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Locomotion: The Next Generation

Written by Iver P. Cooper

In "Harnessing the Iron Horse" (Grantville Gazette 7), I speculated about the evolution of the steam locomotive. My focus was principally on what might appear within the first decade after the Ring of Fire.

In this article, I will look further along the time line, at what might one day replace the steam locomotive. While Steam will be King in the 1630s, and for years beyond, there will be experimentation in the 1640s, and perhaps earlier, with alternative motive power technologies, and that will in turn affect how governments, investors, shippers and passengers view steam.

It may take one or more generations before these alternative systems become commercially significant, but their day will come.

First, let's look at what fuels could be available, and in particular, what the oil situation is likely to be a generation after RoF. Then we'll systematically review our power plant and transmission options, and finally we'll consider the economic aspects of the choice among steam, diesel and electric operation.

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Fuel

Fuel is the food of the locomotive. The important considerations with fuel are energy/unit mass, energy/unit volume, cost, and more difficult to quantify factors such as safety and ease of handling.

The energy densities vary according to the number of C-C and C-H bonds in the molecules of the fuel, but here are some typical figures:

Fuel	energy:mass (MJ/kg)	energy:volume (MJ/liter)
natural gas, uncompressed	53.6	0.0364
natural gas, compressed to 3600 psi	53.6	9.0
liquefied propane	49.6	25.3
gasoline	46.4	34.2
kerosene (jet fuel)	42.8	33.0
diesel, automotive	45.6	38.6
biodiesel	42.2	33.0
coal, anthracite	32.5	72.4
coal, bituminous	24.0	20.0
coal, lignite	14.0
ethanol	30.0	24
methanol	19.7	15.6
peat briquette	17.7
wood (green)	10.9
wood (air dry)	15.5
wood (oven dry)	20.0

(Wikipedia/Energy Density, except wood: PHT)

Wood. For millennia, wood has been burnt to generate heat. Sweden, Norway, Finland, Russia, the Baltic states, Bosnia-Hercegovna, and parts of Germany, Austria and Hungary are heavily forested. Cooper, "The Wooden Wonders of Grantville" (Grantville Gazette 13). The United States and Canada are well-endowed with trees, as is evidenced by the extensive use of wood-burning locomotives for much of the nineteenth century. There are also extensive forests in Central and South America, southeast Asia, Japan, Korea and Siberia, and more limited ones in central Africa, the Himalayan foothills and Deccan plateau of India, and on the periphery of China.

The wood used as fuel needn't be wood that is of value as a structural material (or anything else). In Bolivia, resinous shrubs (yareta) were burnt. (Messerli 174).

Organic waste. 1911EB/Fuel mentions the use of "cotton stalks, brushwood, straw, and the woody residue of sugarcane" as fuel, especially for raising steam. In France and Germany, spent tanners' bark was used to some degree. The dried dung of camels (Egypt), oxen (India), and llama (Bolivia) have also served as fuels.

Coal. From highest to lowest rank (in energy density), we have anthracite, bituminous, sub-bituminous and lignite. In the nineteenth century, a grade between anthracite and bituminous, called "steam coal," was recognized. In addition, note that peat, a precursor to coal, can be used as a fuel. In terms of heating capacity, the general rule is that 2,000 pounds of coal is equivalent to 5,250 pounds (1.75 cords) of wood.

Not that a coal-fired steam engine made particularly effective use of the chemical energy of coal. One pound of good coal in the firebox yields about 15,000 British Thermal Units (BTUs) heat energy, of which 50–80% is transferred to the water. When the steam is released from the steam dome into the cylinders, about 7–11% actually does work (i.e., moves the pistons), and the rest escapes. So the overall thermal efficiency is only about 6% (900 BTU per pound of coal). (EB11). Some sources cite even lower values.

There are major coal fields in modern Germany, England, Belgium, France, Russia, Siberia, the United States, Canada, China, India, Australia and, to a lesser extent, Japan. On the other hand, Scandinavia, the Mediterranean countries, Africa, the Ottoman Empire, Mexico and South America are relatively deficient in coal. Coal is heavy, and it can only be transported economically by sea or by rail.

As a result of the RoF, Germany's natural bounty of coal has been augmented by Grantville's coal mines. Not only is there a considerable amount of coal within the Ring, the miners have up-time equipment for mining it very efficiently. This of course gives all transport technologies that can utilize coal a big boost.

Coal Dust. Diesel's original idea was to use coal dust as diesel engine fuel (Germany having a lot more coal than oil.) There would be expenses associated with drying, pulverizing and sieving coal, but presumably it would still have been less expensive than imported petroleum.

The coal dust was deemed unsuitable after experiments in 1899. (Wells 77). "He observed high wear and accumulation of deposits on the piston and cylinder wall. He ceased working on the concept after an accident (possibly a coal dust explosion) occurred during operation on coal dust." (ADL 2).

The coal dust worked best when the coal was mixed with the air during the suction stroke of the air pump, and this mixture compressed with a bit of liquid oil to make ignition easier. (Wells 78). Even so, there was a problem related to accumulation of a coating of powdered coal on the internal oiled surfaces of the cylinder. Hence, to use coal dust as fuel, the engine needed a separate combustion chamber. It was concluded that liquid fuel was available at a good enough price so that it wasn't worth continuing to pursue coal dust.

