Torque-Long

Folks, I invite those of you who are not railroad buffs or interested in things mechanical to skip this video as it is long and of interest to a limited audience.

Those who chose to at least give it a try may want to fast forward to around 5:00 if you are not interested in steam locomotive stack talk.

For those of you who do not know, a reciprocating steam engine makes maximum torque at stall. This, of course, is torque rise taken to the extreme.

I will also ad that steam locomotives have two double acting cylinders, one on either side. In effect, a four cylinder engine. At low speed, you can count the barks of the exhaust while watching the revolutions of the drivers. Four barks per revolution.

Here, we find NKP Berkshire 2-8-4, 765 pulling a heavy train up a significant hill unassisted. 765 has more than adequate power and steam but she is being worked at the limit of adhesion and her engineer is limiting power to prevent wheel slip. Note the pressure relief valve popping off at about 6:35. Again, plenty of steam pressure and power, but can 765 crest the hill without slipping?

The train continues to slow but the torque continues to rise. Try this with a DE unit.

You will need to watch the entire video (or FF) to see is she stalls.

Dean
NKP 765

I enjoy your steam-train videos. I was in Two Harbors, MN recently and took a look at the DM&IR 2-8-8-4 Mallet #229 on display there; it's one-hundred & twenty-eight feet long. The tender carried 26 tons of coal and 25,000 gal. of water. The engine and tender, ready to run, weighed nearly 1,000,000 lbs. Six-thousand, two-hundred and fifty hp, 140,000 lb tractive effort. The last run was July 5, 1960. This engine and others like it hauled mile-long trains full of iron-ore to Duluth from the Masabi iron-ore range, about 80 miles NW of Duluth. "Lakers" filled with the ore at Duluth sailed the Great Lakes, taking the ore East to where the coal was. The Mallets were built specifically to haul ore for the war effort. The volume of refined steel from the ore the Mallets carried is one of the big reasons why Germany and Japan never stood a chance. Number 229 is outside, under a roof. Mallet #225 is on display outside at Proctor, MN and #227 is inside at Duluth at the Lake Superior Rail Museum. #227 is suspended a fraction of an inch above the rails. The running gear can be set in motion as when the engine was really moving.

I have a friend that belongs to the Fort Wayne Railroad Society and I believe this is their locomotive, great video. I wish more railroads would actively try to keep steam alive. My hats off to those that do.

The D M &I R Yellowstones were legendary, CGID.

Dean