Israeli Start-Up Creates Turbine-Powered Hybrid From a Toyota Prius

[n2doc]

by Scott_Evans

From the Chevrolet Volt to the Chrysler ENVI vehicles to the Fisker Karma, many automakers seem to agree that extended-range hybrids are the way of the near future. While they all rely on traditional piston engines to provide power to their electric motors, Israeli company ETV Motors thinks a tiny jet turbine is a better way to go.

ETV's prototype, a modified Toyota Prius, works the same way a Chevrolet Volt does, just with a different powerplant. The micro-jet engine is not connected to the wheels but rather to an electric generator that produces power to drive the wheels or recharge the battery pack. ETV claims their car can travel 35 to 50 miles on a charge before the jet engine needs to be fired up, but doesn't say how far the car can go with the turbine creating power. Unlike turbine-powered cars of the past, reports claim that ETV's prototype is whisper quiet on the road and can barely be heard starting up.

What remains to be seen, though, is whether the turbine engine is any more efficient than a conventional piston engine performing the same task. ETV claims that their technology will be cheaper than other hybrid systems on the market today, when it finishes development and goes into testing next year. ETV does have an advantage built into their design, in that turbine engines easily run on a variety of liquid fuels including gasoline, diesel, bio-fuels and more. The turbine will run at a constant speed of 80,000 rpm to maximize efficiency.

What may be a bigger breakthrough, though, is ETV's battery technology. The company also claims to have invented a new type of lithium-based battery that uses Lithium Manganese Nickel Oxide. The batteries are the first of their kind to have 4.7-volt cells rather than a standard lithium-ion battery's 3.2-volt cells. The higher density battery stores more energy which allows for greater range with a smaller battery, and the battery is expected to last the life of the car.

http://wot.motortrend.com/6534415/technology/israeli-start-up-creates-turbine-powered-hybrid-from-a-toyota-prius/index.html

[madokie]

1. That all sounds good

I like the idea of using an engine tailored to one speed rather than having a wide operating range like we have with our ICE's. It's much easier to design them to be more efficient that way.

[kristopher]

2. Exactly what I was thinking.

Turbine efficiency is bound to be considerably higher than reciprocating pistons, and a lot less complex.

[excess_3]

3. efficient? how so?

traditionally, small turbines have been very inefficient.

the only advantage I see here,
is the capability to burn any liquid or gaseous fuel

[kristopher]

4. Depends on what you are comparing it to

When compared to large turbines they certainly deliver lower levels of efficiency. When compared to the approximate 15% efficiency of your typical automobile drive train, however, we could expect an 80-100% improvement.

With battery improvements that are in the pipeline this would be a short term accommodation on the path to full electric.

[happyslug]

6. Small Turbines are very efficient, the problem is they have only one speed, FAST

Small Turbines are less fuel efficient in direct drive applications do to the fact turbines in reality have two speeds, very fast and off (Jets use afterburners to increase speed in turbines but only for short bursts of speed, such after burners just go through fuel). Given these two speeds and that most cars end up idling their engines at stop signs and while on low speed streets, conventional piston engines, given the fact they can idle at low engine speeds, use less fuel in such applications then Gas Turbines.

In a hybrid the advantages of low fuel use by piston engines while idling disappears for all the engine is doing is charging the battery and the battery actual provides the electrical power needed to propel the car. Thus a gas turbines better fuel efficiency at its optimum operating speed can come into play no matter what the car itself is doing i.e. if the car is going slow on a low speed street but its battery needs charged the turbine can kick on and operate as its top engine speed and that operation will have no effect on how fast the car is going or is dependent on how fast the car is going (and please note when I am using the word "Speed" I am generally referring to how fast the engine is operating at NOT how fast the car is going unless the use clearly is in reference to the speed of the car itself).

Even in the Prius with its conventional piston engine the engine cuts off once the battery is charged and you go by battery supplied electrical power till additional power is needed, then the piston engines restarts. With Hybrids a turbine's superior efficiency when operating at speed will increase fuel efficiency of the car over a piston engine.

I first read of a proposed Gas Turbine Hybrid in Scientific American in the early 1990s (It was attached to an article about the Peak Oil which the article said would occur around 2010).

