MBTA Buses & Infrastructure

[Joel N. Weber II]

Re: new buses

The Neoplan AN440LF fleet is 12-13 years old and is becoming increasingly unreliable. The T can't wait too much longer to order new buses or bus operations would take a hit..

If the battery buses do turn out to be more reliable than the buses with diesel engines, and the T's management could have determined that today but chooses not to, is the T's management going to look competent 3-5 years from now when the reliability of the T's fleet is compared to the reliability of buses run by agencies that were willing to consider buying current technology instead of new but obsolete buses?

 

[Joel N. Weber II]

They ran the first test of a dedicated bus lane on Washington St. in Roslindale this morning, and quite frankly, it was amazing. I am seeing social medial completely light up with glowing reports, mine included. Aside from a few tepid expressions of anxiety about parking, it is already extremely popular. It's no exaggeration to say that it will save people 10 to 15 minutes on their commute time.

http://www.universalhub.com/2017/imagine-roslindale-square-forest-hills-just-six

How many people are complaining to the government that they seemingly aren't planning to continue ``testing'' this every single weekday this winter?

 

[Joel N. Weber II]

Psyched to see that a priority bus is in the Boston 2030 plan at #6 (page 195)

Good News: it runs North Station-Haymarket-POSq-Atlantics Ave @ South Station-Seaport (D St)

Bad News: they've pegged implementation at $21m and 6 years.

Hello? Just slap some paint down and drop some friggin' traffic cones on Congress Street. Call it 1 year, $2m, and $1m/yr in police detail work.

Hire the Mayor of Everett as a consultant.

Doesn't the North Station to Seaport route also require buying some new vehicles (and probably coming up with more garage space unless we switch to more reliable technology) since there are currently no buses running there frequently, whereas the Everett bus lane just involved speeding up existing buses?

Also, while Everett has done well with upper Broadway, the process of improving lower Broadway hasn't been quite so impressively quick...

 

[bakgwailo]

Re: new buses

If the battery buses do turn out to be more reliable than the buses with diesel engines, and the T's management could have determined that today but chooses not to, is the T's management going to look competent 3-5 years from now when the reliability of the T's fleet is compared to the reliability of buses run by agencies that were willing to consider buying current technology instead of new but obsolete buses?

That still seems like an awful gamble - if it turns out that the electric/battery buses are less reliable it will screw the MBTA for years. Hindsight being 20/20 and all that, I much prefer the T letting others be the guinea pig and picking something with a known track record. When they need to be replaced again in 10-15 years, then they can see if things panned out or not.

 

[Joel N. Weber II]

Re: new buses

That still seems like an awful gamble - if it turns out that the electric/battery buses are less reliable it will screw the MBTA for years. Hindsight being 20/20 and all that, I much prefer the T letting others be the guinea pig and picking something with a known track record. When they need to be replaced again in 10-15 years, then they can see if things panned out or not.

Again, haven't agencies like Foothill Transit and the Worcester RTA already been the guinea pigs? Don't you think you could make your case more convincingly if you could explain exactly what problems they've had or exactly what is more challenging about the MBTA environment than what those agencies deal with? Does the fact that you haven't pointed to specific evidence of problems suggest that your argument is completely non-compelling?

https://www.youtube.com/watch?v=9JpMTWdPZ6c

 

[millerm277]

Re: new buses

Again, haven't agencies like Foothill Transit and the Worcester RTA already been the guinea pigs? Don't you think you could make your case more convincingly if you could explain exactly what problems they've had or exactly what is more challenging about the MBTA environment than what those agencies deal with? Does the fact that you haven't pointed to specific evidence of problems suggest that your argument is completely non-compelling?

They apparently haven't been very happy with them, and there's other agencies piloting them with similar gripes mentioned in the article:

"In Massachusetts, two agencies running small numbers of electric buses - the Pioneer Valley Transit Authority in Springfield and Worcester’s Regional Transit Authority - say the vehicles weaken in extreme cold and snow. They have no plans to acquire additional EVs, officials at those agencies said."

https://www.reuters.com/article/us-...ic-buses-despite-bold-forecasts-idUSKBN1E60GS

 

[fattony]

Re: new buses

They apparently haven't been very happy with them, and there's other agencies piloting them with similar gripes mentioned in the article:

"In Massachusetts, two agencies running small numbers of electric buses - the Pioneer Valley Transit Authority in Springfield and Worcester’s Regional Transit Authority - say the vehicles weaken in extreme cold and snow. They have no plans to acquire additional EVs, officials at those agencies said."

https://www.reuters.com/article/us-...ic-buses-despite-bold-forecasts-idUSKBN1E60GS

I'm not a automotive engineer, but I am AN engineer and that sounds to me like a straightforward design problem. Some amount of power needs to be expended heating the batteries during extreme cold. Maybe the bus even needs to stop to charge more frequently on those days (the Leno video claims a full charge in 10 minutes). That obviously is a hit to energy efficiency, but it may be a worthwhile price to get all the benefits 350 other days of the year. Los Angeles doesn't need to buy buses with that feature, but maybe Boston does.

