GojiMet86 Posted July 18, 2012 Share #1 Posted July 18, 2012 About 12 days, 1 month, 16 years ago, a train collided with the rear end of an train. A few months ago, I was looking around databases, and I came across two reports of the Williamsburg Bridge Collision of 1995. Recently, someone commented on a thread about the incident and I remembered the reports. Here they are, if you want to take a look: http://www.ntsb.gov/...996/RAR9603.pdf Here's a report on another collision between an train and a train a few days later: http://nara-wayback-...996/RAR9601.pdf Link to comment Share on other sites More sharing options...
TheSubwayStation Posted July 18, 2012 Share #2 Posted July 18, 2012 This is an incredible coincidence, as I was just looking at these NTSB reports a few days ago. The most valuable lesson learned from the crash was how the signal system wasn't effective at preventing rear-end collisions at that time. I'd like to believe that all areas of the system where signals were improperly spaced have since been fixed. Link to comment Share on other sites More sharing options...
Joe Posted July 18, 2012 Share #3 Posted July 18, 2012 It wasn't that the signal system wasn't effective, it's that the signal system was designed around certain parameters of the cars themselves. Once those parameters changed -- the signal system also required adjustment, but this was not done. Link to comment Share on other sites More sharing options...
TheSubwayStation Posted July 18, 2012 Share #4 Posted July 18, 2012 It wasn't that the signal system wasn't effective, it's that the signal system was designed around certain parameters of the cars themselves. Once those parameters changed -- the signal system also required adjustment, but this was not done. Yes. After the crash, they made the emergency brakes more powerful and slightly slowed down the SMEE equipment as has been discussed. Additionally, the spacing of some signals was changed, and timers were added in a few areas. Although, I think most of the timers were added as a result of the Union Square crash. Any timers that protect curves or switches are NOT a result of the Williamsburg Bridge accident. Link to comment Share on other sites More sharing options...
Joe Posted July 18, 2012 Share #5 Posted July 18, 2012 Slowing down the equipment did nothing in the way of attempting to prevent these types of crashes in the future. Link to comment Share on other sites More sharing options...
Joel Up Front Posted July 18, 2012 Share #6 Posted July 18, 2012 Didn't it have to do with the dimensions of B Division equipment after unification? Link to comment Share on other sites More sharing options...
TheSubwayStation Posted July 18, 2012 Share #7 Posted July 18, 2012 Slowing down the equipment did nothing in the way of attempting to prevent these types of crashes in the future. Why not? Link to comment Share on other sites More sharing options...
Mr Railfan Posted July 18, 2012 Share #8 Posted July 18, 2012 Yes. After the crash, they made the emergency brakes more powerful and slightly slowed down the SMEE equipment as has been discussed. Additionally, the spacing of some signals was changed, and timers were added in a few areas. Do you have a source for this? Link to comment Share on other sites More sharing options...
GojiMet86 Posted July 18, 2012 Author Share #9 Posted July 18, 2012 Didn't it have to do with the dimensions of B Division equipment after unification? The NYCT tests show that the train [R40 test train] attained an average speed of 36.1 mph at signal J2-128, which was higher than the maximum speed of 27.9 mph on which the signal spacing had been designed Then there's this: The spacing between signals on the Williamsburg Bridge was based on the R-9 car, an earlier class of car that is no longer in the NYCT fleet. Do you have a source for this? They increase the psi of the braking pressure on several cars. Adjustments made to the car's braking pressure varied with the type of car. In the case of the R40 cars, the pressure was increased to 30 psi +/- 2 for empty cars and 40 psi +/- 3 for fully loaded cars. Link to comment Share on other sites More sharing options...
Joe Posted July 18, 2012 Share #10 Posted July 18, 2012 The dimensions of the equipment was irrelevant. The entire signal system was dependent on the cars using cast iron brake shoes. Link to comment Share on other sites More sharing options...
Shortline Bus Posted July 18, 2012 Share #11 Posted July 18, 2012 The accident brought these important changes to the NYC subway. 1)Slower speeds for trains especially crossing the Manhattan and Williamsburg Bridges. 2)T/O's to pay more attention and avoid passing red lights. 3)Upgrades to signals systemwide. Link to comment Share on other sites More sharing options...
TheSubwayStation Posted July 18, 2012 Share #12 Posted July 18, 2012 Do you have a source for this? Yes. It's in the NTSB report that Gojimet86 included. The dimensions of the equipment was irrelevant. The entire signal system was dependent on the cars using cast iron brake shoes. And the older signals were built for slower trains, according to the NTSB report. Now, that isn't to say that the current SMEE equipment has been modified to be quite as slow as the old trains, necessarily. If it was, then the signal upgrades wouldn't have been necessary. Link to comment Share on other sites More sharing options...
