. Railway mechanical engineer . , the one close to the loadis going to take most of the work and the ultimate strengthof the system is reduced. I have attempted in tliis paper to bring to your mindstwo or three very important things in the selection of draftgears and the design of freight cars. One of the most im-portant things is—we will have to increase the travel of thedraft gear above that thought sufficient some years years ago it was felt that 2 in. or 24 in. was as muchtravel as we should have. But I am ready today to say thatwe should have at least 4 in. of travel, or
. Railway mechanical engineer . , the one close to the loadis going to take most of the work and the ultimate strengthof the system is reduced. I have attempted in tliis paper to bring to your mindstwo or three very important things in the selection of draftgears and the design of freight cars. One of the most im-portant things is—we will have to increase the travel of thedraft gear above that thought sufficient some years years ago it was felt that 2 in. or 24 in. was as muchtravel as we should have. But I am ready today to say thatwe should have at least 4 in. of travel, or possibly more, inany draft gear for modern cars. It is evident that this isgoing to allow us to materially increase the gear capacity. Another thing of importance to the railway men today isto know what capacity of draft gear they are getting. I amconfident that the best metliod for tliem to use is the rivet-shearing test, as already described. The numljer of rivetsdoes not enter into the suljject. What they should have is a. Fig. -Deformation of Sills with the Center Line of Draft 33^Down from the Top of the Sills set- of lugs that will shear off just above the force which isnecessary to close the gear under test. I can conceive howa gear can be designed for a final pressure of 350,000 lb.,then a test of rivets .shearing off at 275,000 lb, would not befair. But in any design of a lug, the lug should be mademuch stronger than the rivets in order that the lugs will notbend down and the gear show a false capacity. I can seehow a lug may be built and give false capacity of draftgear, but tlie lugs should be designed stronger than therivets. I myself, have not found a draft gear today butthat will close before it shears off nine 19/32 in. rivets. However, there may be some such gear on the market. One thing that is important in the design of a freightcar is that the underframe of the car should be madestronger than the coupler. It has been the coupler in thepast that has been sa
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectrailroadengineering
