surprising power of smaller locomotives

[markpierce]

On an earlier subject, a reader found it hard to believe the account I related concerning a Southern Pacific Mogul (2-6-0) pulling an 80 or more car train, on level track in central California. I have since received additional confirmation of such prowess. On page 12 of the Summer 2006 issue of "SP Trainline" a former SP engineer/fireman noted that it was not unusual for Moguls on the Friant branch (out of Fresno, CA) to pull 100-car trains of empty drop-bottom gondolas on their way to get more rock. The larger SP Moguls had a tractive effort of about 35,000 lbs. To me, it is amazing how such small locomotives could pull long trains. My understanding is this could be done as long as they were on level track and speed was not important. The engineer/fireman said the Moguls were ideal for switching and local freights. They had excellent acceleration, speed (larger drivers), and stability, as compared to the somewhat more powerful Consolidations. No wonder they outlasted more powerful and modern steam locomotives on the railroad.

Does anyone out there have more examples of the power of smaller locomotives?

[tomikawaTT]

For sheer power in a small package, the eight-coupled high pressure compounds built for the Delaware and Hudson would be hard to top. Thanks to very sturdily constructed track, roadbed and bridges, these locos had very high axle loads, and matching tractive effort (upward of 100,000 pounds starting simple with tender boosters operating.) Thanks to water tube boilers, which put a LOT of evaporative surface into direct contact with the hottest gases generated by big grates covered with burning anthracite, they had horsepower to match.

There were four of them, three consolidations and a 4-8-0. The consolidations were two cylinder cross-compounds, while the 4-8-0 may have been the only four cylinder triple expansion locomotive ever built. It was certainly the only one built for an American railroad. (There were a lot of four cylinder locos on the east side of the Atlantic. I don't know if any were triple expansion compounds.)

In road tests, they proved capable of handling trains that normally required doubleheading when powered by conventional 2-8-0's, getting similar results with half the engine crew and 2/3 the coal consumption. Unfortunately, they were slow - suited to drag coal service, but unable to meet the speed requirements that developed as D&H changed from a coal originator to a bridge route. The next locomotives purchased by the D&H were high-drivered 4-6-6-4's (which developed slightly less tractive effort, but could run at twice the speed.)

Chuck

[markpierce]

I wonder what grades those locomotives encountered, and how many cars they towed.

[tomikawaTT]

D&H's Anthracite country was hilly - grades on the order of 1.5% were common. Since the standard consolidations were rated at 2250 tons from Wilkes-Barre, PA, to Oneonta, NY, I would guess the heavies would have been rated somewhere near 4500 tons. That would translate to 50 loaded hoppers, or about 150 empties.

Of course, comparing these with typical 1900-era Western railroad consolidations would be like comparing Hercules (the original, not Kevin Sorbo) to Joe Six-pack. Even "light" D&H locos would have crushed the roadbed of most railroads.

Chuck

[eridani]

QUOTE: Originally posted by markpierce

I wonder what grades those locomotives encountered, and how many cars they towed.

On the infamous Burma Thailand Railway ( Bridge on the River Kwai) the most common locomotive was the Japanese C56 "Pony" a small 2-6-0 originally designed for Japanese mountain branch lines. It was designed with a wide cab and a small tender so that the engineer could run it in reverse with out the need for a wye or turntable.

The grades reaching the mountain border between Burma and Thailand were often 3.2 and 3.5 and the C56 could pull up to 20 or so cars by itself. For longer trains the Imperial Japanese Army used what they called a push pull system (one loco in front, one in the rear).

