Tesla BAMF & Technical Peak Steel on Steel Acceleration.

[route:oxford]

Earlier this week, TESLA revealed their LGV Tractor unit that can accelerate from 0-60 in 5 seconds unloaded or 0-60 in 20 seconds carrying an 36.3 Tonnes load (80,000lb) and can go on to haul said load for up to 500 miles on battery power.

(TESLA use the technical term "BAMF" to promote the acceleration.)

36 Tonnes is the approximate equivalent of a Mk3 coach.

With matching battery and motor units, what would be the expected 0-60 performance of a TESLA loco hauling a Mk3 with good level rail conditions?

 

[furnessvale]

I'll wait for the technical guys to come in on this, but it looks like Tesla have solved all the battery problems which have beset railways for years.........
..............in their dreams!

 

[NotATrainspott]

What Tesla have done is made electric performance available in a truck format. Electric traction is what makes that sort of performance possible - the batteries just need to be enough to feed the peak demand. On the railways, we already know what happens when electric traction and sufficient power are available. If you coupled a single Mk3 to any modern electric locomotive you'd see exactly what would happens.

 

[43096]

What Tesla have done is made electric performance available in a truck format. Electric traction is what makes that sort of performance possible - the batteries just need to be enough to feed the peak demand. On the railways, we already know what happens when electric traction and sufficient power are available. If you coupled a single Mk3 to any modern electric locomotive you'd see exactly what would happens.

Indeed. Having had a Taurus (6400kW continuous rating) on 2 coaches out of Wien West, I have an idea.

 

[furnessvale]

What Tesla have done is made electric performance available in a truck format. Electric traction is what makes that sort of performance possible - the batteries just need to be enough to feed the peak demand. On the railways, we already know what happens when electric traction and sufficient power are available. If you coupled a single Mk3 to any modern electric locomotive you'd see exactly what would happens.

I don't understand.
Are you saying this new lorry is diesel powered and the batteries are just boosters?
If this lorry is 100% battery powered, what weight of batteries are Tesla proposing to move themselves, the tare weight of the lorry plus a payload of 36 tons over 500 miles on a single charge?

 

[NotATrainspott]

I don't understand.
Are you saying this new lorry is diesel powered and the batteries are just boosters?
If this lorry is 100% battery powered, what weight of batteries are Tesla proposing to move themselves, the tare weight of the lorry plus a payload of 36 tons over 500 miles on a single charge?

It's 100% battery electric. But, the performance figures are just what you get when you use electric traction, so long as you can supply the motors with enough juice. Since the initial post was about what the performance of a Tesla Semi-locomotive would be, my answer is that it would be just like the performance of any electric locomotive.

 

[furnessvale]

It's 100% battery electric. But, the performance figures are just what you get when you use electric traction, so long as you can supply the motors with enough juice. Since the initial post was about what the performance of a Tesla Semi-locomotive would be, my answer is that it would be just like the performance of any electric locomotive.

I accept that Tesla MAY be able to provide sufficient tractive effort to obtain the impressive acceleration figures quoted, after which the installed batteries will probably be flat.

My original point was about the ability of Tesla to provide enough battery power to keep this whole loaded rig on the move for 500 miles and still have any space and payload capacity left to earn money.

 

[D365]

Not so relevant to battery locomotives specifically, but I've been doing research into the potential of bolting Tesla powerpacks to existing suburban EMUs. Sufficient to say that there's not much that can be done without a battery pack under every coach, and that's using a best-case model.

 

[w1bbl3]

Well the quoted 36t is the payload capacity, so far Tesla haven't disclosed the train weight for the tractor and trailer unit. The trailer incidentally has underslung batteries which are factored into the 500 mile range. I expect the operating plan would be 500 mile round trips where the trailer can be changed or a single 400 to 450 mile journey where the trailer is changed at each end.

If your a major supermarket, retailer or courier with a captive fleet of tractors and trailers the Tesla Semi does make expensive sense subject to being able to agree a grid connection if you are a general haulier not so much.

