Silver Line to Chelsea

Here's my "sorry if this has been discussed" question: how is the Silver Line Bus Fleet doing in terms of: overhauls and new procurement?
 
Also wanted to chime in: read a bit about this, and not sure if it has been discussed, but as far as I can tell it looks like the dual mode buses will be running on diesel for this? Would it really be that expensive to string up some catenary for electrified service ? I would think it could also be done in a way to easily add electrified service onto the CR side, too.
 
bakgwailo said:
Also wanted to chime in: read a bit about this, and not sure if it has been discussed, but as far as I can tell it looks like the dual mode buses will be running on diesel for this? Would it really be that expensive to string up some catenary for electrified service ? I would think it could also be done in a way to easily add electrified service onto the CR side, too.
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Yes, diesel mode, and for now, given low oil prices, it is very hard to make the case that electrification adds a benefit worth the cost, and even hard to make pure "CO2" case: the extra environmental costs of manufacturing all that electrical equipment is probably greater than 20 years worth of operating benefits.

Bus electrification (which takes two wires, hot and neutral, and need not be constant tension) is sufficiently different from train electrification that I don't think there's any short term consideration between the bus side and the train side other than they stay far enough out of each other's way.
 
Arlington said:
Yes, diesel mode, and for now, given low oil prices, it is very hard to make the case that electrification adds a benefit worth the cost, and even hard to make pure "CO2" case: the extra environmental costs of manufacturing all that electrical equipment is probably greater than 20 years worth of operating benefits.

Bus electrification (which takes two wires, hot and neutral, and need not be constant tension) is sufficiently different from train electrification that I don't think there's any short term consideration between the bus side and the train side other than they stay far enough out of each other's way.
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Ah, I was thinking more along the lines that the supporting poles/etc could be shared (with the CR side "empty") in some fashion. Probably wouldn't work now that I think about it given height differences. I do think electrification is the way forward though - gas prices won't stay this low forever, and it gives the beneifits of reducing noise and CO2 in the immediate area - not even taking into account the CO2 used to create the wires/etc, there is still going to be CO2 created to generate the power itself. I guess I would just see it as a more permanent investment in the line - kind of like the trackless trolleys over in Watertown. Plus it would give me hope that maybe one day the Silverline could be converted to the true LRV it should have been :)
 
Arlington said:
Here's my "sorry if this has been discussed" question: how is the Silver Line Bus Fleet doing in terms of: overhauls and new procurement?
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Overhauls: of the 32 dual-mode buses, 8 are overhauled and in service, with two more being tested. 5 more are currently at MMA for rebuild.

New buses: 5 New Flyer XE60 battery-electric buses are on order, funded by a $4.1M FTA grant.

Between increased reliability of the old buses and the +5 of new buses (+6 if an option on the larger 60-footer order is taken), that should be enough to run Chelsea service.
 
bakgwailo said:
Ah, I was thinking more along the lines that the supporting poles/etc could be shared (with the CR side "empty") in some fashion. Probably wouldn't work now that I think about it given height differences. I do think electrification is the way forward though - gas prices won't stay this low forever, and it gives the beneifits of reducing noise and CO2 in the immediate area - not even taking into account the CO2 used to create the wires/etc, there is still going to be CO2 created to generate the power itself. I guess I would just see it as a more permanent investment in the line - kind of like the trackless trolleys over in Watertown. Plus it would give me hope that maybe one day the Silverline could be converted to the true LRV it should have been :)
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Electrification is the way forward. The on-order New Flyer XE60s are pure electric; they don't need any catenary to operate. The most infrastructure they'll need is a quick-charge station at South Station. Not only that, but the option order of XDE60s are supposed to feature larger batteries so they can operate solely on battery power inside the Waterfront tunnels.
 
swtat said:
Electrification is the way forward. The on-order New Flyer XE60s are pure electric; they don't need any catenary to operate. The most infrastructure they'll need is a quick-charge station at South Station. Not only that, but the option order of XDE60s are supposed to feature larger batteries so they can operate solely on battery power inside the Waterfront tunnels.
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Now that would be pretty cool. I would only be considered on the battery's themselves - they can be very costly to replace should they die. If they last as long as the lifespan of the bus, though, should be fine.
 
bakgwailo said:
I would think it could also be done in a way to easily add electrified service onto the CR side, too.
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Adding some poles doesn't put a dent in electrifying the commuter rail system. Most of your commuter rail electrification costs come from undercutting the track bed and raising bridges in order to have sufficient clearances.
 
bakgwailo said:
Now that would be pretty cool. I would only be considered on the battery's themselves - they can be very costly to replace should they die. If they last as long as the lifespan of the bus, though, should be fine.
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Many Toyota Prius batteries have lasted over 200k or 300k plus. I think batteries have the ability to last longer than internal combustion engines if designed right.
 
