Since the weather today is so reasonable (5 degrees Celsius and not much wind around these parts) I decided to try a haulage test on D6826.
For this test, I used normal bog-standard Dapol goods wagons, with tension lock couplings and complete with the built-in weight. This means: - that it is only really possible to perform the test on the straight, because any deviation from a straight line will cause the tension- lock couplings to pull the wagons off the track. Replacing them with Kadees will, of course, solve this. - that if I removed all the weights, the loco would be capable of pulling many more wagons.
Here we go: - On the level the locomotive will pull 100 wagons. - Up a 1 in 78 incline the locomotive will pull 70 wagons.
(I also have kit-built 72XX and 5205 class locos, and their haulage capacity is similar.)