N&W Y6b at Maricopa Fall Meet (2025)

On display on 10/29/21 at the Maricopa Live Steamers was an 1-1/2” scale N&W 2-8-8-2 Y6b, the latest work of Bruno Platzer. It is in the process of having its propane burner system installed.
It is probably the first 1-1/2” scale locomotive to make extensive use of “printed parts”. The parts were printed using Shapeways bronze fused gray steel. The finish was very good. The material is tough to machine. Carbide cutters are a must, along with holding the workpiece in a very rigid setup. The material is difficult to drill and almost impossible to tap. Undersized drilled holes are part of the printed part and then finished with the finish size drill. Tapped holes on the prototype were drilled thru on the model and then installed with nuts on the opposite side.
The printed parts for this locomotive, included; most of the spring rigging parts including equalizers and Febreeca pad cradles, most of the brake rigging parts including levers, hangers, cross beams, most of the levers and pull rods for the valve gear system, many exhaust pipes including the huge bridge pipe so evident on the front of the locomotive, many steam pipes, stack, petticoat pipe, exhaust stand, smokebox front and door, steam dome cover, air compressor and power reverse hangers, air tank and running board support brackets, headlight parts, pilot supports, dummy drifting valves and support, and other parts that don’t come to mind right offhand.
Most of the time, parts were modeled in Solidworks right off the prototype drawings and then modified to accommodate changes required for it being a model like section thicknesses. Stl files were than sent to Shapeways.
The locomotive has some of my Berkshire parts on it; pilot and trailing truck frame castings, tender trucks, tender frame, and tender tank with extended coal boards.
Many others provided parts for the locomotive including the rods which were machined by Anthony Ruiz Duarte of Eccentric Engineer. Dan Smoley provided the lubricators.
Jerry Blake also did machining for the locomotive.
The locomotive is owned by Larry Kirchner.
Thank you Jim Nolan for the photos.

Beautiful!

To those who say live steam hobby is dying I respectfully suggest looking at the two posts just this morning showing articulated engines. I think the hobby is doing better than ever.

Berk leading AND trailing trucks? Haven’t seen detail drawings of Y6B trailing trucks but know the basics from another engine- aren’t the centering devices quite different on a Y6B? Wondering how much modification was needed for trailing?

Would love to see more pics of this engine!

Mountaineer

hoppercar wrote: Tue Nov 09, 2021 11:31 amHow come I can't find drawings or information on this loco....and other people just pop them out ??

The N&W Historical Society has an extraordinary collection of drawings to purchase. They'll send digital copies right to your email within a couple days of your order. Between drawings and photographs, they have over 6000 documents on the Y6/a/b classes alone.

https://www.nwhs.org/archivesdb/

https://modelsteamengines.tripod.com/id32.html

I didn't realize the NKP 2-8-4 and N&W tenders were that close in dimensions. N&W used a decent number of different tenders behind their articulateds through the years.

Always thought a N&W 4-8-0 would be neat. Might be a challenge to model with their inward slanted piston valve cylinders and baker valve gear setup with the combination lever trailing the crosshead.

Might be a challenge to model with their inward slanted piston valve cylinders and baker valve gear setup

You don't have to model that valve gear at all if you don't want to. The original M class locomotives delivered in 1906 were delivered with Stevenson gear in between the frames and a 6000 gallon tender. They had the inward slanting piston valve cylinders, which were designed to work with the Stevenson gear. They also had inside steam pipes which delivered steam to the cylinders. Some of these originals were converted to Baker valve gear in the mid to late teens, but most never were. Some locomotives received outside steam pipes, if they started developing leaks on the inside pipes, and some never were converted during their lifetimes. The M1 class, delivered in 1907, had Walscherts Valve gear on them, which ended up being their weak point because of a design error. So, depending on what time frame and what class they were, an N&W M could have Stevenson Gear, Walsherts gear, or Baker gear. The ones that most people think about are the original M class locomotives that was upgraded with Baker valve gear and outside steam pipes, because those were the ones that lasted the longest in service. Thus they were the ones photographed the most. Some of the Stevenson Valve gear locomotives lasted up into the late 1940's. With different pipe configurations, different valve gears and a whole bunch of different tenders, there was a lot of variety with the M class.

thanks for the info Pontiac guy.

pretty interesting, ya "the version" most people think of due to copious photos are the baker VG/piston valves. some with 6 axle tenders. I think most of the surviving ones such as 475, 433 are this variety. I think the inward slant cylinders would require a pattern to be made.