| Steel piers, braced | 313 | |
| Steel shells filled with concrete | 310 | |
| Steel tapes for base-line measurements | 317 | |
| Stiff bottom chords | 171 | |
| Stiff bottom chords in highway bridges | 220 | |
| Stiffeners, crimping of | 94 | |
| Stiffeners for drums | 193 | |
| Stiffeners for girders over drums | 200 | |
| Stiffening angles for stringers | 173 | |
| Stiff top chords for drawbridges | 183 | 191 |
| Stone for masonry, inspection of | 296 | |
| Storage-batteries for operating draw-spans | 120 | 201 |
| Straightening metal | 254 | |
| Strengthening piers of East Omaha Bridge | 314 | |
| Stress diagrams, contents of | 336 | |
| Stress diagrams, styles of | 336 | |
| Stresses, dead-load | 333 | |
| Stresses in anchor-arms of cantilever bridges | 58 | |
| Stresses in cantilever bridges | 58 | |
| Stresses in cantilever-arms | 58 | |
| Stresses in main central spans of cantilever bridges | 59 | 60 |
| Stresses in suspended spans of cantilever bridges | 58 | |
| Stresses in trestle columns, combination of | 88 | |
| Strictness of inspection | 263 | |
| Stringer bracing | 173 | |
| Stringers, proportioning of | 172 | |
| Stringers, timber | 274 | |
| Structure, general layout of | 330 | |
| Structures designed by manufacturers | 3 | |
| Struts of two laced angles | 171 | |
| Study in outlining spans | 50 | |
| Study of aesthetics in any bridge-design | 49 | |
| Styles of bridges for various span lengths | 217 | |
| Styles of drawbridges for various span lengths | 182 | |
| Styles of highway draw-spans | 238 | |
| Styles of railroad bridges for various span lengths | 145 | |
| Styles of stress diagrams | 336 | |
| Submerged piers for bascule bridges | 106 | |
| Subpunching | 256 | |
| Subpunching, necessity for | 9 | |
| Superelevation for wooden trestles | 279 | |
| Superelevation on curves of elevated railroads | 95 | |
| Superelevation on curves of railroad bridges | 143 | |
| Superfluous metal, use of | 17 | |
| Superiority of cantilever bridges, imaginary | 55 | |
| Superiority of Petit truss | 19 | |