Prius batteries are NiCad and have proven durable across an enormous fleet & range of conditions

Lithium batteries (Tesla, Chevy Volt, Nissan Leaf) prefer the same temps as people, meaning they need to be warmed below 30F and cooled above 80F in order to be long-lasting...fortunately if you are willing to include it in the design, temp-management systems are cheap and plentiful (Nissan Leaf has a heater but no cooler (in order to make its $35k price point) so its batteries fail in places like Phoenix AZ)

Either way, moving ions involves inherently less wear and tear than running on explosions.
 
Arlington said:
Prius batteries are NiCad and have proven durable across an enormous fleet & range of conditions

Lithium batteries (Tesla, Chevy Volt, Nissan Leaf) prefer the same temps as people, meaning they need to be warmed below 30F and cooled above 80F in order to be long-lasting...fortunately if you are willing to include it in the design, temp-management systems are cheap and plentiful (Nissan Leaf has a heater but no cooler (in order to make its $35k price point) so its batteries fail in places like Phoenix AZ)

Either way, moving ions involves inherently less wear and tear than running on explosions.
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Exactly - and I couldn't see these running on NiCad - has to be lithium ion which is a bit more temperamental. The tesla pack (85kw), I think, it is about 20k to replace, and a bus would need a much larger pack to haul everything. If they can get the battery's life span down and reliable, or give a lifetime of the bus guarantee, then sure, great. They aren't hazardous to dispose of and in theory could be recycled, just not sure if the tech is there vs good old over head wires that could later be used for LRV. I was also thinking that not just the poles, but the power infrastructure needed could be future proofed for the CR - but, I guess that still isn't going to make much of a dent in anything.
 
Arlington said:
Prius batteries are NiCad and have proven durable across an enormous fleet & range of conditions

Lithium batteries (Tesla, Chevy Volt, Nissan Leaf) prefer the same temps as people, meaning they need to be warmed below 30F and cooled above 80F in order to be long-lasting...fortunately if you are willing to include it in the design, temp-management systems are cheap and plentiful (Nissan Leaf has a heater but no cooler (in order to make its $35k price point) so its batteries fail in places like Phoenix AZ)

Either way, moving ions involves inherently less wear and tear than running on explosions.
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Arlington -- that sounds good until you get into the ugly -- we'll skip the Bad

GOOD has been mostly stated -- Clean Power -- at least if you don't worry about where the electricity comes from and the heat generated at all stages of sloshing the electrons around [barring low cost, reliable, safe super conductors that operate without much cooling]

Well after much soul searching here's the
BAD -- Batteries are not very efficient at storing energy and they gradually get less and less efficient with time -- something about some more massive constituents than just electrons doing some moving -- "good ol lead acid" still is best in that department, although being lead it is destined always to be heavy and there are the issues of disposal

The newer Lithium technologies are much lighter and have a lot more energy density both per unit weight and per unit volume -- although still far far less than gasoline

UGLY -- the newer sexier Lithium Battery Technologies -- store a lot of energy in a small package -- which can lead to fires, and explosions if some generally otherwise ignorable things such as rate of charging and discharging and storage temperature are ignored -- call Tesla or Boeing for examples


Realy UGLY -- the Physics and Chemistry that makes Li good also makes it UGLY -- when you have an ordinary fire you can pour water on it and generally it goes out -- when you have a big-enough Li fire -- the water can chemically react with the Lithium to make LiOH [releasing more energy and Hydrogen gas in the process] so the fire doesn't go out it can get bigger -- to put out a Li fire you need to deprive it of Oxygen -- both from the air and from any extinguishing compound

http://batteryuniversity.com/learn/article/safety_concerns_with_li_ion
A small Li-ion fire can be handled like any other combustible fire. For best result use a foam extinguisher, CO2, ABC dry chemical, powdered graphite, copper powder or soda (sodium carbonate). If the fire occurs in an airplane cabin, the FAA instructs flight attendants to use water or soda pop. Water-based products are most readily available and are appropriate since Li-ion contains very little lithium metal that reacts with water. Water also cools the adjacent area and prevents the fire from spreading. Research laboratories and factories also use water to extinguish Li-ion battery fires. Halon is also used as fire suppressant, but this agent may not be sufficient to extinguish a large Li-ion fire in the cargo bay of an aircraft.

