514 Cherry Update re King & Sumach Noise

At a community meeting on June 27, 2017, the TTC presented updated information about their work on reducing the noise level from streetcars at King & Sumach. In response to complaints after the 514 Cherry route began operating in 2016, the TTC changed the 514 so that late evenings and early mornings it operates to Broadview & Queen (looping back via Dundas and Parliament just like a short turning 504 King car). During these periods, a Wheel Trans bus provided a shuttle service on Sumach and Cherry to Distillery Loop.

The TTC presented updated noise readings for this location showing the combined improvement of the full changeover to Flexity cars from CLRVs and of changes to the rail profile that were made to complement slower operation around the curves.

The chart above shows results for the tightest curve at King & Sumach, the east to south. The data plotted here summarize readings taken over a four-hour period, and so they reflect the contribution of whatever type of vehicles showed up. For the most recent reading on May 4, 2017, when the service should have been largely or completely run with Flexitys, the levels from the middle to the high end of the spectrum are markedly lower than they were in the fall.

From the vehicle tracking data for 514 Cherry, I can confirm that the vehicles in service on that date were:

  • CLRV 4071 from 8:28 to 9:55 am
  • CLRV 4049 from 2:56 to 5:45 pm
  • Flexitys 4402, 4404, 4406, 4409, 4412, 4414, 4423, 4425, 4428 and 4432

Depending on when the measurements were taken, there was at most one CLRV in service on the route, and none for most of the day.

By contrast, on Aug. 10, 2016, all but one car on the route was a CLRV with only a single Flexity in service, 4418, between 5:30 am and 2:07 am the following day.

For the north to west turn, the data show less of an improvement. Oddly, the readings for the gentler left turn curve are higher than for the eastbound right turn, but this could be a factor of the measurement location which is closer to the westbound turn.

As a matter of comparison, the TTC also presented readings from two intersections with comparable curve radii, Queen & Broadview and Bathurst & Fleet.

Note that this chart presents maximum values rather than a four hour average. The higher values for the comparator intersections are almost certainly due to the noise caused by CLRVs or ALRVs which have (a) inherently more squeal and (b) less car design factors to limit noise transmission.

Bathurst & Fleet would have had service only on 509 Harbourfront on May 4 as this predates the return of streetcars to 511 Bathurst. I do not have the tracking data for the 509 on that date, and so cannot comment on the proportion of service provided by each vehicle type. Harbourfront is supposed to be all Flexity, but routinely has a few CLRVs on it. It would take only one noisy CLRV to set the maximum values shown above.

The chart is also unclear about which turn was measured at each location, only that this was done from 8 metres away.

Future work of this type should be more careful in identification of the vehicle type and location specifics for any readings and charts. If nothing else, this will improve credibility with members of the public by showing the improvements new cars bring.

Based on the improvements recorded at King & Sumach, the TTC plans to return full streetcar service to Distillery Loop on a date to be announced in July.

This decision provoked something of a pitched battle between residents at various locations on the route. The high points (if they can be called that) included:

