A manual of the principles and practice of road-making : comprising the location, construction, and improvement of roads (common, macadam, paved, plank, etc.) ; and rail-roads

Front matter

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Preface

Tlie common roads of the United States are inferior to those of any other civilized country. Their faults are those of direction, of slopes, of shape, of surface, and generally of deficiency in all the attributes of good roads. Sonne of these defects are indeed the unavoidable results of the scantiness of capital and of labor in a new country, but most of them arise from an ignorance either of the true principles of road-making, or of the advantages of putting these principles into practice. They may therefore be removed by a more general diffusion of scientific instruction upon this subject, and to assist in bringing about this consummation is the object of the present volume. In it the author has endeavored to combine, in a systematic and symmetrical form, the results of an engineer, ing experience in all parts of the United States, and of an examination of the great roads of Europe, with a careful digestion of all accessible authorities, an important portion of the matter having never before appeared in English. He has striven to reconcile the many contradictory theories and practices of road-making ; to select from them those which are most in accordance with the teachings of science ; to present as clearly and precisely as possible the leading features of those approved, laying particular stress on such as are most often violated or neglected ; and to harmonize the successful but empirical practice of the English engineers with the theoretical but clcijant deductions of t'.U' French.

4 PREFACE. !

Before the construction of a road is commenced, its makers should well determine " What it ought to ie," in the vital points of direction, slopes, shape, surface and cost. This is therefore the first topic discussed in this volume. The next is the " Location^' of the road, or the choice of the grouna over which it should pass, that it may fulfil the desired conditions. In this chapter are given methods of performing all the necessary measurements of distances, directions and heights, without the use of any instruments but such as any mechanic can make, and any farmer use. The " Construction^' of the road is next explained in its details of Excavation, Embankment, Bridges, Culverts, &c. At this stage of progress our road-makers too generally stop short, but the road should not be considered complete till " The Improvement of its surface'^ has been carried to as high a degree of perfection as the funds of the work will permit. Under this head are examined earth, gravel, McAdam, paved, plank and other roads. ^^ Rail-roads,'^ and their motive powers, are treated of in the next chapter. The '* Management of town roads''' is last taken up, the evils of the present system of Road-tax are shown, and a better system is suggested. In the " Ajypendix^' are minute and practical examples of tbe calculations of Excavation and Embankment.

To enable this volume the better to attain its aim of being doubly useful, as a popular guide for the farmer in improving the roads in his neighborhood, and as a College Text-book, introductory to the general study of Civil Engineering, the mathematical investigations and professional details have been printed in smaller type, so as to be readily passed over by the unscientific reader.

The principal additions to the Second Edition were an original Formula for the Calculation of Earthwork (pages 360 to 363), and Tables for the same object.

The present Third Edition contains 30 additional pages, giving the practical details of the construction of Plank Roads (pages 230 to 253), and the results of the latest experiments on the Resistances upon Rai/roads, on Curves, Ascents, &c., (i)ages 26-4 to 278.;

AUTHORITIES REFERRED TO.

Alexander. Amer. Ed. of Simms on Levelling, Baltimore, 1837.

Annales des Fonts et Chanssees, Paris.

Anselin. Experiences sur la main-d'oeuvre des difFerens travaux, Paris.

Bahbage. Economy of Machinery and Manufactures, London, 183L

Berihauli-Ducraux. De I'Art d'entretenir les Routes, Paris, 1837.

Bloodgood. Treatise on Roads, Albany, 1838.

Chevalier. Les voies de communication aux Etats Unis, Paris, 1843

Civil Engineers' and Architects' Journal, London.

Cresy. Encyclopedia of Civil Engineering, London, 1847.

Davles. Elements of Surveying, &c., New York, 1845.

Delaistre. La Science des Ingenieurs, Paris, 1825.

Dupin. Applications de Geometrie, Paris, 1822.

" Travaux civils de la Grande Bretagne, Paris, 1824. Eaton. Surveying and Engineering, Troy. Edgeworth. Construction of Roads and Carriages. Flachat ^ Bonnet. Manuel et Code des Routes et Chaussdes, Paris. Frame. Trigonometrical Surveying, London, 1840. Gayffier. Manuel des Ponts et Chaussdes, Paris, 1844. Gerstner. Memoire sur les grandes routes, Paris, 1827. Grieg. Strictures on Road-police, London. Griffith. On Roads, London.