Joe Posted July 18, 2012 Share #13 Posted July 18, 2012 The speed of the train is not it's braking rate. Link to comment Share on other sites More sharing options...
TheSubwayStation Posted July 18, 2012 Share #14 Posted July 18, 2012 The speed of the train is not it's braking rate. No, but speed affects braking distance, of course. Link to comment Share on other sites More sharing options...
GojiMet86 Posted July 18, 2012 Author Share #15 Posted July 18, 2012 No, but speed affects braking distance, of course. The brakes did not provide enough distance for safety. The train was going fast, but the braking distance designed for the R-9 was too little for the ones designed for the R40. Link to comment Share on other sites More sharing options...
FriedChikkin Posted July 21, 2012 Share #16 Posted July 21, 2012 Good find. I'm going to forward this to people I know whom knew the personnel in question and ask their 2¢. Link to comment Share on other sites More sharing options...
BrooklynIRT Posted July 22, 2012 Share #17 Posted July 22, 2012 The accident brought these important changes to the NYC subway. 1)Slower speeds for trains especially crossing the Manhattan and Williamsburg Bridges. Really? I am not sure about Williamsburg but based on what I read in an old subchat thread (http://www.subchat.com/readflat.asp?Id=169229) and things I have heard over the years, I could have sworn that trains crossed the Manhattan Bridge so slowly because of the structural issues of the bridge that worsened over time, especially as the trains became heavier. The steep grades on the bridge and the GTs that come with them are also factors. Link to comment Share on other sites More sharing options...
TheSubwayStation Posted July 22, 2012 Share #18 Posted July 22, 2012 Really? I am not sure about Williamsburg but based on what I read in an old subchat thread (http://www.subchat.c...t.asp?Id=169229) and things I have heard over the years, I could have sworn that trains crossed the Manhattan Bridge so slowly because of the structural issues of the bridge that worsened over time, especially as the trains became heavier. The steep grades on the bridge and the GTs that come with them are also factors. I think Shortline got that wrong. I'm pretty sure that the Williamsburg Bridge is just as fast as it used to be, because the signals were updated to be farther apart. Yes, there are timers on the downgrade section of the bridge, but the crash happened on the upgrade approach. Link to comment Share on other sites More sharing options...
MHV9218 Posted July 22, 2012 Share #19 Posted July 22, 2012 Just thought I'd note, there were a few main things that came about as the result of this wreck (it's one of the ones that strikes closest to home and so I've read a few things about it): - speedometers were added to all cars - all equipment had its top speed lowered by limiting the motor's output - all equipment had its acceleration decreased through a re-wiring process - R40 brake shoes were changed from cast iron to composite build - R40 variable load valves were replaced - signals were lightly modernized (this was mainly bureaucratic) - new speed restriction notices were posted throughout the system Link to comment Share on other sites More sharing options...
Joe Posted July 22, 2012 Share #20 Posted July 22, 2012 - R40 brake shoes were changed from cast iron to composite build That wasn't done after the accident, it was one of the contributing factors to it. Link to comment Share on other sites More sharing options...
MHV9218 Posted July 22, 2012 Share #21 Posted July 22, 2012 That wasn't done after the accident, it was one of the contributing factors to it. You're right, I don't know why I included that on the list. The composite shoes and rebuilt brake valves were arguably the cause, not the fix. Sleepy typing, good catch. Link to comment Share on other sites More sharing options...
Joe Posted July 22, 2012 Share #22 Posted July 22, 2012 You're right, I don't know why I included that on the list. The composite shoes and rebuilt brake valves were arguably the cause, not the fix. Sleepy typing, good catch. Typical left-hand-doesn't-know-what-the-right-is-doing that runs rampant through the TA. Nothing beats cast iron shoes. Link to comment Share on other sites More sharing options...
TriboroughBridge Posted July 25, 2012 Share #23 Posted July 25, 2012 - speedometers were added to all cars Are you kidding me?! before this accident, not all cars had speedometers?! Link to comment Share on other sites More sharing options...
m7zanr160s Posted July 27, 2012 Share #24 Posted July 27, 2012 Are you kidding me?! before this accident, not all cars had speedometers?! I know, sounds weird, right? Link to comment Share on other sites More sharing options...
realizm Posted July 27, 2012 Share #25 Posted July 27, 2012 Typical left-hand-doesn't-know-what-the-right-is-doing that runs rampant through the TA. Nothing beats cast iron shoes. Suprising to many, newer technological advancements tend to end up inferior compared to to the time and tested technology of the past. I've noticed that but not in terms of transit up to reading your comment. So true. "If it ain't broke, don't fix it" as the saying goes sometimes. Link to comment Share on other sites More sharing options...
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