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USRA Light Mikado e-spec (cab mode)

Here's some things to keep in mind regarding the USRA Light Mikado e-spec (cab mode):

You don't need to keep the coal level in the firebox at 100 percent (unless you need a great amount of steam). When running on level track or on moderate grades keeping the coal levels at somewhere around* 60 percent should provide enough steam.

*You may need 55 percent or maybe 65 percent and at other times maybe even 50- or 70-pecent.  Experiment!

If you do need to climb a steep, long grade, you'll need to increase the coal levels (to obtain enough steam to make the grade).

For a moderate grade that's fairly constant over say 10 miles or so, you may find that coal levels around 70- to 75- percent works well.  (Experiment!)

If you need to start your train and immediately climb a demanding grade you may need to (briefly) increase your coal level to 100 percent, then let the fire burn down a bit, say to the 75- to 85-pecent range. However, you may find that starting with a 85-pecent coal level and and letting it burn down to 60-pecent works well on the grade.  (Experiment!)

Water levels are your friend.  On startup, adding water will increase your boiler's PSI, but once under way increasing the water level will cool down the boiler, especially if you keep the water levels in the 40- to 60-pecent range. Shutting off the injectors and letting the level water work itself down will normally cause the boiler's PSI to start moving upward.

Keep in mind that it will take some time for the boiler to heat up and cool down. For example, adding coal won't get you immediate results. Just like the real railroad firemen, you'll need to anticipate your needs in advance. 

Video Demo: Taking a 50-car train up a 1%+ Grade

In this demo I'm building a very hot fire and keeping the boiler's PSI near its max to demostrate that this e-spec can provide more than enough steam under extreme conditions. In actual practice, I normally make the run up this grade with the boiler PSI around 190 to 193 and take steps (sooner) to lower the boiler pressure before reaching the summit of the grade.  


Princeton grade, map view

Example #1: Princeton to Kellysville: Taking a 50 car train up a ~1% grade 

Let's look at an example using the e-spec for the USRA Light Mikado and run a train consisting of 50 loaded 55-ton coal cars (plus caboose) from Princeton to Kellysville, WV on the Appalachian Coal route comes built in to TS2012.

The Consist

USRA Light 2-8-2 Tender B&O, kuid:123250:100272 (download from Trainz DLS)

USRA Light 2-8-2  B&O #4501 - Cab Driver, kuid:123250:100271 (download from Trainz DLS)

(50) N&W hopper loaded by whitepass, kuid:58422:15103 (download from Trainz DLS)

Caboose-Extended Vision-N&W by mcguirel, kuid2:72938:100843:2 (built in TS12)

Princeton grade, pic #1

Spot the train about 2 power poles from the Princeton station. That would be the approximate location of the yards at Princeton (which for some reason were omitted on the Appalachian Coal route).

At startup the locomotive has about 60% coal.  You're want to increase the coal level to about 100%.  Since we have a 1%+  grade to travel we need to build a fire that will provide enough steam for the first leg of our journey.

Turn the blowers on full and start slowly adding water to the boiler (to bring the level up to about 45- to 50-percent).  I suggest taking about 1 minute to build the boiler pressure up.

Once the boiler is rising and almost ready to pop off start the train.  I usually "take slack" just like was often done in the real world.

Once underway turn the blower off. If boiler pressure is still rising add some more water.  Normally I only have to add water to about the 45- to 50% levels.




Princeton grade, pic #2

You'll want to get a good run at the grade.  Don't worry about maintaining your coal level. Let the coal in the firebox burn down.  If you do things right you won't need to add any coal at all during your upgrade journey.  The route is almost totally downhill on the other side of the grade so you'll need to let the coal level burn down to the 60- to 65-percent level for that phrase of the journey.

Princeton grade, pic #3

If things go right, you should reach about 25 MPH once you reach the beginning of the grade.  Keep an eye on your boiler temperature and add water if needed.  Don't add coal. 

Princeton grade, pic #4

The first part of the grade is a little over 1-percent.  Since you built up a good fire which in turn built up your steam, you should have more than enough steam to make it over the grade, which is about a mile in length.  

Keep an eye on your boiler temperature.  Add water to cool it down. Turn off water to maintain pressure (or to let it build back up).

Princeton grade, pic #6

Your speed will probably decrease to about 10 to 11 MPH on the grade. Near the end of the grade you should detect the tempo of the locomotive's chuffs increasing.  Adjust the cutoff accordingly and start letting the boiler cool down by adding water.  Since you've let the fire burn down it should be nearing the 60% level by now.  Since the rest of the trip is almost all downhill you'll only need about 180 to 190 psi on the boiler.

Princeton grade, pic #5

Once you begin the decent downgrade you'll need to apply brakes throughout this leg of the journey.  Try to keep train speed under 25 MPH otherwise you'll have quite a problem to deal with.

If you remembered to turn off your blowers and added a little water, you should have no trouble keeping the boiler pressure at about 190 psi. If your pressure dips down you can increase your coal level slightly. Don't use too much coal.  If 60% coal isn't doing the job, try increasing to 65%, then give it a couple of minutes and take it from there.  The process of heating up the water in the boiler is a slow one. It can take a few minutes after increasing coal to get results.  Take it slow.  If things get out of hand and your boiler pressure increases too much add some more water.