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CHAPTER 8 TURNOUTS TM 5-628/AFR 91-44
8-1
CHAPTER 8
TURNOUTS
8-1. General.
Major components of a turnout are the switch,
Turnouts are designed to divert trains from one
track to another. Good turnout maintenance is es-
sential for the safe and efficient operation of trains.
frog, and guard rails. Figure 8-1 shows a typical
turnout with the various parts identified.
8-2.
General requirements
b. Rail. All rail used within the limits of a turn-
a. Materials. All materials used within the
limits of a turnout shall:
(1) Be factory designed and constructed.
(2) Be the proper type and size.
(3) Be properly installed.
(4) Not be flame cut or otherwise altered.
out shall be of the same weight and section. Com-
promise joints are not permitted within the limits of
a turnout.
c. Ties. The standards in chapter 5 of this
manual shall apply to ties within the limits of a
turnout. TM 5-628/AFR 91-44
8-2
d. Track geometry.. Turnout track geometry
(3) Worn or chipped switch points. (See
shall conform with the standards in chapter 12 as
para 8-3<i>c and fig 8-3.)
well as those in this chapter.
(4) Point of switch higher than stock rail.
e. Reversing tangent. It is recommended that
(See para 8-3<i>d(1) and fig 8-4.)
the tangent between the frog and any reverse curve
(5) Point rail beyond taper lower than stock
past the frog be no less than 50 feet in length as
rail. (See para 8-3<i>d(2) and fig 8-4.)
shown in figure 8-2.
(6) Damaged or missing switch stand lever
f.
Switch stand placement.
cracked or improper heel joint bars or heel filler.
(1) The switch stand stall be installed so that
(See para 8-3<i>i)
when the switch is lined for the normal (main)
(12) Loose, damaged, or missing rail braces.
route, the connecting rod keeps the points closed
(See para 8-3<i>j)
with a pulling (rather than a pushing) force. In most
(13) Loose, damaged, or missing slide
cases this will mean installing the stand on the
plates; dirt and debris buildup on slide plates.
diverging side of the turnout as shown in figure 8-
(14) Missing cotter keys on switch rod and
2.
switch clip bolts.
(2) When a ground-throw stand is used, the
(15) Debris in flangeways. (See para 8-3<i>k)
handle shall point toward the frog when the switch
(16) Debris obstructing switch rods and
is lined for the normal (main) route.
connecting rod. (See para 8-3<i>g(1))
g. Cleaning, lubrication, and adjustment.
Switches and switch stands shall be cleaned, lubri-
cated, and adjusted at least annually.
8-3.
Switches and switch stands.
a. Switches shall be inspected for the following
defects:
(1) Switch difficult to operate.
(2) Gap greater than
c (0.125) inch
between the switch point and the stock rail.
Checked with points in both positions. (See para 8-
3<i>b.)
latches or switch point lock. (see para 83<i>e)
(7) Insecure, loose, damaged, or improperly
installed switch stand. (See para 8-3<i>f and 8-2<i>g)
(8) Loose, damaged, or missing jam nut at
the switch stand end of the connecting rod. (See
para 8-3<i>g(3))
(9) Bent, damaged, loose, binding, or
improperly installed connecting rod, switch rods, or
switch clips. (See para 8-3<i>g)
(10) Loose, damaged, or missing switch
clip, switch rod, or connecting rod bolts. (See para
83<i>h)
(11) Loose, damaged, or missing heel bolts; TM 5-628/AFR 91-44
8-3
b. Switch point gap.
(1) If the switch can be thrown and locked
in either direction with a
c (0.125) inch spacer be-
tween the switch point and the stock rail, oper-
ations through the turnout shall not exceed 10 mph.
(2) If the switch can be thrown and locked
in either direction with a ¼ (0.25) inch spacer be-
tween the switch point and the stock rail, oper-
ations through that side of the turnout shall not be
permitted.
c. Switch points. A switch point shall be re-
stored or replaced if the point is chipped, broken,
or worn more than ½ (0.50) inch down and 6
inches back from the point. (See fig 8-3). Metal
flow shall be removed to ensure proper closure. If
a switch point is worn or damaged beyond these
limits, operations through the turnout shall not
exceed 10 mph.
d. Figure 8-4 shows the proper elevation of the
switch point and point rail with respect to the stock
rail.
(1) If the top surface of the switch point is
higher than the top of the stock rail, operations
through the turnout shall not exceed 5 mph.
