| FIGURE | PAGE |
|---|
| [1]. | Diagram Showing Manner of Lining in Rectilinear Tunnels | 10 |
| [2]. | B. R. Value’s Device for Locating the Center Line Inside of a Tunnel | 11 |
| [3]. | Triangulation System for Establishing the Center Line of the St. Gothard Tunnel | 12 |
| [4]. | Method of Transferring the Center Line down Center Shafts | 13 |
| [5]. | Method of Transferring the Center Line down the Side Shafts | 14 |
| [6]. | Method of Laying out the Center Line of Curvilinear Tunnels | 15 |
| [7]. | Diagram of Polycentric Sectional Profile | 19 |
| [8], [9] and [10].Typical Sectional Profiles for Tunnel | 20 |
| [11]. | Soft Ground Bucket Excavating Machine; Central London Underground Railway | 22 |
| [12]. | Column Mounting for Percussion Drill; Ingersoll Sargent Drill Co. | 26 |
| [13]. | Sketch of Diamond Drill Bit | 27 |
| [14]. | Diagram Showing Sequence of Excavation for St. Gothard Tunnel | 36 |
| [15]. | Diagram Showing Manner of Determining Correspondence of Excavation to Sectional Profile | 38 |
| [16]. | Polar Protractor for Determining Profile of Excavated Cross-Section | 39 |
| [17]. | Joining Tunnel Struts by Halving | 48 |
| [18]. | Round Timber Post and Cap Bearing | 48 |
| [19]. | Ceiling Strutting for Tunnel Roofs | 49 |
| [20]. | Ceiling Strutting with Side Post Supports | 49 |
| [21]. | Sill, Side Post and Cap Cross Frame Strutting | 49 |
| [22]. | Reinforced Cross Frame Strutting for Treacherous Materials | 49 |
| [23]. | Longitudinal Poling-Board System of Roof Strutting | 50 |
| [24]. | Transverse Poling-Board System of Roof Strutting | 50 |
| [25]. | Shaft with Single Transverse Strutting | 52 |
| [26]. | Rectangular Frame Strutting for Shafts | 53 |
| [27]. | Reinforced Rectangular Frame Strutting for Shafts in Treacherous Materials | 53 |
| [28]. | Strutting of Timber Posts and Railway Rail Caps | 56 |
| [29]. | Strutting Made Entirely of Railway Rails | 56 |
| [30]. | Rziha’s Combined Strutting and Centering of Cast Iron | 57 |
| [31]. | Cast-Iron Segment of Rziha’s Strutting and Centering | 57 |
| [32]. | Cast-Iron Segmental Strutting for Shafts | 58 |
| [33]. | Platform Car for Tunnel Work | 59 |
| [34]. | Iron Dump-Car for Tunnel Work | 60 |
| [35]. | Wooden Dump-Car for Tunnel Work | 60 |
| [36]. | Box-Car for Tunnel Work | 61 |
| [37]. | Elevator Car for Tunnel Shafts | 65 |
| [38]. | Ground Mold for Constructing Tunnel Invert Masonry | 67 |
| [39]. | Combined Ground Mold and Leading Frame for Invert and Side Wall Masonry | 67 |
| [40]. | Leading Frame for Constructing Side Wall Masonry | 68 |
| [41]. | Plank Center for Constructing the Roof Arch | 69 |
| [42]. | Trussed Center for Constructing the Roof Arch | 70 |
| [43] and [44]. A Typical Form of TimberLining for Tunnels | 73 |
| [45]. | Diagram Showing Forms adopted for Side-Wall Foundations | 76 |
| [46] and [47]. Transverse Sections ofTunnels Showing Methods for Increasing the Thickness of the Lining at Different Points | 79 |
| [48]. | Refuge Niche in St. Gothard Tunnel | 81 |
| [49]. | East Portal of Hoosac Tunnel | 82 |
| [50], [51] and [52].Arrangement of Drill Holes in the Heading of Turchino Tunnel | 91 |
| [53] and [54]. Arrangement of Drill Holes inthe Heading of the Fort George Tunnel | 91 |
| [55]. | Diagram Showing Sequence of Excavations in Drift Method of Tunneling Rock | 102 |
| [56]. | Sketches Showing Sequence of Work in Excavating and Lining the Simplon Tunnel | 111 |
| [57]. | General Details of the Brandt Rotary Drills Employed at the Simplon Tunnel | 112 |
| [58]. | Sequence of Excavation in the Murray Hill Tunnel | 124 |
| [59]. | Traveling Platform for the Excavation of the Upper Side of the Murray Hill Tunnel | 125 |
| [60]. | Timbering Used in the Murray Hill Tunnel | 126 |
| [61]. | Diagram Showing Sequence of Excavation in Heading Method of Tunneling Rock | 132 |