Every decade, the idea gets dusted off again. (Groan!) It's believed that in Diesel's experiments, and in later ones conducted during WW II, the coal dust had 10–20% ash and particle sizes of 75–100 microns. There were problems of sludge accumulation, nozzle blockage, and engine wear (35 times normal level in piston rings and cylinder liner).

More recent experiments have had better luck, using slurries of, e.g., 12 micron coal particles in a 50:50 coal-water slurry. (Some coal combustion serving to evaporate the water.) It was still necessary to "harden" the injectors (Cooper-Bessemer used ceramic; General Electric (GE), diamond; Little, diamond, silicon carbide or tungsten carbide), piston rings, cylinder liners and valves. In 1991, a fully modified 2500hp diesel locomotive was run on the GE test track. (theoildrum.com; Wald). The GE work was under contract with the Department of Energy's (DOE) Morgantown, West Virgina Energy Technology Center, so there's a possibility that up-timers in Grantville knew about it.

The materials technology necessary to make coal dust-fired diesels work is probably several decades down the road, but it does mean that we have another alternative to conventional diesel fuel.

Liquefied Coal. Liquid fuel does have certain advantages, and coal can be converted into liquid hydrocarbons by the Bergius hydrogenation process or by the Fischer-Tropsch (FT) process (which first converts the coal to a synthesis gas, a mixture of carbon monoxide and hydrogen, and then that to hydrocarbons). The latter process was used by Germany in World War II (when it was blockaded) and by South Africa (when it was ostracized). FT has high capital and operating costs. It would of course take time and money to reconstruct these processes and it would result in a more expensive fuel.

In 1996 it was calculated that crude oil prices had to be at least $35/barrel for FT fuel to be competitive. (Choi); the oil price was then around $25/barrel. And before you made the capital investment, you of course wanted to be sure that the oil price would remain well above that breakeven point long enough for you to recover and make a good return on your investment.

Raw Coal Tar. This is the water-immiscible residue from the pyrolysis of coal to produce coke or illuminating gas. It was for many years considered to be a waste product, and was used as a secondary fuel under the retorts that produced it in the first place. In Paris, 1830, it sold for 8s/ton, probably mostly for use in waterproofing (Lunge 21). The invention of the coal tar dyes increased the value of coal tar, and in 1883 it sold for 55–63s/ton, dropping to 7s/ton in 1886. (22). When the price was on the low end, or the gas-works or coke-oven was too far from the tar-distiller, it was still burnt. (Lunge 322).

To achieve complete combustion, the tar may be atomized by a steam jet (325), and other tar burner designs were developed in the nineteenth century. The heating value of coal tar is about 37–45% that of coal (329).

Gygax (1446) says that "Many experiments have been made with raw tar as a Diesel engine fuel which have proved conclusively that tar can be used successfully in the ordinary diesel engine," but only "vertical retort" tar has a sufficiently low free carbon content to be suitable.

Coal Tar Oils. It is also possible to use "coal tar oils" as diesel engine fuel. These are distillates (at least 60% distilling at 300^oC) from coal tar (including tar from gas works and coking plants). In 1913, "in Germany and France, the majority of middle sized and large Diesel engines run on tar oil." At the time, Germany was producing 1,400,000 tons of tars, and 400–450,000 tons of tar oil, of which 120,000 could be used in a Diesel engine. The total consumption of Diesel fuel was then 75,000 tons. (Gygax 1450).

It appears that a light oil was blown into the cylinder ahead of the tar-oil charge; it caught fire first and ignited the heavier tar-oil (Morrison 250). However, Morrison doubts that this method would work in an engine faster than 200 rpm. So this might be inadequate for locomotive diesel, but it could be used in a marine engine and therefore free up some conventional diesel fuel for locomotive use.

Tar oils may be made from lignite, not just from bituminous coal. There was significant use of lignite tar-oils as fuel in early twentieth-century Germany. (Gygax).

Naturally, "coal tar oils" may also be burned under the boiler of a steam engine.

Oil. The principal oil regions are in Galicia, Romania, the United States, Canada, Mexico, Venezuela, Russia, the Middle East, and Indonesia The remaining European countries are poorly endowed with oil. Oil can be transported by sea, by rail or by pipeline.

Crude oil is refined into various fractions, notably gasoline, kerosene (jet fuel), diesel oil, fuel oil, lubricating oil, and asphalt. These are differentiated by distillation temperature, viscosity, and cetane number (ignition delay).

It's important to note that the distillation temperature ranges for gasoline (122–374^o F) and No. 1 diesel (300–575^o F) fuel overlap. Where they overlap, gasoline and diesel consumers are in competition for the supply of that "cut."

However, if the demand for gasoline encourages increased prospecting, drilling and production, it will have the side effect of making more No. 2 diesel (distillation 500–640^o F), or heavier oils, all unsuitable for gasoline use, available. And in a like manner, if there is increased demand for diesel, that will "pull" more "light gasoline" onto the market.

In early twentieth-century America, the price of diesel fuel was only about half that of gasoline (SolomonADL 34).

The ideal diesel oil for a diesel engine is dependent on engine speed, with low speed engines such as those on ships favoring heavy, high viscosity oils (no. 5 or 6), and the high speed engines of autos, trucks and buses desiring light, low viscosity oils (no. 1 or 2). Locomotive engines prefer intermediate oils. (Sivasankar, Engineering Chemistry 372).

