96.  Q. How can it be known when the wedges are set up too tight and the driving box sticks, and in what manner can they be pulled down?

A. If wedges are set up too tight, it causes the boxes to stick and the engine to ride rough.  Inspection of the engine when moving will locate the disabled box; usually this gets hot at once and the wedges should be immediately pulled down.  Loosen the jam nuts on the wedge bolts and back them down; if the wedge is stuck very tight it may be necessary to run one or more of the wheels over a block; or to loosen the pedestal, brace bolt and allow the jaws to spread to release the box.

97.  Q. What are some of the various causes for pounds?

A. Wedges not properly adjusted, loose or worn driving box brasses, rod brasses not keyed or in need of reducing, loose side rod bushings or side rod connections, worn cross-heads, wrist pins, broken frame, loose cylinder key, loose piston on rod, or rod loose in cross-head, loose follower bolts or obstruction in the cylinder.

98.  Q. How may a pound in driving boxes, wedges or rod brasses be located, and after locating what should be done?

A. Place the engine at half stroke on side to be tested.  Do not set brake when testing for loose wedges or defective boxes; set brake when testing for other pounds.  Reverse engine from forward to back gear under steam, noting the movement of the axle in the boxes, the driving boxes between the wedges, rod brasses on the pins and movement of cross-head between the guides.  If possible would adjust wedges or rod brasses at once and report repairs needed at the terminal.

99.  Q. How locate loose follower bolts?

A. Shut off steam and allow engine to drift; there will be a pound in the cylinder when the loose follower bolt strikes a forward cylinder-head as the engine passes the forward center on that side; give engine steam while still moving and if the pound stops it is likely to be a loose or broken follower bolt.  When working steam, the compression or pre-admission takes up the lost motion in the rod and connections, so the loose bolt does not strike the head; when shut off the piston travels the extra amount of this lost motion and the bolt strikes the head.

100.  Q. When should cross-heads or guides be reported to be lined?

A. When there is excessive lost motion between the cross-head and the top and bottom guides, or between the cross-head and the guide at the sides, or when the piston rod is not central between the guides.

101.  Q. When should driving box wedges be reported to be lined?

A. When they have been set up as far as possible and the boxes are still loose between the wedge and shoe.  At this time would also report any excessive flange wear on any one particular tire.

102.  Q. When should rod brasses be reported to be reduced?  When to be lined?

A. Rod brasses should be reported reduced when they are larger than the pins and are pounding and cannot be keyed up properly.  They should be reported to be lined when the key has been drawn or driven to its full length and the brasses do not close together or are too loose in the strap lengthwise of the rod.