OF THE VERTICAL DEPTH (HEIGHT) OF THE RAIL.
Mr. Barlow’s general results are as follow:—
| Distance from inside to inside of tie. | Height of rail. |
|---|---|
| 3′ 0″ | 4½″ |
| 3′ 9″ | 4⅝″ |
| 4′ 0″ | 4¾″ |
| 5′ 0″ | 5″ |
| 6′ 0″ | 51 16″ |
In the London edition (1836) of Barlow’s Strength of Materials, page 402, in a report to the London and Birmingham Railway Co., upon the best form and upon the strength of rails; after a carefully conducted set of experiments, and an elaborate theoretical deduction of results, the writer comes to the following five sections of rails possessing the maximum strength, with the least weight.
| Dimensions. | No. 1. | No. 2. | No. 3. | No. 4. | No. 5. |
|---|---|---|---|---|---|
| Height, | 4½ | 4⅝ | 4¾ | 5 | 55 16 |
| Breadth at top, | 2¼ | 2¼ | 2¼ | 2¼ | 2¼ |
| Depth of top, | 1 | 1 | 1 | 1 | 1 |
| Thickness of rib, | 0.6 | 0.75 | 0.8 | 0.85 | 1.0 |
| Width of lower flange, | 1¼ | 1½ | 1½ | 1⅔ | 1⅔ |
| Depth of lower flange, | 1 | 1 | 1 | 1⅛ | 1½ |
| Weight per yard, | 51.4 | 58.8 | 61.2 | 67.4 | 79 |
| Distance C. to C. of ties, | 3′ | 3′9″ | 4′ | 5′ | 6′ |
This table shows the ratio of material which should be placed in the top and bottom.
With the above dimensions, and joining the curve of the head to the rib at two and one fourth inches from the top of the head, we obtain a strong and well-shaped rail, with the least material possible. See fig. 136.
As an example of the application of the above, the table below has been formed, showing four standard forms, which will be found to unite all of the requirements of good rails; the general form being that of fig. 136.
| Dimensions. | The weight of the rail being, in lbs., | |||
|---|---|---|---|---|
| 60 | 65 | 70 | 75 | |
| Width of head, | 2½ | 2½ | 2½ | 2½ |
| Rad. of top, | 12 | 12 | 12 | 12 |
| Height of rail, | 4 | 4¼ | 4½ | 4¾ |
| Thickness of rib, | 0.6 | 0.6 | 0.65 | 0.7 |
| Breadth of base, | 3½ | 3½ | 3¾ | 4 |
| Depth of head at point A B, | 2¼ | 2¼ | 2½ | 2½ |
| Thickness at edge of lower web, | ½ | ½ | ½ | ½ |
and the following figures show the weights which should be applied to differently spaced sleepers.