Re: Non-standard Standard Gauge?

Some of the above posts are asking for real details of today’s standards and practice.
First I will detail the gage between the top of rails measured 5/8” down from the top. Second section will be about guard rail distance which is more critical and has less play allowed than gage.

Standard gage is 4’-8 ½”up to 8 degrees of curve inclusive. 4’9” on sharper curves. You add ¼” for each 10 degree of curvature up to 58” for MCB wheel design and that is the same for 3’ gauge, C&TS which had 5 5/8” wide MCB wheels
.
Gage of 4’8 ¼” is permitted on high speed tangent track except through crossing, through any turnout, track crossing and detectors, and 31’ away from any spiral. Change of gage from 4’ 8 ½” to 4’8 ¼” shall be made in not less than 30’ of track. Gage shall be changed in adjusting the rail opposite the line rail. Gage must never be less that 56”

Class of track determines the permitted wide gage before remedial action is immediately required as given in the first of two gage measurement as follows. The second gage is the gage the track is to be maintained to- not less than:
Class 1: 58” -57 ¾”. Class 2&3: 57 ¾” -57 ½”; Class 4: 57 ½”- 57 ¼”; Class 5: 57 ½”- 57 ¼”; Class 6: 57 ¼” requires immediate correction and should be maintained to less than 57”

The Standard Gauge tool had an out-of-service gage as the tool falls in at 58 1/8”.
The 3’ Narrow Gauge track tool also has an out-of-service gage that will fall in at 37 5/8”.

Second Section-- is gage of guard rails and is more important as it is controlled by the back to back distance between the standard gauge wheels with the Master Car Builder [MCB] design with full 5 5/8”wide wheel with width of flange of 1-19/64. There is a Industrial design wheel with a thinner flange that will not track through a switch guard rail because of the thin flange, the guard rail will not pull the wheel over so the other flange will not hit the point of the frog and derail that wheel. Coal mines use an industrial wheel. See the Porter Locomotive book for a design of that industrial style wheel. The EBT also uses MCB wheels.

Gage line of frog point to face of guard rail must be 4’-6 5/8” REGARDLESS OF TRACK GAGE. If track gage is increased, the flangeway is correspondingly increased. In other words The distance gage line of wing rail of frog to the face of guard rail must not exceed 4’-5”.

Most main high speed railroads use the 56 ¼” gage on tangent track to reduce car hunting at speed.

The US Federal Government after over a decade of study only established track standards for Standard Gauge track and there are no track standards ever established for Narrow Gauge track and therefore the FRA has no jurisdiction to measure or review any statistics of narrow gauge track, even tie counting. The low speed and light weigh never created a problem requiring any kind of statistics. (just have narrower width wheels on inspection car than on the train cars). There is no description of what is a defective tie on NG track as only ties on standard gauge track is described.



Edited 2 time(s). Last edit at 01/26/2019 04:46AM by OC MP62.