. Science of railways . the lever. A slight pull on this lever pushes in-ward the valve and permits the steam to flow intoa chamber and to open automatically the largevalve and sound the whistle. By this device thelargest whistles under the highest pressure ofsteam are operated with ease and rapidity. The Ashcroft four-tone chime whistle is shownin Fig. 5. These whistles are pitched to first,third and fifth of the common musical scale, whichharmonizes the sound and gives an agreeablemusical chord. The chime whistle has proved much more pene-trating than the single bell whistle, as shown inFig.
. Science of railways . the lever. A slight pull on this lever pushes in-ward the valve and permits the steam to flow intoa chamber and to open automatically the largevalve and sound the whistle. By this device thelargest whistles under the highest pressure ofsteam are operated with ease and rapidity. The Ashcroft four-tone chime whistle is shownin Fig. 5. These whistles are pitched to first,third and fifth of the common musical scale, whichharmonizes the sound and gives an agreeablemusical chord. The chime whistle has proved much more pene-trating than the single bell whistle, as shown inFig. 1, and can be heard at a greater distance,without the harsh, disagreeable noise. Many railroads have adopted a chime whistlefor passenger runs, in order to distinguish passen-ger from freight trains; but new locomotives arebeing added so rapidly, and are of such size as tohaul very long trains, and thus require a whistleof maximum penetrating qualities to be heard atthe rear end of the train. LOCOMOTIVE APPLIANCES. 365. The Hancock Single Bell Whis-tle.—The accompanying illustra-tion represents the Hancockplain whistle for freight whistle has a much higherpitch than the chime whistleand is very simple and substan-tial in its construction. Thebell, bowl, plate and valve aremade of composition. A bolt ofcold rolled steel extends itsentire length, holding the partstogether. The stem supporting the bell and the nut are of castiron. The lever is a steel slot in the valve, where itengages the end of the lever,is provided with a chilled ironpiece which is cast into the Hancock Plain Whistle valve. The end of the leverwhich operates the valve is alsohardened. The screw, shown incut, prevents the valve fromdropping out when the lever isremoved.
Size: 960px × 2604px
Photo credit: © Reading Room 2020 / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bo, bookcentury1900, bookdecade1910, bookidscienceofrailway14kirk
