Part 12

As to the operation of the system in general, the current may be developed by single-phase, two-phase, or three-phase generators, and supplied to the transformer substations just as it was formerly supplied to the rotary converter substations. Only a single phase is used on any section of the trolley line. The voltage on this transmission line will depend upon the existing conditions, and can be figured out like any other problem in power transmission.

[Illustration: Truck Complete with Single-Phase Motors and Contact Shoes.]

Three-phase generators would ordinarily be used, as less copper is required to supply a given amount of power. The common frequency is 25 cycles per second. At the transformer stations, the voltage is then stepped down to that required on the trolley, which may be 2,000, 3,300, 6,600, or even 11,000 volts. While we cannot speak yet of a standard voltage, 3300 seems to be finding considerable favor. The voltage for which the motors are wound is 200 or 250, the General Electric motors using the former voltage, and the Westinghouse the latter. When operating on alternating current the motors are connected in parallel, and when running on direct current they are connected in series. Motors have been constructed from 50 to 225 horsepower, and there is no apparent reason why larger ones could not be made to operate with equal satisfaction.

[Illustration: Magnetic Speed Indicator.]

Among the roads in this country which are either using, or planning to use single-phase current, may be mentioned the Ballston-Schenectady line, which was one of the first systems to be equipped and has been in successful operation for some time. This road uses the alternating-current motor developed by the General Electric Co. The motors are adapted for operation on the 2,000-volt alternating-current trolley between cities, and on the standard 600-volt direct current in Schenectady. They are wound for 400 volts, and are operated in series on the 600-volt direct current. The frequency used is 25 cycles. Current is supplied by an overhead trolley, no feeders being used.

A second road of importance is one in Georgia between Atlanta and Marietta, which is 15 miles in length. This uses the Westinghouse equipment. The current on the trolley is 2,200 volts and 25 cycles. It is transmitted at a voltage of 22,000.

Another road of importance is the Indiana and Cincinnati interurban line, 41 miles in length, which has been in operation on regular schedule since July 1st, 1905. For 37 miles the road is operated from alternating current, and for 4 miles, from direct current. Four 75-horse power motors per car are used, capable of a maximum speed of 65 miles per hour.

[Illustration: Armature Quill.]

The Bloomington, Pontiac and Joliet Electric Railway is a single-phase road equipped with General Electric apparatus, and has maintained a regular schedule over a distance of more than 10 miles since March, 1905.

The plans are now being laid for a single-phase road, which will run south from Spokane, Washington, a distance of 150 miles. The current on the transmission line is 45,000 volts, which is stepped down to 6,600 on the trolley. The car will be capable of operating on current from a 6,600-volt alternating, a 700-volt alternating, or a 575-volt direct-current supply.

Perhaps the most important move which has been made in the direction of single-phase traction thus far is the decision of the New York, New Haven, and Hartford road to establish a long-distance passenger traffic on the single-phase system. According to the latest plans this road will operate between the Grand Central Depot and Woodlawn, N. Y., over the terminal tracks of the New York Central road, on direct current taken from the trolley. From Woodlawn, N. Y., to Stamford, Conn., the road will be operated on the single-phase system.

[Illustration: A Pair of Drivers with Single-Phase Motor Mounted upon Quill.]

The equipment is being supplied by the Westinghouse Co. The current is generated by revolving-field type turbine-driven alternators. The armatures are designed for either three-phase or single-phase connection. The current is generated at 25 cycles and 11,000 volts, being delivered directly to the trolley, and thence to the cars, without the intervention of any transformers. The double catenary suspension from messenger wires is used to support the trolley. The locomotives are each equipped with four 200-H. P. gearless motors, designed to operate on 235-volt alternating current and 275- to 300-volt direct current. The armature is not mounted on the shaft direct, but is built upon a quill through which the axle passes with about ⅝-inch clearance all around. There is a flange at each end of the quill from which seven pins project and fit into the hubs of the driving wheels. On the direct-current part of the line, current is delivered to the car through eight collecting shoes from a third rail. On the alternating-current section, current is delivered through two pantograph bow trolleys. On the direct-current section the series-parallel method of speed control is used, current being fed directly to the motors which are connected two in series permanently and the series-parallel control is applied to the motors in groups of two. The alternating-current speed control is accomplished by six taps from an auto-transformer for the corresponding running points. The cars weigh 78 tons and are capable of a speed of 60 to 65 miles per hour. The electro-pneumatic unit-switch type of control is used. At each end of the cab is a master controller from which the main controller is operated. Several locomotives can be operated together on the multiple-unit system, if desired.

[Illustration: Six-Unit Switch Group, Single-Phase System.]

The Washington, Baltimore and Indiana single-phase road is the latest in the field, contracts having been placed very recently. The current will be transmitted at 33,000 volts and 25 cycles, then being stepped down to 6,600 volts on the trolley. The road will be 60 miles long and will be equipped with General Electric apparatus. Four 125-H. P. motors capable of operating on either alternating current or direct current will be used, and the cars will be capable of a speed of 60 miles per hour.