Petroleum Residues. These are the liquid and solid residues of crude oil distillation, and are a considerable proportion (over 50%) of heavy crudes, such as the shallow Wietze oil or that of Baku. At Baku, they are called "massud," and have a heating value nearly twice that of coal, one pound raising 12–15 pounds steam. The petroleum tar is atomized with steam in a "forsunka" burner. (Lunge 329). Gygax (1455) says that residues containing up to 46–48% asphalt (the material left behind after distillation to 350^o C) "have been used successfully as Diesel engine fuels."

Natural Gas. As of the RoF, some Grantville vehicles and installations are powered by natural gas. Flint, 1632, Chapter 8. Others are converted to run on natural gas, post-RoF. Jones, Anna's Story (Grantville Gazette 1); DeMarce, "Second Thoughts" (RoF2), Howard, "A Gentile in the Family?" (Grantville Gazette 19). A tram is running on natural gas as of early 1634. Zeek, "The Minstrel Boy" (Grantville Gazette 15).

Natural gas is practical as a vehicle fuel only if compressed (CNG) or liquefied (LNG) to increase its energy/volume ratio. Chad Jenkins realized this fairly early, and cornered the market on pressure tanks and their connections, which were the initial limiting factor insofar as natural gas conversions were concerned. Rittgers, "Von Grantville" (Grantville Gazette 4). Of course, both compression and liquefaction require energy.

Grantville has natural gas, but its real-life counterpart, the Mannington field, is not a major field. The largest natural gas field in Europe is the Slochteren field, near Groningen, in the Netherlands; it was discovered before WWII. There are two major fields in Norway (Ormen Lange and Troll), and at least three in western Siberia (Yamburg, Urengoy, Medvezhye). The Groningen field is mentioned in "Grantville literature" but I am not sure about the others.

The most economical way to transport natural gas over long distances is by pipeline. However, CNG or LNG can be transported in railroad tank cars, etc. My expectation is that at least up to 1650, natural gas will be exploited only within driving distance of Grantville.

Biofuel. A biofuel is one derived at least in part from living organisms. Biodiesel, in turn, is the biofuel equivalent in distillation temperature and viscosity of petroleum diesel.

One option is to ferment the carbohydrates in plants (wheat, corn, sugar beets, sugarcane, potatoes, etc.) to alcohols. (Destructive distillation of wood will also produce alcohol, and it can be applied to wood that isn't useful as a structural material.)

A second option is to use vegetable oil or animal fat. In 1631, Ed Piazza tells Mike that you can run diesel engines on vegetable oil, but that it would take until the next year to make it in quantity. Flint, 1632 (Chapter 11). Note that in OTL, whale oil was used as an illuminating fuel. However, McDonnell, "How to Keep Your Old John Deere Plowing: Diesel Fuel Alternatives for Grantville 1631–1639 (Grantville Gazette 4) identifies cod liver oil as the most economic raw material.

In general, the component molecules of vegetable oil are fairly high molecular weight, making for a viscous fuel. The molecules can be degraded to make them more suitable for fuel use.

A third option is to incompletely burn plant material, resulting in a syngas (carbon monoxide and hydrogen).

Hydropower. This is relevant only to railroad systems with central power plants. The power generated is dependent on the elevation change and flow rate of the rivers, so mountainous areas with good precipitation are favored. (Within Europe, the countries with rivers whose energy could be harnessed include Norway, Sweden, Russia, Germany, Switzerland, France, Italy, Spain and the Ottoman Empire.) Even so, quite expensive engineering works might be needed to dam rivers, protect towns and farmland from flooding, etc.

There is no guarantee that the dam will be near the railroad line. Hence, it might be necessary to transmit the power over a greater distance than would be necessary with a coal- or oil-fueled plant (the railroad could be used to bring coal or oil to such a facility, if need be).

Water power, by its nature, tends to fluctuate. Therefore, it's necessary to have a reserve power plant to fill in the gap if the hydroelectric power supply is interrupted by drought or a freeze.

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Fuels for Steam Locomotives. In OTL, steam locomotives burnt wood, coal, oil and occasionally more exotic materials.

The first American railroads to convert to coal were those which serviced coal fields. They were followed by railroads operating in the heavily populated northeast (where timber was cut down to make houses and furniture), or across plains or deserts. Eventually, the opening of large new coal fields persuaded even the heavily forested south to adopt coal. The American far west was coal-poor, so railroads in that area were eager to switch to oil burning after the big California oil strikes.

In general, a firebox design that was suitable for burning wood worked reasonably well with bituminous coal. However, one could use a less elaborate smokestack (because coal produced fewer sparks), introduce a firebrick arch (to force the gases into an indirect path, allowing for more complete combustion), and replace copper with wrought iron or steel (because the coal products corroded the copper). (Solomon ASL 29ff).

Anthracite burns slowly because of its lack of volatile gases, and hence is best suited to a broad shallow firebox.

Lignite has a low energy content, and thus you need a large firebox, with a large grate area, to get adequate power. Raw lignite is composed of small, light particles and hence throws out a lot of sparks, like wood. The lignite may be bound into briquettes but this adds to cost.

Oil provides a higher energy density than coal. As of 1915, despite Europe's greater access to coal than oil, several railroads in France, Austria and England were "using oil fuel more or less extensively" (Gibbings 2).

