| Thinning paints | 260 | |
| Thoroughfares, closing | 262 | |
| Thoroughness in inspection | 281 | |
| Threads, specifications for | 259 | |
| Thrust transference, provision for | 26 | |
| Tie-plates | 174 | 232 |
| Tie-spacing for elevated railroads | 102 | |
| Timber | 261 | 293 |
| Timber-bolts | 142 | |
| Timber caissons | 308 | |
| Timber compression-members | 276 | |
| Timber, defects in | 299 | |
| Timber, extreme fibre-stress for | 156 | |
| Timber for trestles | 277 | |
| Timber, grillage | 303 | 309 |
| Timber inspection | 297 | |
| Timber inspectors, reports of | 299 | |
| Timber piers | 314 | |
| Timber portions of highway bridges | 214 | |
| Timber portions of railroad structures | 141 | |
| Timber stringers | 274 | |
| Timber trestles | 273 | |
| Titles for drawings | 339 | 342 |
| Toggle-links for draw machinery | 208 | |
| Toggles for semi-cantilevers | 62 | 63 |
| Top chords, sections of | 170 | |
| Tops of columns in trestles and elevated railroads | 26 | |
| Tops of trestle columns | 179 | |
| Torsion, avoidance of | 20 | |
| Tower-bracing | 179 | |
| Tower-bracing for draw-spans | 191 | |
| Tower Bridge of London | 105 | |
| Towers for draw-spans | 183 | |
| Towers of Halsted Street Lift-Bridge | 108 | |
| Tower-spacing in elevated railroads | 149 | |
| Tracing-cloth, quality of | 346 | |
| Tracing-cloth, working on | 336 | |
| Track-segments of drums | 194 | |
| Traction-bracing in truss-bridges | 173 | |
| Traction load | 154 | |
| Train-sheds, arches for | 79 | 81 |
| Transference of thrust, provision for | 26 | |
| Transferred load | 154 | |
| Transferred load for draw-spans | 185 | |
| Transits for triangulation | 323 | |
| Transverse struts, sections of | 171 | |