For rail the core issue would be charging time for each coach and power requirements to charge a whole train length, also the long term effects of rapid charging on battery longevity.

 

[furnessvale]

Well the quoted 36t is the payload capacity, so far Tesla haven't disclosed the train weight for the tractor and trailer unit. The trailer incidentally has underslung batteries which are factored into the 500 mile range. I expect the operating plan would be 500 mile round trips where the trailer can be changed or a single 400 to 450 mile journey where the trailer is changed at each end.

If your a major supermarket, retailer or courier with a captive fleet of tractors and trailers the Tesla Semi does make expensive sense subject to being able to agree a grid connection if you are a general haulier not so much.

For rail the core issue would be charging time for each coach and power requirements to charge a whole train length, also the long term effects of rapid charging on battery longevity.

Thanks for that. I wonder how many tons of batteries are involved for a 500 miles range.

Every ton has to come out of payload. Max payload in the UK is 29-30 tons BEFORE you start adding heavy batteries to tare weight.

Tesla also seem to have forgotten to put enough axles under their rig for max weight, it should have 6 not 4.

I think Tesla need to look at max vehicle and axle loads available to them in their target markets, be it the US, UK or Europe, and then work back from that to find their allowable payload. Even now, 36 tons is impossible in most of the US and Europe and the UK. I would be surprised if they can carry 20 tons which will shoot holes in their projections.

 

[furnessvale]

I have just been reading that Tesla are claiming a 98% recovery rate for their regen braking.

Given that Pendolinos are supposed to recover around 20%, perhaps Alstom and others should hot foot it to the states to find out his secrets.

 

[CosherB]

I'll believe all of the hype and hyperbole when I see it for real.

 

[coppercapped]

Thanks for that. I wonder how many tons of batteries are involved for a 500 miles range.

Every ton has to come out of payload. Max payload in the UK is 29-30 tons BEFORE you start adding heavy batteries to tare weight.

Tesla also seem to have forgotten to put enough axles under their rig for max weight, it should have 6 not 4.

I think Tesla need to look at max vehicle and axle loads available to them in their target markets, be it the US, UK or Europe, and then work back from that to find their allowable payload. Even now, 36 tons is impossible in most of the US and Europe and the UK. I would be surprised if they can carry 20 tons which will shoot holes in their projections.

This whole truck business is a smoke screen to cover Tesla's appalling third quarter financial results, a $671 million loss.

The shares have also taken a dive since the Republicans stated they want to remove a $7,500 tax credit for electric vehicles.

And the third point is that Tesla hasn't been shipping its Model 3 car - it shipped only about 220 against a target of 1500 for the quarter, to which must be added the first 30 production models which were delivered in July - to Tesla employees.

Musk will have to be careful that the money doesn't run out before the production has been ramped up.

One source of information is here.

 

[edwin_m]

Acceleration is limited by the available adhesion. If all axles are motored then the maximum acceleration as a percentage of gravity is the same as the coefficient of friction between wheel and road or rail. If not all axles are motored then it is factored down by the percentage of weight that sits on motored axles. Assuming 15% friction is available on rail, and guessing that one third of weight is on the tractor axles, the acceleration will be 5%g or about 0.5m/s2. Rubber on road has a greater coefficient of friction so can accelerate better.

60mph (not km/h I presume, OP doesn't state) is about 27m/s s so if unlimited power and motor torque is available the acceleration time will be about 54s. As mentioned, a loco with little or no load will do a lot better than that because most or all of its weight is on powered axles.

 

[Billy A]

Well the quoted 36t is the payload capacity, so far Tesla haven't disclosed the train weight for the tractor and trailer unit. The trailer incidentally has underslung batteries which are factored into the 500 mile range.

Are you sure it's the payload? Maximum weight legislation in the US is a complex subject but trucks travelling between states are often limited to 80,000 lbs gross (36 and a bit tonnes, in English) so I think that's what Tesla are talking about.

 

[WatcherZero]

This whole truck business is a smoke screen to cover Tesla's appalling third quarter financial results, a $671 million loss.

