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TRACK JOINTS.

1606. There are two forms of rail joints in general use, viz., suspended and supported. Both forms have merits peculiar to themselves, but both are rarely found on the same road, either one or the other being used exclusively. A cut of a suspended joint is given in Fig. 489, and of a

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supported joint in Fig. 490. In the suspended joint there are two joint ties spaced about 6 inches in the clear, The joint is spaced midway between the ties, which should be carefully selected, have broad faces, and be of uniform thickness throughout. In the supported joint the tic is placed directly under the joint. The angle splices A and B, which are shown in section at C, vary in length from 24 to 36 inches. Those 24 inches in length have 4 bolts, and those from 30 inches upwards have 6 bolts. A joint to be perfect should have the same strength as the rail itself, but such a joint has not yet been devised. A vast amount of time and money has been expended upon the development of rail fastenings. Iron chairs and fish-plates, once in universal use, have disappeared. The angle splice shown in section at C, Fig. 489, is generally accepted as the best rail fastening yet invented. The prerequisite of a good rail fastening is a strong shoulder which will closely fit under the head of the rail, and a broad base closely fitting the base of the rail and extending its entire width, reaching down so as to bear upon the tic. The plates do not fit closely to the web of the rail, but are curved as shown in the section C. The holes in the plates as well as those in the rails are oblong so as to admit of the expansion and contraction of the rails due to change of temperature.

Bolts should be of a size suited to the weight of the rail though there is small danger of getting them too heavy Track bolts are usually fitted with nut-locks of either metal or fiber. Trackmen should avoid straining the bolts when setting up the nuts. A half turn of the wrench after the nut has come to a bearing is sufficient. Though there are still some railroad men who strongly adhere to the supported joint, yet general experience has abundantly proved the

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superiority of the suspended joint. The angle splice in general use on trunk lines is 3 feet in length, carries 6 bolts, and complete weighs from 40 to 60 pounds. The joint is suspended, and the ends of the splices also come midway between ties, as in Fig. 491.

The angle splices should be slotted and spikes driven through them into the tic to prevent the creeping of the rails. In the suspended joint there are two slots in each splice, as shown in Fig. 489, and in the supported joint but one.

Spike slots in the rails are not admissible, as they prevent the full expansion and contraction of the rails.