(2) If the point rail beyond the taper is
lower than the stock rail, operations through the
turnout shall not be permitted.
e. Switch stand lever latches and point locks.
Switch stand lever latches or switch point locks
shall be installed on all switches. Where latches or
locks are missing, damaged, insecure, or otherwise
inoperative, operations through the turnout shall
not exceed 10 mph.
f.
Switch stand. The switch stand shall be fully
secured to the headblock ties to prevent any unin-
tentional movement of the switch points. Where
operations through the switch result in visible lat-
eral movement of the switch stand or opening of
the switch points (point gap), operations through
the turnout shall not be permitted.
g. Connecting rod, switch rods, and switch
clips.
(1) These parts shall be installed and main-
tained to allow unobstructed motion when the
switch is thrown. Rod ends and clips shall not con-
tact adjacent ties. Damaged parts shall be replaced,
and improperly installed parts shall be adjusted.
Washers or similar spacers shall not be permitted
between the switch clip and the switch point.
(2) If the connecting rod, switch rod, or
switch clip is insecurely fastened or is damaged,
operations through the turnout shall not be
permitted.
(3) The jam nut at the switch stand end of
the connecting rod shall be kept tight against the
switch stand clevis. TM 5-628/AFR 91-44
8-4
(4) Where washers or similar spacers are
outside of the stock rail on both sides of the turn-
between the clip and switch point, operations
out.
through the turnout shall not exceed 10 mph.
(2) It is recommended that rail braces be in-
h. Connecting rod bolts, switch rod bolts, and
stalled on each tie from the point of switch to
clip bolts. Connecting rod and switch rod bolts
within two ties of the switch heel.
shall be installed with the nut on top and cotter
(3) If there are less than four rail braces
keys in place. Clip bolts shall have cotter keys. All
fully secured to the tie and tight against the outside
bolts shall be kept tight.
of each stock rail, operations through the turnout
i.
Switch heel (bolts, fillers, and joint bars).
shall not exceed 5 mph.
The heel of the switch shall be secure and the
k. Debris in flangeways. Flangeways shall be
supporting switch ties solidly tamped. The inside
kept clear of debris. Any obstructions, including ice
joint bar (nearest and track center) should be a bent
and packed snow, shall be removed.
bar per AREA design. If any heel bolts are loose or
missing, or the heel is otherwise not fully secure,
8-4.
Frogs.
operations through the turnout shall not exceed 5
mph.
j.
Rail braces.
(1) Rail braces are essential to provide
proper lateral support to the stock rails. Rail braces
shall be fully secured to the tie and tight against the
a. Frog point. A frog shall be restored or re-
placed if the point is chipped, broken, or worn
more than ½ (0.50) inch below the original top sur-
face and 6 inches back from the original point lo-
cation. (See fig 8-5)
b. Frog surface. A frog shall be restored or re-
c. Guarding face of self guard ed frogs. The
placed if the tread surface is worn more than
d
raised guarding face on a self-guarded frog shall
(
0.375
) inch below its original contour. (See fig
8-5)
not be worn more than
d (0.375) inch. (See fig 8-6) TM 5-628/AFR 91-44
8-5
d. Repairing self guarded frogs. If repairs are
f.
Flangeway width. Standard frog flangeway
made to a self-guarded frog without removing it
width is 1 / (1.875) inches. Where existing
from service, the raised guarding face must be re-
flangeway width is less than this amount, the re-
stored before rebuilding the point.
strictions in table 8-1 shall be applied. (See fig 8-7)
e. Frog bolts. All frog bolts shall be in place
and tight.
7
8 TM 5-628/AFR 91-44
8-6
g. Flangeway depth. Standard frog flangeway
depth is 1 / (1.875) inches. Where existing
7
8
flangeway depth is less than this amount, the re-
strictions in table 8-1 shall be applied. (See fig 8-7)
8-5.
Guard rails.
a. Guard rails shall be in place, properly posi-
tioned, and fully secured.
b. Guard rails shall be installed so that the
straight guarding face (the portion of the guard rail
parallel with the running rail) extends in advance of
the frog point a distance at least equal the values
given in table 8-2.
c. Guard check gage. Standard guard check
gage is 54% (54.625) inches. Where guard check
gage measures less than this amount, the
restrictions in table 8-1 shall be applied. (See fig 8-
7)
d. Guard face gage. Standard guard face gage
is 53¾ (52.75) inches. Where guard face gage