | Rail (Radius) | 77" | 103" | 135" | |
| GAGE LINE OFFSETS ON CURVED CLOSURE RAIL | |||||
| (12) | 1st Point Y1 [+] | 17/64" | 17/64" | 17/64" | |
| (13) | 1st Point X1 | 5-9/16" | 5-5/8" | 5-11/16" | |
| (14) | Mid-Point Y2 [+] | ||||
| (15) | Mid-Point X2 | ||||
| (16) | 3rd Point Y3 [+] | 7/16" | 7/16" | 7/16" | |
| (17) | 3rd Point X3 | 7-1/2" | 7-3/4" | 8" | |
| PROPERTIES OF FROGS | |||||
| (18) | Frog Angle * | 7d 09' | 6d 22' | 5d 43' | |
| (19) | Overall Length | 2-5/8" | 2-15/16" | 3-5/16" | |
| (20) | Toe Length | 1" | 1-1/8" | 1-1/4" | |
| (21) | Heel Length | 1-5/8" | 1-13/16" | 2-1/16" | |
| (22) | Toe Spread | 1/8" | 1/8" | 1/8" | |
| (23) | Heel Spread | 13/64" | 13/64" | 13/64" | |
| POINT OF FROG TO INTERSECTION OF CENTER LINES | |||||
| (24) | PF to ICL | 6" | 6-3/4" | 7-1/2" | |
| DATA FOR CROSSOVERS -- PF to PF ON PARALLEL TRACKS | |||||
| OO--Distance for 2-1/4" Track Centers Along: | |||||
| (25) | Straight Track | 5-15/16" | 6-11/16" | 7-7/16" | |
| (26) | Crossover Track | 6-1/16" | 6-13/16" | 7-9/16" | |
| On3--Distance for 3" Track Centers Along: | |||||
| (25) | Straight Track | 11-7/8" | 12-7/8" | 14-15/16" | |
| (26) | Crossover Track | 12-1/8" | 13-1/16" | 15-1/16" | |
| Increment for 1/8" Change in Track Centers Along: | |||||
| Straight Track | 1" | 1-1/8" | 1-1/4" | ||
| Crossover Track | 1" | 1-1/8" | 1-1/4" | ||
* the d stands for degrees (2d 01' is 2 degrees 01 minutes)
NOTES:
- Recommended to use gages for dimensions marked [+]
- Switch heel joints should not be out of square more than 1/32".
- Refer to RP-15.1 for suitable rails.
- Slip-on joint bars may be used up to 1/2" long and B&S gage No. 29 thick. The fit must be snug on the base of the rail. At the heel of the switch it may be necessary to cut away a portion of the stock rail base.
Return to Frog Numbers 4, 5, 6, 7 or 8, 9, & 10.