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| Re: Why Do I Call It Bullshit? (1645372) | |||
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Re: Why Do I Call It Bullshit? |
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Posted by Stephen Bauman on Mon Nov 24 07:08:55 2025, in response to Re: Why Do I Call It Bullshit?, posted by Train Dude on Mon Nov 24 00:38:55 2025. Hence during an emergency brake application on the williamsburg bridge, the signals did not provide a large enough block for an emergency brake application.I've discussed this before. The NTSB ran fully instrumented braking tests on the WB. The results were printed in the report. These results showed the speed when emergency brakes were applied and the distance it took to stop the train. It's possible to determine the braking rate from this data and the fact that the train was on a 2% uphill when emergency brakes were applied (also in the NTSB report). Based on this input, the emergency braking rate was something like 1.6 mph/sec, not the 3.0 mph/sec +/- 30% spec. Had the brakes been within spec, a collision would have been avoided by something like 50 ft. The explanation you just gave might be true but was not sufficient to cause the collision. Another design fault concerns the introduction of the R10's. They introduced higher speeds over pre-war equipment (BMT Multi's and experimentals excepted). Given the higher speeds, there was an equal design obligation to increase emergency braking rate so that the faster equipment was compatible with the signal system. That wasn't done. They actually made things worse by not applying the dynamic brakes during emergency application. It's important that the air brakes alone should be sufficient to stop the train but that's not an excuse not to apply the dynamic brakes during an emergency brake application. The NTSB did run a test when full service braking was applied, instead of emergency braking on the WB. The train came to a halt something like 150 ft short of a collision. |
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