1934 Mil­wau­kee Road ‘F6’ 4-6-4 No. 6402

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THE CLAIM On July 20 1934, haul­ing a nor­mal ser­vice train, No. 6402 was on a special tim­ing to Mil­wau­kee to prove the fea­si­bil­ity of a new high-speed ser­vice. The run was an out­stand­ing success and was di­rectly re­spon­si­ble for the in­tro­duc­tion, less than a year later, of what were to be­come the fastest sched­uled steam-hauled train ser­vices the world has ever seen: the ‘Hi­awathas’. The ‘Hud­son’, with a load of 375 im­pe­rial tons be­hind the ten­der, ran the 85 miles from Chicago to Mil­wau­kee in 67 min­utes 35 sec­onds, from start to stop. This was well inside the even­tual ‘Hi­awatha’ sched­ule of 75 min­utes, that reg­u­larly fea­tured run­ning at over 100mph.

ANAL­Y­SIS

No. 6402’s run on July 20 1934 had a slow start and fin­ish. In be­tween, it ran the 68.74 miles be­tween May­fair and Lake in 45 min­utes and 53 sec­onds, an av­er­age pass-to-pass speed of 89.89mph. Times were made at each sta­tion to the near­est sec­ond, and the record­ing speedome­ter chart showed a max­i­mum of 103.5mph. But did the de­tailed sta­tion times sup­port that max­i­mum? The most im­por­tant of those was the 3 min­utes and 12 sec­onds for the 5.1 miles be­tween Oak­wood and Lake: an av­er­age of 95.6mph. This time was re­ported by the late Brian Reed in his book­let, Loco Profile 26, The Hi­awathas. Within the pub­li­ca­tion, there is a short sec­tion of a speed recorder speedroll from a later run by an ‘A’ class ‘Atlantic’. On that re­pro­duced speedroll, some­one has recorded the gra­di­ent. It starts at 1-in-386 down­hill through Oak­wood, which be­comes 1-in-185 to 1-in-154 uphill through Lake. For a sig­nif­i­cant part of the time that No. 6402 was av­er­ag­ing 95.6mph, it was climb­ing steeply on a grade where speed must have fallen off quickly. In all prob­a­bil­ity, the max­i­mum would have been at the bot­tom of the grade through Oak­wood, which was at a point just over half­way be­tween Oak­wood and Lake. I have ex­per­i­mented with a com­puter spread­sheet model for this dis­tance in an at­tempt to estimate what could have hap­pened. The ‘best fit’ is that No. 6402 passed Oak­wood in the low 90s and, on the steep climb through Lake, it was run­ning in the high 80s. That model sug­gests a max­i­mum speed of at least 101mph at the bot­tom of the dip, just as the 1-in-185 uphill grade started. But my es­ti­mates are just that. No other data is avail­able. And what did renowned steam ex­pert Brian Reed, who men­tioned some of the tim­ing data in his book, say about this run? “This was the first North Amer­i­can high-speed steam run to have tim­ing and run­ning data suf­fi­cient to sup­port most of the speeds claimed… This must be taken as the first time a US steam lo­co­mo­tive topped ‘the hun­dred’.”

DID IT REACH 100MPH?

In all prob­a­bil­ity, Mil­wau­kee 4-6-4 No. 6402 slightly ex­ceeded 100mph. But nei­ther the full tim­ing log or any other de­tails re­main avail­able to sup­port this con­clu­sion with 100% doc­u­men­tary ev­i­dence. How­ever, such a run as that of July 20 1934

“THE ‘HUD­SON’ RAN THE 85 MILES FROM CHICAGO TO MIL­WAU­KEE IN 67 MIN­UTES STOP” 35 SEC­ONDS, FROM START TO

PERRY OTTO/DENVER PUB­LIC LI­BRARY

Three years af­ter its pur­ported ‘ton’ run, Mil­wau­kee ‘Hud­son’ No. 6402 idles on shed in Chicago on Au­gust 6 1937.

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