The Catacombs The Continuity Guide
Moonbase Guide
by Martin Willey

Travel Tube

Breakaway Breakaway Black Sun

Travel tubes provide rapid transit between sections of the base and to the launch pads.

The concept is derived from underground mass-transit railway systems, notably London's "Tube" with the distinctive round tunnels and trains. The idea also seems to be based on Robert Salter's proposals for a tube shuttle, which he was promoting in the 1970s. This was a vactrain, travelling through a de-pressurised tube. Because there was little air resistance, and combined with maglev technology, speeds could be potentially faster than sound. The idea was revived in the 2000s, under the name hyperloop.

A lunar vactrain/hyperloop would not need a tube, just a track, because there is no air on the Moon, although within the base a partially pressurised system may be safer. The travel tube is evidently not a vacuum, as the creatures in Space Warp and The Beta Cloud use it without causing decompression.

Access to and from corridors is via the double side doors. Access to spaceships on the launch pad is through the end door. This opens into the Boarding Tube.

In Year 1 there are six seats (the Toga chair); in Year 2 there are four.

The opposite end of the travel unit has no interior door. Instead, there is a communications panel with two black and white screens. Externally, we never see an end without a door. Arguably the travel unit has a symmetrical outer shell for ease of manufacturing, and one door is non-functional when the interior is fitted.

When travelling, the forward side is illuminated with white light; the rear side with red light. There are two rails, one at the top, one at the bottom.

In the original concept, Alphans would key in a destination to their commlock, point it at the tube door keypad, and be automatically taken to their destination anywhere on the base (like a taxi-request application on a smartphone). In two episodes, Alphans use either the door keypad or communications panel to start or stop the travel tube, but normally they just enter and sit down. This suggests the travel tubes lines are like subway lines, travelling between two fixed points with perhaps several stops along the way. It is possible there are two parallel tubes, to allow units to pass in either direction like trains, switching to a single tube for stops/end stations. This would allow multiple units continuously moving in both directions. A single tube design would require a single unit per tube, with longer waits at all stops.

Breakaway Breakaway Breakaway


Space Warp

The exterior shots of Moonbase Alpha clearly show the travel tube buildings. All scales of exterior model are square in profile.

There are approximately 19 long radial tubes from the main buildings, terminating at launch pads or small buildings. There are also smaller spokes between larger buildings, and a few shorter orbital lines at right angles, usually attached to launch pads.

All the lines are surface lines, with no elevated lines for higher floors of the buildings. There may also be some underground tracks. All the lines are straight, with no curved tracks. The junctions of radial and orbital lines may have a building (perhaps a turntable), but some do not, with a sharp right angle turn.

Exterior vs Interior

The exterior travel unit has end doors on both ends. The interior only has one end door. The doors are different shape: angled sides for the exterior (like an Eagle door), straight for the interior and opening in the middle.


Travel Tube

Early Keith Wilson art of the Travel Tube interior, 1973. The seating continues round all sides. Elements that will survive to the final set include the rounded shape, the side door with tube map over the door, a strip of lights around the walls, and the two video screens at the end of the cabin. The short cables hanging from the ceiling are presumably hand-grips, like London tube carriages. 55 x 80 cm. This drawing sold for £380 at an auction in July 2022.

We don't see the interior often in Year 1 (it is featured only in 6 episodes, Breakaway, Matter of Life And Death, Black Sun, Missing Link, Guardian Of Piri, The Troubled Spirit). We see angles of it in other episodes, from the corridor set or Eagle set. It is featured in 8 Year 2 episodes.

Andrew Novinc VR Space:1999 Andrew Novinc VR Space:1999

Cut-away view of early year 1 Travel Tube interior, by Andrew Novinc. See 360° panorama here

Andrew Novinc VR Space:1999 Andrew Novinc VR Space:1999 Andrew Novinc VR Space:1999
Andrew Novinc VR Space:1999

The end door of the travel tube opens into the boarding tube, which in turn connects to the Eagle passenger module or other spaceships. In Year 1, the left door (seen through this open door) normally goes to the corridor; in year 2 the corridor is via the opposite side door (see set plan).

Renders by Andrew Novinc

Breakaway Matter Of Life And Death Black Sun The Troubled Spirit

The interior is 20ft/6 metres long, 10ft/3 metres wide.

In Year 1 the unit features 6 seats. The chairs are the Artemide Toga, designed by Sergio Mazza in 1968.

The floor is raised, with sloping ramps down to each of the three doors.

Uniquely in Moonbase Alpha, the walls have a brown patterned texture (probably carpet tile). Darker and lighter vertical stripes can be seen, created by the diagonal patterns seen at an angle. The white "ventilation" panels on the walls and end of the seat frame are the same as seen in the Eagle command module and passenger module. They are actually bath trays; there are no ventilation holes.

