The Impacts of The Number of Vehicles per TU 106 Impacts of Signal Block Length

# The impacts of the number of vehicles per tu 106

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The Impacts of The Number of Vehicles per TU 106

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Impacts of Signal Block Length The way capacity equations and their diagrams developed previously are based on the assumption that each TU has exact information about the location and movement of the TU ahead of it or leading TU at any time. The previous equations developed correspond to the zero block length (or continuous information, location and movement of LTU at any times), so they represent the highest achievable capacity for any given speed. For most signal-controlled rail systems, spacings between TUs are detected through block signals. Under control of block signal, the minimum headway that can be operated will increase with the length of blocks. 107
Impacts of Signal Block Length The more general equation for spacings including any lock length D : min min 1 g s s s D nl D For computation of minimum TU spacing, the ratio s D g min is rounded up to the next integer. Thus block signal control increases spacing between vehicles by a certain distance. The increase of spacing is at least equal to D when stopping distance is an integer multiple of block length. The increase of spacing is at most 2 D , when the ratio in non-integer. 108

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109
Train Control with Fixed Block Signal System At normal speed The closest position to the LT at reduced speed The minimum separation is one block length at reduced speed of the FT; and two block lengths at normal speed of the FT Initial Final position for each set of signal indication 110

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Minimum Spacings of Consecutive TUs for Block Signal Control The increase of spacing is D The increase of spacing is between D and 2 D (For Reference Only) 111