INDEX

Air brakes, 56

Air compressors, 57 automatic governor for, 57 Westinghouse, 58

Alternating-current generators, 105

Alternating-current switchboards, 110

Alternating-current systems, 113 single-phase motors, 114 three-phase motors, 113

Alternating-current transmission, 99

Armature coils, 8

Armature leads, 9

Armature tests for grounds, 133

Armature winding, 5 defects of, 124 mistakes in, 126

Automatic governor for air compressors, 57

Ballast, 85

Bearings of railway motors, 13

Block signals for electric railways, 94

Bond testing, 120

Bonding and return circuits, 88

Booster feeder, 98

Brackets, 75

Brake leverages and shoe pressure, 54

Brake rigging, 53

Brake shoes, 64

Brush holders, 10

Brushes, 10

Burn-outs, 123

Canopy switch, 39

Car, failure of to start, 127

Car bodies, 67

Car circuit breaker, 39

Car construction, 67

Car equipment, 3

Car heaters, 34 electric, 34 hot-water, 36

Car painting, 72

Car repair shops, 134

Car weights, 72

Car wheels, 51

Car wiring, 37

Cast-welded joints, 87

Coefficient of friction, 65

Common T-rail, 84

Commutator type single-phase motor, 139

Compressors, 57

Conductivity of steel rail, 80

Conduit systems, 81 contact plow, 82 cost of, 82 current leakage, 83

Contact plow, 82

Contact shoes, 45

Controller construction, 19

Controller notches, 27

Controller wiring, 20

Controllers, 16

Cost of power, 119

Couplers, 66

Current required to heat cars, 35

Current leakage, 83

Defects of armature windings, 124

Direct-current feeding, 98

Double-current generators, 105

Drawbars, 66

Economy in power, 118

Electric car accessories, 39 canopy switch, 39 car circuit breaker, 39 contact shoes, 45 fuses, 41 lamp circuits, 43 lightning arresters, 41 trolley base, 44 trolley poles, 44 trolley harp, 45 trolley wheels, 44

Electric cars, road tests of, 117

Electric heaters for cars, 34

Electric railway, 1

Electrically welded joints, 87

Electrolysis, 95 prevention of, 97

Feeder panel, 110

Feeder systems, 92

Feeders, 75

Field coils, 8

Field tests for grounds, 133

Four motors, 19

Fuse blows, 130

Fuses, 41

Gearing, 12

G. E. electric brake, 61

G. E. train control, 29

Generator, starting up, 108

Generator D. C. panels, 106

Generators, 105

Girder rail, 83

Grounds, 123

High-tension lines, 77

High-tension oil switches, 111

Highway crossings, 80

Hot-water heaters for cars, 36

Insulators, third rail, 79

Interurban railway, system of distribution for, 101

Joints for rails, 86

Lamp circuits, 43

Lightning arresters, 41

Locating defects in motor and controller wiring, 128

Location of power houses, 101 third rail, 79

Lubrication of railway motors, 13

Magnetic blow-out, 26

Maximum traction trucks, 51

Momentum brakes, 59

Motor leads, 9

Motor suspension, 14

Motor-coil testing, 121

Motors, 3 as emergency brakes, 63 of the New York Central electric locomotive, 15

Multiple-unit control, 29

Oil switches, high tension, 111

Open-circuit tests, 128

Opening cases for inspection, 10

Overhead construction, 73 brackets, 75 feeders, 75 high-tension lines, 77 section insulators, 76 span wires, 74 trolley wire, 73 trolley-wire clamps and ears, 73

Potter third-rail shoe, 46

Power cost of, 119 economy in, 118 taken by cars, 115

Power house location, 101

Power stations, general plan of, 105

Power supply and distribution, 98

Railway motors bearings, 13 brushes, 10 characteristics of, 3 gearing of, 12 lubrication of, 13

Rate of retardation in braking, 66

Resistance of track, 91

Resistances, 38

Return feeders, 92

Reversal of motor, 26

Reversed fields, 133

Rheostat control, 17

Road tests of electric cars, 117

Sectional insulators, 76

Series-parallel control, 17

Shanghai T-rail, 84

Short-circuit tests, 130

Single trucks, 48

Single-phase electric railway, 136

Single-phase motors, 114, 139

Sleet on trolleys and third rails, 46

Sliding and spinning wheels, 119

Span wires, 74

Sparking at the commutator, 127

Sprague multiple-unit system of control, 29

Steel car framing, 71

Storage air brakes, 58

Storage batteries in stations, 113

Street railway motors, general data on, 6

Supplementary return feeders, 92

Swing bolster trucks, 49

Switchboards, 106 alternating-current, 110

Switches, third rail, 79

Swivel trucks, 48

T-rail, 84

Thermit welding, 88

Third rail, 79 advantages in operation, 80

Third rail conductivity of, 80 cost of, 80 highway crossings, 80 insulators for, 79 location, 79 switches, 79

Three-phase motors, 113

Track brakes, 63

Track construction, 83

Track resistance, 91

Track sanders, 65

Track support, 85

Transmission systems, efficiency of, 101

Trilby groove rail, 84

Trolley base, 44

Trolley harp, 45

Trolley poles, 44

Trolley wheels, 44

Trolley wire, 73

Trolley-wire clamps and cars, 73

Trucks, 46 maximum traction, 51 single, 48 swing bolster, 49 swivel, 48

Type L controllers, wiring of, 24

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Transcriber’s Notes:

• Text enclosed by underscores is in italics (_italics_). • Text enclosed by equals is in bold (=bold=). • Text enclosed by pluses is in small caps (+small caps+). • Obvious typographical errors have been silently corrected.