Missing Link Guardian Of Piri

The light strip along the side indicates motion. It only moves from the communications panel side to the door. Only in Space Warp do we see it moving in the opposite direction, from the end door.

The white curved overhead panels are usually illuminated, but sometimes not. The triangular end panels are also sometimes not illuminated. In Missing Link they are red, while the overhead panels are turned off.

In one episode, End of Eternity, the illumination is red, but we don't see clearly inside the travel unit.

Brian The Brain The Seance Spectre Space Warp The Seance Spectre

The slightly modified Year 2 version. Note the set has shrunk. Along the side walls there were 3 white "ventilation" panels and 3 seats; now there are only 2 of each.

Communications Panel

Black Sun

Close-up of the control panel (as seen in Breakaway, Matter of Life And Death and Black Sun). For later episodes it will be revamped.

Missing Link

Later version, from Missing Link onwards. The two screens, Emergency Procedure label and line of lights below are identical. The dial or round button above the "Emergency Procedure" label is a red button, which Koenig presses to try to call Paul Morrow. There are additional red lights/buttons on each side, under the screens, with red Letraset panels, and a yellow Letraset panel bottom centre.

Missing Link

In Missing Link, Koenig presses the far left red button to start the travel unit. It normally starts automatically, except in one other episode, The AB Chrysalis, when Alan uses the door control panel inside the side door frame.

Guardian Of Piri The Beta Cloud Space Warp The Seance Spectre

The communications panel doesn't change in year 2, although the line of red and white lights/buttons is no longer illuminated.


Matter Of Life And Death Matter Of Life And Death

In Matter Of Life and Death, they enter through both the left and right doors. Neither opens to a corridor. Both side doors are also used in Missing Link (the right door has a wall behind him; the left door is the standard corridor). Normally in Year 1, the left door is used. In Year 2, the right door is used.

Space Warp Space Warp

In Space Warp, two rare Year 2 uses of the left door.

Seed Of Destruction Dorzak Space Warp

The end door has straight sides, unlike the exterior shots of the travel tube unit. There is a storage area with fixed rails and normally a variety of different boxes.

The Beta Cloud

The door control panel is on the inside frame of the door. The label above the control panel is the Emergency Procedure label, also on the communications panel. The label on the right side door disappears part way through Year 2, but remains on the other doors.

Breakaway Breakaway Brian The Brain

View showing the graphic over the door, presumably a schematic topological map of the travel tube network, like the London underground map. The graphic over the two side doors is similar but not identical. The two side door plans are shorter and some details are different.

The two graphics, as rendered by Andrew Novinc. Some text is uncertain. The taller map is over the end door; the shorter one is over the side doors. Apart from some rearrangement of labels, the end-door map is missing two connections. See more on the map.

Guardian Of Piri Voyager's Return End Of Eternity The Last Enemy A Matter Of Balance A Matter Of Balance Brian The Brain The Beta Cloud The A B Chrysalis Dorzak Dorzak
The Seance Spectre

Appearing in The Seance Spectre are two buttons by the door. The top green one is "Re-start" (white text on red), the lower red button is "Emergency Stop" (red text on white). Note the inner side of the door has labels, including the number "2"

Exterior door signage

End Of Eternity Earthbound The Troubled Spirit End Of Eternity

In the corridor in Year 1, the sign is normally "Travel Unit 2", although "Travel Unit 7" also appears.

Voyager's Return

Some episodes have additional labels.

Alpha Child

In Alpha Child the travel tube door is open and labelled "Medical Centre", even though the travel tube interior is clearly seen (with a gurney). Perhaps a special travel tube connecting wards and treatment rooms?

Collision Course Dorzak The Beta Cloud

In the boarding tube the sign says "Travel Unit 12"

Catacombs Of The Moon The Mark Of Archanon The Mark Of Archanon Seed Of Destruction The Beta Cloud The Beta Cloud

In Year 2, the reception sign reads "Travel Tube", with no number. There is normally a sign by the side reading "Travel Tube to Launch Pad 4".

Space Warp Space Warp Space Warp Space Warp

In Space Warp, the Launch Area has two travel tube doors, marked (in duplicate) "Travel Tube 1" and "Travel Tube 2b". Travel Tube 1 is a normal double doors, with no travel unit behind it.


A Matter Of Balance

The set did not lend itself to revamps, but in A Matter of Balance it is briefly seen as the Nuclear Generator Room, attached to the Equipment Room, and filled with hexagonal boxes. The raised floor, distinctive brown walls and motion indicator are visible.

Copyright Martin Willey