ENGINEERING. 



247 



A plan has been adopted for a circular ele- 

 vated railroad around the city of Vienna, to 

 pass through all the suburbs and to connect 

 with all the railroads entering Vienna. This 

 will transform Vienna from the most deficient 

 capital in Europe in facilities for local transit 

 to one of the best- appointed cities in the world 

 in this regard. Such a scheme can be carried 

 out with less destruction of property in Vienna 

 than in any other city. It will pass nearly the 

 entire way through waste lands on the bank 

 of the Danube Canal and the river Wien, and 

 the long strip of common along the projected 

 Gurtelstrasse Boulevard. The remaining por- 

 tion passes through one of the old and squalid 

 quarters of the city. The Franz Josefs Quai 

 Park on the bank of the Danube Canal is chosen 

 as the site of the central station. This is in 

 the very center of the business part of the city. 

 All the other stations are located with refer- 

 ence to street-traffic and the main arteries of 

 circulation. Along the canal the line is car- 

 ried over ground which is now unoccupied, on 

 an elevated structure which is so high that the 

 approaches to the bridges are in no way inter- 

 fered with. It crosses the Stubenring on an 

 ornamental viaduct to the left side of the river 

 Wien. As far as the slaughter-house on the 

 opposite side of the city from the central sta- 

 tion the road is elevated throughout. Beyond 

 that point it makes a sharp turn, and enters a 

 cutting in the common - land of the Gurtel- 

 strasse. Farther on it alternates between via- 

 ducts and cuttings, until near the Lunatic Asy- 

 lum it is carried through a tunnel about 1,500 

 feet long. It then proceeds through an open 

 cutting with retaining walls until it leaves the 

 route of the Gurtelstrasse and enters the 

 walls of the city again near the central station. 

 The total length of the proposed Ring Railway 

 is 12-844 kilometres, of which 7'572 is on via- 

 ducts supported by iron columns, 0'816 on ma- 

 sonry viaduct, 3-243 in cutting with retaining 

 walls, 0-470 in bank with retaining walls, 0-449 

 in tunnel, 0-085 in covered cutting, and 0-209 

 on the level. There are in the plan 19 sta- 

 tions, of which 15 are elevated and 4 sunk. 

 The line is to be double throughout. Branches 

 are to be constructed to form junctions with 

 all the railroad lines which converge at Vi- 

 enna. The total length of the main circuit and 

 branches together is about 28J- kilometres, or 

 17 miles. In accordance with this plan, every 

 railroad terminating at Vienna will be brought 

 into communication, not only with the central 

 station but with all the other railroads. It 

 will give to each railroad, in addition to its 

 own terminus, 19 stations in the circumference 

 of the city. The present facilities for reaching 

 Vienna by rail are inconvenient in the extreme, 

 but this plan would render them superior to 

 those of any other city. Every part of the 

 city will in like manner be connected with all 

 the other districts and with the railroads. The 

 importance of the connection of the capital by 

 this means with every railway in Austria from 



a strategical point of view has commended the 

 scheme especially to the military authorities. 

 The maximum gradient is one in 60, the mini- 

 mum radius 200 metres. In the neighborhood 

 of the Danube Canal and the river Wien costly 

 foundations will be necessary. It is proposed, 

 where the foundations will be entirely hidden 

 under the surface, to sink shafts, timber them in- 

 side, and fill themup withbeton. TheStubenring 

 and the approaches to the Tegethoff, Schwarz- 

 enberg, and Elizabeth bridges are crossed by 

 ornamental viaducts in which the main girders 

 are concealed by light cast-iron arches, so as 

 to render the crossing of such important streets 

 rather an architectural improvement than a 

 blemish on the beauty of the city. The main 

 span of the Stubenring viaduct is 80 feet, the 

 height above the roadway 16 feet 10 inches. 



The work on the Arlberg Tunnel is proceeding 

 at a more rapid rate than was attained on the 

 Mont Cenis or St. Gothard. The former was 

 bored at the rate of 1,112 metres ayear, the lat- 

 ter at the rate of 1,670, whereas the Arlberg is 

 expected to be pierced at the rate of 2,160 me- 

 tres a year. The cost as well as the speed of 

 mountain tunneling has been affected by im- 

 provements in engineering. Owing to the tech- 

 nical advances, but in a large measure also to the 

 comparative shortness of the bore, the cost per 

 lineal metre of the Arlberg Tunnel is estimated 

 at only $750, while the St. Gothard cost $1,250, 

 and the Mont Cenis $2,000. On the Austrian 

 side the same method of drilling employed in 

 the other tunnels is used. The perforators drill 

 twenty to twenty-five holes at one time, each 

 1 to 2 metres deep. They cover a space of 

 seven square metres. With each blast the 

 tunnel is lengthened 1J metre. The perfora- 

 tors move forward on wheels. The drills work 

 with quick strokes, the impulse being imparted 

 by compressed air at a pressure of five atmos- 

 pheres, supplied through flexible tubes. The 

 air is compressed by means of turbine water- 

 wheels at the end of the tunnel. On the west 

 side of the tunnel a new kind of perforator is 

 being tried. The drills have each a diameter 

 of 2| inches. They pierce the rock with a ro- 

 tary action given them by means of a water 

 pressure of from 60 to 100 atmospheres. These 

 perforators, with six or eight drills, accomplish 

 equal results with lighter charges of dynamite 

 as the pneumatic perforators with their twenty- 

 five or thirty chisels. After each blast the 

 loosened material must be removed. The 

 work of taking away the excavated material is 

 of equal magnitude as that of boring the rock, 

 and consumes as much time. The smoke of the 

 explosion in the unventilated space makes it 

 a difficult and dangerous task to remove the 

 rubbish after each blast. The miners in the 

 Arlberg have found that they can neutralize 

 the ill effects of the poisonous air to a consid- 

 erable extent by covering their mouths and 

 nostrils with sponges steeped in vinegar. The 

 work on the Arlberg Tunnel was commenced 

 in June, 1880. By July, 1881, the east gallery 



