Montgolfier-class Super Dimensional Tender/ Mobile Dock (SAD)

Montgolfier-class Super Dimensional Tender 1

ROBOTECH Technical Files

by Pieter Thomassen, with Peter Walker

edited by Tim Wing


  • Montgolfier-class reference file
  • Montgolfier-class gallery

Designation: Montgolfier-class Super Dimensional Tender/Mobile Dock (SAD).

Names and disposition:

  • SAD-1 UES Montgolfier, commissioned 2025, in service
  • SAD-2 UES Wright, commissioned 2026, in service
  • SAD-3 UES Bleriot, commissioned 2027, in service
  • SAD-4 UES Lindbergh, commissioned 2028, in service
  • SAD-5 UES Gagarin, commissioned 2029, in service

Ship’s complement:

  • Ships’ crew (1910 men),
  • Naval Air Group (490 men),
  • Directorate of Ships detachment (650 men),
  • Life support limits are for a full complement and about 4500 supernumaries (7500 men total). Usually, about 800 to 1000 personnel are on-board the ship in a replacement pool for the line vessels.


  • Length: 1120 meters over all.
  • Height: 357 meters with scaffolding retracted, 850 meters with scaffolding extended.
  • Width: 450 meters with scaffolding retracted, 475 meters with scaffolding extended.
  • Mass: 11,400,000 metric tons operational (typical), 32,000,000 metric tons maximum, while transporting ships in the dock.
  • Fuel mass: 1,280,000 metric tons, maximum (typical)

Propulsion systems:

  • Main power system: RRG mk 14 protoculture-fueled Reflex furnace. The powerplant of the Montgolfier-class vessel can deliver up to 25.9 Petawatts of power, and can operate for forty-seven minutes at maximum power before overheat initiates autoshutdown.
  • Maneuvering thrusters (8): Fusion-plasma reaction thruster clusters mounted on the main hull; top, sides and bottom halfway forward and aft.
  • Reaction thrusters (8): Westinghouse HSP-24 Fusion-Plasma Reaction Thrusters with protoculture energizer. These engines are mounted in the port and starboard engine bays, in two quadruple square banks of four engines each.
  • Secondary reaction thrusters (4): Rolls-Royce Sparrowhawk Fusion-Plasma Reaction Thrusters with protoculture energizer. These engines are mounted as a quadruple bank in the central engine bay, directly behind the main hull.
  • Anti-gravity System (1): 27 RRG Cyclops anti-gravity pods.
  • Space Fold (1): RRG (Robotech Research Group) Mk3b spacefold. This system generates a spherical fold bubble and can transport 30 to 40 subluminal ships in its fold radius. This system is a Mk3 fold, modified to allow for larger masses but with no larger fold-sphere.
  • Planetary Capabilities: The Montgolfier-class has atmospheric capabilities through its reaction thrusters and anti-gravity system. The folding drydock under the hull, however, would not survive a re-entry into the atmosphere. The ships’ lower body has sufficient strength to let the ship land on it, if the scaffolding were to be removed. The ship would float in an ocean, though it would be best to do this with an unloaded ship rather than with a loaded one. However, because of its mission profile, this class never operates in an atmosphere, in addition to losing its drydock during re-entry.

Note: Because of the location of the thrusters, the Montgolfier-class is generally incapable of using its reaction engines when a ship is in the drydock. However, it is possible to tow another vessel if that vessel’s engines can be brought at least partially on-line, of if the vessel’s mass is significantly less than the Montgolfier’s. However, folding to a safe location with the crippled vessel is the preferred action.

Endurance and mobility limits:

The dry stores endurance is limited to about 20 years; the on-board recycling installations are very extensive, and only incidental biomass losses need to be replenished. Water stores are recycled almost completely. The hydroponics installations on board will provide the crew with a steady supply of fresh foods, and much will even be ‘exported’ to smaller ships in their fleet.

The mecha consumables supplies (mainly missiles) are very extensive, and can sustain continuous combat operations for over fifty days against the Invid, mostly because the Montgolfier-class also serves as primary resupply bases. The ship-launched missile magazines should suffice for twenty large battles or forty or more skirmishes, for the same reason.

The Reflex furnace can function for about 30 years at normal usage levels before an energizer rebuild is necessary.

At full power, the main propulsion systems can produce up to 275 Giganewtons of thrust at a minimal reaction mass efficiency profile, or as little as 12.3 Giganewtons of thrust at a maximum efficiency setting. At lower power levels, these thrusts are commensurately smaller.

At full power (and when not towing another vessel), the Montgolfier-class can achieve a maximum delta-v of 138 kps at the cruising acceleration of 0.1 gees, a maximum delta-v of 27.6 kps at the battle acceleration of 1.0 gees, and a delta-v of at most 7.7 kps at the flank acceleration of 2.5 gees. At lower power levels, and with larger loads, these ranges are commensurately smaller.

