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June, 1914 or try to put it in both the ahead and astern position at the same time, as it is necessary to move the controlling lever sideways before it can be moved from one position to the other. The governor, which controls the speed 6: rotation of the turbine. shaft, is shown on the right of the diagrammatic sketch, Fig. 1. As will be seen, it is of the common fly-ball type, and is driven through the turbine shaft by a worm £ and wheel D. The only mov- able part of the governor is the hollow spindle B, having the ports N and H in it. The movement of the spindle B is restricted by a diaphragm K to which it is attached. The upper side of the diaphragm is open to atmosphere, and the space below G is filled with oil. High pressure oil at about 65 pounds gauge per square inch is admitted to the revolving spindle B through the ports A. The Governor When the governor spindle is revolved by the turbine shaft, the balls M M are thrown outward by centrifugal force, thus pulling the spindle B downward against the resistance of the diaphragm K, opening communication through the port H in the spindle, and J in the upper spindle bushing, to the space G, the latter communicating through a port L to a pipe connected to the space N of the air cylinder relay. As the pressure in the space G, below the diaphragm K, increases, it resists the FIG. 2 downward thrust of the spindle B, due- to the centrifugal action on the governor weights until the upward pressure on the diaphragm exactly balances the down- Ward thrust of the spindle, thus permit- ing the upward movement of the spindle B by the elasticity of the diaphragm K until the communication through the Ports H and / is cut off. Thus it is evident that for any given number of Tevolutions of the governor spindle, there must he a- constant fixed pressure of equilibrium in the space G below the diaphragm. Should the pressure in the Space G exceed that corresponding to the speed of rotation of the governor at any instant, the spindle B will be THE MARINE REVIEW forced upward, thus opening communica- tion between the space G and the atmos- phere through the ports N in the gover- nor spindle body. In the center part of the diagrammatic sketch is shown the air relay cylinder, relay valve and operating cylinder, which controls the opening and closing of the nozzles of the turbine according to the speed of rotation desired. Referring to this part of the illustration, and starting with the turbine at rest, the piston Y, which opens and closes the nozzle valves, is at the farthest end of its travel to the right, and all the turbine nozzles are closed. Now when air ftom the bridge control valve is admitted to the space P. to the left of the air operating cylinder. the piston Q will be forced to the right against the resistance of a small spring, thus carrying the relay plunger O with it. The movement of the latter es- tablishes communication between the space Fk, supplied with high pressure oil. and the space X, to the right of the piston Y, and the space W, to the left of the piston Y, is brought into com- munication with the space T, and there- by with the oil return to the reservoir. which is open to atmosphere. Thus the piston Y, will be forced to the left by the oil pressure and through a rack en- gaging with the gear cut in the peri- phery of the nozzle valve, will rotate the latter and open high pressure nozzles, thus admitting steam to the turbine. As there is nothing to resist the motion of the piston Y, nozzles in excess of those necessary to give the desired speed, are opened instantaneously and thus the tur- bine begins to speed up very rapidly. Now, . however, as the turbine gains speed and the governor revolves, the governor spindle B is forced down and high pressure oil is admitted through the ports H and J and through the pass- age L to the space N to the right of the piston Q, thus tending to push it to the left against the air pressure in the space P. As the piston Q moves to the left, it carries the relay plunger O with it, and when the oil pressure in the space N balances the air pressure in the space P, or in other words, the space J' in the bridge control valve, the piston Q will take a fixed position, and the piston VY will take up a position such that the ports communicating with W and X are both closed, thus maintaining a constant speed of revolution. Exceed the Speed Should the turbine tend to exceed the speed fixed by the air pressure in the space P, the piston Q would move to the left and bring the space X into com- munication with the space S, connected to the oil exhaust, and the space o would be brought into communication with the space R, supplied with high pressure oil. This would cause the pis- 233 ton Y to move to the right until suffici- ent nozzles had been shut off to reduce the speed, until the oil pressure in the space N was again brought into equili- brium with the air pressure in the space jie The principal features in which the above arrangement of the controlling system differs from that installed origin- ally on the "Neptune," is in the substi- tution of a rectilinear operating piston and a semi-circular slide valve for con- trolling the steam to the nozzles in place of the rotary valves and wing pistons used for moving the valve previously employed. Also far: greater sensitive- ness of the speed control and _ air pressure control have been obtained by the substitution of the diaphgrams R' R' in the air relay, and the diaphragm K in the governor in place of the pistons used for this purpose in the first "Nep- tune" installation. Although up to date no difficulty has been experienced with sticking of these pistons, experiments made in the shops at East Pittsburgh indicate that such might arise, and this, as well as leakage, was the chief reason for the changes made, although the greater sensitiveness obtained by the use of diaphragms in- stead of pistons was also partly the ob- ject, Bridge Operating Stand The bridge operating stand which sup- ports the bridge control valves is shown in Fig 3, from which it will be seen that there is a rotary slide valve on top of the stand between the port and star- board control valves. This latter valve is not showninthe diagrammatic sketch previously described, and is not shown in detail because of the difficulty of showing the various ports in it. Its function, however, is to permit operating both turbines, either ahead or astern, by either the port or starboard control valve, or to cut out both the starboard and port control valves. In addition to these functions which this valve _per- forms on the bridge control stand, the similar valve on the control stand in the engine room has a position for cutting out the bridge stand and other operating stands in other portions of the ship; "B" thus when the control system on the bridge is connected, all control stands excepting that in the engine room, are made inactive, while if the stand in the engine room is being used, all other stands (including the one on the bridge) are disconnected. This arrangement avoids interference, permits rapid changes from one station to another, but always leaves the engine room. stand operative in case of an emergency. Ordinarily, except when maneuvering, the bridge stand is always connected up so that both turbines are controlled by moving either the port or starboard con-