By the engine used in the movie was not a C56 but preserved ones left over from the war can still be seen in Thailand

[andrechapelon]

QUOTE: Originally posted by markpierce

On an earlier subject, a reader found it hard to believe the account I related concerning a Southern Pacific Mogul (2-6-0) pulling an 80 or more car train, on level track in central California. I have since received additional confirmation of such prowess. On page 12 of the Summer 2006 issue of "SP Trainline" a former SP engineer/fireman noted that it was not unusual for Moguls on the Friant branch (out of Fresno, CA) to pull 100-car trains of empty drop-bottom gondolas on their way to get more rock. The larger SP Moguls had a tractive effort of about 35,000 lbs. To me, it is amazing how such small locomotives could pull long trains. My understanding is this could be done as long as they were on level track and speed was not important. The engineer/fireman said the Moguls were ideal for switching and local freights. They had excellent acceleration, speed (larger drivers), and stability, as compared to the somewhat more powerful Consolidations. No wonder they outlasted more powerful and modern steam locomotives on the railroad.

Does anyone out there have more examples of the power of smaller locomotives?

You think that's amazing? A Southern Pacific A-3 4-4-2 was rated at 2400 tons in freight service in the San Joaquin Valley. An A-3 had 81" drivers and about 27,000 lbs tractive effort without the booster with which some were equipped. I saw the tonnage rating in a book somewhere. Wish I could remember the title.

In Lucius Beebe's "The Central Pacific and Southern Pacific Railroads" there's a picture of an A-6 4-4-2 being used as a rear end helper on a freight train. An A-6 was a modernized A-3 and was equipped with a feedwater heater, booster and Walschaert valve gear (A-3's were Stephenson equipped). With the booster engaged, an A-6 had nearly as much starting tractive effort as a P-6 4-6-2.

Andre

[tomikawaTT]

eridani

The C56 class were fitted with six-wheel tenders with slope sided tanks. Water capacity was only 10 cubic meters, which made frequent refills a must. The ones used in Thailand had been re-gauged from 1067mm to 1000mm, probably by fitting the drivers with new tires. Other classes of standard JNR locomotives were also found on the Royal Thai Railways. I personally saw a D51 there in 1965.

One key point about the cars in C56-hauled trains - they were four wheelers, and typically didn't weigh as much fully loaded as an American car would weigh empty.

If I, personally, want to see a C56, I can go out to the layout room and check my locomotive storage box. Or I can turn my head 90 degrees and be face to face with one. (Judging by the "cold air exhaust" and the snow on the ground, it's a safe bet that photo wasn't made in Thailand!)

Chuck (Who models JNR in HOj, and served in Thailand)

[marknewton]

You're twisting my words. I asked for more information, I didn't flatly reject your claim. You mention a hundred empties. How many loads do you reckon they would have brought back? And if speed was important, and the track not level? How many then?

Cheers,

Mark.

[Anonymous]

a former SP engineer/fireman noted that it was not unusual for Moguls on the Friant branch (out of Fresno, CA) to pull 100-car trains of empty drop-bottom gondolas on their way to get more rock. The larger SP Moguls had a tractive effort of about 35,000 lbs. To me, it is amazing how such small locomotives could pull long trains.

WOW! 100 cars.

Let's see, CGW's K-5 Pacifics had around 42,000 pounds TE.....

[emdgp92]

There's a little Plymouth narrow-gauge diesel at the Greene County (PA) museum that's used to pull their  2-6-0 out of its shed. Up until recently, that diesel not only had to move the Mogul, but the dead switcher it was coupled to as well. A 2-6-0, especially a narrow-gauge one, isn't a very big steamer, but the little Plymouth didn't seem to have much trouble moving it.

[markpierce]

You're twisting my words. I asked for more information, I didn't flatly reject your claim. You mention a hundred empties. How many loads do you reckon they would have brought back? And if speed was important, and the track not level? How many then? Cheers, Mark.

I'd like to know too.  None of the S.P. tonnage tables I have show anything smaller than  2-8-0s.  I did talk to a fella last week that drove a "Valley Malley" 2-6-0 pulling sixty-five cars at 30 m.p.h. on level track.  The Friant branch had maximum eastward (northbound/inbound) grade of 0.966 percent and maximum westward (southbound/outbound) of 0.656 percent.  From pictures I've seen the trains did not exceed much over 30 cars.  Twenty to 30 cars may have been typical for a "heavy train."