Project Segway – Grade Tests for Olympia

(Occasionally, other events do occur and so I will from time to time go off-topic to discuss another railroad related project or event that is going on currently – we will get back to our regularly scheduled programming…)

Picking up from the previous post ( ProjectSegway – The Olympia Helix Tests ), I realized that the designed grades on my Olympia iN the Office plan were just unrealistic for the length of trains that I wanted to run. But, before I go too far in redesigning the plan, I wanted to test out a more moderate set of grades. So, this weekend, I went about testing a 3% grade with a 170mm curve using sectional Rokuhan track re-purposed from the helix. I tested the Rokuhan Shorty Mechanism, a Microtrains Z-scale GP35, and an AZL F59. All three locomotives pushed the cars up the grade. Pulling performance may be different. I videoed the tests and they can be seen below.

This test apparatus was just a short stretch of straight and level track, which transitioned to a 3% grade using Woodland Scenics Foam inclines along another straihgt section. These inclines were taped to my kitchen counter using blue painters tape. The grade continued at 3% around a 180 degree curve of 170mm radius, and into a final straight section still at 3%. Trains were powered by a BlueLine controller powered by a 9V battery.

In summary, weight makes a huge difference. With the Rokuhan Shorty, I could only push 1 car up this grade. That is until I taped a quarter above the drive truck. With a quarter in place, I could push 4 cars up the grade and around the curve. With 2 quarters, I could push 7 cars. The Microtrains GP35 would push 9 cars, and the AZL F59 would push 14 cars.

The Rokuhan Shorty mechanism weighs all of 8.47g (0.3 oz), the Microtrains GP35 weigh 35.8g (1.26 oz) and the AZL F59 weighs 50.37g (1.78 oz). Each of those quarters weighed 5.67g (0.2 oz), so they more than doubled the weight of the Shorty. So, weight is a big deal, and I found that it made a difference adding it over the driving truck (which I did) versus over the training truck. So, use of the shorty will need to carefully build weight into the mechanism. None of this is a surprise. The video also clearly shows the added effect of the curve causing most of the locomotives to slow down as they pushed their trains up the hill.

With the quarters, I may have been able to get the shorty to push more up that 5% grade. However, the GP35 was only able to reliably push three cars up that grade, and the F59 did four. So, I have a couple of data points. I really should put together a proper grade/curvature chart for N and Z scale, which would also cover Nn3. Something else to add to the list of tasks to do.

That said, this gives me some data for the redesign of Olympia in the Office. If I can keep the grades down to say 3%, I think I would be a lot happier. And just for reference, if you poke around on the web, you do find that Z-scalers often recommend 2.5% as a maximum grade for Ztrak layouts and trains, so these results are quite consistent with those experiences.


Cameron Turner