2x3x1 DPUs are a nice touch. Looks like 1st gen Geeps pulling those modern aluminum coal gons, too. call the prototype police!!!! So cool to see the infinity helix in action. I wonder how many derailments preceded this successful run??
In Oct 2014, James Risner, the builder, posted a Youtube video of an HO flat spiral outward with a single level looping over and inward from the outside to the center of the flat spiral. The 2014 video was done with 8 locos and 200+ silver coal cars that look just like the 6 locos and silver coal cars in this 2016 video. This is a beautiful combination of a stacked helix and a bowl-shaped helix...and looks like it would be a great eye catcher at train shows. Maintenance/track cleaning of the two flat loops at the bottom that spiral out from the middle of the bowl to the outer stacked loops would be possible, as long as the 8,000 K'Nex pieces supporting the bowl and stacked loops make the entire helix sturdy enough to allow it to be lifted off of the supporting platforms, and tipped onto its side to reach the two flat outbound loops from the underside. Some of the comments after the 2014 video said Risner has too much time or $$ on his hands, but with 5 Million views of his 2014 video and 1 Million of the 2016 one, if he wants to drum up business at train shows or attract views to an online train store, the time and $$ might be worth it.
Maybe too much information, but just for laughs, here's a description of what went on in my head when I watched this video: I was fascinated by the video, and looked up Risner on YouTube to see what else he had. I was shocked when I saw that his spirals were labeled HO scale. Immediately, an N scale gremlin between my ears whispered that the HO guys couldn't possibly do a spiral like that, and as evidence, pointed to the hoppers passing in front of the bins on the shelves. I have similar bins that are 8 inches wide and 3 to 4 inches high. In this video, it looks like 2 coal hoppers passing in front of the shelves on the top outer loop are a little wider than the green bin on the shelf. "See that! It should only take one 8 inch car to cover an 8 inch bin in the background. Since it takes 2 cars, they must be 4 inch long N scale hoppers." But my rational self replied that, if 2 HO hoppers were at a 45 degree angle to the front of the bin, then it would take the length of both of them (16 inches) to cover the 8 inch wide bin. Then the gremlin said the radius of the smallest loop looked too small for HO. I estimated the number of cars (15 or 16 8-inch cars) and calculated a minimum circumference of (8 x 15 =) 120 inches and radius of 19 inches. The gremlin reluctantly admitted that HO 4-axle GPs could indeed negotiate a 19-inch radius at the start of the center loop, because, that extreme tightness would only be held momentarily due to the radius continually increasing as the track spirals outward. Next, the gremlin pointed to the K'Nex pieces and claimed they'd be too small to hold the weight of HO locos and rolling stock. I pointed out that the pieces were probably 1/4 inch diameter plastic tubes and were less than 2 inches apart from each other, so they could easily support HO locos, rolling stock, and the plastic subroadbed/ramp. Finally, he claimed the 19 inch radius of the first loop would require too steep a grade to provide adequate clearance for an HO loco or car to pass into or out of the bottom of the helix. But when I ran the numbers for him (clearance = 2.25 inches for trains plus 1/2 inch for subroadbed and track = 2.75 inches of rise; 120 inch circumference of run; 2.75 rise divided by 120 inches run = 2.29 percent grade), he sighed and grudgingly acknowledged,"Okay, it really can be done in HO...but HO is still Horribly Oversized."
