Prototypes and Unreleased Sets

Imagining what could have been is always exciting. Luckily, a little bit of information has surfaced offering a peek into experiments Lego designers performed with the system over the years. While it's unfortunate that these ideas did not make it to market, they can still inspire us!

Jacobs Bogie

Perhaps the least surprising item on this list is the Jacobs bogie which appears in figure 12 of the US4861306A patent. I have personally handled this piece. It is the same size as monorail motor bogie and uses the same couplers. It sports four studs. A Jacobs bogie is shared between two railcars. The benefit of this arrangement is reduced friction since its use replaces two bogies with one.

Seatron Monorail

The Seatron monorail is the most well-known monorail prototype. It was first revealed in the "The Truth About SPACE!" article in BrickJournal issue 6 volume 2. The monorail bogies and bases appear to match the released versions. There are some interesting recolors in the yellow motor, blue lower ramp, and blue large curve (see image below). The upper ramp could be painted or printed - likely a light gray base with blue added. The track supports are also all blue.

Apparently the monorail was going to be central to the theme. It was going to connect underwater astronauts or aliens with spaceships via the platform in the picture. Since the other monorail sets had underperformed the plan was scrapped and the theme morphed into Aquazone.

Wild West Monorail

At least two monorail steam trains were designed while the Wild West theme was being prototyped. This was an odd choice since the traditional Lego train system was available. The prototype photo shows two black motors, two black straight tracks, one black upper ramp, and what is probably a black short right curve. Interestingly, the monorail base used under the passenger car appears to be 18 studs long rather than the 20 studs used in the system which was released. There do not appear to be battery boxes, but it is possible the trains were not intended to actually run.

Some other interesting details include the use of printed dishes as wheels, the driving rod design on the yellow and red loco, the printed 2x2 corner slope cow catchers, and the stickers decorating the upper loco.

Martian Monorail

In the mid-2010s I came across an online discussion regarding what happened to the monorail system. I have since lost the link, but that someone purporting to be Lego designer stated a martian themed monorail had been playtested in the late 90s (perhaps as part of what would become the Life on Mars theme). The design performed poorly. This was the last attempt to get a monorail set produced that I could find. The time period given roughly corresponds to the July 14th, 1999 date when the last renewal fee was paid on the monorail patents. Unfortunately, I have not been able to further corroborate the story.