Please note I am NOT an advocate of Hybrids, I believe they are a blind alley on the way to better fuel economy. Hybrids only exists do to the fact most people are NOT willing to down grade the performance of their car to improve fuel economy. In the 1970s I remember reading the Auto expert in Popular Mechanic or Popular Science (I can NOT remember which) who said he could NOT see why anyone actually needed a car with an engine larger then 2.5 liters (and that was in the days where most US made cars had 5.0 liter or larger V-8s, through by the mid 1970s even US car makers were downsizing engine size). Today, why do we need a car that goes 105 mph? Yes, some areas out west are miles and miles of miles and miles but even Montana had to pass a speed limit, furthermore as you double speed, you square (and sometime cube) the fuel usage. For example people will use twice as much fuel at 60 mph that they use at 40, everything being the same (i.e. in a car design to operate at 60 mph). Al Gore's son when he are chased by the Police in early 2008 had his Prius going 105 mph so such top speed can be achieved but other then running from the Police why do you need to be able to go 105 mph? Police, Fire, Ambulances and other emergency vehicles can be designed to go that fast but why should a car whose existence is to get its owner to and from work?

Thus I am more an advocate of the "City Car" concept then the hybrids. The VW Lupo was the classic "City Car". The Lupo did 78 mpg (Through that is NOT an EPA calculation do to the fact the Lupo was Never sold in the US). The Lupo did this by using a very small engine and having an electrical system that turned on and off that engine when it was not needed. Other power hogging devices were NOT put in the car (Power windows for example) or replaced by much high price mechanical systems that did not need power (An Advance Rack and Pinion Steering instead of power assisted steering). The engine was a 1.0 liter diesel tied in with a Automatic transmission (With manual override). In addition the car used a lot of light-weight aluminum and magnesium alloys to minimize weight and thus reduce fuel usage. VW stop making it in 2005 for all of the above made the car expensive to produce and the City Car Market is known to be very price sensitive (And thus was replaced by the less efficient but cheaper to make VW Fox).

The Daimler SMART car is another example of the City Car, again reduced top speed capacity do to use of a very small engines (Again like the Lupo a 1.0 liter engine). The SMART car does NOT do as while on the EPA tests as does the Prius for the SMART is not really designed for operating at 50 mph (Thorough even the SMART car can get to 90 mph on a flat road).

The Classic examples are the Japanese Kei Cars, these have engines SMALLER the 630 cc(.63 liter) but like the Lupo NOT imported into the US (Through at one time Nissan was suppose to do so in 2009, but I have not heard of that plan since mid 2008 when gasoline prices started to fall). These all promise to get better then the 78 mpg of the Lupo but as top operating speeds of less then 50 mph.

Now some people will say such cars can NOT operate on US Roads, but the laws that cover those roads (Except limited access highways like the Interstate highway system) not only permit such cars but permit bicycle, horse drawn and even people drawn carts (The police don't like them for people complain that they slow down automobiles, but unless it is a road that was purchased and built for exclusive use of cars, such as the Interstate Highway System, such man and animal powered vehicles are legal, no law says they are legal for the no one wants to address the issue for the courts have long held that to ban them you have to provide an alternative at a similar price, i.e. free and the State and Local Government do not want to provide such free transportation so they ignore the "problems" caused by Bicycles and hand and animal powered vehicles on roads originally built for such vehicles, which are most roads that predate the adoption of limited access highways in the 1930s).

Just a comment that the future of transportation, given the expectation that over the next ten years gasoline prices will go up, the best way to use oil efficiently is to cut down the top speed of automobiles and that can be done by restricting how large an engine a person can buy in a car for his personal use.

Now, the price of gasoline is expected to go down the next six months to a year, do to the drop in usage do to the recession, but that appears to be only a temporary reduction, the over all trend is upward and once the economy re-starts I expect to see the price of oil get back to what it was in the spring of 2008.

More on the Lupo:
http://en.wikipedia.org/wiki/Volkswagen_Lupo

More on the SMART car:
http://www.smartusa.com/
http://en.wikipedia.org/wiki/Smart_(automobile)

On Kei Cars:
http://en.wikipedia.org/wiki/Kei_car
http://wikicars.org/en/Kei_car
http://www.autoblog.com/tag/kei+car/
Please note the above blog shows a 1.5 liter engine Nissan that it calls Kei Car, but Kei Cars are NOT to have engines bigger then 630 cc (or .63 liter).
http://en.wikipedia.org/wiki/Kei_car

[excess_3]

10. do you have any numbers on, fuel consumption of small turbines?

(thanks for posting that stuff)

I find it hard to believe,
that a small turbine is any better
than a diesel.
when both are properly sized.
and run at full load.

