Proceedings Constitution and By-Laws Volume 21 (Paperback)

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1918 Excerpt: ...should be notched not less than y$" for the stringers and attached to them by hook-bolts or some suitable substitute at every third tie. There should be not less than 6" thickness of timber above the dapping. For wide spacing of girders or stringers, or when one rail is elevated while the stringers are at the same level, deeper ties may be required. The case of burning of stringers by a short circuit cited above illustrates the importance of ample depth of ties above the dapping. Inside guard rails are a very important adjunct to a bridge carrying a track, to prevent the wandering of a derailed car; such guard rails should be fully spliced or their efficiency will be greatly reduced. Care should be taken that bolts are so placed that neither heads nor nuts can be sheared off by a derailed car. Some engineers do not realize that outside guard timbers do not answer the same purpose; and the requirements of at least one Railroad Commission until recently called for lining angles on these timbers, apparently with this misunderstanding. A brief consideration of this subject will show the fallacy of this view; if a wheel is retarded by rubbing against the inside rail, it will tend to turn the axle a little, directing the car toward its normal location; but the retarding of a wheel by rubbing on the outside guard timber will swing it further out of line and away from its proper place. This change of direction, too, will throw it against the guard more nearly at right angles, thus making it more likely to climb the guard and leap into whatever disaster is lurking beyond. Though the outside guard timbers are not qualified for guiding a derailed car, they do have a very important office. Without them or some substitute, the ties would be likely to become bu...