PRR's Altoona test plant reported a peak of 3550 horsepower for the K4. Experimental improvements to K4 5399 included poppet valves, front end throttle and an improved superheater, which yielded a peak of 4200 HP. Both numbers would of course be reduced at the rear of the tender. Neither seems especially remarkable for a passenger locomotive.
3550 HP at the Drawbar IIRC the dyno at Altoona was compensated to show Drawbar HP. So getting that from at the time of the testing more than likely a NON SUPERHEATED HAND FIRED Pacific Type Locomotive. Remember that the Best 4-8-4 got maybe 5000-5500 HP at the Drawbar and remember this at the time the K-4 wer built they used regular bearings no rollers on anything that right there cost them 10% or so. When they were rebuilt with Superheaters and stokers and Roller Bearins which some were they might have reached 4000 HP. I know I read someplace that alot of the improvements from the K5 prototypes were later retrofitted onto the K4's
A standard K4s under test produced 3,520 IHP (at the cylinders) at about 60 mph, rated evaporation 70,000 lbs steam/hr. Locomotive drawbar HP (on the test plant) was less than that and drawbar HP at the rear of the tender was even less, about 2,720 at 40 mph. The first poppet valve K4, 5399, produced about 4,180 IHP at 80 mph, also rated at 70,000 lbs of steam/hr. Other 4-6-2's may have done better, but the K4 has been analyzed microscopically by comparison to any other of that wheel arrangement. Does that make it the best or highest HP? No, just the highest measured under certain test conditions.
The K4's were always superheated if they had the designation K4s, the "s" signifiying superheater-equipped. No. 1737 may have been built saturated, but I doubt it. All other were built that way, not rebuilt. They were built handfired, not doubt about that, and stokers helped immensely!
Unless someone is privy to more test data than I have here, no 4-8-4 ever tested at 5,500 dbhp. Most of the argument revolves around two top contenders, 5,050 dbhp (NYC S1b) and 5,250 dbhp (N&W J), and even these figures aren't comparable. The N&W J and ATSF 2900's may have been capable of 5,500 dbhp or more, but no such reading was ever recorded, AFAIK. Neither was pushed to that point by their respective owners. I've run this idea into the ground on other threads here.
For a 1914 design, the K4 did very well for itself over something like 40+ years of service. On the NY&LB, it took two diesels to equal the performance of one K4 in 1956-57.
A lot of the improvements incorporated into the K5 (higher boiler pressure, feedwater heater, larger boiler barrel) were not incorporated into the K4's. The K4 was a much better balanced design because of the K5's drafting and steaming problems. They never lived up to their potential.
feltonhillTrue, they were much higher maintenance locos than the dirt-simple K4, but they could easily outperform doubleheaded K4's on large trains. As a result, the productivity per locomotive mile was higher than a K4. What was the T1 operating cost per passenger train mile? Don't know, at least not yet. They cost more per locomotive mile than a K4, but did more work per assignment with only one crew
A PRR memo dated April 3, 1951 almost answers your question about cost per passenger mile. I say almost because the memo gives cost per loco mile, regardless of the number of passengers. It says the T1 cost $1.5816 per mile. The K4 cost $1.1554 per mile. So, clearly you are exactly right - one T1 was cheaper than doubleheaded K4s. By comparison the cost of 6000 diesel horsepower was $1.1450. And most trains didn't need 6000 horsepower.
My source for this info is Eric Hirsimaki's "Black Gold - Black Diamonds," volume 2.
tpatrick By comparison the cost of 6000 diesel horsepower was $1.1450. And most trains didn't need 6000 horsepower. My source for this info is Eric Hirsimaki's "Black Gold - Black Diamonds," volume 2.
By comparison the cost of 6000 diesel horsepower was $1.1450. And most trains didn't need 6000 horsepower.
I'm afraid this raises some questions for me. In a thread, a heated exchange, about two years or more ago, it was stated that diesels were found to have a replacement life cycle at just under 14 years. No one knew this when they came on board. That wasn't the case with steam, not by a long shot. Also, I wonder if financing costs were included in the operating costs for the diesels since GMAC made their initial acquisition more palatable to CEO's and CFO's at the time.