Gibbings (8–10) has listed numerous advantages of oil over coal: reduction (at least in oil-rich countries) of cost (40%) and weight (30%) of fuel; can travel further without refueling); less manual labor in stoking and station management (pipes and pumps replaced shovels and cranes; at one station, two men were able to do the work formerly done by 26); no smoke, ash or clinker; rapid adjustment of fuel to load without waste; higher evaporative efficiency, elimination of losses (2–10%) due to weathering of coal; elimination of damages for setting fire to adjacent crops and properties as a result of sparks; more rapid steam raising (40 minutes); improved shed economics; greater shelf life.

To burn oil fuel, the firebox must atomize the fuel (convert it to a mist)(Gibbings 16), and this is usually done with a steam jet as disclosed in 1911EB/Fuel.

Oil Shortage or Glut?

We are going to be producing oil no matter what, since we need it for cars, trucks and aircraft. The question is, when will we have enough to use oil products in locomotives?

First, let's look at the demand side. Historically, oil demand was at first just for illumination—the kerosene (later used as jet fuel) was the cash fraction and everything else was essentially waste. The automobile created the demand for gasoline, which is a lighter fraction. The lightest fraction was used by the chemical industry. In the twentieth century, heavier fractions were variously used as fuel oil in stationary power plants, ships or locomotives, or cracked to make gasoline or chemical feedstocks.

In the 1630s and 1640s, the demand for oil for fuel use may be limited by the number of engines available. At first the only engines will be the ones that came through the RoF, and then there will be a trickle of post-RoF builds.

Mannington, per the 2000 Census, had 1342 auto, vans and trucks kept at home for household use. To that you may add motorcycles, trailers, tractors, and government and commercial vehicles—call it 1500 total. It doesn't much matter for purpose of calculating oil demand whether their engines are kept where they are or are re-purposed as marine or aircraft engines.

Only late model, high-performance engines are likely to be earmarked for aircraft use. Huff, "Aircraft in the 1632 Universe," Grantville Gazette 12, assumes that a year 2000 auto engine would normally get 25mpg but, rigged as an aircraft engine, would only do half as well—thus consuming four gallons an hour. However, he also assumes that it will be running on M85, that is on a mixture of 85% methanol and 15% gasoline. I imagine that there are other engines that can be used with such a mixture.

Perhaps a quarter to a half of the Grantville vehicles are carbureted and therefore can be modified to run on natural gas.

We know that the coal trucks have diesel engines, some of which were re-purposed for use on the ironclads. It is canonical that the diesel engines in Grantville can run on vegetable oil. While supplies of that are no doubt limited, that still helps reduce the demand for crude oil.

I would imagine that even if gasoline were readily available there would be limits to how many miles the land vehicles would be driven. Initially, the only area with asphalt roads is the RoF, 6 miles in diameter. Canon does speak much about road construction but I have the impression that the amount of construction, in mileage, of good roads was not very high. The fifteen mile "luxury road" (graded and graveled, not even paved) built to bypass Forchheim in 1633 consumed the entire budget for road improvements in the prince-bishopric of Bamburg. DeMarce, "Bypass Surgery" (1634: The Ram Rebellion).

The number of new engines built in the 1630s is likely to be very small relative to the number that came through RoF. And of course there are going to be up-time engines that stop working, too.

Still, let's say that we have 1500 vehicles driven an average of 10 miles/day, and getting 20 miles/gallon. Then the demand for gasoline would be 750 gallons/day. A barrel of oil is 42 gallons. The gasoline fraction varies from say 1–30% depending on the source. (The shallower Wietze oil is on the low side.) Let's assume 10%, so one barrel of oil provides about four gallons of gasoline. And we would therefore need about 200 barrels crude per day to keep all 1500 vehicles running.

Of course, oil is in demand as an organic chemical feedstock, not just as a fuel. But that's equally true of coal, and it's at least plausible to assume that the supply of oil will not be exhausted by these non-fuel uses.

Railroad use is probably not going to add significantly to the demand. In 1980s Africa, which is not heavily industrialized, the oil consumption by the railroads is just a few percent. (Alston 35).

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Now let's look at the supply side. Oil supply is certainly going to increase, as we drill more producing wells. The production rate will accelerate because our prospecting and drilling efficiency will increase. If the price of oil is initially high (because of high demand) then of course that's going to coax more investors into the oil industry.

In 1631–34, the supply of gasoline is clearly limited. In canon, we initially are collecting some condensate from gas wells in Grantville. By 1633, we are exploiting one German oil field: Wietze. The down-timers knew of the existence of tar deposits and oil seeps there, and the oil was sold as a medicine as early as 1480 (Clark 7). In OTL, a well (drilled looking for coal) struck oil at 200 feet on May 29, 1858. (Clark 25) Mining of oil-bearing sands began in 1917, so strictly speaking, we don't even need drilling technology to obtain Wietze's black gold.

The oil extracted by mining at Wietze was a heavy oil, more useful as a source of lubricating oil than of gasoline; gasoline content was under 5%. Corwith, "The Oil Mines at Wietze and Pechelbronn" (Grantville Gazette 23). I would expect that the drilled oil isn't much better, certainly no better than 10%.

It's possible to find light oils at Wietze; they are in Upper Triassic (Rhaet) rock at a depth of 330–350 meters. Find it, and almost 20% of production distills at under 250^o C [482^o F]. (Kauenhowen 480, 482). But in OTL, the light oil was discovered only in 1900.

