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104 Civil and Medtanical l~ngineering. nuts to be jammed against each other, it is evident that each will be forced equally against the thread of the screw in opposite directions. When an additional external strain comes upon the nuts, it is equally clear that the inner one will be partially or wholly forced awa.y from the thread on which it was previously bearing; and if the external strain is equal to the initial strain put upon the nuts by the act of locking, the inner one will be nearly relieved from pressure on the thread of tile bolt, (and would be quite so but for the elasticity of the threads,) and will become merely u distance piece between the press- ing body and the outer nut, the pressure on which will meantime have increased. In such a ease it is evident that the outside nu~ does all the work, and in all eases the strain on the enter nut must be greater than on the inner one, and hence it should be the larger of the two. Nothing could be more meaningless than to place a thick nut inside of a thin one. To my surprise the only engine that I have observed that has these nuts properly arranged (though I trust there are others) is 5Jr. Col liss', the gibs of his cross-head being sustained in this ms,met. In the American department, as a rule, no difl\~'rence is made in the size of the nuts, I presume with the object of saving the l~bor of turning down the nuts from the size in wifieh they are purchased; but this is eertainly better than to turn down one hue and then give it all the work to do, using a thick one to keep it tight. TENACITY OF STEEL RAILS, AT the Ch'~lk Farm Station of the London and North-Western Railway a ])'esscmer steel rail is now to be seen still in use, and in good order, which has out-lasted twenty-five iron rails successively placed next to it on the same line. Judging by this example, the steel rails are at least twenty-five times as durable as iron ones. Steel rails are very tough, as some experiments made within the last few days at the works of h[essrs. John Brown & Co., and Messrs. Cammell &~Co., of Sheffield, conclusively illustrate. These experi- ments were made chiefly for the satisfaction of the lion. W. J. Mac- Alpine, formerly engineer of the State of New York, and much con- nected with railways in America, who contemplates the more extended introduction of steel rails into that country. The result was to show the great toughness and powers of endurance of the steel rails. In one of the experiments a ram of a ton weight was suffered to fall upon a rail of 68 pounds to the yard, supported on iron blocks 3 feet apart in the clear, from a height of 20 feet, and the only effect ~as to bend the rail. The rail was then turned upside down and the blowy repeated, when the rail was bent straight, but without any eraeklng being visible. Finally, the rail was exposed to the test of ~ ton ram f~lling through 30 feet, when tile rail was very much bent and twisted, but not a crack was visible. ]Yy'the mode of manufacture now adopted, perfect uniformity in the composition of the rails is insured.

Tenacity of steel rails

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Page 1: Tenacity of steel rails

104 Civil and Medtanical l~ngineering.

nuts to be jammed against each other, it is evident that each will be forced equally against the thread of the screw in opposite directions. When an additional external strain comes upon the nuts, it is equally clear that the inner one will be partially or wholly forced awa.y from the thread on which it was previously bearing; and if the external strain is equal to the initial strain put upon the nuts by the act of locking, the inner one will be nearly relieved from pressure on the thread of tile bolt, (and would be quite so but for the elasticity of the threads,) and will become merely u distance piece between the press- ing body and the outer nut, the pressure on which will meantime have increased. In such a ease it is evident that the outside nu~ does all the work, and in all eases the strain on the enter nut must be greater than on the inner one, and hence it should be the larger of the two. Nothing could be more meaningless than to place a thick nut inside of a thin one.

To my surprise the only engine that I have observed that has these nuts properly arranged (though I trust there are others) is 5Jr. Col liss', the gibs of his cross-head being sustained in this ms,met. In the American department, as a rule, no difl\~'rence is made in the size of the nuts, I presume with the object of saving the l~bor of turning down the nuts from the size in wifieh they are purchased; but this is eertainly better than to turn down one hue and then give it all the work to do, using a thick one to keep it tight.

TENACITY OF STEEL RAILS, AT the Ch'~lk Farm Station of the London and North-Western

Railway a ])'esscmer steel rail is now to be seen still in use, and in good order, which has out-lasted twenty-five iron rails successively placed next to it on the same line. Judging by this example, the steel rails are at least twenty-five times as durable as iron ones. Steel rails are very tough, as some experiments made within the last few days at the works of h[essrs. John Brown & Co., and Messrs. Cammell &~ Co., of Sheffield, conclusively illustrate. These experi- ments were made chiefly for the satisfaction of the lion. W. J. Mac- Alpine, formerly engineer of the State of New York, and much con- nected with railways in America, who contemplates the more extended introduction of steel rails into that country. The result was to show the great toughness and powers of endurance of the steel rails. In one of the experiments a ram of a ton weight was suffered to fall upon a rail of 68 pounds to the yard, supported on iron blocks 3 feet apart in the clear, from a height of 20 feet, and the only effect ~as to bend the rail. The rail was then turned upside down and the blowy repeated, when the rail was bent straight, but without any eraeklng being visible. Finally, the rail was exposed to the test of ~ ton ram f~lling through 30 feet, when tile rail was very much bent and twisted, but not a crack was visible. ]Yy'the mode of manufacture now adopted, perfect uniformity in the composition of the rails is insured.