widely used and have decreased the amount of wear. The ends of 6-hole joint bars are also
subject to a great deal of end wear. Badly battered rail causes rough riding, damage to
equipment and lading, and, eventually, pumping ties below joints.
The abrasive action of the wheels grinding on the top of joint bars can result in
wear. On some bars, the abrasion has been found to be as much as 1/16 of an inch deep and to
extend 8 inches on either side of the bar's center. Most of the wear on 4-hole bars occurs in the
(2) Cracks and fractures. A break in a joint bar may start at the top and continue
downward, often into a bolthole. Most cracks, however, start either from the spike slot or from
the flange angle and, as often as not, work their way to boltholes. Cracks become breaks if the
cracked bar is not replaced.
(3) Loose bolts. Both a rail and a rail joint tend to yield, and rightly so, under a load.
But when a poorly supported rail joint gives under a load, a lateral thrust that comes from under
the head tends to move the bar away from the rail. The impact of the thrust falls upon the
boltheads and the nuts and loosens them; loss of support results.
c. Methods. Rail-joint maintenance is a continual process. One authority advises that
main-line rail joints be inspected daily and repaired promptly. With about 270 rail joints per
mile of track, maintenance of them is also an expensive process.
On one inspection, you find a number of rails with battered ends, severe wear on
the top of several bars, a crack in one bar running from the spike slot to a bolthole, and several
loose bolts in some newly applied bars. What procedures do you follow to correct these and
(1) Batter and wear. Badly battered rail and badly worn joint bars should be replaced.
However, you have the alternative of building up the low spots by welding and then grinding the
weld to the proper contour. But welding and grinding are time-consuming processes.
(2) Cracks and breaks. Replace any badly cracked or broken joint bars at once.
Figure 3.21 shows two examples of broken joint bars, both of which had had boltholes made by