troubles have been made the subject of questions except those that are peculiar to this style of gear, or that must receive different treatment from that which they would in connection with the Stephenson link motion. There are many troubles that can, and will, occur on the road that are not noted here, but by understanding that which has been explained in this book, any engineer that can keep the wheels turning in the presence of the common disabilities that occur to engines of the link-motion class, can also be ready to meet any troubles that may possibly happen to the Walschaert gear. Addendum to Answer to Question 53 on page 179: In case of broken eccentric rod or eccentric crank, if it is possible to secure the link block in the exact centre of the link, do so, and disconnect the suspension bar from the radius rod; remove the broken parts-and the eccentric rod, if the eccentric crank is broken-and proceed. This method will permit the valve to have its short-lapand-lead-travel, and will provide the lead port-opening when the piston is at either end of the cylinder; preventing compression and vacuum in the cylinder when the main rod is left up and the piston is in motion, and permitting oil from the lubricator to reach the cylinder and prevent its cutting.. FIFTH DIVISION SETTING VALVES WITH THE WAL SCHAERT VALVE GEAR AN understanding of the method of valve setting, or "squaring the valves," was a very real necessity to roundhouse men, and enginemen as well, in the days when the Stephenson link-motion was exclusively used on locomotives, and this has influenced a great many to think that about the first knowledge an engineman or shopman should obtain of any newly adopted style of valve gear is "how to set the valves." It is not remarkable that this idea should so widely prevail, for it was usual that any engine that came out of the back shop with valves squarely set, would not continue in service very long until its irregular exhausts, in either or both points of full gear, indicated that one or both of the valves were “out." On the preceding pages of this book, the many causes that may separately or collectively throw the valves of the link motion out of true have been mentioned; but this fact has been repeatedly emphasized, that the valves of the Walschaert gear do not get out of square in service, nor if they did would it be possible for them to be squared |