ONE HUNDRED AND FIFTY MILES IN SIXTY MINUTES.

Press, Volume LIII, Issue 9321, 23 January 1896, Page 6

ONE HUNDRED AND FIFTY MILES IN SIXTY MINUTES.

4> Charles 11. Cochrane, in LinpincoWs Magazine, {U.S.) It is generally conceded that sixty miles ; an hour i 3 the practical limit of speed on steam railways, as at present constructed, j It is rather startling, therefore, to be told that a company lias been formed and that capital has been obtained for the purpose of j erecting a railway which "will bear trains at double this speed. A hundred and twenty miles an hour is a speed that, if maintained, j would carry one around the world in a trifle ■ over eight days. It is faster than the hurricane, the carrier-pigeon, or anything J else that moves upon this mundane sphere. Yet the National Rapid Transit Company is asking the United States Senate for | privileges looking to the establishment of a line between New York and Washington, and specifying in the proposed bill that the schedule-time shall not be less than 100 miles an hour, which necessitates a speed of 120 miles per hour to cover loss from stops. Further, the General Electric Company of New York is willing to guarantee motors, generators, and other electric mechanism for such a road, warranting them to maintain a speed of 150 (note the fifty) miles an hour when delivering a hundred horse-power per motor, with two motors per car. All this is possible through what is known as the Brott rapid transit system. This system makes use of what is miscalled a bicycle railway. It is not a bicycle construction in any proper usage of the word, which means two wheels; but the likeness to the bicycle is found in the fact that the supporting wheels are in line and run on a single rail, instead of on a parallel track, as~ in the ordinary railway. It is an elevated road, as no chances can be taken with grade crossings. The supporting wheels —or traction wheels, as they are called—have very wide flanges, to keep them on the track, and balance is assured by side wheeb which may occasionally touch the side stringers if the cars oscillate a littleIt is well known that a body running on wheels arranged in a line tends to remain upright, so that these side wheels will have little to do except when a train is starting or stopping. These side wheels are to have pneumatic tires, to prevent jar to the passengers when they impinge against the stringers. The cars are to be made of steel and vulcanised timber. The electric motors will be of the gcarless type, operating directly on the axle, one on each side. The electric current will be taken from a conductor on the trolly principle, and powerstations will be erected about fifty miles apart to supply the current by feeder-wires to intervening points. The conductor, which will be almost too large to be termed a wire, will probably be carried under the cars instead of overhead. It will deliver the current to the car-motors at a pressure of 1,000 volts, double that vised on streetrailways. The generators at the powerstations will develop it at 10,000 volts, and transformers will be used to reduce it as it readies the conductors. The three-phase alternating current system will be used. The elevated double-track construction is such as to mutually brace the tracks. An even grade will be maintained by simply altering the length of the poles, which will be cheaper than the building of embankments and cuttings necessary in the construction of surface-roads. An almost absolutely straight line will be preserved, as curves interfere with speed. The supporting poles will be about 25ft apart, and will be set into underground sills and braced below the frost-line. Light trains, preferably of two cars, will be run, and as the system is entirely express, a higher rate of fare may be expected than is charged on existing lines.

An experimental single-track line of thirty miles is to be built between Washington, D.C., and Chesapeake Bay. The construction is most economical, requiring no iron or steel except for the track-rails, It should be observed that the cross-sill or tie rests on the gronnd, and to it are secured the posts that support the stringers and side rails. The centre stringer has supports midway of each span, and being so near the surface the roadway will have all the strength and stability required. The centre rail will have normally an elevation of about two feet, except at road crossings, where it will be elevated to afford passage underneath. The cross-ties may lie on the ground or be elevated, as the nature of the ground renders desirable. A steel-truss construction will be used in crossingriversordeep gullies. The wood used in construction is to be subjected to a preserving process. The peculiar storey-and-a-half design of the car is noteworthy, the half-storey being below, and constituting a room 40ft long, 6ft wide, and 4ft high, suitable for carrying baggage, the mails, &c. It is reached by outside doors. Above is the compartment for passengers. Another line is projected in the vicinity of Minneapolis. The simple construction would seem to be well suited for pleasure railways and light passenger traffic, and the success of these lines would undoubtedly lead to the construction of express lines between the great business centres of the world.

It is interesting to consider the reasons for believing that it is practicable to maintain the hi«h speeds possible with this system. The principal resistance to speed is, of course, frictional, and in the case of a railway is of three sorts —flange friction. Journal friction, and rolling friction. As »

bicycle rail-car will tend to stand upright without mechanical assistance, the side friction of the flanges \rill be reduced to a minimum. A reduction in the curves of the track will also effect a saving, and between the two the saving of flange friction ought to be at least seventy-five per cent. Journal friction can be reduced in about the same proportion by using modern steel ball-bear-ings. Rolling friction can be reduced by the use of lighter cars. It does not amount to much, anyway. Locomotives have a reciprocating motion of the pistons that cannot approach in speed the rotary motion of an electric motor. With every stroke the piston and connections have to come to a dead halt and be reversed. A rotary motion is continuous, and in practice admits of certainly twelve times the speed obtainable with an equivalent reciprocating mechanism. Improved tracks, having no severe grades or curves, w ill do the rest.

How about the resistance of the air ? some one will query at this point. It is scarcely worth figuring on. If air-resistance increased with the square of the velocity, as many have maintained, how would it be posssible to fire a projectile twelve miles with a single impulse ? It is now claimed that it does not increase in that ratio. Mr P. O. Crosby has demonstrated that air-pressure increases with the velocity, so that at 160 miles an hour there would be twice the resistance at sixty miles an hour. It remains to bo seen whether his conclusions will be accepted by physicists ; but, whatever this resistance may amount to, it is in practice reducible about two-thirds by making the forward end of the train in the form of a pointed cone, so that the air simply glances off.