The Practicality of Articulated Subway Trains in New York

Toronto Rocket articulated subway train

Toronto, ON. Articulated subway train interior. (c) 2014 C. Walton

 

Most people have probably seen or have ridden articulated buses in their normal everyday life or have heard of them in many large cities such as New York, Los Angeles, and Chicago.  Many may have seen light rail trains with an articulation in the middle of the car, such as those in Boston, San Diego, and Pittsburgh.  But when it comes to larger trains such as subway or commuter rail trains, it’s a pretty foreign concept in certain parts of the world.  Though, not as uncommon as you think.

There are many cities that have operated or are beginning to operate articulated subway or metro trains.  Here’s a short list:

  • London Underground: S7 and S8 stock on their Sub-surface lines (Metropolitan with S8s, District and Hammersmith & City with S7s)
  • Toronto Transit Commission: Toronto Rocket (TR) trains on the Yonge-University-Spadina Line (YUS, or Line 1)
  • RATP Paris:  MP89CA, MP89CC, MF01/MF2000, and MP05 stock on Lines 1, 2, 4, 5, 9, and 14.
  • Stockholm Metro:  Bombardier C20 stock used primarily on the Red Line trunk T13/T14

Out of these 4 cities, I have visited and ridden the trains in three of them.  Even with my experience riding scores of articulated buses in North America and my rides on several light rail systems in every country I have visited, an articulated subway train was an acquired taste.  A really cool experience in its own way.  But why articulated trains?

LU Metropolitan S8 Stock

London Underground S8 Stock on the Metropolitan Line. (c) 2013 C. Walton

One of the main reasons that some cities choose articulated metros is capacity.  A standard metro might have 4-6 cars, each car roughly 50-75 feet long, with end doors to walk between cars in case of emergencies.  Some subways allow people to walk freely between cars, while others lock the doors for safety reasons.  If each 60-foot car of a 6-car train can hold 200 people, for example, then the train has a capacity of 1200.  That means 1200 people crammed into a subway train with nowhere to go while in motion unless something happens.  Now, if that same train had articulation between every car, and the midsections have space for about 10 people, then the capacity of that same 6-car train would increase by 50, and they would be able to move a bit more freely throughout the train.

  • Well, why don’t you just add more trains?  Maybe the signalling system isn’t capable of taking on more trains at speed without causing delays or risk of collisions.  Or maybe the transit system has no money or space in storage yards for additional trains.
  • Well, why don’t you just make longer trains?  Maybe there is no money or space in storage yards for longer trains.  Or maybe the cost of expanding/lengthening subway platforms is way too high.  Or just maybe, it’s not physically possible due to the way the original subway stations were constructed.
  • Well, what about offensive odors and petty crime spreading to other cars?  Well, I’m pretty sure that in the cities that have articulated trains, there isn’t much of that kind of problem.  Or maybe they value free movement between cars over smells and petty crimes.

Another reason many subways tend to go with articulated trains is cost.  Most European metros have found that it doesn’t make sense to have a train of 6 subway cars, for example, and every car has propulsion, traction motors, current collectors, braking systems, and operating cabs that are only used when they are in the front of the train.  That would be considered wasted space if it means that taking them out wiill mean more standing and seating capacity per train.  This is especially true for them if they don’t often split or cut trains during off-peak periods such as in New York prior to the 2000s when trains of 10 cars would be reduced to 8, 7, 6, 5, or even 4-car trains during off-peak hours.  So, less cabs in the trains means less moving parts necessary to operate the train safely.  Some systems still have powered trucks, but the power for those trucks may be shared with a truck at the front or rear of the train.  This means less wear and tear and having to replace items regularly such as brake shoes, current collectors, couplers, and linkbars in between cars that don’t have couplers.  Some cities already “unitize” their trains, that is, take their single units and mate them into pairs or sets to reduce components needed for each individual car.  Articulated trains take it a step further by increasing the amount of free space for riders taken up by unused cabs, component rooms, end doors, and spaces between each car.

With all of that said, does every city in North America with a subway need articulated subway cars?  Maybe, maybe not.  With the recent incident in the Washington, DC Metro system, would articulated trains have made a difference?  It could have, only because passengers wouldn’t be confined to a single car waiting for someone to evacuate them.  However, in DC, the trains have a single train operator on board, unlike New York, which, except for OPTO instances (one-person train operation), has a train operator and train conductor on board.  Nevertheless, with most subway systems having trains with mated subway cars equipped with full-size cabs at one end and windows to the next car at the other end, you could make the argument that articulated cars would be the next logical step.

Which brings me to the question, would that thinking work here in New York?

