The following text may have been generated by Optical Character Recognition, with varying degrees of accuracy. Reader beware!

the escape of any steam leaking past the dummy when running ahead with- out the necessity of its passing through the astern reaction blading, and thus causing additional lost work. Lf THE MARINE REVIEW bines, is provided. The automatic stop plunger in the spindle trips a valve which releases the steam pressure under the piston of the automatic stop valve in the main steam line, the NRX WRN SQV AMAL . SN OR MNQQQAAAAHN LJ J ELG: 10 This is one of-the decided advan- tages of the impulse wheel when used in this manner, as the steam leaking by the dummy cannot cause any addi- tional resistance in the astern impulse wheel when the turbine is running ahead. By-passing the reaction blad- ing obviates any loss at this point. This by-passing valve is operated automatically by a piston resisted by the spring, which normally holds the valve in an open position, as shown, but as soon as steam is admitted to the first astern nozzle, the pressure back of the piston brings the valve to its seat. An automatic Stop of the usual type fitted on all Westinghouse tur- automatic stop valve being placed ahead of the control, valve so that it serves for both ahead and astern operation. Fig. 9 is a semi-plan view and July, 1914 longitudinal section: of the turbine. Fig. 11 shows the method employed to hold the impulse blades. As will be seen from the illustration, slots are cut in the narrow rim on each side of the impulse disc and T-headeq shanks on the blades are fitted in these slots, the blades thus being lit. erally hung on a cantilever project- ing from the impulse wheel disc. A groove is turned in each side of the projecting cantilevers, in which caulk- ing pieces are inserted, one of these being dovetail and the other flat. The purpose of these is solely to hold the blades from moving sidewise in the slots. This construction permits mak- ing the blade attachment as strong as the cross section of the blade itself, and at the same time reduces the weight of the rim supporting the blades to a minimum and_ simplifies the distribution of stresses at the rim materially. There is no change from hoop stress to disc stress as the slots eliminate the tangential stress ordi- narily existing in the rim. In the past two years an entirely new method of blade attachment has been developed by the Westinghouse Machine Co., in which all dependence upon the frictional grip on the blades is eliminated. This new blade attach- ment is illustrated in 12, 13 and 14. Fig. 13 is a cross section of a model, which shows the undercut groove and a second smaller groove at the bottom of the primary groove, in which the upset ends of the blades fit. Gradual Taper As will be noted in Fig. 14, the ends ef the blades are thickened by up- setting on a gradual taper extending from one to three or four inches from the root of the blade, the actual sec- tion of the blade being increased about 50 per cent at the root, and at the same time a lip is formed which hooks under the dovetailed: shape packing pieces shown. In the small- er blade sections the packing pieces are slipped in by turning them side- wise in the groove until all the blades have been inserted except one or two where the undercut in the turbine A a at ea