Indeed, they are already taking $5000 deposits for the trucks despite not planning to actually launch sales and finalise spec and price till 2019!

There are several technical questions with the truck, its battery capacity of 1000 kwh would cost $400,000 alone already many times the cost of a $150,000 diesel truck. Its got half the standard 1000 mile range, the 30 minute charging time to 80% charge is ten times faster than Teslas current fastest charging technology. It would require drawing 1.5 MW from the grid while charging raising obvious infrastructure questions. The question of weight (they've jumped straight to the maximum road legal weight with no indication of carrying capacity) finally they have no industrial capacity to begin construction, they aren't even making a quarter of their target car production at the moment and keep launching new models killing production line optimisation efforts.

 

[NotATrainspott]

Thanks for that. I wonder how many tons of batteries are involved for a 500 miles range.

Every ton has to come out of payload. Max payload in the UK is 29-30 tons BEFORE you start adding heavy batteries to tare weight.

Tesla also seem to have forgotten to put enough axles under their rig for max weight, it should have 6 not 4.

I think Tesla need to look at max vehicle and axle loads available to them in their target markets, be it the US, UK or Europe, and then work back from that to find their allowable payload. Even now, 36 tons is impossible in most of the US and Europe and the UK. I would be surprised if they can carry 20 tons which will shoot holes in their projections.

I do think a company worth dozens of billions of dollars will have done its homework before launching a product like this. The worldwide articulated lorry market is not small and there's plenty of data about what sort of trips they need to do. They're not amateurs any more.

Indeed, they are already taking $5000 deposits for the trucks despite not planning to actually launch sales and finalise spec and price till 2019!

There are several technical questions with the truck, its battery capacity of 1000 kwh would cost $400,000 alone already many times the cost of a $150,000 diesel truck. Its got half the standard 1000 mile range, the 30 minute charging time to 80% charge is ten times faster than Teslas current fastest charging technology. It would require drawing 1.5 MW from the grid while charging raising obvious infrastructure questions. The question of weight (they've jumped straight to the maximum road legal weight with no indication of carrying capacity) finally they have no industrial capacity to begin construction, they aren't even making a quarter of their target car production at the moment and keep launching new models killing production line optimisation efforts.

Where did you get $400,000 from? The price point Tesla's business model is built around is $100/kWh and every indication is that it'll be achieved by 2020. Reaching that figure is why the Gigafactory was built.

Remember too that the battery is the only really expensive bit about an electric vehicle. The motors and drivetrain systems are much, much cheaper than equivalent internal combustion units. Even when the battery might be the most significant part of the cost, it doesn't indicate that the rest of the truck would be similarly expensive. The sorts of companies this truck is aimed at just care about the long term. Walmart can easily borrow billions to fund trucks and renewable electricity generation when they work out that the reduction in operating costs is so significant.

The hard bit of the Model 3 production line seems to be the battery and drivetrain. But, these are actually things that the truck can largely share. Once you've got the production line to build Model 3 battery packs, having a slightly different line installing the cells and cables in a slightly different configuration for truck use doesn't require the wheel to be re-invented.

 

[WatcherZero]

You would have thought that, however they have had significant trouble adapting to the Model 3 from previous models.

 

[furnessvale]

You would have thought that, however they have had significant trouble adapting to the Model 3 from previous models.

Also, no mention of the battery capacity and weight needed to propel this vehicle as claimed in the almost unwatchable video at the start of this thread.

 

[route:oxford]

Acceleration is limited by the available adhesion. If all axles are motored then the maximum acceleration as a percentage of gravity is the same as the coefficient of friction between wheel and road or rail. If not all axles are motored then it is factored down by the percentage of weight that sits on motored axles. Assuming 15% friction is available on rail, and guessing that one third of weight is on the tractor axles, the acceleration will be 5%g or about 0.5m/s2. Rubber on road has a greater coefficient of friction so can accelerate better.

