[MoC] Pennsylvania Railroad T1

[Commander Wolf]

EDIT: Instructions are now available on Rebrickable: https://rebrickable.com/mocs/MOC-102718/NonsenseWars/148-pennsylvania-railroad-t1-duplex-v3-power-functions

You can see some new footage and an updated explanation in the following videos. Also cleaned up dead links from the original post.

 

 

Spoiler

The Pennsylvania Railroad T1s were the last steam locomotives built by the Standard Railroad of the World. Designed in 1945 to replace K4 Pacifics built 20 to 30 years earlier, the 52 T1s had a controversial operational record at best. Most infamously, high power (nominally more than a Big Boy by some metrics!) and not so high adhesion (about half) often caused heavy wheel slip at speed, and along with it, heavy maintence costs. All were replaced by diesels and scrapped by 1956.

In my opinion, the T1 is nonetheless one of the most beautiful steam locomotives of all time - Raymond Loewy's streamlined casing is a masterpiece. But, in the great tradition of strealined casings, it seems they were gradually shed throughout the years. I am modelling #5503, as per the model below. While she was originally delivered without the wheel fairings and with the blunter nose cone, the "breadbox" under the nose was reduced in size only after she entered service.

5503 is built at a scale of about 16.5" per stud (slightly smaller than my previous 15" per stud models because things just work out better that way). This makes her an 8-wide model, and her 86 studs of length include 47 of locomotive, 36 of tender and 3 studs in between. The locomotive is articulated 4-4-4-4, FF-BF-BF-F(sliding)F, the tender rides on 4-axle trucks with 2 sliding axles in the center of each, and the whole lot actually runs very well through curves, switches, and everything in between.

This is the first train model that I've built with the aid of LDD. I say "with the aid" because in practice I end up switching between virtual and physical prototypes to make sure that some virtual edit still clears real switches or curves. Overall it was very convenient! Having tested and rejected the old Lego CAD programs many years ago, I was pleasantly surprised by the shallow learning curve of LDD, and I'd definitely recommend trying it if you haven't.

SNOT internal structure in the boiler

Inverted 1x4x1 panels for the "shoulder" above the boiler

1x4x2 fence for the grill in the "breadbox" (thanks jtlan!)

SNOT panels for the "skirt" of the tender

And while I don't have the pf equipment for the tender on hand, it is "pf ready"... meaning there is designated space for the motors, battery box, and receiver.

I was aware of Mr. Sava's T1 model prior to developing my own, though I wanted to develop my own interpretation, so I tried to look at it as little as possible. Ultimately I think it turned out quite well, though I have to give credit for the tile rods - I couldn't get anything to work with Technic 1x1s and cross axles. As with any Lego model, there are bound to be tradeoffs. Among other things:

The second cylinder is a full stud back of where it should be in order to accommodate the working rods.

The "piston rods" more closely model the track in which the rods travel, also in order to accommodate the motion

The curve above the nose is far too steep, but I think a steep rounded roof expresses it better than a shallower, stepped assembly

The scale is 10% smaller than all of my previous locos

And the full gallery once moderated.

Edited February 21, 2022 by Commander Wolf

[Man with a hat]

What an impressive work. And thank you for showing us the inner workings as well. What a nice piece of engineering.

and I think the curve above the nose is a good choice. It really captures the look of the original very well.

[UrbanErwin]

The model looks great, even though I don't like the look of the prototype. I especially like your solution for the tender bogies

[zephyr1934]

Wow, that is one impressive build with a ton of great technical solutions. Thanks for sharing all of the tricks and solutions along the way.

[Daedalus304]

I have long been a fan of the T1, and your version of it is very good and certainly nice to see! One thing that stuck out to me in particular was the way you articulated the leading truck and the front engine... if you did what I think you did, that is an absolutely brilliant solution. Bravo!

[Commander Wolf]

Thanks for the comments guys!

