that side for the marker.  If the eccentric had been keyed on, would move the cam until the key-way in the axle came in line with the slot in the cam.  Knowing the position of the eccentric in relation to the crank pin, an inspection would show where it belongs.  The eccentrics are usually opposite the third spoke in the driving wheel from the pin, sometimes ahead of the pin, in other cases back of the pin, depending on whether it is an inside or outside admission valve, a go-ahead or back-up eccentric.

63.  Q. What should be done in case of a broken eccentric strap or rod?

A. For a go-ahead strap or rod take down all broken parts, disconnect valve rod, cover ports, and come in on one side.  It is safer to take down also the back-up strap and rod on that side.  If the back-up strap and rod is broken, it is possible to secure the bottom end of the link so it will not turn over, work the engine full stroke ahead, proceeding with full train until the main line is clear.

64.  Q. How should the engine be disconnected if the lower rocker arm became broken?  If link block pin?

A. Would remove broken parts; if moving link would strike anything connected with the rocker box or broken arm it would be necessary to take down both eccentric straps and rods.  Block valve central over ports and come ahead on one side.  If a link block pin was broken, it might be possible to put a bolt in there to do the work, otherwise block the valve on the center of its seat and if the link will not clear the lower end of the rocker arm take down the eccentric straps and rod.  In any case where necessary to take off the eccentric rod always take off the strap also.

65.  Q. For what breakdown is it necessary to take down the main rod?  The side rod?

A. A broken main crank pin, broken main rod or strap, broken piston rod when near the middle of the rod, broken cross-head or guide, broken valve or seat when steam cannot be kept out of the cylinder.  Side rods must come down for broken side rod, broken main pin, or broken side rod pin affecting that rod.

66.  Q. If it is not necessary to take down the main rod of disabled side of the engine, how would you arrange to lubricate the cylinders?

A. If cylinder and piston are in good shape and it is possible to block the valve to admit a small quantity of steam into the back end of the cylinder, oil from the lubricator will go through this opening and oil the piston rod and cylinder packing.  If not possible to block the valve properly, cover the ports and oil the cylinder through the indicator plug openings or relief plug holes.  If not possible to do this, slack off the bolts on the front cylinder head, wedge the head open so oil can be introduced.  In some cases it may be necessary to take the head off; that however, allows dust and grit to enter the cylinder.

67.  Q. What is the by-pass valve, and what is its duty?

A. By-pass valves are connected to the steam port leading to the cylinder.  Its duty is to open when the engine is drifting with steam shut off, and close when working steam, to allow air to pass back and forth from opposite sides of the moving piston.