60mph (not km/h I presume, OP doesn't state) is about 27m/s s so if unlimited power and motor torque is available the acceleration time will be about 54s. As mentioned, a loco with little or no load will do a lot better than that because most or all of its weight is on powered axles.

It's mph - Americans are hopeless with metric.

So essentially a Tesla powered rail vehicle wouldn't accelerate any quicker than a Pendolino.

 

[edwin_m]

I do think a company worth dozens of billions of dollars will have done its homework before launching a product like this. The worldwide articulated lorry market is not small and there's plenty of data about what sort of trips they need to do. They're not amateurs any more.

If something is seen as a disruptive technology then certain investors will throw billions at it, almost regardless of practicality. So they can afford to take some risks and lose out on the odd failure - which after all is a good route to success - just so long as they keep saying and believing the hype.

 

[NotATrainspott]

You would have thought that, however they have had significant trouble adapting to the Model 3 from previous models.

The Model 3 is a new generation of vehicle rather than just a reconfigured version of the S. The Model '1' was the Tesla Roadster, which demonstrated what was possible using lithium-ion batteries in a car. The Model '2' was the Model S, which demonstrated what was possible when you designed a car from the ground up to use those lithium-ion batteries. The Model X was just meant to be a Model S in a hat - a way of adding a popular new model while not having to pay to re-engineer everything from scratch. If they hadn't gone for the daft falcon doors that would have worked just fine. The Model 3 uses a new generation of systems, like the the new 2170 battery cells rather than the standard 18650s used in the Roadster, S and X and every other application of standard cylindrical lithium-ion cells. Future Tesla vehicles like the Model Y, Semi and Roadster II will use those same technologies.

If something is seen as a disruptive technology then certain investors will throw billions at it, almost regardless of practicality. So they can afford to take some risks and lose out on the odd failure - which after all is a good route to success - just so long as they keep saying and believing the hype.

Is anyone genuinely saying that battery-electric vehicles aren't practical now? The major players in the trucking industry are all working on battery models now. It's not a question of if, but of when, and investors are obviously excited about being first on the bandwagon and able to get the most out of the first-mover advantage. Without investing, companies aren't going to have an easy time adjusting if they want to continue doing high-value, profitable work. A company which didn't bother investing in electric vehicle technology could clearly survive in future by just buying in whatever systems (batteries etc) they need from external companies but then they're just bolting things together, being totally replaceable by any upstart with their own factory. Sony, LG, HTC etc are finding it tough right now when they've got no special role in developing the software for their phones and they're being out-competed by Chinese OEMs making slim profits on huge volume. All the value is in the hard bit that Google and Apple had the foresight to invest in, and Samsung are desperately playing catch-up for.

 

[furnessvale]

NotATrainspott, you obviously have some detailed knowledge of battery powered road vehicles.

Perhaps you could assist with some ballpark figures as to how much onboard stored electrical energy will be required to move 36 tons 500miles over level ground at, say 50mph, and how that converts into batteries, especially the weight which, of course has to be deducted from payload.

 

[Bald Rick]

I have just been reading that Tesla are claiming a 98% recovery rate for their regen braking.

Given that Pendolinos are supposed to recover around 20%, perhaps Alstom and others should hot foot it to the states to find out his secrets.

Apples and oranges I'm afraid.

The 20% that Virgin claim is that in braking they regenerate approximately 20% of the total power used; ie if a trip from London to Birmingham uses 1000kWh, 200kWh is regenerated through braking. Personally I don't believe the 20% figure on long distance high speed operations, although it is likely on commuter operations.

The 98% that Tesla claim is a different measurement. That is that 98% of the electricity generated during braking makes it to the batteries. The other 2% is lost (as heat) as it gets converted and conducted from the motor/alternators to the batteries.

 

[furnessvale]

Apples and oranges I'm afraid.

The 20% that Virgin claim is that in braking they regenerate approximately 20% of the total power used; ie if a trip from London to Birmingham uses 1000kWh, 200kWh is regenerated through braking. Personally I don't believe the 20% figure on long distance high speed operations, although it is likely on commuter operations.

