22.  Q. If a transmission bar on a cross compound is broken, what would you do for the right side?  For the left side?

A. For right side would cover ports on that side, take out pop from cylinder head, open separate exhaust and run in with other cylinder.  For left side, cover ports and fasten valve stem same as for right side.  Would leave main rods up, keep separate exhaust open in both cases and see that cylinder is well oiled.

23.  Q. In the event of a cross compound beginning to jerk badly and cylinder head pops in low-pressure cylinder popping, where would you look for the trouble?

A. That either the high-pressure valve or piston packing was blowing live steam into the receiver and then into low-pressure steam chest.  If possible would locate trouble and report accordingly.

24.  Q. If during a trip you found the piston valve rings of a cross compound were broken, what would you do?

A. If nothing but rings were broken, would reduce boiler pressure about 25 per cent. and go on with my train if possible.

25.  Q. If piston valve on cross compound was broken so it became necessary to remove it, what should you do?

A. Remove the broken piston valve, reduce boiler pressure to 100 pounds and proceed.

26.  Q. What is the difference between a Vauclain four-cylinder compound, a four-cylinder tandem, a balanced and a Mallet compound in their arrangement of cylinders?

A. A Vauclain compound has two cylinders on each side, one above the other, and both piston rods connected to one cross-head.  A four-cylinder tandem has four cylinders, the high pressure being ahead of the low pressure on each side, and both pistons connected to one piston rod and one cross-head.  A balanced compound has four cylinders, the two high-pressure cylinders being between the frames, each having a main rod connected to a crank axle.  The two low-pressure cylinders are located outside the frame, each having a main rod and crank pin connected to the driving wheel center.  A Mallet compound consists of two separate and independent engines, one fixed to the boiler, the other swinging from a center and sliding back and forth under the front end of the boiler.  The rear engine works steam at high pressure; steam from this engine exhausts through a receiver pipe having flexible joints to the forward engine which works the steam at low pressure, then exhausts it to the front end and stack.

27.  Q. How many main steam valves has each type?

A. The Vauclain has one valve on each side, distributing steam to the high and low-pressure cylinder on that side.  The four-cylinder tandem has two valves on each side, one for each of the two cylinders.  A Baldwin balanced compound has two valves the same as the Vauclain.  The American balanced compound has four valves, one for each cylinder, the two valves for one side of the engine being connected to one valve rod.  A Mallet compound has a separate valve for each cylinder the same as a simple locomotive.