| [62]. | Method of Strutting Roof, St. Gothard Tunnel | 135 |
| [63]. | Sketch Showing Arrangement of Tracks, St. Gothard Tunnel | 135 |
| [64]. | Arrangement of Drill Holes in the Fort George Tunnel | 137 |
| [65]. | Longitudinal Section of the Heading and Bench Excavation at the Fort George Tunnel | 137 |
| [66]. | Diagram Showing the Arrangement of Drill Holes in the Heading and Bench of the Gallitsin Tunnel | 140 |
| [67]. | Diagram Showing Modification of the Heading and Bench Method | 140 |
| [68] and [68A]. Diagrams Showing Sequence ofExcavation in the Belgian Method | 145 |
| [69]. | Sketch Showing Radial Roof Strutting, Belgian Method | 147 |
| [70]. | Sketch Showing Roof Arch Center, Belgian Method | 147 |
| [71]. | Sketch Showing Method of Underpinning Roof Arch with the Side Wall Masonry | 149 |
| [72]. | Longitudinal Section Showing Construction by the Belgian Method | 149 |
| [73]. | Diagram Showing Sequence of Excavation in Modified Belgian Method | 152 |
| [74]. | Sketch Showing Failure of Roof Arch by Opening at Crown | 153 |
| [75]. | Sketch Showing Methods of Repairing Roof Arch Failures | 154 |
| [76]. | Diagrams Showing Sequence of Excavation in German Method of Tunneling | 155 |
| [77]. | Diagram Showing Sequence of Excavation in Water Bearing Material, German Method | 156 |
| [78]. | Sketch Showing Work of Excavating and Timbering Drifts and Headings | 157 |
| [79]. | Sketch Showing Method of Roof Strutting | 157 |
| [80]. | Sketch Showing Roof Arch Centers and Arch Construction | 158 |
| [81]. | Sketch Showing Method of Excavating and Strutting Baltimore Belt Line Tunnel | 162 |
| [82]. | Roof Arch Construction with Timber Centers, Baltimore Belt Line Tunnel | 163 |
| [83]. | Roof Arch Construction with Iron Centers, Baltimore Belt Line Tunnel | 164 |
| [84]. | Diagram Showing Sequence of Excavation in English Method of Tunneling | 167 |
| [85]. | Sketches Showing Construction of Strutting, English Method | 168 |
| [86] and [87]. Sketches of Typical Timber Roof-ArchCenters, English Method | 169 |
| [88]. | Sequence of Excavation in the American Method | 172 |
| [89]. | Strutting the Heading in the American Method | 172 |
| [90]. | Temporary Timbering of the Roof in the American Method | 173 |
| [91]. | Showing Crown Bars Supported by Segmental Arches | 173 |
| [92]. | Transversal and Longitudinal Section of a Tunnel Excavated and Strutted According to the American Method | 174 |
| [93] and [94]. Diagrams Showing Sequence ofExcavation in Austrian Method of Tunneling | 177 |
| [95], [96] and [97]. SketchesShowing Construction of Strutting, Austrian Method | 178 |
| [98]. | Sketch Showing Manner of Constructing the Lining Masonry, Austrian Method | 179 |
| [99]. | Diagram Showing Sequence of Excavation in Italian Method of Tunneling | 183 |
| [100]. | Sketch Showing Strutting for Lower Part of Section | 183 |
| [101] and [101A]. Sketches Showing Construction ofCenters, Italian Method | 184 |
| [102]. | Sketch Showing Invert and Foundation Masonry, Italian Method. | 185 |
| [103]. | Sketch Showing Longitudinal Section of a Tunnel under Construction, Italian Method | 186 |
| [104]. | Sketch Showing Sequence of Excavation, Stazza Tunnel | 186 |
| [105]. | Sketch Showing Method of Strutting First Drift, Stazza Tunnel | 187 |
| [106] and [107]. Sketches Showing Temporary StruttingArch Construction, Stazza Tunnel | 187 |
| [108]. | Sketch Showing Preliminary Drainage Galleries, Quicksand Method | 190 |
| [109]. | Sketch Showing Construction of Roof Strutting, Quicksand Method | 190 |
| [110]. | Sketch Showing Construction of Masonry Lining, Quicksand Method | 191 |
| [111]. | Sketch Showing Pilot Method of Tunneling | 193 |
| [112]. | Diagram Showing Sequence of Construction in Open-Cut Tunnels | 197 |
