6991 Monorail Transport Base

6991 Monorail Transport Base is a Space Unitron set released in 1994. It contains a Monorail track with a large, one-way station. Two terminals and a train are also included, as well as wheeled ground vehicle and four Minifigures, three of them being Unitron astronauts and one being a Spyrius Droid.
== Description ==
The Monorail Transport Base was part of the Unitron space sub-theme released in 1994. It was the last Monorail set released by the LEGO group, and also the largest. It is the only monorail in which the modules can be removed and placed on other Unitron sets. There are also accessory monorail tracks which can be added to make larger routes. The set comes with multiple baseplates, allowing the set to serve as a connection between two Unitron bases. The two bases each are built differently. The first one, where the monorail ends/begins, has the monorail track placed high-up and has a raised level below it. On its base is another beginning/end to the track, and, interestingly, there is a Spyrius droid on it. The second "base" is a waystation with a special track piece that allows to stop the train or change its direction, and consists of a larger building on a raised baseplate.
The pieces mainly come in one of a few colours. The monorail tracks are light grey, along with a few other pieces. The transparent pieces are mostly transparent light green and transparent light blue. The remaining pieces are mostly black and white. An anomaly in the overall color of the set is the Spyrius Droid, being red with a clear transparent helmet.
The two vehicles in the set are both in the style of the theme. One vehicle is a large-wheeled land vehicle. It has no weaponry, but has a large enough space on top of it to allow it to transport small to medium space vehicles. The second vehicle, the monorail itself, is much longer than the land vehicle. It also features no weaponry, but travels along a long monorail track. It can transport people and weapons. The monorail is motorized and contains a light and sound function.
== Background ==
Monorail Transport Base was a direct base and transport of the Unitron. On at least one occasion, it was attacked by Spyrius.
== Notes ==
* This is the last set that included the grey monorail track pieces, which appeared in only two other major sets: 6990 Monorail Transport System (1987) and 6399 Airport Shuttle (1991). Those sets also utilized the same gear drive system. Among the three sets, the Monorail Transport Base was the smallest (containing the least parts) and the only one to include switch tracks. The only other appearance of these switchtracks was in the accessory set 6347 Monorail Accessory Track from 1991.
* The ramp baseplate with crater print was used by just two other sets, 6988 Alpha Centauri Outpost (1991) and 6959 Lunar Launch Site (1994).
* This was the largest Unitron set and the only set of this subtheme that was released outside the USA. It is also one of just three monorail sets, the others being from Town and Futuron.
== Minifigures Included ==
== See also ==
* 6990 Monorail Transport System
* 6399 Airport Shuttle
* 6921 Monorail Accessory Track
* 6347 Monorail Accessory Track
* Unitron
* Monorail
== External links ==
Category:Monorail
Category:9V