Pechelbronn, which is in modern France, was added to the USE's Upper Rhenish province by the 1634 peace treaty (Flint, 1634: The Baltic War, Chapter 68). It likewise has both heavy and light oil deposits. The light oils lie at 150–600 meters. (Rice 281). Pechelbronn production in 1950 was about 500,000 barrels of light oil annually. (Bateman 692).

While Germany does not have any giant oil fields, it has quite a few salt dome deposits like Wietze. Germany's total oil reserves are sufficient to support USE military forces and industry for a long time. In 1880–1918, Germany produced about 17 million barrels. (Day 134), an average of 436,000 annually or 1194 daily. Just a smidgeon compared to the USA, but plenty relative to what the USE can consume in the near-term.

OTL, Wietze production (including mining) was 826 tonnes in 1892, 27,042 in 1900 (KKGG; Volkswirtschaftliche Chronik 23)(an average annual rate of increase of 55%). One metric ton is about 7 barrels, so in OTL 1900 we have 190,000 barrels/year, or 520 barrels/day.

There are several larger fields in Germany. In 1937–1993, the Reitbrook field (discovered 1937, first oil sand at about 750 feet, 1000 acres producing) produced a total of 15.7 million barrels of oil (average 280,000 annually). Nienhagen (discovered 1909) production mid-twentieth century was around 300,000 tons (2,100,000 barrels) annually (Ludmer 259; Tiratsoo 120ff; Pennwell 146). None of these would impress a Texan, of course!

The question is, how fast can we scale up the production rate of crude oil and, in particular, of gasoline and diesel fuel?

By 1635–36, it's likely that there will be additional wells drilled at Wietze, boosting production. However, it's less predictable that they would have found the light oil, and nothing in "Grantville literature" would have told the field management that in fact there's light oil to be found.

Until we have a lot of drilling rigs, scale up will be slow. Wietze is a "Hanoverian" field, and in 1897, the 80 shallow wells in operation in that area averaged 20 barrels/day (Emmons 513). So each new well might add only 20 barrels/day to total production—and with Wietze heavy oil, less than 2 of those barrels will be gasoline. For a big increment, we need to drill deeper or start mining (for which "quantity has a quality all its own"). And I doubt the up-timers will know about the OTL oil mining at Wietze, so they will have to think of it on their own .

In 1950, Germany was producing about 4.5 million barrels annually (Bateman 692), but it will take decades to reach that level.

Developing new fields will help. But while Germany has many small oil fields, there are numerous reasons why an area that in fact contains an oil field might be neglected:

—we lack accurate information as to where to start looking.

—it's too remote for it to be convenient to send prospectors or drillers, and it would be expensive to transport back any oil found.

—the members of our limited corps of geologically trained prospectors have been sent to more promising areas.

—if the locals aren't aware of surface oil signs, and we have to map the surface geology to find favorable structures, it can be very time-consuming, especially in marshy or forested areas.

—the locals might not let us look where we want to look.

—the oil field may lack surface evidence of oil or even of favorable structures.

—there may be legal uncertainties as to who can grant the right to drill, or the owner may simply refuse for fear of disturbing agricultural activities, or the owner may have too high an opinion of the oil prospects and demand too much money.

—there may be a shortage of drilling crews or equipment, so we can't drill everywhere we'd like to.

—drilling may prove too time-consuming, expensive or hazardous, because of very hard rock, "caving" formations, water infiltration or high pressure gas.

—we lack the resources (money, fuel, wire cable, drillpipe, casing) to drill deep enough to reach the pay depth.

—our exploratory well may be dry, discouraging further attempts in the same area for several years (even though we may be close to, or even nominally within, the bounds of an oil field).

—inept development may cause the early depletion of the field.

—the oil found isn't worth the lifting cost (it's contaminated with water or sulfur, it's heavy, it costs too much to ship).

The bottom line is that since there's a lot of luck in the oil business, Eric can justify an oil shortage or an oil glut, or even a fluctuation between them, as he pleases.

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I have no doubt that there was, in the short term, a serious oil shortage as reflected in canon. But if we hit the light oil stratum at Wietze, or find another major field, gasoline and diesel fuel production could increase dramatically. To the point that we had a quite abundant supply of fuel, relative to transportation demand, at least until the number of "down-time" engines in operation exceeded the number of "up-time" ones.

I expect that by the 1640s, perhaps sooner, we will be producing light oil at Wietze, we will be mining heavy oil at Wietze and Pechelbronn, and we will perhaps have started development of additional Hanoverian oil fields.

Looking further afield, both Gustavus Adolphus and Albrecht von Wallenstein are expansionist monarchs, and they are probably both eyeing Galicia (southeastern Poland). In OTL, the Swedes invaded Poland (including Galicia) in the 1650s. Rail or pipeline transport would make it feasible to use Galician (or Romanian, if the Ottomans played ball) oil elsewhere in Europe. Consideration of the economics of pipelines must be relegated to another article.

Overseas oil is also a possibility. I anticipate several objections: (1) most of the oil is outside USE control; (2) it's too risky to rely on overseas oil because it can be interdicted by an enemy navy; (3) it would be too expensive to transport it; (4) we will lack the tanker capacity to transport the necessary quantities (5) we don't have access to suitable port facilities.