| [113]. | Sketch Showing Method of Timbering Open-Cut Tunnels, Double Parallel Trench Method | 198 |
| [114]. | Side-Wall Foundation Construction Open-Cut Tunnels | 198 |
| [115]. | Wide-Arch Section, Boston Subway | 204 |
| [116]. | Double-Barrel Section, Boston Subway | 205 |
| [117]. | Four-Track Rectangular Section, Boston Subway | 206 |
| [118]. | Section Showing Slice Method of Construction, Boston Subway | 206 |
| [119]. | Double-Track Section, New York Rapid Transit Railway | 212 |
| [120]. | Park Avenue Deep Tunnel Construction, New York Rapid Transit Railway | 214 |
| [121]. | Harlem River Tunnel, New York Rapid Transit Railway | 215 |
| [122]. | Sketch Showing Underground Stream, Milwaukee Water-Works Tunnel | 229 |
| [123]. | Sketch Showing Methods of Lining, Milwaukee Water-Works Tunnel | 232 |
| [124]. | Longitudinal Section of Brunel’s Shield, First Thames Tunnel | 241 |
| [125]. | First Shield Invented by Barlow | 242 |
| [126]. | Second Shield Invented by Barlow | 243 |
| [127]. | Shield Suggested by Greathead for the Proposed North and South Woolwich Subway | 245 |
| [128]. | Beach’s Shield Used on Broadway Pneumatic Railway Tunnel | 245 |
| [129]. | Shield for City and South London Railway | 246 |
| [130]. | Shield for St. Clair River Tunnel | 247 |
| [131]. | Shield for Blackwall Tunnel | 248 |
| [132]. | Elliptical Shield for Clichy Sewer Tunnel, Paris | 249 |
| [133]. | Semi-Elliptical Shield for Clichy Sewer Tunnel | 250 |
| [134]. | Roof Shield for Boston Subway | 251 |
| [135]. | Transversal and Longitudinal Section of Prelini’s Shield | 252 |
| [136]. | Elevation and Section of Hydraulic Jack, East River Gas Tunnel | 260 |
| [137]. | Cast-Iron Lining, St. Clair River Tunnel | 262 |
| [138]. | General Elevations and Sections of Shields | 270 |
| [139]. | Plan and Elevation of First Bulkhead Wall in South Tube, Manhattan | 273 |
| [140]. | Typical Cross-Sections of One Tube of Pennsylvania Railroad Tunnel under the Hudson River | 278 |
| [141]. | Sections of Cofferdam, Van Buren St. Tunnel, Chicago | 283 |
| [142]. | Showing Working Platforms and Piles Sunk in Dredged Channel | 286 |
| [143]. | Showing Sheeting-Piles for the Sides of the Caisson and Trussed Beam for the Roof | 287 |
| [144]. | Showing the Caisson with the Working-Chamber | 287 |
| [145]. | Showing the Tunnel Constructed within the Caisson | 289 |
| [146]. | Showing Sides of the Caisson and Supports for the Roof | 290 |
| [147]. | Showing the Roof of the Caisson Formed by the Upper Half of the Tunnel | 291 |
| [148]. | Showing the Tunnel Completed by Building the Lower Half within the Caisson | 292 |
| [149]. | Transversal Section of the Caissons for the Tunnel under the SeineRiver | 294 |
| [150]. | Showing the Joining of the Caissons at the Pont Mirabeau Tunnel under the Seine River | 295 |
| [151]. | Cross-Sections and Plans of the Detroit River Tunnel | 298 |
| [152]. | Tunneling through Caved Material by Heading | 306 |
| [153]. | Tunneling through Caved Material by Drifts | 307 |
| [154] and [155]. Filling in Roof Cavity Formedby Falling Material | 307 |
| [156]. | Timbering to Prevent Landslides at Portal | 308 |
| [157]. | Shortening Tunnel Crushed by Landslide at Portal | 308 |
| [158]. | Extending Tunnel through Landslide at Portal | 309 |
| [159] and [160]. Relining Timber-Lined Tunnel | 316 |
| [161]. | Relining Timber-Lined Tunnel, Great Northern Ry | 317 |
| [162]. | Relining Timber-Lined Tunnel, Great Northern Ry | 318 |
| [163]. | Relining Timber-Lined Tunnel, Great Northern Ry | 319 |
| [164]. | Construction of Centering Mullan Tunnel | 320 |
| [165]. | Centering Mullan Tunnel | 321 |
| [166]. | Relining Timber-Lined Tunnel, Norfolk & Western Ry | 322 |
| [167]. | Relining Timber-Lined Tunnel, Norfolk & Western Ry | 323 |