About the chassis: the front truck is just a regular 2 axle truck. The structure supporting the first set of drivers cantilevers over it, and the structure of the second set of drivers cantilevers over that. The trailing truck with the sliding axle is towballed to the back of the second set of drivers and pinned to the body. The body is also pinned to the cantilever of the first set of drivers.

Most of the joints are pinned here because I had a lot of trouble navigating bumpy tracks with my ACE 3000 and 5AT locomotives which pivoted on turntables. The pins give a bit of vertical play such that leading and trailing flanges are less likely to leave the track when you go over a bump before a turn, etc. In general I think it's been working pretty well, but we'll see when 5503 runs at a show.

[ScotNick]

I haven't been too keen about American engines, but I really like this one! You did a great job on this, especially the curves!

[Daedalus304]

Oh yes, that is exactly what I thought you did, and it is just as clever as it seemed. It seems like a great way to minimize your pilot truck's swing out, and having your drivers rotate behind it like that is great. Good job!

[LEGO Train 12 Volts]

This is a wonderful MOC!

I like your building technique ...I've already seen your work on brickshelf last sunday and now I know who you're! ;-)

[SavaTheAggie]

I started following your progress when you started uploading photos on Brickshelf. You've done a great job on her. I can't say I agree with all the design choices you've made, but you've also built in some great features that I'm a bit envious of, like the angled firebox.

Well done.

--Tony

[Commander Wolf]

I haven't been too keen about American engines, but I really like this one! You did a great job on this, especially the curves!

Yeah some guy on BrickLink made a ton of $$$ off me as I basically had to buy every curve-slope on the loco. This was one of the big benefits of CAD: you can see what your model would look like before deciding whether or not to buy the parts.

I started following your progress when you started uploading photos on Brickshelf. You've done a great job on her. I can't say I agree with all the design choices you've made, but you've also built in some great features that I'm a bit envious of, like the angled firebox.

Yeah, the firebox is only possible because I decided early on I couldn't have an interior. The box doesn't take up much space, since it's just a ring that goes around the load-bearing structure, but the SNOT in the boiler meant that the hinge and supporting stuff had to go behind the box inside the cab along with the SNOT for the doors and the trim just ahead.

Anyway, running quality is pretty important to me so I usually end up doing a lot of tweaking (like lightly oiling axles and joints in the motion) trying to make everything run as smoothly as possible. This isn't quite as smooth as my ACE was probably due to the working rods and such, but I'm pretty satisfied with the performance, and I finally put together a quick video.

Lighting isn't amazing, so I might reshoot it; maybe when I get all the PF stuff together.

[Anticyclone]

Nice SNOT work! You've captured the shape and curves very well in LEGO.

[Commander Wolf]

Alright, a final update for this model. I went to Toys R Us the other day and picked up a 60052. I stole the PF components from the set, installed them in the T1 tender, and ran some tests.

The wheels are geared up 2:1 from medium motors, both by neccessity and to try to increase the top speed.

It was a real pain to fit all the wires into the thing. If not installed a certain way, the PF cables coming out of the motors might not have enough horizontal slop and might prevent the bogies from swiveling freely.

It's probably possible to dump the "coal" ontop of the PF equipent and hide just about everything, but I didn't try it.

Ran some tests and stitched some clips together to make another short video:

Overall the performance was pretty uninspiring. It can start two 9v motors at notch 3 or 4, but you really aren't going anywhere 'til you notch it up all the way. Even then it's not particularly fast, and I bet it's running through those AAA batteries like water.

[Dutchiedoughnut]

I think your gearing may be too high... Did you try (for the fun of it) to run them at 1:1 or even 1:2?

[Dan-147]

I think your gearing may be too high... Did you try (for the fun of it) to run them at 1:1 or even 1:2?

More like the opposite. That would only make it run even slower. There doesn't seem to be an issue with torque so the solution would be to gear it even higher, maybe in two stages. Only problem is available space...

Dan-147