MARIENFELDE-ZOSSEN ELECTRIC-RAILWAY TRIALS. 325 



The collectors. — The collectors are constructed according to the sys- 

 tem developed by the Siemens & Halske Company on their Gross- 

 Lichterfelde experimental track; they are nearly identical on both 

 cars, differing- only as to the details. In the Siemens car they have 

 the form of two masts supported by the cars at either end and mov- 

 a])le around their vertical axis. These masts consist of two Mannes- 

 mann tubes, each about 200 millimeters in diameter, inserted one into 

 the other. B}' lueans of a crank acting on a double-toothed gearing, 

 any desired rotation of the masts may be effected from the motorman's 

 stand. The sliding rings are attached to an insulated tube. Contact 

 springs, screwed b}' means of hard-rubber insulators on a special flat 

 iron frame, are flxed to the three sliding rings. Into the insulating- 

 tubes and partly into the lower part of the collector, the upper tube is 

 slipped, so as to be readil}" dismounted after loosening a few screws. 

 This tube bears, at central distances of 1 meter each, three rotating 

 axles for the contact bows proper. The wind pressure against the bow 

 on one side of the rotating axle is balanced by means of a vane attached 

 to the other side of the axle. The Allgemeine Elektrizitilts Gesell- 

 schaft car is likewise fitted with two groups of three collectors each, 

 one for each phase, which, however, instead of being placed on one 

 common mast, are arranged one behind the other. Both arrangements 

 have so far given full satisfaction, it being impossible to decide which 

 is the more available. Sparking between the overhead wires and the 

 collector bows, as occasionally noted in connection with the earlier 

 experiments, was recently prevented by some slight improvements in 

 the construction of the collectors. One of the most difficult problems, 

 namelv, the transmission of high amounts of energy from a stationary 

 conductor to a train running at enoi-mous speeds, has thus been satis- 

 factorily solved. 



The motor car^. — The two motor cars used with these trials were 

 constructed by Messrs. Van der Z,ypen & Charlier, Colognc-Deutz, in 

 accordance with the electric apparatus supplied by the two electric 

 firms. The cars, intended for about 50 passengers, are 21 and 22 

 meters in length, respectivel}^, and correspond as to their dimensions 

 and equipment with the technical regulations of the Association of 

 German Railwa}" Administrations. The body of the car rests b}^ 

 means of two center bolts on two trucks without any special springs. 

 In addition there are on the frames of each truck four steps limiting 

 the lateral oscillation of the body b}^ bearing part of the weight of the 

 car. Lateral oscillations of the body were moreover observed only 

 for lower speeds, up to 100 kilometers per hour, whereas with higher 

 speeds the run of the cars was perfectly steady, much more so than 

 with ordinary rapid trains. Each of the trucks is fitted with three 

 axles, the external axles bearing the motor, whereas the central ones 

 serve as runniny- axles. The distance between the axles was at the 



