{"product_id":"american-railway-signaling-principles-and-practices-interlocking-circuits-chap20","title":"American Railway Signaling Principles and Practices Interlocking Circuits Chap20","description":"\u003cbody\u003e\n\u003c!-- HTML Generated by Auction Wizard 2000 - http:\/\/www.AuctionWizard2000.com\/ --\u003e\n\n\n   \u003cmeta charset=\"UTF-8\"\u003e\n   \u003cmeta name=\"viewport\" content=\"width=device-width, initial-scale=1.0\"\u003e\n\n\n\u003c!-- AW2KLOT#:198116 --\u003e\n\u003cbr\u003e\n\u003ctable style=\"width:98%;padding:2px;margin:auto;border:5px outset #673434;background-color:#FDF3D0\"\u003e\u003ctr\u003e\u003ctd style=\"border:1px inset #673434;margin:5px;\"\u003e\n\u003ctable style=\"width:100%;border:0px;padding:5px;\"\u003e\n\u003ctr\u003e\u003ctd\u003e\n\u003c\/td\u003e\u003c\/tr\u003e\n\u003ctr\u003e\u003ctd style=\"padding:5px\"\u003e\n\u003cdiv style=\"text-align:center\"\u003e\n\u003cspan style=\"font-family:Arial Black;font-size:1.5em;color:#000000;font-weight:normal;font-style:normal;text-decoration: underline;\"\u003eRailroadTreasures\u003c\/span\u003e\u003cspan style=\"font-family:Arial Black;font-size:1.5em;color:#000000;font-weight:normal;font-style:normal;text-decoration: underline;\"\u003e \u003c\/span\u003e\u003cspan style=\"font-family:Arial Black;font-size:1.5em;color:#000000;font-weight:normal;font-style:normal;text-decoration: underline;\"\u003eoffers the following item:\u003c\/span\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"text-align:left\"\u003e\u003cspan style=\"font-family:Times New Roman;font-size:1.0em;color:#000000;font-weight:normal;font-style:normal;text-decoration:none;\"\u003e  \u003c\/span\u003e\u003c\/div\u003e\n\n\u003c\/td\u003e\u003c\/tr\u003e\n\u003ctr\u003e\u003ctd style=\";padding:5px\"\u003e\n\u003cdiv style=\"text-align:center\"\u003e\u003cspan style=\"font-family:Arial;font-size:1.13em;color:#000000;font-weight:normal;font-style:normal;text-decoration:none;\"\u003eAmerican Railway Signaling Principles and Practices Interlocking Circuits Chap20\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"text-align:center\"\u003e\u003cspan style=\"font-family:Arial;font-size:1.13em;color:#000000;font-weight:normal;font-style:normal;text-decoration:none;\"\u003e  \u003c\/span\u003e\u003c\/div\u003e\n\n\u003cdiv style=\"text-align:left\"\u003e\u003cspan style=\"font-family:Calibri;font-size:1.13em;color:#000000;font-weight:normal;font-style:normal;text-decoration:none;\"\u003eAmerican Railway Signaling Principles and Practices Interlocking Circuits Chapter 20  XX\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"text-align:left\"\u003e\u003cspan style=\"font-family:Calibri;font-size:1.13em;color:#000000;font-weight:normal;font-style:normal;text-decoration:none;\"\u003eCopyright  1933   \u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"text-align:left\"\u003e\u003cspan style=\"font-family:Calibri;font-size:1.13em;color:#000000;font-weight:normal;font-style:normal;text-decoration:none;\"\u003eApprox 170 pages\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"text-align:left\"\u003e\u003cspan style=\"font-family:Calibri;font-size:1.13em;color:#000000;font-weight:normal;font-style:normal;text-decoration:none;\"\u003eStapled \u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"text-align:left\"\u003e\u003cspan style=\"font-family:Calibri;font-size:1.13em;color:#000000;font-weight:normal;font-style:normal;text-decoration:none;\"\u003eIn the description and explanation of the operation of interlocking circuits given in this chapter it is to be understood that the circuits, special symbols and wire nomenclature are not necessarily specifications, nor the recommended practice of the Signal Section, American Railway Association; they are indicative of those that are now in use in connection with the interlockings described. These descriptions are given with the thought that they will enable the student to more readily understand circuits of a similar nature, the details of which, however, may be somewhat different, depending upon the practice of the individual railroad.\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"text-align:left\"\u003e\u003cspan style=\"font-family:Calibri;font-size:1.13em;color:#000000;font-weight:normal;font-style:normal;text-decoration:none;\"\u003eGeneral.\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"text-align:left\"\u003e\u003cspan style=\"font-family:Calibri;font-size:1.13em;color:#000000;font-weight:normal;font-style:normal;text-decoration:none;\"\u003eInterlocking circuits were considered and designed to bring about more adequate facilities to handle properly, speedily and safely the units which comprise mechanical interlocking. Many circuits have been designed and tried as a means of overcoming some incumbrance which had been experienced with mechanical devices with the result that today many obstacles formerly encountered have been overcome. Circuits designed for special reasons will not be considered; the most important in general use will be covered in this chapter.