Hughes. Making and Repairing Roads, London. Journal de I'Ecole Polytechnique, Paris. Journal of the Franklin Institute, Philadelphia. Jullien. Manuel de j'ingenieur Civil, Paris, 1845. Laws of Excavation and Embankment on Railways, London, 1840. Lecouiit. Treatise on Railways, London, 1839.

Mncneill. Tables for calculating Cubic quantities of Earthwork, London Niihan. Course of Civil Engineering, New York, 1846. Mirlette. Manuel de I'Agent-voyer, Paris, 1842. MrAdiint. System of Road-Making, liondon, 1825.

6 AUTHORITIES.

Millington. Civil Engineering, Philadelphia, 1839.

Morin. Aide-Memoire de Mecanique, Paris, 1843.

Moscly. Mech. principles of Engineering and Architecture, London, 1843

Navie.r. Travaux d'entretien des Routes, Paris, 1835.

" Application de la Mecanique aux constructions, Paris.

Nimmo. On Roads of Ireland, &c.

Parnell. Treatise on Roads, London, 1838.

Paterson. Practical Treatise on Public Roads, &c., Montrose, 1820. Penfold. On Making and Repairing Roads, London, 1835. Poncelet. Mecanique Industrielle, Paris, 1841. Potter. Applications of Science to the Arts, New York, 1847. Railroad Journal, New York, 1832-1847. Renwick. Practical Mechanics, New York, 1840. Reports of U. S. Commissioner of Patents, Washington. Reports of U. S. Engineer Corps, Washington. Reports to Parliament on Holyhead roads, &.C., London. Ritchie, Railways, London, 1846.

Road Act of New York, Rochester, 1845. Roads and Railroads, London, 1839.

Sganzin. Course of Civil Engineering, Boston, 1837.

" Cours de Construction par Reibell, Paris, 1842.

Siinms. Telford's rules for making aiid repairing roads, London.

" Public Works of Great Britain, London.

" Sectio-Planography, London.

Stevenson. Civil Engineering of North America, London, 1838. Telford. Reports on Holyhead roads, London. Tredgold. On Railroads, London, 1835.

Wood. On Railroads, Philadelphia, 1832.

ANALYTICAL TABLE OF CONTENTS.

Paoe

Chapter I.— What Roads Ought To Be-- 25

1. AS TO THEIR DIRECTION 26

Importance of straightness ib

Advantages of curving ib.

Pleasure drives 30

2. AS TO THEIR SLOPES 32

Loss of power on inclinations ib.

Undulating roads 37

Greatest allowable slope 38

Considered as a descent ib.

" an ascent 40

Least allowable slope 43

Tables of corresponding slopes and angles 44

3. AS TO THEIR CROSS-SEOTION 45

Width ib.

Shape of the road-bed 48

Foot-paths, &c 53

Ditches ib.

Side-slopes of the cuttings and fillings 55

4. AS TO THEIR SURFACE M

Qualities to be sought t ib.

Smoothness and hardness ib.

Resistances to be lessened ib.

Elasticity ib.

Collision 59

Friction 60

3 CONTEXTS.

. P.voc

0. AS TO THEIR COST ,^

Comparison of cost and revenue ih.

Amount of Traffic 06

Cost of its transportation ih.

Profit of improving the surface 67

" *' lessening the length 68

" " avoiding a liill jft.

Consequent increase of travel 70

Chapter Ii.— The Locatiox Of Roads 72

1. AF.RANGEMENT OF HILLS, VALLEYS AND WATER-

COURSES 74

Line of greatest slope 75

Inferences from the water-courses 78

2. RECONNAISSANCE.. rl

3. SURVEY OF A LINE S6

Measurement of distances 87

" directions. 90

" heights 93

4. MAPPING THE SURVEY 101

Plot of the distances and directions ih.

Profile of the distances and heights 103

6. CALCULATING EXCAVATION AND EMBANKMENT 112

Preliminary arrangements 113

Seclio-Planography ib.

Tabular entries 115

Cubical contents 117

Balancing the excavation and embankment 118

Shrinkage ib.

Change of grade 119

Transverse balancing 122

Distances of Transport 123

7« ESTUtfATE OF THE COST 124

Earthwork ib.

Wages ib.