'at full load' is completely doable in a diesel,
when driving an electric generator,
'full load' in a diesel can be at various RPMs, BTW

[happyslug]

11. According to this Article "Micro-Turbines" can reach 90% efficiency

Typical micro-turbine efficiencies are 25 to 35%. When in a combined heat and power generation system, efficiencies of greater than 80% are commonly achieved. Through the article admits most of this is new and most only get 5-6%. but we are talking about turbines that can fit in the palm of your hand designed to replace batteries. Later on in the same article they mention the greater efficiency of gas turbines over piston engines BUT not at idle (If an engine has to idle for long periods of time or otherwise NOT reach its peak speed, conventional piston engines are more efficient, gas turbines are only better at top speed and thus why people are looking at them for hybrids for with hybrids the engine does NOT have to idle, it can just be turned off till needed.

http://en.wikipedia.org/wiki/Gas_turbineThrough most

While looking at other article to support my claim, I ran across this article on Gas turbine Locomotives used in the 1950s-1970s. These were NOT true hybrids, they had no way to store electrical power. Thus these gas turbine locomotives, like diesel locomotives, used their engines to generate electrical power that propelled the actual locomotive. Notice the problem, no storage of electrical power thus the gas turbine must operate even when the locomotive is NOT moving (Railroads do the same with diesel, but diesel can idle at low RPMs, Turbines can not). Thus these early gas turbine locomotives all failed do to excess fuel use. A hybrid would solve that problem (Union Pacific seem to have solved some of the problem by running multiple locomotives, just turning on the Gas Turbine locomotives when extra power was needed, but was on its routes through the mountains where the extra power was needed).

http://en.wikipedia.org/wiki/Gas_turbine-electric_locomotive

One last comment, remember most Gas Turbine Research has been in regards to Jet Engines or Auxiliary Power Units (APUs). APUs tend to be Gas Turbines in stationary units to provide electrical power for Large Air Conditioning systems, the energy used is Natural Gas. These tend to be the size of a car's engine but stationary. High efficiency are reported for them. Now, when I did a Google search on APUs I ran across a lot of Diesel engines APUs, mostly for truckers who are becoming more and more under "No Idle" Rules, thus these APUs provide power to their trucks when the truck is sitting but some power is needed. Given then Truckers, like a lot of people, are price sensitive (i.e. the price of the unit is often more important then the price of operating the unit) cheaper conventional diesel engine are used. People forget that Gas Turbines, over the life of the engine, will provide more economical overall price (If engine operates near full speed and most engines do not) then any other engine, but at a much higher up front cost. This seems to be the big reason Gas Turbines have NOT made it into the Automobile market, prices that make diesel engines look cheap for a car most people only want to keep for 3-5 years (Cars last over 10 years today, but most New Car Buyers trade them in after 3-5 years which is NOT enough time to get maximum return on the investments, jets and ships are used for 20 or more years and thus Gas Turbines are looking better and better for them).

Thus the main reason Gas Turbines are not researched is the high cost to produce and the high price the finished product must sell at to make a profit. Car makers have made Gasoline and Diesel engines for over 100 years (Diesel for a lesser time period) AND as such have a system to make such engines. When it comes to capital expenditures, the huge expenditure is in making a Car's Engine, the body and other items do not require the Capital investment the engine requires and once spent the tendency is to use what you have which is piston engine technology. Thus the Automobile makers tend to stay away from Turbines and stay with their more cost effective (Noted I used the term Effective not Efficient) piston design and as such any switch to turbines will take decades.

The Model T came out in 1907 but horses were still being used to haul Milk in most Major Cities till the late 1930s (and came back for the duration of WWII). Thus you can say it took 30 years AFTER the gasoline engine was ready for widespread use to replace the horse (Gasoline engines existed as early as the US Civil War, but NOT for widespread use till about 1900). The Gas Turbine/Hybrid car has not even been built yet, talked about, researched etc., but is no where near production, thus the Gas Turbine is like the Gasoline Engine of the Post Civil War Era, something everyone knew was coming, but needed extensive work to get it to replace existing technology (And while the Gas Turbine is more efficient then the Piston Engine, its overall efficiency is NOT as great as the Gasoline powered car over a horse drawn wagon).

[hunter]

5. Multi-fuel capability is more of a military consideration than anything else.

For large civilian vehicle fleets the cost of each vehicle is lower and the efficiency is higher when the vehicles are optimized for one specific highly refined fuel.

If this company gets off the ground I suspect they'll be selling F-34 / JP-8 fueled vehicles to military customers.