A large Li-ion fire, such as in an EV, may need to burn out as water is ineffective. Water with copper material can be used, but this may not be available and is costly for fire halls.
When encountering a fire with a lithium-metal battery, only use a Class D fire extinguisher. Lithium-metal contains plenty of lithium that reacts with water and makes the fire worse. As the number of EVs grows, so must the methods to extinguish such fires.
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and then there is the problem of damage to a cell from impact, shock, excessive vibration or even flexing -- and if one cell starts to go -- is the ol chain reaction
During a thermal runaway, the high heat of the failing cell inside a battery pack may propagate to the next cells, causing them to become thermally unstable also. A chain reaction can occur in which each cell disintegrates on its own timetable. A pack can thus be destroyed in a few seconds or over several hours as each cell is being consumed. To increase safety, packs should include dividers to protect the failing cell from spreading to the neighboring one. Figure 1 shows a laptop that was damaged by a faulty Li-ion battery.
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^ New Flyer's website shows batteries on the roof of the bus so at least they've put it out of reach of ordinary fender-benders and where any fire won't kindle the bus from below.
 
So batteries are bad because they can't store very much energy, and they store way less energy than gasoline. But what makes them even worse is that they store a whole lot of energy in a small package and can thus burn or explode. Got it.

You know what else can burn and explode? Tanks of diesel fuel, gasoline, or compressed natural gas. Remember that Bolt Bus that blew up on the Mass Pike last year? Bus fires happen practically every day in this country. Here's one from Monday, and here's another from Wednesday. These aren't even caused by collisions, they just happen when those millions of little explosions under the hood get a bit too carried away. Nobody cares about these stories precisely because they are so commonplace, but if they were caused by batteries I can guarantee that you would have heard about them already. Your Porsche is WAY more likely to blow up than your Tesla, and it'll give you much less time to escape when it does. Just ask Paul Walker.

I'm sure that most people on this board fully understand the limitations of battery technology. But most people ALSO fully understand the limitations of internal combustion technology, and one cannot consider the faults of one propulsion technology without considering the faults of the other.
 
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JumboBuc said:
So batteries are bad because they can't store very much energy, and they store way less energy than gasoline. But what makes them even worse is that they store a whole lot of energy in a small package and can thus burn or explode. Got it.

You know what else can burn and explode? Tanks of diesel fuel, gasoline, or compressed natural gas. Remember that Bolt Bus that blew up on the Mass Pike last year? Bus fires happen practically every day in this country. Here's one from Monday, and here's another from Wednesday. These aren't even caused by collisions, they just happen when those millions of little explosions under the hood get a bit too carried away. Nobody cares about these stories precisely because they are so commonplace, but if they were caused by batteries I can guarantee that you would have heard about them already. Your Porsche is WAY more likely to blow up than your Tesla, and it'll give you much less time to escape when it does. Just ask Paul Walker.

I'm sure that most people on this board fully understand the limitations of battery technology. But most people ALSO fully understand the limitations of internal combustion technology, and one cannot consider the faults of one propulsion technology without considering the faults of the other.
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Let us also remember the CNG buses if we are talking about explosive. Yet, I don't recall anyone of them going up. Li-ion batteries are like anything else - if there were manufacturing flaws/defects, you are going to have a bad time. If they are designed and made correctly, they are pretty damn safe - look at all the laptops/cell phones/etc for the past decade+. Also probably getting a bit off topic here - sorry guys.
 
The nice thing about having the simplest possible infrastructure like a plain old road or rail is that you can try out different technologies on top of that infrastructure. Batteries, diesel, natural gas, pedal power... pulled by mules whatever works best.
 
swtat said:
Prius batteries are NiMH, a completely different chemistry. The new buses will utilize lithium-iron-phosphate (LiFePO4) batteries.
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Sorry, yes. Nickel + typo = NiCad ;-)
 
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