deathtopumpkins wrote:The age of the system is ABSOLUTELY relevant, when it means that you have curves tighter than anywhere else in the country, and when it means that you have clearances that require custom-designed equipment.
Also, no, there probably isn't any track or other hardware that dates back to the 1890s, but it's not like every so often the T rips the entire thing out and rebuilds from scratch. You're always going to be a lot more prone to things like minor derailments on a system that's been continually in use for 100+ years, even if you maintain it and replace things periodically, than on a system that was built new, from scratch, with generous clearances and curvature, intended for modern light rail vehicles instead of trolleys from 100 years ago.
What's ridiculous is you ignoring that.
Actually, when the Bredas were suspended from service they had to do painstaking amounts of rail grinding and renewal throughout the Green Line because part of the fix for the derailment issues was resurfacing track to be
just...so with a much narrower tolerance for imperfections than the cars were originally supposed to support. It's why when they did finally start getting flushed into service in halfway-decent numbers they could only be introduced on one branch at a time. The rail grinder was working overtime across the system to get them certified for service.
That was 12-15 years ago. Track that was
just so in 2002 is no longer quite as so in 2016. That doesn't faze the Kinkis one bit because they're designed to tolerate a much wider and cruddier range of track conditions. And PCC's will run on godawful spaghetti rail without flinching. Track across the Green Line is in very good condition by any league-average measure in the transit world because that systemwide grinding blitz is still recent enough history on rail that on the most tangent stretches hasn't come close to a league-average replacement age. But it's a state-of-repair problem all the same because the Bredas didn't live up to the track condition tolerances the T thought it was getting upon purchase. They are requiring escalating maint intensity for the whole works--the vehicles themselves and the track structures--as the cars age. And it is not a normal aging curve. The tolerances were supposed to be a lot more generous than this.
With the whole system hurting for SGR funds spread incredibly thin and far too many unfilled job vacancies in the MOW ranks offering up too few overnight man hours for staying on top of these too-narrow tolerances, the track is teetering at
not *quite* so. Is that bad? Sure...derailments inching up over a 3-year span isn't a good trend. Are they being flat-out negligent with the current rate of rail resurfacing? Not so simple an answer. Because the Kinkis are very well within current track condition tolerances...the Boeings were very well within current track condition tolerances...and the new CAF's are quite likely by virtue of a much-improved truck design to be very well within current tolerances. The 8's, by product of all the compromises that had to be made to get them safe to run, are big outliers there. This was a known worry for when the Bredas hit their teenage years, because anything less than
just so becomes more a reliability unknown when moderately worn trucks have to stay on moderately worn rail. They were always going to be running up an ever-escalating treadmill. And that's why the Type 9's are not a moment too soon...and if the 24 base units and +30 options are good performers they need to
immediately plunk down for the triple-digit whammy follow-up order with CAF to get this replacement marathon started. MOW can only do so much more to already pretty decent track to make it totally immaculate before even that's not going to be good enough to stay a step ahead of attrition on >20 year old trucks (and afteraffects of that attrition wearing down the trainlining reliability of both halves of the 7-8 lash-up).
Now...note who's a conspicuous #2 on that derailment list in the Globe article: MUNI, the other very dissatisfied Breda customer from the same era. They don't have the issue with the trucks design that the T does because their cars don't need to conform to nearly as narrow width. But MUNI's order were morbidly, stupendously overweight for what they thought they were ordering. So guess what...MUNI too needs more immaculately-surfaced and regularly-surfaced track than first anticipated because those cars extract a bigger pound of flesh from the infrastructure than they were ever supposed to. MUNI's behind the MOW 8-ball too. All the mass tie replacement they did to minimize the amount of bouncing those porkers did on the trackbed upon first being introduced is now starting to near re- replacement age for wood and various types of streetcar sleepers (lot of theirs also wood beneath the asphalt). So they're seeing an unfavorable derailment trend too, for similar reason of the vehicles performing
below the default track tolerance spec...not the agency being negligent about staying on-spec. It's an above-and-beyond induced hardship on them too.