[happyslug]

7. Do you know the Difference between JP-8 and Diesel is?

The tax rate is the big difference (JP8 and Commercial JP-A are NOT taxed while Diesel #1 and #2 are). As far as the Jet Engine or Diesel engine (or even the oil furnace in your home) Diesel #1, JP-8, Home Heating oil #1 are the same. Now each grade of oil have different specification but the range of those specs overlap extensively, thus except for the additions in the fuel, all are interchangeable within a oil grade # (thus #1 Kerosene and #1 Diesel can be used in any thing designed for #1 Diesel or Kerosene, Fuel Oil or even Jet Fuel) Furthermore the difference between #1 and #2 has more to do with the fuel use in Cold Weather, #1 works better in cold weather being closer to Gasoline in nature (Through Gasoline is NOT in the fuel list, it is called a "Higher Fuel" for the engines that use it need a spark plug unless Fuel Oil engines which do not but work off compression instead).

Now, JP 8 has some additions that makes it rougher on fuel pumps and ejectors of diesel engines over the long term (i.e. years NOT months of use) as compared to No 2 Diesel, but that is the result of the additions to the fuel not the fuel itself (and the fact that JP-8 is a variation of Kerosenes and Diesel #1 then Diesel #2), but a change in the maintenance of such engines should correct that problem.

For more on JP-8 and Diesel:
http://www.quartermaster.army.mil/OQMG/professional_bulletin/1997/Autumn/singlefuel.html
http://en.wikipedia.org/wiki/JP-8

Classes of Oil:
http://en.wikipedia.org/wiki/Fuel_oil

US Army new Stove that uses Diesel/JP-8 to replace the WWII era M2 Gasoline Stoves:
http://www.dscp.dla.mil/subs/rations/dfs/mbuabt.asp

I mention the stoves for they were the one area the Army had a problem replacing MoGas (Gasoline) with diesel (and now JP-8). Gasoline just burns cleaner then Diesel and thus in the M2 Stoves you jut burned the fuel below the food knowing the gasoline vapors will NOT get into the food. You can NOT do that with Diesel or JP-8, thus the Army could not just replace the small burners of the M2 with diesel burners. Instead the Army had to design a whole new stove which separates the diesel fumes from the heat.

When I was in the National Guard in the 1980s the talk was to convert from the M2 Gasoline Stoves to microwave ovens powered by electricity from diesel generators. That plan must have failed and now a new stove is being introduced to get the Army away from gasoline. Small diesel engines could provide the electrical power for in that application for the lack of power at low speeds that I speak of below does NOT come into play in operation of generators.

People tend to forget one of the reason the Army replaced the M151 Jeeps with the Humvees was do to a switch to Diesel fuels and the problem the Army had in designing a small diesel engine that can provide the needed power in four wheel drive situations. The Jeep's engine was gasoline powered with gasoline's superior power at low speeds and high revolutions. Diesel's engines of the same size could NOT provide any where near the power needed to get out of mud holes (larger diesel engines could but not the engine size needed in a Jeep). A good comparison was the Army's use of the Commercial "Gator" series of Diesel off road vehicles in Afghanistan. The Gator provided a small, Jeep Size vehicle, with a diesel engine for off road use but could NOT be used on any highways do to its low speed and thus was hauled to where it was needed by Truck (the Gasoline engine of the M151 could do BOTH Missions). To achieve its high off road capability the Gator had to compromise top speed, its top speed is 18 mph, thus it can not be used on road.

On the other hand once you go to a large enough diesel engine the power problems in low speed situation (Mud holes) solves itself just be the size of the engine. Thus Tanks and 2 1/2 ton trucks converted to Diesels in the 1960s without much problems, but the Army had problems when it came to a vehicle the size of the M151 (Which is 2/3 the size of today's Civilian Jeeps and twice the off road ability).

Now by the 1970s it was clear the M151 had to be replaced, while no one questioned its off road capability, it had a terrible record as to safety. Thus the M151 had to be replaced but with what? A new Jeep was not possible given the problem of designing a effective small diesel engine. A hybrid would have solve the problem (Electrical motors have tremendous low speed power) but not in the cards in the 1970s. Thus the Humvee was adopted for it used what the Army thought was the smallest Diesel it could purchase commercially and provide the power for off road use. Replacing the Jeep with the Humvee was one of the last steps in switching from Gasoline to Diesel but it had to be done to make the conversion (and replacement of the WWII era M2 stove seems to be the last big hurtle on that conversion).