Quality 125

Land. Bridges, &.c 13"3

CONTENTS. 9

Page

8. FINAIi LOCATION OF THE LINE J34

Rectification 135

Curves 137

Circular arcs ]38

Parabolic arcs 1-13

Staking out the side-slopes 145

CHAPTER III.— CONSTRUCTION OF ROADS- 147 Problems on removing earth ib

Loosening ib.

Scraper or scoop 155

Barrow wheeling 156

Carts, etc J58

Deep cuttings 159

Spoil banks. 160

Side-slopes ib.

Tunnelling KU

Blasting ib.

Formation of banks ib.

Protection of slopes JG7

Swamps and bogs 1G8

Side-hills 169

Trimming and shaping 171

2. MECHANICAL STRUCTURES 173

Bridges ib.

Culverts and drains 178

Catchwaters, or Water-tables 180

Retaining Walls 182

Chapter Iv.— Improvement Of Their Surface 188

How to improve them ih.

Effects of wheels on their surface 191

2. GRAVELROADS 193

Directions for their construction ih

10 CONTENTS.

Page

3. BROKEN-STONE ROADS 194

Mc Adam roads ib.

Fundnmental principles 195

Quality of the stone 196

Size of the broken stones 198

Breaking them 199

Thickness of the coating. 200

Application of the materials 201

Roiling the new road. 204

Keeping up the road 205

Repairing it 209

Specification ib.

Propriety of a pavement foundation 212

Foundation of concrete 215

4i PAVED ROADS 216

Pebble pavements ib.

Squared stone pavements 217

Foundations 218

Of sand. ib.

Of broken stones 219

Of pebbles ib.

Of concrete ib.

Quality of stone 220

Size and shape 221

Arrangement 222

Manner of laying 223

Borders and curbs 224

Advantages. 225

Paved and McAdam roads compared ib.

Roman roads 226

6. ROADS OF WOOD 228

Logs ib.

Charcoal 229

Plank 230

Blocks 254 contents: 1 1

Pagk

6. ROADS OF OTHER MATERIALS. 255

Bricks ib.

Concrete ib.

Cast iron ib.

Asphaltum 256

Caoutchouc ib.

Of stone ib.

Of wood 259

Of iron 260

CHAPTER v.— RAIL-ROADS 261

I. What Rail-roads ought to be 264

1. AS TO THEIR DIRECTION 270

Economy of straightness ib.

Evils of curves 271

2. AS TO THEIR GRADES 276

Loss of power on ascents ib.

Compensating power of descents 280

3. AS TO THEIR CROSS-SECTION 282

The broad and narrow gauge question ib.

Advantages of the broad gauge 283

Objections to it 284

The break of gauge 285

Width of road-bed 288

II. The Location of Rail-roads 290

III, The Construction of Rail-roads 291

1. FORMING THE ROAD-BED ib.

Excavations ib.

Tunnels 292

Ballasting 294

Bridges and viaducts 295

12 CONTENTS.

Page

2. THE SUPERSTRUCTURE i-97

Rails supported at intervals ib.

Their shape ib.

Their weight ib.

The distances of their supports ib.

Theii- end joints 300

Theirchairs 301

Stone blocks 303

Wooden cross-sleepers 304

Eails on continuous supports 305

Inclination of the rails 308

Elevation of the outer rail ib.

Sidings, crossings, &c 309

Single rail railroad 311

IV. The Motive powers of Rail-roads 312

1. HORSEPOWER. ib.

Table of power at different speeds ib.

2. STATIONARY ENGINES 313

A Broadway raUi-oad 314

History ib.

Principles 321

Speed and power 324

"Working expenses 826

Safety of travelling 828

Signals 331

4. ATMOSPHERIC PRESSURE 334

History of its application ib.

Description of present system 335

Advantages 338

COTS'TENTS. 13

Chapter Vi.— The Management Of Town Roads 341

The present Road-tax system 342

Its defects 343

"New system proposed 345

Appendix

Calculations of Excavatiox and Embankment 349

1. By averaging end areas. 350

Error in excess 351

2. By the middle areas 354

Error in defect 355

3. By the Prismoidal formula ib.

Proof of its correctness 356

Easier rules 357

Fonnula for a series of equal distances 360

Explanation of Tables 363

4. By mean proportionals 364

5. Calculation of irregular cross-sections ib.

Their mean heights 367

6. Tables for calculating Earth-work 369

Slopes H to 1; Base 20 ib.

Slopes 2 to 1; Base 20 371

MANUAL OF ROAD-MAKING.