472 Mr. Alexander Siemens [Feb. 26, 



During the year 1902 the speeds of the cars were not allowed to 

 exceed 125 km. per hour, as it had not been possible to arrange for 

 the relaying of the permanent way, but observations were made ou 

 air resistance at various speeds, and on tractive force for the cars 

 alone or when drawing other vehicles. 



Exact measurements were also taken of the electric losses in 

 feeders and conductors, and further trials were made with the brakes. 



Some trials were also run with an electric locomotive, constructed 

 by Siemens and Halske, for utilising three-phase currents of 12,000 

 volts direct in the motors, and dispensing with the heavy transformers 

 used on the motor cars. 



The locomotive succeeded in drawing a train of 11 carriages, 

 weighing 153 tons, at a speed of 51 km. per hour, when the current 

 had 45 periods and 12,500 volts pressure. 



At the time of the experiments it had been fitted with two motors 

 only, but eventually it will have four, and then it will be capable of 

 exerting about double the power. 



As the motors gave no trouble, and no difficulty was experienced 

 in handling these high tension currents, these trials show the possi- 

 bility of a very simple construction of main line electric locomotives. 



The result of the 1902 experiments was that some alterations in 

 the construction of the bogies of the motor cars were undertaken — 

 notably, the wheel-base was lengthened from 3*8 to 5*0 m. ; this 

 change involved a modification in the brake mechanism, which had 

 again failed to give satisfaction, and it also very much improved the 

 steady running of the cars at the very high speeds. 



In the beginning of last year the relaying of the permanent way 

 was commenced, and it was made equal to the standard permanent 

 way of the Prussian State Main lines for express traffic, with the 

 addition of guard rails. 



When the alterations to the motor cars had been finished, further 

 trial runs were made, during which the Siemens car attained, on the 

 15th of September, a speed of 145 km., and in the following week, on 

 the 23rd of Sej^tember, a speed of 175 km. 



During the latter run, as mentioned before, the collector did not 

 work satisfactorily, and a slight alteration was made in its construc- 

 tion. 



On the 26th of September the speed of the Siemens car reached 

 189 km., and on the 6th of October the speed of 201 km., or 125 

 miles per hour, was first accomplished. 



It is notable that the electrical appliances and connections of this 

 car remained exactly the same from 1901 to the present time. 



The car of the Allgemeine Elektricitiits Gesellschaft commenced 

 to run a few days later, aud attained, on the 28tli of October, the 

 maximum speed of 210*2 km. i)er hour, with a periodicity of 47*5 

 per second. During this run the conductor was damaged, and the 

 generating machinery rather strained. 



In consequence of this, the speed of further runs was somewhat 



