MODERN TRAMWAYS

BELOW ABOUT 100 AUTOMOBILES PER 1000 OF POPULATION PUBLIC TRANSIT VEHICLES ARE NOT SERIOUSLY HAMPERED BY OTHER FORMS OF TRAFFIC. ABOVE THIS LIMIT, COMMERCIAL SPEED DECLINES RAPIDLY, ESPECIALLY IN TOWN CENTERS. IN SUCH CIRCUMSTANCES THERE IS NOT MUCH POINT IN ASKING CAR OWNERS TO USE PUBLIC TRANSPORTATION, AND TO BECOME EFFECTIVE AGAIN THE FACILITIES MUST GO UNDERGROUND. HOWEVER, FOR BUSES THIS IS IMPRACTICAL AS THEY THEN LOSE ONE OF THEIR PRINCIPAL ADVANTAGES OVER RAIL SYSTEMS, VIZ., MOBILITY. THE PRESENT ARTICLE IS AN ANALYSIS OF RESPONSES FROM 42 CITIES, 17 OF THEM IN GERMANY, ON THE FUTURE OF UNDERGROUND TROLLEYS. THE SURVEY WAS PROMPTED BY THE FACT THAT BETWEEN 1970 AND 1985 THE 20 TROLLEY COMPANIES STILL OPERATING IN POLAND, WHERE THE AUTHOR IS A PROFESSOR AT THE WARSAW POLYTECHNIC INSTITUTE, WILL NEED TO PURCHASE NEARLY 3000 NEW MOTORCARS TO REPLACE WORN OR OBSOLETE EQUIPMENT. ANSWERS WERE SOLICITED IN THE FOLLOWING CATEGORIES: COMPOSITION OF THE VEHICLE FLEET (RIGID-BODY AND ARTICULATED MOTORCARS, TRAILERS), CAR DIMENSIONS, COMPOSITION OF SETS, MULTIPLE CONTROL, TRACTION MOTORS, CONTROL, SPEED, BRAKING, AND CONTROL SYSTEMS. THE RESPONSES ARE SUMMARIZED AS FOLLOWS: (1) COMPANIES THAT HAVE RETAINED TROLLEYS HAVE UNDERTAKEN EXTENSIVE MODERNIZATION PROGRAMS. ONE-THIRD OF THE MOTORCAR FLEET IS ALREADY REGARDED AS MODERN BY THE COMPANIES. HOWEVER, AS THESE HAVE HIGH CAPACITY, THEY ACCOUNT FOR ABOUT HALF OF PASSENGER CAPACITY. (2) MOST OF THE NEW CARS ARE OF THE RIGID-BODY TYPE MOUNTED ON TWO BOGIES; ABOUT ONE-THIRD OF THE NEW FLEET CONSISTS OF SINGLE- OR DOUBLE-ARTICULATED MOTORCARS. (3) TWO-THIRDS OF THE NEW CARS ARE PROVIDED WITH AUTOMATIC CONTROL, THE MAJORITY BEING OF THE PCC (ACCELERATOR CONTROL) TYPE; OF THE LATTER, 75% ARE OPERATED BY TWO COMPANIES. (4) WHILE A LARGE NUMBER OF AUTOMATIC CONTROL SYSTEMS ARE IN USE, THE "CHOPPER" (THRYISTOR) SYSTEM WITHOUT STARTING RESISTORS HAS SEEN ONLY EXPERIMENTAL USE. (5) ALL THE ROLLING STOCK IS FITTED WITH ELECTRODYNAMIC (RHEOSTATIC) BRAKES. MOST CARS ARE ALSO EQUIPPED WITH ELECTROMAGNETIC RAIL BRAKES. THIRTEEN COMPANIES OPERATE CARS FITTED WITH PNEUMATIC OR HYDROPNEUMATIC BRAKES.

Subject/Index Terms

Filing Info

  • Accession Number: 00241537
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Dec 30 1971 12:00AM