Access to Oil. As I said in Cooper, "Mineral Mastery" (Grantville Gazette 23), "The oil fields which can be developed by anyone are those of the Gulf Coast, parts of the Arabian Peninsula, and perhaps California and Nigeria. Access to the fields of Mexico, Venezuela, the Middle East, Galicia and Russia is likely to be restricted on the basis of nationality." I would add that while Trinidad is under Spanish dominion, it would be relatively easy to seize it (we collected oil there, without much hindrance, in Cooper, "Stretching Out, Part 4: Beyond the Line," Grantville Gazette 16). Also, Suriname is under USE control and there is some possibility of finding the oil at Tamburedjo.

The fact that an oil field is under Spanish, Ottoman or Persian control doesn't mean that the oil won't be developed, it just means that the USE will probably have to buy it from a local entrepreneur. And the fact that we are presently at war with Spain (and facing hostility from the Ottomans) doesn't mean that they won't be perfectly willing to sell oil to us; the Spanish and Dutch traded war materiel even when they were at war.

When the giant oilfields of the Middle East were opened up, the price of heavy heating oil in Hamburg fell, from 146DM/ton in 1957 to 88 in 1958 and 66 in 1959. Likewise, light heating oil dropped in price from 242 to 144. The result was that "within Germany, oil was absolutely cheaper than coal," and homes and factories switched from coal to oil heating. (Milosch 85–6). So the cost advantage of coal over oil, even in Europe, is not eternal.

Military vulnerability. While I don't doubt that there will be efforts to copy USE military innovations (steamships, ironclads, explosive shells, etc.), I think that the USE has the technological edge and the population base to keep that edge. (Given the rivalries among Spain, France, England, and between the Ottomans and the Hapsburgs, I doubt that any combination against the USE will be maintained for long.) Consequently, I think that we will be able to break blockades of our ports and also provide adequate convoy escort service for our tankers. Which are likely, in the 1640s, to be oil-fired steamships.

Transport Costs. With regard to the cost of transport, in the seventeenth century it was much cheaper to transport goods by water than by land. Cooper, "Hither and Yon" (Grantville Gazette 11). (This is nothing new; in Roman times, the cost of transporting wheat by sea was 1.3%/100 Roman miles, and by land, 55%. In the early eighteenth century, English land transport was still over 20 times as expensive as transatlantic shipment. Duncan-Jones 368). "In 1816, the cost of shipping a ton thirty miles overland in the United States was the same as shipping the same ton to England. The average cost was seventy cents per ton per mile (a ton-mile)." (Mabry)

Because oil has a higher energy content than coal, and the diesel engine is more efficient than the steam engine, the cost of fuel per unit power generated would be equal if the cost of oil was about three times the cost of coal. (Wells 85).

In 1915, the cost of oil was perhaps 18s6d–28s/ton in oil-producing countries, whereas in non-producing countries without substantial tariffs, it was 38s–59s/ton. In Germany, the duty was 32s/ton, resulting in a price of 62s–79s/ton. (Id.) (implying a duty-free price of 30–47). The estimated cost of coal was 14s/ton. (86).

Wells compares marine diesel with marine steam; with oil at 40s/ton (consumed 10 tons/day) and coal at 14s/ton (consumed 42 tons/day), and with engine-room staff being 16 for the coal-powered ship and 8 for the diesel, the cost per ton mile (counting fuel, wages, and provisions) was .0067d/ton-mile for coal and .0035d/ton-mile for diesel. (86ff).

It is interesting to note that in 1900, Germany imported 145 million gallons of crude and refined oil from the United States, and 32 million gallons from Russia, while producing 15 million gallons. Plainly, the Germans were willing (if not eager) to pay the piper to get petroleum, despite their huge coal fields.

Transport Capacity. With regard to transport capacity, in the seventeenth century, a large transatlantic trader would be 250–500 tons "burden" (originally a measure of what could be carried in wine barrels). Oil is roughly 7 barrels to the ton so such a trader could carry 1750–3500 barrels. A dedicated tanker with an oil compartment, I suspect, could carry perhaps one-third more, getting us up to the 5000 barrel range. If this were a light crude, like that of the Gulf Coast, it could be 50% gasoline (EPA/Appendix 6A), which would be 2500 barrels (~100,000 gallons)—enough for 133 days supply at the 750 gallon/day demand level.

Of course, if the overseas field produced a heavy crude, like that of Wietze, it would be prudent to refine it on the spot and only ship over the useful fractions.

Once steel production ramps up enough for steel steamship construction to be practical, we will see tankers with a carrying capacity of several thousand tons, which in turn will make it that much easier to supply oil.

In OTL, the "real" price of oil (in 2008 dollars) fluctuated erratically over the first decade of production, hitting a high of about $110/barrel and a low of under $40. From the late 1870s until the early 1970s, it remained under $40/barrel and indeed I would estimate the mean as about $20/barrel. Production isn't likely to climb as quickly as it did in OTL (where most early development was in America), but, on the other hand, the population, and hence the demand for oil, will also be smaller.

Ports. After the Baltic War, USE territory includes the ports of Stettin, Stralsund, Rostock, Wismar, Lubeck and Kiel on the Baltic Sea, and Hamburg, Bremen and Emden on the North Sea. The allied Union of Kalmar has its own ports, including Stockholm and Copenhagen on the Baltic Sea and Aarhus, Malmo, Goteborg, Oslo (Christiania), and Bergen on the North Sea. In addition, there is river traffic down the Rhine to Rotterdam, and then by canal to Amsterdam.

