. Electric railway journal . ■=v. That is, L : I = \/im • the negative feeder tap point through half the resist-ance of the particular section of the track as shown inthe above formulae. Transposing the above equations ~2T \~2~e or _L~T This distribution of current and of voltage drop is asshown in Figs. 1 and 2. In Fig. 1 are illustrated theconditions for equal sub-section lengths and equal in-tensity of loading, while Fig. 2 is for unequal the lower parts of the figures the directions of thecurrents are shown by the arrows. Point X is the tap-ping point for the negative feeder and
. Electric railway journal . ■=v. That is, L : I = \/im • the negative feeder tap point through half the resist-ance of the particular section of the track as shown inthe above formulae. Transposing the above equations ~2T \~2~e or _L~T This distribution of current and of voltage drop is asshown in Figs. 1 and 2. In Fig. 1 are illustrated theconditions for equal sub-section lengths and equal in-tensity of loading, while Fig. 2 is for unequal the lower parts of the figures the directions of thecurrents are shown by the arrows. Point X is the tap-ping point for the negative feeder and Y and Y arethe artificial dividing points where the direction ofcurrent reverses. The following keys will be useful ininterpreting the figures. Fig. 1 X = negative feeding point, Xa — potential at feeding point,Y, Y = artificial dividing points,0, 0 = neutral or zero potential points,Yc, Yc = loading or current distribution,Yd = potential at dividing points,L, I = lengths of subsections. Yb. P Points for tapping voltmeterpilot wires from the power-he Pi Points for tapping voltmeterpilot wires from the substation Tw □ Collies 073,000 C. M z Electric Ry. Journal Fig. 2 as in Fig. 1 excepting that Xc, Xc = respective sub-section loadings. In both figures Yb -f- Xa = Yd -f- Xa = section voltage drop, e. By the above method we obtained a number of pointson the system corresponding to X in the diagrams,which should constitute tapping points on the rails forthe negative feeders. The voltage midway betweenthese points should be seven with equal loading inten-sity. After the best points for the taps were foundtheoretically they were readjusted, where necessary, tofit junction points on the track, to keep the current den-sity in the rails at a minimum value. For the presentscheme a density of 13 amp to 14 amp per square inchwas arranged for. The rails are all bonded togetherat junction points and the respective rails are bondedtogether for 55 yd. and cross-bonded for 110 yd. The
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