\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"text-align:left\"\u003e\u003cspan style=\"font-family:Calibri;font-size:1.13em;color:#000000;font-weight:normal;font-style:normal;text-decoration:none;\"\u003eSignals and switches, originally, were operated by means of wire or pipe lines manipulated by mechanical levers. Mechanical locking was interposed between levers to prevent the establishing of conflicting routes and to enforce a predetermined order in their operation; mechanical detector bars were added to the switches to prevent their operation while trains are passing over same, and electrical slots were designed for mechanical signals to provide a means of returning the signal automatically to display its most restrictive indication by the movement of a train. Of the three features mentioned the latter two are fast becoming obsolete, the mechanical locking remaining in practically its initial state.\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"text-align:left\"\u003e\u003cspan style=\"font-family:Calibri;font-size:1.13em;color:#000000;font-weight:normal;font-style:normal;text-decoration:none;\"\u003eThe use of wire for operating signals mechanically was found to be unreliable and while the use of pipe was more satisfactory, nevertheless various reasons have brought about the necessity for a substitute. In the operation of switches, mechanically-operated pipe connections are still used extensively.\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"text-align:left\"\u003e\u003cspan style=\"font-family:Calibri;font-size:1.13em;color:#000000;font-weight:normal;font-style:normal;text-decoration:none;\"\u003eFor convenience and to better present the circuits involved, they will be classified as to their use with respect to the various units with which they are used and as they have been applied to the various types of interlockings: namely, mechanical, electromechanical, electro-pneumatic, electric, automatic, and electric without mechanical locking. The type of interlocking commonly used, the best known and the one to which the greater number of revisions and application of new designs have been applied, is the mechanical interlocking. Many plants of this type are still in service; however, in most cases revisions have been made to substitute power-operated for wire and pipe-connected signals, and electric switch locking for the mechanical detector bars.\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"text-align:left\"\u003e\u003cspan style=\"font-family:Calibri;font-size:1.13em;color:#000000;font-weight:normal;font-style:normal;text-decoration:none;\"\u003eWhile all the circuits necessary for the complete control of the electrical units involved are shown, no attempt will be made to explain in detail the operation of the several circuits, it being considered sufficient to explain one circuit of each type used.\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"text-align:left\"\u003e\u003cbr\u003e\u003c\/div\u003e\n\n\u003cdiv style=\"text-align:left\"\u003e\u003cspan style=\"font-family:Arial;font-size:1.0em;color:#000000;font-weight:normal;font-style:normal;text-decoration:none;\"\u003eAll pictures are of the actual item.  There may be reflection from the lights in some photos.   We try to take photos of any damage.    If this is a railroad item, this material is obsolete and no longer in use by the railroad.  Please email with questions. Publishers of Train Shed Cyclopedias and Stephans Railroad Directories. Large inventory of railroad books and magazines. Thank you for buying from us.\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"text-align:left\"\u003e\u003cbr\u003e\u003c\/div\u003e\n\u003cdiv style=\"text-align:center\"\u003e\u003cspan style=\"font-family:Arial;font-size:1.13em;color:#CE0000;font-weight:normal;font-style:normal;text-decoration:none;\"\u003eShipping charges\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"text-align:left\"\u003e\u003cspan style=\"font-family:Arial;font-size:1.0em;color:#000000;font-weight:normal;font-style:normal;text-decoration:none;\"\u003eUS Shipments:  When you add multiple items to your cart, the reduced shipping charges will automatically be calculated.   For direct postage rates to other countries, send me an email.   Shipping varies by weight.\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"text-align:left\"\u003e\u003cbr\u003e\u003c\/div\u003e\n\u003cdiv style=\"text-align:center\"\u003e\u003cspan style=\"font-family:Arial;font-size:1.13em;color:#CE0000;font-weight:normal;font-style:normal;text-decoration:none;\"\u003eTerms and conditions \u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"text-align:left\"\u003e\u003cspan style=\"font-family:Arial;font-size:1.0em;color:#000000;font-weight:normal;font-style:normal;text-decoration:none;\"\u003eAll sales are final. 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