More on John Deere "Gator":
http://en.wikipedia.org/wiki/John_Deere_Gator
http://www.globalsecurity.org/military/systems/ground/m-gator.htm

One last comment, the M151 was brought out of retirement in the mid 1990s to patrol the area between Macedonia and Serbia when Macedonia declared its Independence and both sides agree to US patrol of the border. The roads in the area are so narrow the Humvee was useless, it was to wide and thus the US Marine Corp (Which from what I remember had the honor of patrolling that area) used M151s for only the M151 could provide the off road ability AND be small enough to operate on those goat paths called roads in that part of Europe. At about the same time someone was trying to interest the Army and Marines in building a Hybrid about the size of a M151 Jeep for such situations. The proposal went no where but the Situation in Macedonia shows they is still a need for a vehicle the size of the M151 Jeep.

[hunter]

8. JP-8 can be a much dirtier than ultra low sulfur diesel highway fuel.

With up to 3000 ppmw sulfur JP-8 is not something you want your neighbor to use in his house or his car.

I read your interesting post (thanks!), and I skimmed through some of your links, and it's pretty clear the original post is NOT happy good E/E news.

When Arnold Schwarzenegger buys a shiny new mini turbine powered hybrid humvee I will not be impressed... :P

[kristopher]

9. How is a dramatic improvement in efficiency

not "happy good EE news"?

[hunter]

14. It depends what you are increasing the efficiency of, doesn't it?

Cars would be one example. I'd pick fewer automobiles over increasing numbers of more efficient automobiles.

If automobiles didn't require any fuel at all they would still be very destructive.

[kristopher]

15. That's 'birther' logic.

I live in the real world where real options are required.

[hunter]

16. Real world?

In the real world options are always a temporary situation.

As they say in the Emergency Room, "the bleeding always stops."

In my vision of a better future there are far fewer automobiles.

But it will not be a better future if we continue to waste diminishing resources trying to sustain it.

I very much doubt renewable energy schemes can support a society dependent upon the automobile. If we continue to burn fossil fuels at a high rate then climate change will simply break apart the economy that makes the mass market for automobiles possible.

[kristopher]

18. Some things are a matter of opinion others are matters of fact...

That's why I relate you to the birthers. They too care not for verfiable fact if it gets in the way of their preselected conclusions. You say you doubt renewable energy "schemes" can support a society dependent on the automobile, however the FIRM resource availability numbers and the FIRM numbers flowing from the various energy extraction technologies PROVE that you are not correct. It is, as now, a complex system, but it isn't too complex to understand if you wanted to.

[hunter]

19. In the real world growth always stops, especially exponential growth.

In the real world most species of life have gone extinct and most complex systems have failed.

I have zero confidence that our present economic system will remain viable. Ominous signs of increasing instability are everywhere.

In the sustainable economic system that emerges I don't expect there will be much room for personal automobiles.

It makes no difference to me if you are betting (or hoping...) there will be room for your car. As a society we will either have the capacity to support the widespread use of personal automobiles as we do now, or we won't. I'm betting we won't.

[wuvuj]

12. I've had experience driving both a diesel and gas powered...

...Ford Escort 2 wheel drive car. The diesel engine was rated somewhat under the gas engine as far as HP...but it seemed to drive just as fast as the gas engine..and as a plus it had much more torque at low engine speeds...but probably a little heavier than the gas engine...I got a constant 49 mpg with it. While the gas version might have done 30 mpg?

Geared right...I'd guess a similarly rated diesel engine would outperform a gas engine off road...and likely equiv on road too.

[happyslug]

13. The problem with diesel is NOT top speed but acceleration

Race cars tend to use Alcohol for the simple reason it is even better then Gasoline at providing a burst of acceleration in adverse conditions. Top speed is NOT the issue, all four type of engines (Alcohol, Gasoline, Diesel and Gas Turbines) provide excellent top speed performance. The problem for off road vehicles is NOT top speed but power under adverse road conditions (i.e. a mud pit). All else equal (And that is rarely the case) Gas Engines provide more power in such saturations (And Alcohol does it even better, but expensive thus only used in Race Cars).

The John Deer "Gator" is an excellent example of this, its max speed is driven by its wheels which provide excellent off road performance but without an ability to go faster then about 20 mph. The old M151 jeep could go anywhere the Gator can go AND go on Highways at speeds up to 50 mph. The reason? The M151 had very narrow wheels which when combined with the gasoline engine could provide power in both situations while the gator do to it having a JP8 powered engine had to opt for one or the other in terms of Wheels and Transmissions.