Interesting tidbit from the Jay Leno video - diesel bus garages expend significant energy on ventilating fumes. That inevitably means (costly) inefficient climate control at garages as well. There are so many positives to gain from electric buses, I'm very optimistic about them. More so than electric cars to be honest.

 

[Arlington]

Yes, in the cold, battery performance deteriorates. That's a 3 part fix:

1) Heating the battery. Initially with resistance heat (2011 Nissan Leaf called this the "cold weather package" but made it standard by 2013 production year). Extremely simple upgrade with no moving parts and little tech/failure risks.

2) Changing from A/C to a heat pump (4x more efficient than burning battery amps), which is also a tiny tech upgrade. Heat Pump can then both circulate heat (winter) or cool (summer) the battery and also take over passenger cabin heat. Tesla uses heat pumps and Leaf got them in 2014.

3) Slightly more charging availability and/or battery capacity (the ecoliner has 3 gallon-of-fuel equivalent of electricity). That's the kind of thing where battery tech could easily grow that to 4 in just one product cycle, and devote it all to cold-weather cushion.

Electric buses will soon totally dominate for transit on reliability--they have so few moving parts. If you look at what goes wrong on high-production electrics (Leaf) and range extended electrics (C-Max, Volt, i3) its always stuff like the entertainment system and power accessories, not the drive train. Swapping e-drive into buses will very soon be a no brainer.

 

[Arborway]

Re: new buses

I always complain the T gets stuck in its "this is the way it's always been done, so we can never do things differently, even if it would probably help us a lot in the long run" mentality. For example, I'm pretty annoyed that they're not going with articulated, married pairs for the new Orange and Red line trains.

However, I have to side with them on the cautious procurement of battery buses.

Betting the farm on battery-powered buses without testing a dozen or two first could very easily end-up like the Breda debacle all over again. MBTA management is undoubtedly very aware of this.

 

[Joel N. Weber II]

2) Changing from A/C to a heat pump (4x more efficient than burning battery amps), which is also a tiny tech upgrade. Heat Pump can then both circulate heat (winter) or cool (summer) the battery and also take over passenger cabin heat. Tesla uses heat pumps and Leaf got them in 2014.

Heat pump capacity and efficiency tends to go down as the temperature differential increases. It may turn out that different heat pumps may have slightly different performance, but the ``HEATING DATA'' table near the bottom of http://www.chiltrix.com/chiller-technology.html shows that if you're heating to 86F, 4x Coefficient of Power (COP) happens somewhere around a 40F outside temperature, and at -4F you only get about 2.3x.

3) Slightly more charging availability and/or battery capacity (the ecoliner has 3 gallon-of-fuel equivalent of electricity). That's the kind of thing where battery tech could easily grow that to 4 in just one product cycle, and devote it all to cold-weather cushion.

I assume that when comparing battery buses ordered by the MBTA vs buses ordered by Los Angeles, the MBTA will order bigger batteries (assuming similar route lengths and speeds) to cope with the extra energy requirement for heating in the winter.

My understanding is that Proterra is now offering much larger batteries than they were when Worcester's buses were built, such that once a day charging is now a viable option.

 

[Joel N. Weber II]

Re: new buses

They apparently haven't been very happy with them, and there's other agencies piloting them with similar gripes mentioned in the article:

"In Massachusetts, two agencies running small numbers of electric buses - the Pioneer Valley Transit Authority in Springfield and Worcester’s Regional Transit Authority - say the vehicles weaken in extreme cold and snow. They have no plans to acquire additional EVs, officials at those agencies said."

https://www.reuters.com/article/us-...ic-buses-despite-bold-forecasts-idUSKBN1E60GS

I'm not sure the article you cite is necessarily objective. Worcester may not have any immediate plans to buy more pure EV buses at the moment, but do they have any plans to buy any more buses at all right now? Why doesn't that article indicate whether Worcester has any plans to buy any buses with diesel engines in the future?

http://www.paulgraham.com/submarine.html discusses how PR works, and if it turns out that New Flyer's EV buses aren't as good as Proterra's (which doesn't seem terribly implausible when Proterra is claiming EV buses aren't any more expensive than diesel and New Flyer isn't) and if New Flyer wants to portray things in the way that would best help their sales figures, it seems like that Reuters article would be what New Flyer would want out there.

