. The street railway review . he handled onthe stub. Now, C = 3,600 -=- M, as in the study of (i) .d M = (2 T -f T -^ N) + I (2) Since the stop enters but once, and the groups of N cars musteach wait until the preceding group has cleared the inbound trackbefore proceeding. (In the case of the loop, the diflfercnt groups ofN cars can follow each other directly upon the inbound track.) From (i) and (2) we have C = 3,600 N ^ (2T -)- T -F NI) (3) But, T = D H- (S + ) (4) So thatC = 5,280 S N H- [2 D -f (S T X 1466) -f (S N I X )]. (s)In cases where I may be neglected, equation (5
. The street railway review . he handled onthe stub. Now, C = 3,600 -=- M, as in the study of (i) .d M = (2 T -f T -^ N) + I (2) Since the stop enters but once, and the groups of N cars musteach wait until the preceding group has cleared the inbound trackbefore proceeding. (In the case of the loop, the diflfercnt groups ofN cars can follow each other directly upon the inbound track.) From (i) and (2) we have C = 3,600 N ^ (2T -)- T -F NI) (3) But, T = D H- (S + ) (4) So thatC = 5,280 S N H- [2 D -f (S T X 1466) -f (S N I X )]. (s)In cases where I may be neglected, equation (5) becomes C = 5,280 S N -^ (2 D -f ST) (6) Fig. 3 represents a typical stub track, and Fig. 4 shows the trafficcapacity of three stubs, 300 ft., 150 ft. and 75 ft. long, respectively,for comparison with the loops of Fig. 2. For the sake of simplicitythe value of I is assumed equal to zero. As one would naturally expect, the capacity of a stub track ofequal platform length with a loop track, operating under similar ^S?. C^yfS ^£^/P//Oa/P=C ^o FIG. 2—TRAFFIC CAPACITY IN CARS PER HOUR. conditions of car size, speed and duration of stops, is always muchless than that of the equivalent loop. Thus, with 20-second stops,the 7S-ft. loop handles 255 cars per hour, against 195 on the stub,a difference of 31 per cent in favor of the loop. With 30-secondstops, the 75-ft. loop handles 190 cars per hour and the stub 153,the difference being but 24 per cent. Comparing 10-second stops onthe 300-ft. loop and stub, we find that the loop has an advantage ofnearly 81 per cent, while on the 25-second stop it has an advantageof but 58 per cent. This leads to the general conclusion that an in- Niiv. 15, IxiS. STREET RAILWAY REVIEW 801 crease in tlic IciiRtli of stop rapidly cuts down the advantage of tlicloop in comparison with the stnl) tracl< of equal length, and thatthe difference in traffic capacity of loops antl stnhs grows smallerand smaller and of less advantage to the loop as the
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Keywords: ., book, bookcentury1800, bookdecade1890, booksubjectstreetrailroads