The 98% that Tesla claim is a different measurement. That is that 98% of the electricity generated during braking makes it to the batteries. The other 2% is lost (as heat) as it gets converted and conducted from the motor/alternators to the batteries.

Thanks for that. Even so, a 2% transmission loss seems very impressive. Like most of the video presentation, Tesla were studiously giving answers to questions no one was asking.

Regarding Pendolinos, given the twisting nature of the WCML, I am not too incredulous at the Virgin claim.

 

[dubscottie]

I'll believe all of the hype and hyperbole when I see it for real.

Reminds me of DeLorean. Looks like a massive con job.

 

[hwl]

Apples and oranges I'm afraid.

That is that 98% of the electricity generated during braking makes it to the batteries. The other 2% is lost (as heat) as it gets converted and conducted from the motor/alternators to the batteries.

That 2% sounds very heroic - it would require permanent magnet motors, SiC MOSFET electronics and optimum conditions that don't exist across the whole motor speed range...
I might there for suggest the 2% loss rate is the best achievable not the average. (The best SiC MOSFET available today gets 98.2% under very limited conditions, hence this is where i suspect the 98% number is lifted from)
How are they accounting for the blower motor energy usage needed to help keep traction motor efficiency high at lower rpms for example?
One gets the feeling the numbers used are very selective!

 

[jon0844]

Reminds me of DeLorean. Looks like a massive con job.

And a great deal of the press, or at least what Joe Public now read, won't be asking tough questions and are in awe of Elon Musk, so would never dare say anything remotely negative. (A bit like Apple to a degree, but much of that is about not risking being taken off the press list and not being given early access to devices or invites to keynotes).

These are sites or publications with little technical knowledge, and are just as excited about Hyperloop (and the belief it's just around the corner), Solar freakin' roadways, modular roads or some other pie-in-the-sky idea. Not that electric vehicles, solar charging or home battery packs are pie-in-the-sky, but perhaps not quite as well developed as some would like us to believe.

The people that do ask questions are likely dismissed as being overly pessimistic, or perhaps unaware of just how clever Elon is - and must know more than anyone else, or how could be so successful and rich?

He is a visionary, but I suspect things aren't quite going to plan. Now it's a case of asking for money up front for something tomorrow, to cover the bills for today. Just like taking out a new credit card to borrow money to pay the minimum balance on your maxed out cards.

If investors get cold feet (I assume they won't, as it's Elon freakin' Musk) then there could be problems.

More likely is that other companies will catch up, or perhaps even overtake, if Tesla experience more problems that gives others that opportunity.

 

[43096]

These are sites or publications with little technical knowledge, and are just as excited about Hyperloop (and the belief it's just around the corner), Solar freakin' roadways, modular roads or some other pie-in-the-sky idea. Not that electric vehicles, solar charging or home battery packs are pie-in-the-sky, but perhaps not quite as well developed as some would like us to believe.

You could just as easily level this criticism at some on the railway, including DfT, who think that batteries or fuel cells or any number of other (unspecified) new technologies are an alternative to electrification. Roger Ford's view of them as "bionic duckweed" is pretty much spot on.

 

[janahan]

Having regularly using the 521 London Bus between Waterloo and Holborn every day (a BYD tech fully electric bus), I really think that electric traction over batteries is REALLY the way forward. These things have crazy acceleration, and insane torque (probably a bit too high for a bus, as there are plenty of standing pax, and you REALLY have to hold on sometimes).

I am not sure how often they are charged, but they are running a fairy intensive route, and it does seem quite obvious they use regenerative braking (you can hear the sound from the traction motors change during braking), and its pretty effective.

I guess with new work on carbon tube tech, and other nano tech, together with super caps, stored electric vehicles are only likely to improve. And in the case of rail, where you actually have existing electric infrastructure (OHL, etc) I only see battery only and "bi-modes" becoming more prevelent in the future, as the cost of the battery tech may soon become cheaper (both buy and maintain), and weigh less than the equivalent diesel engine/fuel tank/.