Mon Oct 10th, 2005 at 04:04:37 AM EST
for those of you more interested in hardcore politics, there is a thread about Merkel becoming Chancellor just below... Jerome
'Normal' steam locos are loved for the puffing steam, lots of visible moving parts, lots of external details. Less was visible on streamlined locos, hence they are less popular, even tough they include some of the best-designed, fastest, most powerful and efficient, but also rarest and (due to the ascent of diesels and electrics) shortest-lived steamers. For example, the Chicago, Milwaukee, St. Paul & Pacific's class F7 "Hiawatha":
From most books (including the Guiness Book of World Records), you'll conjure that the world's unquestionably fastest steam locomotive was the London North-Eastern Railway's class A4 #4468 "Mallard", with 126 mph (202.8 km/h). However, it's not at all this straightforward!
The Mallard on 18th March 1938 on the 11.15 Harrogate to Kings Cross at New Barnet, photo from the Ken Nunn collection via German Steam
The British contender
...looks much less convincing if you know the details - general 'knowledge' conserved the national-propagandistic accounts of the (pre)war period:
- The 126 mph figure corresponds to a blip on the speed graph, with physically impossible accelerations. It must have been due to a jolt, or,
- according to British railfans who unearthed a second speedgraph copy without the bump, later doctoring.
- Indeed the railway engineers themselves (including designer Sir Nigel Gresley) certified 125 mph (201.2 km/h) as the true top speed achieved - but that is within the margin of error with the other two contenders below.
- The Mallard achieved the record downhill, and
- with modifications unfit for more than a single run - indeed the Mallard broke down at the end of the record run with a hot axle.
The German contender
With the largest wheels of the three contenders, the Deutsche Reichsbahn's [class] 05 [no.] 002 represented an effort by railway and industry steam developers to remain in competition with diesel trainsets (e.g. the Fliegender Hamburger, or last week's Pioneer Zephyr), and cars on highways then favored by Hitler.
It first came short of expectations, but on one test run in 1936, the train was late, so the engineer thought he'll do an unscheduled no-holds-barred run - achieving a certified record of 200.4 km/h (124.5 mph). A conservative choice, the actual curve would have allowed the same speed claims as the British.
05 002 leaving Hamburg Hbf on train FD23 for Berlin in 1938. Photo Carl Bellingrodt, from the Joachim Buegel Collection, via German Steam
There are half a dozen US record claims higher than the above (up to 140 mph = 225 km/h, for the Pennsylvania Railroad's class S1, pictured below), as well as several earlier US record claims higher than the then European record. What they all share is lack of credibility:
- the speeds were calculated by inexperienced clockwatchers rather than measured by a dynamometer car,
- indeed when experienced clockwatchers were present on the very same run, they reported much lower top speeds (but company PR forgot to mention that),
- calculations based on specifications make the claimed speeds physically impossible (small wheels, instability, not enough steam).
There was one exception: just the Milwaukee's "Hiawathas". In my opinion, the F7 has every reason to claim the title of the fastest locomotive in the world:
- It pulled the fastest regular trains in the steam era, maintaining top speeds above 100 mph (160 km/h).
- On a test run with dynamometer car, 125 mph was reportedly achieved.
- Calculations imply it was suited for such a speed - by its good design, and it was also the most powerful of the three contenders.
- Possibly due to belief in the higher record claims of others in the USA, this wasn't considered a record run, just a regular test run - I suspect if they had pushed the F7 to its limits, the European contenders would have been left behind.
(Most of the above based on research by British railfan Bryan Benn.)