From http://www.masstransitmag.com/press...ra-buses-to-withstand-cold-weather-challenges

Providing the Worcester community with cleaner air, fuel conservation and maintenance cost savings, the Proterra transit EVs replaced traditional dirty diesel buses and were put in service just prior to one of the worst winters on record took hold Dec. 2014-March 2015.

Faced with 39 straight days of sub-freezing temperatures, with an average of 14˚F, and a total snowfall of 115.6 inches, WRTA successfully operated their Proterra buses in normal service during this period. Accumulating more than 27,000 miles,

https://www.youtube.com/watch?v=8BOK_CwVies

 

[dwash59]

Re: new buses

I'm not sure the article you cite is necessarily objective.

So, you think the Proterra press releases are objective?

And you think Proterra should supply the order for 194 buses to the MBTA when that is close to the number of buses they have received orders for in the history of the company? And if we just count buses they've built, 194 is more than the number they've built in company history. I'm not even sure that if you asked them, they could deliver the buses in the timeframe that the MBTA needs them. When King County Metro ordered 73 buses from them in January 2017, the agreement was 8 delivered in 2017-2018, 12 in 2019. If you ordered 194 buses today, you may not see any until 2020.

 

[Joel N. Weber II]

Re: new buses

So, you think the Proterra press releases are objective?

I certainly believe that it's worth carefully evaluating the claims in Proterra press releases rather than dismissing them just because WRTA has experience with their products but the MBTA doesn't.

And you think Proterra should supply the order for 194 buses to the MBTA when that is close to the number of buses they have received orders for in the history of the company? And if we just count buses they've built, 194 is more than the number they've built in company history. I'm not even sure that if you asked them, they could deliver the buses in the timeframe that the MBTA needs them. When King County Metro ordered 73 buses from them in January 2017, the agreement was 8 delivered in 2017-2018, 12 in 2019. If you ordered 194 buses today, you may not see any until 2020.

I'm skeptical of this ``the MBTA needs them'' claim. If we were to get a small number of Proterra buses in the short term, and find storage space for all of the older low floor buses with diesel engines and put the same level of effort into running 14 year old low floor buses that went into keeping 21 year old high floor buses running, is there really no way to get through the time it would take Proterra to ramp up production?

I think getting Proterra to ramp up production is likely lower risk than the Hyundai-Rotem commuter rail project, in that it appears that Proterra has already successfully built some buses that are very much like what we would want. If the Hyundai-Rotem risk was worth taking when there was no valuable technology improvement expected from taking that risk, why would it make any sense to avoid taking advantage of technology improvements because of some sudden new risk aversion?

 

[Arlington]

and at -4F you only get about 2.3x.

Which is 2.3x more heat than you get with resistance heat (COP =~ 1) and therefore even at -4F, cuts in half the energy drawn from the battery to do any heating. And by ~20F you're back to COP = 3.

For the cost of a valve and a bit of electronics, next gen e-buses can reverse the operation of the A/Cs already onboard and can radically improve their cold weather performance, particularly if some of that pumped heat is directed to keeping the battery in warmish (40F ~ 60F?) (which increases its usable capacity).

 

[Arlington]

Re: new buses

So, you think the Proterra press releases are objective?

I think the point is that the told from another perspective, the e-buses had high-dispatch reliability during their maiden winter (which was a brutal winter that, for example, killed many a HSP46 in their maiden winter on the Commuter rail, and killed many subway traction motors)

 

[Joel N. Weber II]

Which is 2.3x more heat than you get with resistance heat (COP =~ 1) and therefore even at -4F, cuts in half the energy drawn from the battery to do any heating. And by ~20F you're back to COP = 3.

For the cost of a valve and a bit of electronics, next gen e-buses can reverse the operation of the A/Cs already onboard and can radically improve their cold weather performance, particularly if some of that pumped heat is directed to keeping the battery in warmish (40F ~ 60F?) (which increases its usable capacity).

I certainly don't disagree that using a heat pump is desirable even at -4F when the COP is only 2.3.

