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[SPer]

Why is diesel-electric locomotives is better than steam locomotives on Western railroads

[DSchmitt]

Diesels replaced steam because they are more efficient:

 

http://www.railway-technical.com/st-vs-de.shtml

 

The author of the article (Al Krug) home page:

http://www.alkrug.vcn.com/home.html

7/6/17 Tales from the Krug  http://krugtales.50megs.com/

[ndbprr]

The first road diesels on the PRR were two E7s. They ran Harrisburg to Detroit and back on a secondary train. At one point the wheels needed to be turned on a lathe since they had worn. The shop foreman said they must have soft wheels since none of the new T1 steamers needed it. The truth was the highest mileage T1 had run 125, 000 miles while the diesels had run over 500, 000 miles. 4 times the mileage with virtually no maintenance or down time. Wasn't much of a decision by any railroad to replace steam as fast as the money could be had

[daveklepper]

Very expensive to carry water to the middle of the desert.     

[feltonhill]

Where did you get the 125,000/500,000 comparative figures for the PRR T1/E7s?   Initially the highest mileage T1's matched or slightly exceeded the two E7's.  Later the E7's and other diesels pulled ahead dramatically.  I've seen various ratios, just never this particular one.

[ndbprr]

Trains issue about the E7s. Probably mid 70s written by the PRR person assigned to the engines who then joined EMD.

[feltonhill]

I thought that may be the source.  It was January 1979, pgs48-50.  It's misled many people, myself included. 

After years of digging, I've used that article as an example of the myths surrounding T1 mileages.  It compared the T1 and two new E7's on test from EMD. I’ve found considerable reason to question the quoted T1 mileage during the time from Sept 1945 through April 1946, the 6-month period mentioned in article.  During that time, the E7's ran 69,000 miles, about 11,500 miles per month.  The author, W. A. Gardner, was told that the highest mileage T1 during that period ran only 2,800 miles.  According to mileage reports I have from PRR's Chief of Motive Power, 5504 was the highest mileage T1 at the time, posting 40,642 miles since its in-service date of 12/5/45.  This is an average of about 8,294 miles/month.  For the month of April 1946, it posted 10,793 miles, only slightly less than the E7's at that time.  Also during April, 5512 posted 11,442 miles and 5508 posted 10,942 miles, also about the same as the E7's.  Maximum mileage figures for the T1 fleet stayed in this range until March 1947.  I could never understand where the 2,800 mile figure came from.  It’s certainly not supported by any existing data.  You have to be careful about believing everything you read.  Sometimes the research is there, sometimes it's not.

Back to the subject of this thread. - Offsetting this, the fleet average for the 30 T1's in service in April 1946 was about 7,244 miles/month, substantially less than the two E7's.  For comparative purposes, the K4 fleet was averaging about 6,186-7,016 miles per month, based on the previous 3-month's data. 

More telling than that, diesel mileage increased as time went by, so that by Oct 1947 the fleet average was about 19,620 miles per month.  By this time, T1 fleet's mileage had slowly declined to about 6,738 miles per month.  The K4's decline was more significant; they were down to about 4,808 miles per month.  So the T1's had a bit more staying power than is sometimes thought.  However, the real trend was clear enough with diesels setting the pace going away.  It was all over but the shouting...

[erikem]

SPer

Why is diesel-electric locomotives is better than steam locomotives on Western railroads

Several reasons, lack of water or good water for some roads (notably AT&SF), oil more more readily available than coal (SP, AT&SF, WP, parts of UP), heavy grades favoring the full horsepower at low speeds available from diesels.

- Erik

[Overmod]

I suspect the "2800" mile figure is a typo, a transpose of the '2' and '8' that proofreading didn't catch.

One potential issue involves the ability of the E units to run across multiple divisions without stopping, and to be more quickly turned for equivalently long return runs.  This was mentioned (in connection with Fs) as one of the nails in the coffin for developing the V1 turbine in freight service.

'Statistical' mileage for the T1s is also skewed by the time individual engines were out of service for repairs or updates, and perhaps further skewed by the long time that certain engines (for example, 5500 and 5547) were out of service for their extensive modifications.  There might also have been reluctance to schedule T1s for long runs or to assign them to the 'general pool' of engineers, or to keep them relatively close to locations which could turn them or service them.

I concur that the 'correct' comparison is between T1s in full service and E7s in comparable service... not average statistics.