  • Wheel squeal at King and Sumach prevented some nearby residents from getting a full night’s sleep, and the respite with no cars making turns was 3 to 3.5 hours. (It was unclear whether the residents have ever had a Flexity-only late night or early morning service as a reference point because service was cut last November before the route conversion was completed.)
  • Squeal is worst after rain because the normal film of grease on the track (both from natural causes and from wheel greasers) washes away. Wet track actually is very quiet because the water acts as a lubricant, but track that is drying out can be extremely noisy. This also happens during periods of high humidity. The TTC was criticized for taking noise measurements only under ideal conditions.
  • Residents at King/Sumach who predate the installation of the intersection were used to quieter streetcar operation, and enjoyed a long period of no streetcars at all while the King leg of the Don Bridge was closed.
  • The Wheel Trans shuttle bus is utterly unreliable running on a schedule unknown to riders and with unpredictable headways that can be considerably longer than the round trip route would imply. Operators often bypass waiting passengers. There are safety issues for the large number of disabled transit users living in this neighbourhood if they are forced to make a transfer to an unreliable, infrequent service.
  • Residents along the Cherry Street portion of the route complained that they effectively lost service because the bus was so unreliable, and in any event, its wide headways and forced transfer at King Street added to travel times. They also noted that the change was implemented without notice to the wider community. (There were also complaints about poor publicity for the June 27 meeting.)
  • Aggrieved King/Sumach residents proposed that the 514 Cherry route be completely converted to bus operation during the hours when the shuttle runs now to eliminate the transfer connection and improve service to the Distillery. This option was rejected by the TTC and by some users of the 514 who noted that streetcars can be very crowded at late evenings downtown where the route is supposed to provide supplementary service on King.
  • Early morning trips from Leslie Barns to Distillery Loop make the west to south turn for which no automatic greasing is provided.
  • Not all who attended from King/Sumach objected to the streetcars, but as this was a small meeting, it is not clear what the balance of opinion in the neighbourhood might be.
  • Notable by its absence from any comments were complaints about noise from eastbound streetcars clattering through the trailing switch of the north to east curve. The slow order at this location appears to have dealt with this issue.

In addition to operating the 514 Cherry route with only Flexitys, the TTC is working on a design of a noise absorbing ring that will damp the high frequency vibrations. Wheel sets for two cars are now being manufactured, and they will be installed on test cars in the fall.

Further noise readings will be taken through the summer and fall to track conditions as they evolve, and the level of grease application will be increased. (There is a trackside greaser southbound at Distillery Loop, and the Flexitys have on board greasers that are triggered by GPS information to activate where lubrication is required.)

In a separate article, I will turn to the general unreliability of service at Distillery Loop on the 514 streetcars. The TTC puts this down to the usual problems of mixed traffic operation on King, but there are also issues with uneven headways departing from both the Distillery and Dufferin terminals following layovers that can be fairly long. Line management, as elsewhere on the system, is a problem for this service.

See the TTC’s King-Sumach page for complete information.

 

9 thoughts on “514 Cherry Update re King & Sumach Noise

  1. Have the automated greasers been activated on the 514 Flexities? Did I understand they are GPS activated? If so, that should be interesting given how the TTC’s fleet is prone to GPS errors.

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  2. I hope that at the meeting someone explained decibels and frequency in terms of human hearing. In an understandable way. And that the public cared to understand.

    A difference of 10 decibels is a ten-fold change in power, so going from 80dB to 70dB implies that the acoustic energy is now 10% of what it was. Physiologically it won’t sound one-tenth as loud, though.

    I don’t envy the PR or scientific people that the TTC would send to a meeting like this. I don’t envy the east-end folks who have to put up with yet another slow order and unreliable service either.

    Weren’t the old Toronto Railway Company King car barns just further east off King? I wonder if any parts of that building are still around, or were around recently. (The fire in, what, 1916 didn’t do them any good.)

    Steve: The explanation focused on the fact that the high hertz values are the annoying squeal, not on the relative meaning of the change in values besides saying “look there is a big change”. The scientific folks were there but never spoke. It was not a well-organized presentation.

    The former King Barns site now has a brand new TCHC building on it, so no remnants of anything.

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  3. From the presentation it appears that they are keeping the speed limit on King Street through the switches? Isn’t that a bit slow for just going straight? It’s a bit of a pain, because invariably, the car is ready to leave, but decides not to enter the intersection, as the countdown is normally on 2 by then, and there’s no extended signal.

    Altering the timing would help east-west service.

    Steve: The TTC’s whole approach to intersections is getting very frustrating with the combination of slow orders, a ridiculous (and mostly ignored) rule that streetcars should not pass each other on special work (!), the noise issue, and the crying need for better signal priority, they keep hobbling operations and then complain about “slow” streetcars. On a route like King with many intersections, all of this has an effect as regular riders know, even if they are unfamiliar with the technical details.

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  4. Ed wrote I hope that at the meeting someone explained decibels and frequency in terms of human hearing. In an understandable way. And that the public cared to understand.

    A difference of 10 decibels is a ten-fold change in power, so going from 80dB to 70dB implies that the acoustic energy is now 10% of what it was. Physiologically it won’t sound one-tenth as loud, though.