These ports were visited by merchant ships of moderate size and therefore should be able to accommodate tankers of up to 100–200 tons burden, at least. By the time we have locomotive-grade diesel engines, say the 1650s, it's quite likely that at least one of these ports will be improved by dredging so it can accommodate larger vessels. Remember, there are a lot of goods that the USE is going to be importing and exporting by sea so there are considerable economic advantages to having a deepwater port.

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Motive Power

The motive power for the railroad has two basic elements, the power plant and the transmission.

The power plant (engine, prime mover) converts some other form of energy into a mechanical form—the rotary movement of a turbine or the reciprocating movement of a piston.

The transmission takes the kinetic energy of the turbine or piston and uses it, directly or indirectly, to turn the wheels. For a stationary power plant, transmission normally is electric, but we will briefly discuss pneumatic systems.

The first "locomotives" in the new time line were pickup trucks (with gasoline or diesel engines) hauling rail cars on strap rail tracks. There were also horse-drawn trains.

Steam locomotives appeared at least by 1634, possibly earlier. Steam locomotives have been discussed at length in Cooper, "Harnessing the Iron Horse: Railroad Locomotion in the 1632 Universe," Grantville Gazette 7; Edelberger, supra; Evans, "Fire Breathing Hogs" (Grantville Gazette 20).

Eventually, the steam locomotive will face competition from Diesel (especially diesel-electric) and straight electric locomotives, and perhaps other kinds as well. The 1953 Encyclopedia Britannica "Locomotive" article devotes three pages to steam, three to "straight electric," and three to diesel-electric locomotives.

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Power Plant Distribution

We have several choices as to how to distribute the power plant. First, it can be mobile or stationary.

A mobile power plant usually burns fuel, converting chemical energy to heat energy, and using the expansion of heated gas to operate the turbine or piston.

If it is mobile, we can put it onto a locomotive that pulls or pushes the other cars of the train. Or we can put it on every car of the train, in which case there is no dedicated locomotive. This may be advantageous if a single high-powered prime mover has substantially higher initial costs, or operating costs, than the equivalent series of low-powered prime movers. Or to improve traction by taking advantage of the weight of all the cars rather than just the locomotive.

If traffic is so light that the locomotive is only pulling one car, you might do better to replace the train with a single "railcar" ("rail motorcar"): a self-propelled passenger, mail or express freight car which travels on the rails.

We can take the prime mover out of the train entirely and instead use a stationary power plant, transmitting the power to either a single locomotive (really a glorified "motor") or to individual cars each equipped with its own motor. (The latter are often referred to, rather cryptically, as "multiple units"; they are designed so that they can still be controlled from one cab even though each one propels itself.)

Finally, we can equip the locomotive, or individual self-propelled cars, with a portable energy storage unit, that is charged up at a stationary power plant.

We still have the question of whether it's better to have one or two large stationary power plants, or many small ones. The latter is most likely to be considered an option when an electric railway is running on direct current, because that can't be transmitted efficiently over a long distance. Still, power plants tend to have economies of scale favoring bigger but fewer facilities.

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Mobile Power Plant Types

The steam (piston) engine is an external combustion engine, that is, the fuel is burnt in one chamber (the firebox) and the combustion gases serve to heat a working fluid (water in the boiler) inside the engine so that the resulting steam moves the piston in another chamber (the cylinder). A steam turbine engine is similar except that the steam moves turbine blades instead of pistons.

In an internal combustion engine, the fuel is burnt to generate a combustion gas, and the combustion gas expands against the piston or turbine, in the same chamber. The combustion can be continuous or intermittent. The ignition of the fuel may be by means of a spark, as in an Otto ("gasoline") engine, or by compression, as in a Diesel engine.

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Transmissions

Mechanical transmissions. In the nineteenth century steam "rod" locomotive, a connecting rod mechanically transmitted the forces on the piston to the wheel. This transmission has the disadvantage that there is a one-to-one relationship ("direct drive") between a piston stroke and a wheel rotation.

This relationship can be altered by interposing a gear, so the engine turns a gear and the gear turns the wheel. A geared locomotive (Shay, Climax, Heisler) uses reduction gearing so it can achieve higher tractive effort (pull) at low speed than would be possible with a rod locomotive having the same size driving wheels. Most geared locomotives are single-speed, but a few had the ability to switch from one gear to another, and thus to change the engine-wheel speed ratio, like a car or truck transmission.

Other transmissions. It is also possible to convert the mechanical energy into some other form of energy (electric, hydraulic, pneumatic) and then back again "at the wheel." This allows for continuous variation of the ratio, and thus for greater versatility.

If a locomotive type has a "two-part" name, like "diesel-electric", the first part identifies the power plant(e.g., diesel engine) and the second part the transmission (e.g., electric).

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Pistons versus Turbines

Most locomotive engines, whatever their type, drive a piston. However, it is possible to re-engineer them so that the expansion of the compression gas or the steam turns the blades of a turbine instead.

The turbine's advantages are that it has fewer moving parts (potentially reducing maintenance, and requires less mass and volume for a given power level.

Also, two cylinder piston engines produce various vibrations as a result of the incompletely balanced movements of the pistons, and these can lead to mechanical wear, an unpleasant ride, hammering of the track, etc. (The balancing problems are exacerbated if the engine is coupled to a mechanical transmission, as more mass is involved.) A turbine avoids the problems of balancing reciprocating masses.

