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[quote user="MichaelSol"] [quote user="Bucyrus"]  You are comparing a steamer to a diesel with the steamer having higher maximum horsepower and higher tractive effort than the diesel.  [/quote]No. You need pick a speed. At lower speeds, the Steam engine starts out as a lower TE/ lower hp engine. The Diesel-electric has plenty of both -- it's just that the train doesn't need it there.At the speed at which the engines have equal TE -- and the same ability to move the identical train -- above that point the Steam engine develops a higher TE than the Diesel-electric. At the speed at which the engines develop equal HP, above that speed the Steam engine continues to develop horsepower and the Diesel-electric doesn't.Maybe another way to phrase this is no matter what the metric, at each point where those metrics are in fact comparable -- that is, at which the engines are exactly comparable -- above those points the Steam engine develops a greater ability to move a heavier train faster.Let me get back to your comment from one other perspective.[quote user="Bucyrus"]  You are comparing a steamer to a diesel with the steamer having higher maximum horsepower and higher tractive effort than the diesel.  [/quote]You have wanted to compare outputs of one motive power type at 20 mph with the output of another at 60 mph and call them comparable, even though one is at the maximum of a power curve and for the other motive power, it is near the end of its power curve.Say your Ford pickup develops 150 hp at 20 mph. And for comparison, you can find a vehicle that develops the same hp at 60 mph. Indeed, you look around for a vehicle that specifically can develop no more hp at 60 mph than your pickup first does at 20 mph out of some sense of "fairness". You are probably comparing your heavy Ford pickup with a Volkswagen and saying that they are "comparable" vehicles because one finally develops at 60 mph, the hp that the other first does at 20 mph.If you truly wanted comparable vehicles from an engine standpoint, wouldn't you really look for two engines with similar outputs at similar rpms?   [/quote]If I were going to compare two vehicles to see how much horsepower they produced at a variety of speeds, I would pick two vehicles that had identical maximum horsepower ratings to begin with.In your table of comparison below, the diesel is capable of producing a maximum of 5,600 hp, while the steamer is capable of producing 8,400 hp.  <table border="0" cellspacing="0" cellpadding="0"><tbody><tr><td>MPH      </td><td>Diesel-electric         </td><td>Steam </td><td>      HP  needed</td></tr><tr><td>5</td><td>    4,278</td><td>1,806</td><td>         307</td></tr><tr><td>10</td><td>    5,133</td><td>3,613</td><td>         743</td></tr><tr><td>15</td><td>    5,600</td><td>4,516</td><td>      1,239</td></tr><tr><td>20</td><td>    5,600</td><td>5,600</td><td>      1,839</td></tr><tr><td>25</td><td>    5,600</td><td>6,323</td><td>      2,562</td></tr><tr><td>30</td><td>    5,600</td><td>7,226</td><td>      3,426</td></tr><tr><td>35</td><td>    5,600</td><td>7,677</td><td>      4,446</td></tr><tr><td>40</td><td>    5,600</td><td>7,948</td><td>      5,641</td></tr><tr><td>45</td><td>    5,600</td><td>8,129</td><td>      7,028</td></tr><tr><td>50</td><td>    5,600</td><td>8,310</td><td>      8,624</td></tr><tr><td>55</td><td>    5,600</td><td>8,400</td><td>     10,447</td></tr><tr><td>60</td><td>    5,600</td><td>8,310</td><td>     12,513</td></tr><tr><td>65</td><td>    5,600</td><td>8,219</td><td>     14,840</td></tr><tr><td>70</td><td>    5,600</td><td>8,129</td><td>     17,445</td></tr></tbody></table> All I would conclude from this comparison is that this particular steamer is more powerful than this particular diesel.  The steamer produces more horsepower and more TE at all speeds, except at below 20 mph where the diesel can take advantage of its transmission.  From this comparison, I don't see how you can draw any conclusion about the general, inherent ability of reciprocating steam versus internal combustion diesel propulsion.
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