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34 Appendix H Total Brake Force Graphs from DOT DOT provided the two brake force graphs presented below in response to the committeeâs request. The graphs present the total brake force buildup across 100 cars for ECP brakes versus conventional brake systems (Figure H-1) and ECP brakes versus DP or EOT systems (Figure H-2). According to DOT, the graphs illustrate a significant advantage attributable to the ECP brake system. In addition, the graphs present the best possible case for DP or EOT systems relative to ECP, because the derailment initiates at the head end of the train. The benefits attributable to DP or EOT systems relative to ECP will drop off for derailments that initiate farther back in the train.23 FIGURE H-1. According to DOT, there is a significant benefit to ECP brakes in total momentum removed from the train, especially in the initial several seconds (critical time). The advantage for ECP brakes at 10 seconds after initia- tion is about 46 percent. This advantage tapers to about 22 percent at 20 seconds. 23DOT Response to NAS Letter Report on Electronically Controlled Pneumatic Brakes: Total Brake Force Plots, dated July 12, 2017, received from Kevin Kesler (DOT) on July 13, 2017. 0 20 40 60 80 100 120 0 5 10 15 20 25 Pe rc en ta ge  o f T ot al  T ra in  B ra ki ng  F or ce  (% ) Time (s) Total Train Braking Force ECP Conventional Difference
