I can't answer for a 2-4-0 but I have a bit of knowledge regarding a 4-4-0 class 8-18-C.
The amount of cars that can be pulled is based on two main factors: 1) The grade you are running over and 2) the weight of your load. I have pulled 5 cars on a level grade with no problems, but on a steep grade I am lucky if I can make it up with 1 car. American type 4-4-0s are not heavy haulers. Rather, they are built for a speed greater than say a 2-6-0. But the moguls can pull a heavier load at slower speeds.. Baldwin claims the 4-4-0 narrow gauge is capable of 40 mph. I can confirm that as I have had my locomotive up to 40 mph when on the U.S. Gypsum Railroad back in 1992 running on !00# rail. The speed limits on the D&S and C&T are considerably less. While my locomotive can do the 40 mph easily, I found the limiting factor was the tender. It holds over 1000 gallons of water, is not baffled internally. When wood is piled high, a side sway can set up at speed so much so that it literally pitches wood off the tender. Below 40 mph there was no problem generally.
On the range of a 4-4-0, on a straight and level road, I have got as much as 60 miles before needing to re fuel. Once again, it depends on grades and load and condition of fuel. The more uphill you need to go, the more often you need to take on water. On the D&S and the C&T when going up grade I never passed a water tank that I did not like. Water in the water tank by the track does me absolutely no good. So in my case I usually stop at all of them going upgrade. Of course going down grade or on a level, the mileage is much better. Another factor concerning mileage is the type of wood we are burning. I found the best is split pine that is dry, and full of pitch. It burns hotter than hell. However, we have graded wood into 4 different classes which are pretty self explanatory. They are 1) uphill wood 2) downhill wood. 3) death wood and 4) atomic wood. Uphill wood is dry and provides sufficient heat to pull upgrade without having to stop and "blow the engine hot." Downhill wood is somewhat moist but we can keep boiler pressure up with no load on the engine, and yet the air pump works great. Death wood is moist (not sufficiently dry) turns the fire orange and black, makes lots of smoke, and we cannot make steam pressure even on a level grade and in fact eventually lose pressure. Atomic wood burns so hot that we can lift the safety valves going up grade.
So, there you have it. As you can see there are various factors that enter into how much fuel you need and how often you need to stop for water.
The Baldwin 4-4-0 class 8 18 C on a level grade can pull 670 gross tons and down to 85 gross tons on a 100 foot grade.
As to the Baldwin 2-6-0 class 8-18 D Baldwin says on a level grade it can pull 840 gross tons, down to 110 on a 100 foot grade.
The Baldwin 2-6-0 class 820 D on a level can haul 965 gross tons, down to 125 gross tons on a 100 foot grade .
I have no information on a 2-4-0.
These figures come out of the 1877 Baldwin Narrow Gauge Locomotive catalog original edition. I am sure after 1877 Baldwin made bigger more powerful locomotives. But, in the early days of the narrow gauge railroads, this is what they were....
Hope this helps answer your questions
Dan Markoff
Eureka & Palisade Locomotive #4 EUREKA
