LAST OF THE STEAM GIANTS

As half of a century rolls by, the reign of steam power on railroads marches towards its end. Diesel and electric locomotives are poised to take the led. And yet, it is now that steam power reaches its peak in engineering: Giant articulated steam locomotives with two sets of driving wheels, four cylinders, and enormous high-pressure boilers continue to roam the rails. Their great strength and immense amount of power allows them to pull the heaviest trains with ease, keeping pace with newer modes of power for a little longer.

One of the biggest and strongest ever built was the Iron Sirius of the Plaiwelle Railroad. Its class was the pride of the line, the king of the fleet, the only locomotives that could haul a several-thousand-ton train over the Blocky Mountains unassisted. Even as the railroad began shifting towards more advanced forms of motive, this monster steam locomotive continued to steam on, becoming one of the last steam locomotives to operate on their rails.

The Iron Sirius was loved by so many people,the railfans watching the trains go by, the crews operating it, the engineers at the workshops, and even the board of directors of the Plaiwelle Railroad. As such, it was one of a fortunate few that was marked for preservation, and stood on display outside of the railroad's headquarters for several decades. Visitors would come by to wonder at this titanic machine, climbing inside the cab to imagine how it must've been like to drive it.

With so many people enthralled by the locomotive, a group of people at the railroad decided to make the seemingly impossible happen. They moved the engine into the workshop with the intent of making it steam again. Numerous old parts were refurbished, many were replaced, and the fuel type was converted from coal to cleaner, more efficient recycled engine oil and cooking oil. After years of hard work, the Iron Sirius was fired up again.

DESIGN PROCESS

INSPIRATION

This locomotive is a 1:48 scale model of a gigantic articulated locomotive built in the 1940s, one of the largest in the world. I had the opportunity to see one of these up close a long time ago, and that is the main reason why I was inspired to create this design. I chose to make it in 1:48 scale because this is a common modelling scale for model trains, and it doesn't look too oversized compared to the official driving wheel parts. I also enjoy the challenge of creating such a large model that not only looks accurate to the prototype, but can also function and run on regular track.

CHALLENGES

A major challenge in building a locomotive like this is the articulation, or the ability to flex around curved track. This required a lot of trial-and-error in Studio and some real-life parts, lining up the wheels on curved track while making sure other parts of the build did not intersect. Some details on the undercarriage had to be simplified to achieve the appropriate range of motion and stability for standard curved track, but that is a sacrifice I am willing to make for the sake of functionality. The engine units use 4x4 turntable parts, allowing for both articulation and torque transmission from the motors to the wheels. The pilot and trailing trucks use rotating pins and linkages. The tender uses rotating pins and laterally sliding axles.

Both engine and tender are composed of "SNOT Cores" which are hollow structures composed of modified bricks and brackets (Studs Not On Top or SNOT parts) and bar-holding clips or holes. Exterior details are built as large, flat panels that are wrapped around the cores. The idea is simple, but the real trick is building a core that has all the necessary attachment points while being rock-solid. Mixing bricks and brackets allows not only allows for enhanced stability, but also helps with finer details such as the boiler being narrower at the front and wider at the back and the inset ladder at the rear of the tender. One section I am particularly proud of are the sides of the second half of the boiler, where a pair of long, flat assemblies are held at a non-system width by bars and clips to match the width of the sideways slopes and fill out the curve.

While many builders may give their models a completely stud-free finish, I find that studs can be useful as detail on their own. They can give the impression of rivets, bolts, small access panels, or the rough surface of a firebox or f coal. Sometimes individual, isolated studs can represent lights or buttons. It all depends on where the studs are and how they are arranged.

The name Iron Sirius on the alternate brick-built tender logo is based on the naming conventions used in older train sets, consisting of a mineral to describe the color of the locomotive and an object related to the sky. Sirius originates from the name of the brightest star visible from Earth in the night sky, which is part of the constellation Canis Major, or the Great Dog. This is further enforced by the dog that accompanies the engineer and fireman. The shape of the logo is based on the logo found in other train sets, consisting of a circular target with two arrows pointing outwards at the sides.

SPECIAL FEATURES

The tender has easily removable top panels, revealing a large hollow cavity inside containing several alternate parts. These include a pair of smoke deflectors, an alternate dynamo setup, alternate firebox sides, alternate tender logos, and the top of an oil tank to replace the coal load. These parts can be used to customize the appearance of the locomotive, reflecting several design changes for improved operation over the years. A flat-ended wrench tool on the rear of the tender can be used to help pry off tiles for customization.

The locomotive can be motorized in two different ways. Personally, I prefer to power the engine directly through the drive wheels on the engine. However, there is also the option to put standard train motors or 9V motors in the tender for those who prefer that method.

BUILD STATS:

Parts:
- Engine = 1723
- Tender = 690
- Alternate Parts = 119 parts
- Track = 8 parts
Lengths:
- Engine = 71.1 studs
- Tender = 37.3 studs
- Engine + Tender = 111.6 studs
Widths: Mostly 9 studs, 12.8 studs at the motion
Heights: 14.2 studs from rail to chimney, 15.1 studs overall
Functions and Features:
- 1:48 scale
- Working driving wheels and motion
- Runs on R40 curves
- Fully decorated interior for engine cab
- Working hatches on cab roof and tender sides
- Removable coal/oil load
- Alternate parts and tool for locomotive customization stored inside tender
- Powered-Up Requirements
  - Option 1: Engine + 1 Hub + 2 Large Motors
  - Option 2: Tender + 1 Hub + 2 Train Motors
  - Cab roof hatch and removable coal load allow for access to Hub switch.
  - Option 2 requires removal of alternate parts from tender.