When I was in the National Guard in the 1980s I drive M35 2 1/2 tons trucks. My unit had three types, the original M35 series with a Gasoline engines, some "Multi-fuel" engines versions and mostly diesel powered trucks. The "multi-fuel" were Diesel trucks that were designed to be able to use Gasoline in a pinch (Gasoline mixed with lubricating oil, I forget the exact mixture we only had to do it once, our mechanics hated those things even without using gasoline in them). Both the true Diesel and gasoline trucks were viewed as better trucks, through the Gas jobs had engines and transmissions that were 40 years old at the time I was driving them (and these gas jobs were re-engined as diesels with new Transmissions by the time I was leaving the Guard in 1989). If you took into consideration that the Gasoline jobs were 40 years old and needed rebuilt (and broke down frequently do to their age) they actually had more power then the Diesels when we went off road (Which the M35s were designed to do). I mention this for the Trucks, engines and transmissions were all similar (The Diesel Trucks were all converted Gas jobs with new Engines and Transmissions so a good comparison). In Convoy on the highway both went about the same top speed.

Now I mentioned No Special Convoys for any type of M35 truck. The older soldiers in my unit mentioned the M135 series of Trucks they had prior to getting the M35 series. The M135s had to go in their own convoy for on the flats they could keep up with the M35s, but once you hit the mountains the M135 fail far behind. This was to do with the M135 being 1950s designed automatics while the M35s were post WWII manual transmissions. Yes the M35 were designed first but as an "Interim" design till the M135 could be produced, the M135 came on line during the Korean War and promptly show that the older M35 and WWII era 2 1/2 ton trucks with manual transmissions were way better, thus the Army retired the M135s starting in the 1950s (First to the National Guard and other Countries and then the junk yard) and kept the older M35, some to this day (Through most have been rebuilt at least one more time since the 1980s when I was driving them).

The other Special Convoy Vehicles were the Dodge Pickups the Army purchased as part of the 1970s Government efforts to bail out Chrysler. These were all dogs, we tried NEVER to take them off road and when we did kept a M35 around to pull them out of any mud pits (Which almost never stopped a M151 Jeep or a M35). The army had purchased these Pickups with bad tire and rather then turn them in, the Army restricted the top speed the pickups could go, thus all such pickup has to go in their own convoy when none of them could go faster then 50 mph even down hill.

Anyway, back to the M35s. The Gas jobs always gave me the feeling I had more power from a Standing stop then any of the Diesels, once the trucks was moving the Diesel equaled the Gas jobs but it as that initial movement that gave the gas jobs an edge and that was do to its Gasoline engine not anything else.

Side Note: When Diesel-Electrics locomotives (Which is the better name for what most people call Diesel Locomotives) started to replace Steam engines this first occurred on passenger trains. The reason for this is often shown in old Comedies of the 1920s-1950s (The Music Man starts with such a scene). The train would stop with a jerk and then restart with a Jerk. These Jerks were do to the rapid setting of the brakes on each car of the train when the train came to a stop and the rapid release of those brakes when the train re-started. Steam engines needed that jerk to start moving for while Steam Engines had more power then a Diesel, the Steam engine had a hard time starting to move, thus the jerk caused by the release of the brakes propelled the engine forward and started it to move, once it started to move the steam engine could take over. The problem was getting it to START moving NOT moving per se. Diesels being Diesel generators supplying electric power to Electric engines could start without that push, electric engines have the highest ability to accelerate. Thus the first trains (Other then switching engines in train yards) to use Diesels were Passenger trains to eliminate the need for that Jerk to start the train. There were other reasons for Diesel to replace Steam (Steam engines needed perfect tracks, diesels do not, so less maintenance of tracks were needed, The above jerk was rough on the track, without those jerks less maintenance needed, no need for water towers for Diesels and finally the ability to operate diesels powering a train from one locomotives instead of having a crew in each engine) but the ability to get rid of the Jerk to push the Steam engine was one of the more important factors. I mention this for people tend to forget that top speed is NOT always the same as the ability to start, two different set of forces are at work and an engine must be able to do both, gasoline engines just do a better job at such starts then any other engine (With the exception of Electric Motors).

The opening Scene of the Music Man I make Reference to:
http://www.youtube.com/watch?v=JZ9U4Cbb4wg

[JohnWxy]

17. very clever! You really can just run at an optimal speed for the turbine. No need to have a broad

power range for moving a vehicle from a dead stop to highway speeds. Very Interesting.