    I hope someone explained it but… Remember those vehicle fact sheets the TTC used to publish for the subway cars and streetcars that had a good amount of technical information? I was talking about those with a couple of other people a few weeks ago and they haven’t put out anything like that in many years. None of us knows why but there’s a suspicion that the TTC thinks the average person on the street isn’t smart enough to understand that stuff. If that’s the case, they probably did one of their “good news” style over substance presentations.

    So, to add to what Ed wrote, under most circumstances, a 10 dB increase or decrease is perceived as a doubling or halfing of loudness respectively. Another useful one to know is that 3 dB increase or decrease is approximately doubling or halving of power. One implication is that for sound reproduction is that to get twice the loudness out of a speaker, you need to feed in 10 times the power. Going from a 10 watt to a 100 watt amplifier will double the volume. Going from 10 watts to 20 and trying to get double the volume with only a 3 dB power increase typically results in disappointment and equipment damage.

    Did anybody at the meeting mention what the Y axis on the charts was measured in though? “Decibels” as you mentioned is just a ratio. Without a reference value that the measurements are with respect to, it’s a chart that has “more loud” and “less loud” without anything quantitative to pin it to. I’d assume these are dB SPL measurements, but that might not be correct, and if they are, was any weighting used? I looked at the PDF on the website and it doesn’t specify elsewhere in the text. There are different implications for some areas on those charts if they’re unweighted or even dB(C) vs. dB(A). If I was grading that presentation PDF, I would’ve come down severely on how the test methodology and results were documented.

    Steve: I agree that it was a poor presentation, and the methodology is sloppy. At the very least, readings should have been broken out by vehicle type so that the very different spectra of the new and old cars were clearly shown. This would actually have helped the TTC’s argument that the conversion to new cars would solve a lot of the reported problems.

    Anyone who wants a detailed description of the technical issues of sound levels and perception should read any of the technical appendices to the GO Electrification TPAP, for example the section for the USRC. Look at Appendix A starting at page 73 of the pdf.

    That said, I don’t think the people at this meeting were interested in a detailed scientific explanation. My concern is that when this presentation finds its way to higher powers, the holes in it could undermine credibility with politicians who may well intervene.

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  5. The TL;DR of discussing the presentation materials would be: the graphs, to someone unknowledgable, would show a minor decrease of Noise, from 80 Noises to 70 Noises, which is only a 15% reduction, and not anything to write home about. (As if 80 short-turns are down to 70: a little better, but hardly a solution.) Whereas really the perceived noise has been cut in half, and the building-shaking energy is down a significant amount too, at certain frequency ranges.

    Obviously if the presenters had put some thought into the presentation, and gotten some technical advice (or even checked Wikipedia), the graphs would be laid out differently and would show a dramatic reduction in noise.

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  6. Ed says “…decrease of Noise, from 80 Noises to 70 Noises, which is only a 15% reduction, and not anything to write home about.”

    You seem to have missed the point that it is a logarithmic scale, not a linear scale. The reduction is by a factor of 10 on the power level and a perceived halving of noise. This is far better than 15%.

    Thank you TTC passenger for giving a detailed explanation about the different types of sound scales.

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  7. Residents also need to account for the fact that any noise would happen within a small band of time with large gaps of silence in between.

    Why just this evening at 11pm, all 5 scheduled 514 cars were traveling eastbound within a 9 minute band between Parliament and John when on paper they’re on a 15 minute headway.

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  8. Why just this evening at 11pm, all 5 scheduled 514 cars were traveling eastbound within a 9 minute band between Parliament and John when on paper they’re on a 15 minute headway. Ah, route management at its best!

    Steve: Line management indeed. The 514 is often a shambles and there appears to be no attempt to maintain a reliable headway to Distillery Loop. Those cars are just King extras as far as many at the TTC seem to be concerned.

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  9. I have ridden car 4403 a few times in the past few days. It has a wheel squeal issue as it travels and it turns into a loud groan sound when braking. Are the early Flexities already showing their age?

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