Turbines can be driven by combustion gases or by steam. The first combustion gas turbine-mechanical locomotive appeared in 1933. Unfortunately, the turbine's power and efficiency are very strongly dependent on the rotational speed; that is, it runs best only close to full "load." That's a problem if the turbine is driving the wheels directly (mechanical transmission), since locomotives need to accommodate a broad range of speeds. A turbine-mechanical locomotive doesn't run downhill, idle, or creep along very well. A workaround is to have several turbine engines which can be brought on line as needed.

Another problem with a turbine-mechanical locomotive is that it needs an "extra" turbine dedicated to reversing, because a turbine can turn in only one direction.

The first combustion gas turbine-electric reached the market in 1941. Turbines produce a rotary motion of the shaft, and that's exactly what generators need to convert mechanical energy into electrical energy. So the turbine-electric combination is a natural one. The turbine can be run near full speed and if the load is light, the excess energy perhaps can be fed into batteries or even into a resistance heater to keep the fuel warm. Still, it's best to operate them close to full load as much as possible, i.e., on high-speed, long-distance runs.

Union Pacific was the principal proponent of the gas turbine-electrics, and it used Bunker C oil as fuel. However, after a while this fouled the turbine blades (presumably as a result of incomplete combustion) and thereby increased maintenance costs. (Wikipedia).

A steam turbine (MRT) works pretty much like a gas turbine, except it uses pressurized steam rather a combustion gas, and it usually burns coal rather than bunker fuel. The first steam turbine-mechanical locomotive (with four turbines) was built in 1907, and the first steam turbine-electric in 1910. The most successful was probably the LMS Turbomotive 6202 (1936–49).

The advantages and disadvantages are similar to those of the combustion gas turbine. However, there seems to have been a problem of reliability on steam turbine-electrics; coal dust or leaking boiler water got into the traction motors. The C&O introduced steam turbine-electrics with much fanfare in December 1947 and quietly sold them for scrap in 1950. (Shuster 299).

Steam turbines do work quite nicely in stationary power plants, however, provided that they are large enough (Stott 1172).

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Steam-Electrics

The piston motion of a steam engine may be used to rotate a DC current generator, rather than a wheel, and the generated electricity then transmitted to a motor.

If there were two pairs of pistons, you could fully balance the lateral forces without resort to wheel-mounted weights that would cause rail pounding.

The first steam-electric locomotive was the Heilmann (1893). It was used to haul a test train, and performed well, but the design didn't catch on commercially.

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Diesel "Compression Ignition" Internal Combustion Engines

In the old time line, the Diesel engine was invented in 1893, the first Diesel locomotive was put into operation in 1912, and "diesel electric" locomotives were first used in passenger service in the Thirties.

In the Diesel locomotive, a Diesel engine (a "compression ignition" internal combustion engine) is used to convert the chemical energy of fuel into mechanical energy. Air is compressed (more so than in a gasoline engine), fuel is injected and ignited by the heat of compression, and the combustion gases expand, driving a piston.

The diesel fuel, being liquid, can be stored in small tanks located in otherwise wasted spaces and still easily delivered to the engine when needed. The handling of wood or coal for a steam engine is much more cumbersome. Of course, an oil-fired steam engine would have the same fuel handling advantage.

Diesel engines are 3–4 times as thermally efficient as steam engines (Vauclain), and diesel fuel has a higher energy content. A given weight of diesel oil in a diesel engine might do eight times the work of an equal weight of coal in making steam for a steam engine, so if it were four times as expensive, fuel costs would be halved by diesel use. (Mike's). Also, please remember that "alternative" fuels for diesel engines exist, as discussed in the "Fuel" section.

A steam locomotive might need a pound of water for every pound of coal; diesels require much less water. Dieselization reduced the B&O's water bill by over 80%. (Holt)

Because it doesn't need to stop for water, and fuel stops are less frequent (every 500 versus every 100 miles), diesels make better time, and "crew districts" (typically eight hours travel) are larger. That reduces labor costs. (Solomon 13, 15).

Maintenance-wise, steam locomotives were typically out-of-service half the time, diesels more like 5–10%. (Coifman; Solomon 14). However, steam locomotives had a longer service life; 20–30 years versus 14. (Solomon 17).

It is much easier to operate diesel-electrics locomotives in combination ("multiple units," MU) to haul a single train than to coordinate the operation of multiple steam locomotives (Coifman). Hence, we can increase traction without increasing locomotive size. Big heavy locomotives require gentler curves and increase track maintenance costs.

The great disadvantage of the diesel was initial cost, typically 2–3 times that of a steamer. Diesel engines had many more parts and they had to be machined to higher tolerances (1/10,000th vs. 1/100th inch) (Solomon 17; Francis 67; Wikipedia/Diesel Locomotive).

Weight was also a problem for early diesel. The high compression ratios needed for ignition meant the engine had to be strong enough to contain the gases. Until the Thirties, when high strength/weight alloys became available, that meant using a thick, heavy, cast iron or steel block. The Winton W40 had a engine weight-power ratio of 200 pounds/hp (as opposed to 20 for the 1933 Winton 201A). (Solomon 41ff)

Naturally, that also meant that the vehicle weight-power ratio was undesirable, making it difficult to scale up to a locomotive suitable for mainline service. A Baldwin diesel-electric locomotive (1925) weighed 275 pounds per horsepower. A steam locomotive of the same period was more like 140 pounds/hp. (Vauclain 46).

Modern diesels are more compact, of course; the 1960s Napier ...