The "blind ends" of an A Division R142 subway car.  (c) 2003 C. Walton

The “blind end” of an A Division R142 subway car. (c) 2003 C. Walton

Most of New York City subway trains prior to the 1990s were single-car or two-car married pairs.  Each single car had all of the components needed to safely run that car and could theoretically be run by itself; married pairs have some of their own components needed to power the car but share other components with its mate that are needed to operate the car.  Each car had its own set of third rail contact shoes, air brakes, and trucks with propulsion systems, but both cars in the pair worked off of one air compressor and one electric converter to power and operate both cars.  If a train had a mechanical problem, that car or pair of cars would be isolated and run until it could get to a maintenance shop for repair.  This meant that when a train reaches the shop, it needed to be cut from the train, which took several moves if the car or pair was in the middle of the train.  Thus, each car or pair of cars had to have a cab on both ends for singles or a cab on one end of each car in the pair.

With that in mind, NYC Transit decided to try out some new technology, ordering two prototype New Technology Test (NTT) trains, one for both the A and B divisions.  There were many things tested with these trains, but what was tested and later implemented into the New A and B division trains was unitized trains with cabs only in the “A” cars of the train, the end cars of the 4-car or 5-car sets and nothing but end doors and windows on the “B” cars of the train.  Granted, the previous car classes to these NTT’s, the R62 and R68 series, were originally single-car units until they were “unitized” and made into 4-car and 5-car sets.  The only difference is, the cabs were left intact, save for the removal of brake valves and master controllers which weren’t needed in the middle cabs.  With the NTT trains, the trains came with cabs removed to allow for more rider space.

The question is, can this be taken a step further with articulation in between the cars?  Yes and no.  Allow me to explain.

1. Yes, because if New York City transit took the bold step in the 1990s to unitize their 1980s equipment into 4-car and 5-car sets, and then took the bold step in the 1990s and 2000s to order subway cars with cab cars and cabless, see-through cars, then it’s time to experiment with articulated trains.  Not that it hasn’t been done before, since the Brooklyn-Manhattan Transit Corporation (the BMT) had experimented with articulated cars up until the 1930s.  The early BMT articulated sets, the “D-Types” were super-heavy and super-slow, and the “Multis” and “Bluebirds” were successful but never expanded due to the city’s 1940 buyout and subsequent 1941 Unification period.  So we know it’s possible.  Most modern articulated trains have larger gangways, much like an articulated bus, but some have fixed gangways, much like some older light rail vehicles.  The older BMT articulateds are of the latter type.  If we are to allow more capacity on our subway lines, such as the ever-so-crowded Lexington Avenue and Queens Boulevard Corridors or the L train, we should at least explore the use of modern articulated cars to allow people to walk freely between cars without getting ticketed.  There still needs to be safety precautions, but nonetheless it should be discussed.  We have an upcoming subway car order to really have this discussion, the R211 cars which will replace the R46 cars from the late 1970s, currently found on the A, F, and R lines.  Even though these cars won’t be coming in for another 5-7 years, we should have the conversation now.

BMT's D-Type "Triplex" subway cars.  (c) 2004 C. Walton

BMT’s D-Type “Triplex” subway cars. (c) 2004 C. Walton

2. No, because of several things.  Unless New York City Transit decides to install cab signalling in the entire subway system, much like was done in Philadelphia, and unless NYCT perfects Communications-Based Train Control to a point where we won’t need our old signals anymore, articulated trains would make it ten times more difficult for a train operator to investigate why a train was placed in emergency (meaning the braking system brings the train to a fast and immediate stop).  With our current system, we can go in-between cars and check for anything that might have hit one of the 20 car-borne tripping devices on a 10-car train if we can’t stop the train and walk along the tracks.  The devices are designed to place a train in emergency if it passes a signal showing a red light or lights, preventing the train from running into another train or derailing over an improperly set switch.  However, anything on the tracks can trip the device and bring the train to a grinding halt…such as garbage bags, newspapers, track workers’ tools, and even…bodies.  Scary to think about, but anything is possible in our system.  And if we can’t determine what caused our train to stop (assuming that no one pulled the emergency brake cord), then how do we prevent or curtail these occurrences?  Let’s add to this equation the sharp curves used in our system, such as near City Hall on the R line and the South Ferry (old station) Loop on the #1 line.  Assuming that NYCT will continue to buy subway cars with two trucks per car, an articulated train would have trouble negotiating some of these tight curves, possibly causing the gangway to violently swerve from side to side; just think of your experience on the R train leaving City Hall in either direction and how the cars’ ends swing out away from each other.  The only way an articulated train would work in this scenario is if the articulated joint is located above a single shared truck between cars.  It would take turns a lot better, and would mean fewer trucks and fewer components to be replaced.  Not sure if NYCT is ready for that right now.  We can learn a lesson from the BMT and have 6 trucks on a 5-car train; or, we can attempt to learn a lesson or two from the London Underground, which is running the S7s and S8s with two trucks per car and gangways.

The R211 class has some time to be refined and designed, but for now, we are awaiting 300 R179 cars from Bombardier, same ol’ design just like the current new kids on the block, the ever-so-omnipresent R160s that grace the E, F, J/Z, M, N, and Q lines (and sometimes the L and R lines, though the L line has mainly the predecessor R143 cars).  Double end doors and see-through glass and all.  I wonder if an R160 can be modified to have articulated midsections to test the waters?

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