The other challenge with heating in extreme cold is that if the energy requirement for the heating / cooling is basically proportional to the difference between inside and outside temperature, and if you want an inside temperature around 72F, then an outside temperature of 99F gives you a 27F difference, and a -8F outside temperature gives you an 80F difference, which suggests the worst case winter BTU/h requirement may be roughly 3x the summer requirement (although I'm ignoring the possibility that some energy might be expended on dehumidification in the summer). If you're serious about using the heat pump to minimize the battery draw in Boston's coldest weather, you might want a much larger heat pump than you'd want if you were just going to use it for cooling in the summer. (And this is somewhat climate dependent: this imbalance between worst case heating and worst case cooling probably doesn't look the same in Arizona or southern California.)

 

[JeffDowntown]

I certainly don't disagree that using a heat pump is desirable even at -4F when the COP is only 2.3.

The other challenge with heating in extreme cold is that if the energy requirement for the heating / cooling is basically proportional to the difference between inside and outside temperature, and if you want an inside temperature around 72F, then an outside temperature of 99F gives you a 27F difference, and a -8F outside temperature gives you an 80F difference, which suggests the worst case winter BTU/h requirement may be roughly 3x the summer requirement (although I'm ignoring the possibility that some energy might be expended on dehumidification in the summer). If you're serious about using the heat pump to minimize the battery draw in Boston's coldest weather, you might want a much larger heat pump than you'd want if you were just going to use it for cooling in the summer. (And this is somewhat climate dependent: this imbalance between worst case heating and worst case cooling probably doesn't look the same in Arizona or southern California.)

Your temperature differential analysis is overly simplistic. You are missing a key element in HVAC design for enclosed spaces -- waste heat.

All of the systems on a bus are inefficient, meaning in addition to doing what they are supposed to do, they also generate heat. The motors, drivetrain, batteries, braking, electronics, hydraulics, lighting, signage all generate heat while operating. The passengers also give off heat. The net result is that unless you are in extreme Arctic conditions, most enclosed spaces require greater cooling capacity than heating capacity. The waste heat really adds up.

 

[Arlington]

^ Seems to me that we're converging on the answer that even in cold climates any problem of e-transit's winter performance is highly solvable with a combination of:

1) It is mostly a "yard" problem, not a "run" problem: passenger heat on a full bus at mid run is probably not a big deal to begin with. Sourced heat is needed overnight (to keep batteries optimal) and at the start of a run.

2) Modern high-efficiency A/C takes very little to become a modern high-efficiency heat pump, and can greatly improve performance vs resistance heat. (BTW did the tested buses have braking-recovery systems? Many rail systems dump dynamic braking energy I(from motors dragging on wheels) into external resistors. This could be partially diverted to under-seat resistors if it isn't going back into batteries)

3) Battery capacity can be improved with a mix of resistance heat, heat-pump heat (proven versions of both are available now) and generational improvements in energy density (which battery makers are delivering at about 10% per year right now)

 

[Joel N. Weber II]

Your temperature differential analysis is overly simplistic. You are missing a key element in HVAC design for enclosed spaces -- waste heat.

All of the systems on a bus are inefficient, meaning in addition to doing what they are supposed to do, they also generate heat. The motors, drivetrain, batteries, braking, electronics, hydraulics, lighting, signage all generate heat while operating. The passengers also give off heat. The net result is that unless you are in extreme Arctic conditions, most enclosed spaces require greater cooling capacity than heating capacity. The waste heat really adds up.

Some of those things like motors and brakes are typically outside the passenger compartment. I doubt there's any design where the friction brakes heat the passenger compartment, although a liquid cooled motor should be able to have its waste heat go to the passenger compartment.

The Chiltrix performance page I mentioned above lists roughly 30,000 BTU/h capacity for cooling water to 60F when the outside temperature is 100F, and the units not listed capacity that I assume is BTU/h for heating at -4F outside, 86F inside is only about 16,000, which suggests that a typical heat pump may be able to deliver roughly double the BTU/h in our worst case summer than our worst case winter.

 

[Joel N. Weber II]

My understanding is that the T has roughly 1100 buses, and only expects about 750 of those to be in revenue service during the weekday peak, which seems to indicate that we expect roughly 350 buses, or about 1/3 of the buses, to be broken at any given time.

While I'm sure the MBTA's buses have a more difficult life than the typical privately owned automobile, I'm also under the impression that Amtrak manages to get its long distance rolling stock to run more hours of the month more reliably than the T's buses.

Does the T have any New Flyer buses that haven't run in revenue service in months that could be overhauled well enough to get another four or five years out of them in a manner that would end up being more cost effective than a complete replacement?

If we simply scrapped the 200 or so worst buses to reduce the fleet to 900 buses, we'd only need to achieve about 84% availability to have 750 working buses. I don't know whether that 84% can be reached or not, but it might be worthwhile to look at whether there are reasonable steps that could be taken towards that goal before ordering more buses.