The cited memo accounts for costs of fuel,water, lubricants, other supplies, enginehouse expenses and repairs. There is no mention of initial acquisition cost.
Another memo, dated October 21, 1947, compares T1, Q2, GG1 and 6000 HP diesel locos. There is a line titled Relative First Cost per Locomotive. T1 is the baseline at 100, the GG1 is 114 and the diesel is 220. On the freight side of the table, Q2 is 100, GG1 is 140 and diesel is 267. Apparently the Q2 was cheaper than the T1.
At the bottom of the table is a line :"Fixed Charges." This may be where acquisition cost comes in, but I'm not sure of that. Anyhow, that line shows fixed charges of .2984 per mile for the T1 and .3120 for the diesel. Total costs per mile: T1 = $1.6657; diesel $1.2960. It may have been much better had the T1 been a better runner. Its annual mileage was only 79200 vs. 228760 for the diesel. Incidentally, the GG1 managed a respectable 141240 miles per year costing $ .9736 per mile. This, too, is from the Hirsimaki book.
I remember that thread. There is a certain former poster whose name has not been seen since then. It was quite entertaining.
Thanks for your informative reply. Interesting figures, to say the least.
You can doubtlessly see my quandary; if a single steamer could perform at the same level as the two, three, or four diesels it would have taken in that era to match the steamer's performance, instead of an even match with the diesel having to be given a major, third line, overhaul at 14 years, or replaced outright, there really would be, on a mile-for-mile basis, the need to replace two, three, or four such platforms. Would their costs have been fully amortized to that point, or would GMAC have rescued them yet again with newer engines? What was the cost of a life-cycle replacement of up to eight diesels, or fewer of their more potent replacements, while the lone steamer was merely in need of yet another washout and piston rod packing? I ask this not knowing the answers, and don't mean to give the impression that I am leading you and onlookers to a Grand Slam...but the questions pertain, I think.? A whole bunch of diesels, with the costs of two initial purchases, were needed to replace a single steamer, with no changes of crewing numbers between the them, which still had more than half of its useful life ahead of it.
As the King of Siam was fond of saying, "Is puzzlement!"
-Crandell
Again it's Hirsimaki to the rescue. And the answer is that in practice a single steamer did not equal several diesels. Indeed, it was just the opposite. In 1947 PRR put three ABBA sets of F3s to work on trains between Chicago and Enola, e/b Train CG-8 via Columbus and w/b LCL-1 via Crestline. The diesels ran straight through without change, needing 2 steam helpers w/b from Altoona to Gallitzin. To completely dieselize this run they needed one more diesel set, so it was often still a steam operation. With steam they used five locos, relay style, from division to division, plus six helpers, in ones and twos at various points along the way. Around Horseshoe, the steamers needed three helpers. In short, a single set of diesels did the work of nine steam locomotives.
"The three F3 sets made 33 eastbound and 32 westbound trips by September 23. Each took about 48 hours. This is a reduction of 586 steam engine handlings during this period and provided a good example of the hidden economies of dieselization," to quote Eric Hirsimaki.
By June 1948, 18 diesel locomotives (generally 3 or 4-unit sets) were doing the work of 90 M1s, J1s or Q2s because they could run straight through without change.
A memo from PRR President James Symes of May 9, 1949 titled "Five Year Diesel-Electric Acquisition Plan, 1950 -1954," speaks to your question about costs of acquisition. The bottom line shows a planned investment in 749 units totalling just over 1 million HP. The projected cost was $124.3 million. Operating savings, before depreciation, were $33.2 million per year. That is a return on investment of 26.7%. Again, that is before depreciation. Not bad.
I don't know whether this answers your questions, but it is a good indication of the logic of the time as seen by at least one railroad.
Finally let me recommend the "Black Gold - Black Diamonds" volumes by Eric Hirsimaki. They are excellent reading, filled with tables and quotes. He really did his homework. Equally thorough and informative is his work "The Nickel Plate Years." I'm going to read them again, for the third time.
Thanks for that. I guess I should put BGBD on my wish list for next Christmas. It's time I got a decent RR book anyway.
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