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278 description, the reader will be able to judge for himself how completely the various objections referred to have been avoided in the design of the Westinghouse marine turbine, of which one form only is hereinafter described, a number of suitable ar- rangements being available for the THE MARINE REVIEW monel metal, the valve seat E of cast iron and the balancing pistons D and retaining caps P are all made of bronze. The nozzle valve proper A, as pre- viously mentioned, is moved by a rack which engages with gear teeth cut in the periphery JT of the valve, by means of which it can be partially FIG. 8 several different classes and conditions of service. Fig. 4 is a cross section on the center line of the ahead high pres- sure nozzles, showing the nozzle valve and balancing pistons, and Fig, 5. is a partial longitudinal section through the turbine showing the nozzle valve and nozzles. The valve A is made of rotated. To permit the movement of the valve with the least possible force, the valve is supported upon internal and external rollers R and R'. The pressure of the steam on the valves is balanced by means of small pistons D, of which there is one for each pair of nozzles, there being 12 July, 1914 nozzles in the ahead and 16 nozzles in the astern. The space between the balancing pistons D and the retaining plugs P is connected to the space ¢ of the second nozzle in each group of two, thus at any instant the yn- balanced steam pressure can only pe equal to the area of one of the ports in the valve E£, admitting steam to the space C. As will be readily seen from the developed cross section of the nozzle valves the ports BB in the valve 4 and the ports in the valve seat E are so arranged that as the valve is moved to the left, the ports in E communi- cating with the nozzles are opened in succession, thus maintaining the ful] boiler pressure at the entrance to the nozzles, whether one or all of the nozzles are open. In order to avoid leakage and dis- tortion, the nozzle valve A is of rec- tangular section, cored out as shown in the developed section, Fig. 4, thus permitting the valve face to make a steam-tight joint at each port which is not open, while at the same time the box construction ensures the cir- cumferential rigidity necessary. The main. steam supply for the ahead opens into the. space S, Fig. 5, in the lower half.of the turbine cylin- der. Leakage from the space S into the turbine cylinder is prevented by dowel rings as shown. Dummy Strips As will appear later, there is but one dummy in the turbine, which di- vides the high pressure ahead from the astern turbine. This is shown in detail in Fig. 5. The dummy cylinder ring is a separate casting, which is supported from the nozzle ring G. The dummy strips are of the stand- ard type employed in all Westing- house turbines, and are 24 in number. Fig. 6 shows one of the ahead noz- zle blocks and sliding valve partly assembled, and also four of the bal- ance pistons in place. -Fig. 7 shows an ahead nozzle block, slide valve and balance pistons completely assembled ready to put in the turbine casing. A cross sectional elevation of the completely assembled turbine is shown in Fig. 8. It will be' noted that the turbine spindle is made in three parts, these being steel castings, one of which forms the forward spindle end and astern impulse wheel and _ reac- tion drum. The middle section of the spindle forms the ahead impulse wheel and part of the ahead reaction drum, the remaining part of the re- action drum and after spindle end being formed in a separate piece. The various parts of the _ spindle are bolted together. This spindle con-