The fold systems are not navigationally guaranteed for any single jump beyond 10 kiloparsecs. If longer voyages are required, the ships must conduct multiple consequetive fold jumps.

The maximum sustained atmospheric speed is limited to Mach 3. A higher speed can be attained while accelerating to orbit, but this stresses the engines to above their sustainable heat tolerances, and must be limited to orbital ascents. The maximum hover time on the anti-gravity systems is limited only by the protoculture supplies and maintenance requirements. However, no Montgolfier-class vessel has ever operated in planetary atmosphere for reasons outlined above.

Weapon systems:

  • Vickers MP-18 particle gun turrets (10): Designed to counter other ships and to provide orbital support fire, these weapons are capable of delivering 3000 MJ of particle energy once every three seconds at the maximum discharge rate out to an effective range of 300,000 km. These weapons are identical to those of the later Ikazuchi class. Three turrets are mounted on the upper hull, replacing the double and quadruple barreled turrets of the Tokugawa precursor design, three more are on the lower hull, and the last two are located on each flank.
  • PL-2a Point Defense turrets (12): Mounted behind movable panels in the upper main hull (6) and the lower main hull (6), these standard REF weapons can fire 56 MJ of particle energy four times per second.
  • Mk.253 MLS missile systems (6): A VLS-type missile launcher with 10 individual launch silos. The silos each contain 6 ready missiles in a rotating mechanism, which can be reloaded while firing. The ready magazines store 200 missiles per launcher. These launchers typically fire Warhawk and Spacehawk missiles. Typical warheads are anti-mecha cluster munitions, nuclear reaction anti-warship and nuclear reaction re-entry capable weapons. Two launchers are located near the engines and two amidships.

Air group and mecha complement:

Though the Montgolfier-class did have sufficient hanger capacity to embark a single carrier air wing (~160 aerospacecraft), it rarely did. More often, if any mecha were carried at all, they were in the form of pre-positioned replacement mecha. At maximum capacity, with no room for actual flight operations in the hanger bay, the Montgolfier-class could carry approximately 1250 Veritech mecha, aerospace fighters, or Destroids of all types. Around 2000 Cyclones of various versions were also typically stored after 2028.


  • DS-2 Barrier Defense System: An advanced forcefield system which covers the full four pi steradians around the ship with a yellow-greenish forcefield (or if desired, only part of the ship). This field will stop all solids and directed energy weapons (except lasers through a narrow band). However, excess energy which cannot be shunted from the field will be stored in large inboard capacitators. The storage wattage is high but not infinite, and when the barrier overloads the field will discharge the stored energy particles. This discharge will have the force of a high-yield (>4 MT) fusion bomb. However, as the discharged energetic particles’ vectors will be away from the field and its generating vessel, the vessel will survive, though it will suffer severe damage to its internal electronics and power systems, and will not be battleworthy until repairs are made .
  • DS-1 Pinpoint Barrier Defense System: A smaller defensive system which uses four movable forcefield disks, conformal to the ship’s surface, to repel light missile attacks, or energy beam fire. It serves as a back up to the DS-2 system.
  • The vessels of this class were all fitted with Shadow devices as they came in for refit after the Third Robotech War. During these refits they were also equipped with a protoculture-sensor tuned to detect Invid energizer configurations at distances of over 2 AU. This system is substantially inferior to those used in the Ikazuchi refits.

Design notes:

After the Expeditionary Forces were assigned the two captured manufacturing satellites as space habitats and production centers, there was still a void in the support lines for the far-flung scout flotillas, who now were required to make far longer and deeper voyages than originally envisioned. Specifically, the journey back to one of the factory bases after exhausting some of the supplies was taking more and more time, and even small repairs that required only a basic drydock had to be carried out in one of the satellites. In addition, the habitation standards on board the vessels were insufficient for near-permanent habitation. As a result, the Expeditionary Forces designed a tender vessel to serve as mobile dry dock and general tender, supply base, and as rest and recovery craft for fatigued crews.

To start with the production as soon as possible, the Montgolfier-class was based on an existing design, the Tokugawa-class. This design was upgraded with new gun armament, but its combat power was virtually eliminated by deleting most of the hangar bays, retaining only enough Fleet Air Arm mecha for self-defense, if ant at all. The freed-up space was then used for storage holds, and for enlarged living quarters. In addition, an Earth-simulation system identical in function to that used on board of the SDF-1 UES Macross during its long return voyage was installed, giving the main living holds a blue sky and the illusion of a planet side stay. To accommodate ships that had been damaged or needed a minor refit, a retractable scaffolding was added under the hull. When extended, this formed an open-space dry dock which could accommodate all but the largest Expeditionary Forces vessels.

The tenders followed much the same operational schedule during their early life. They would fold from one of the factory satellites, after loading up to capacity, to a central point in empty space, almost two-thirds the distance between the satellites and the foremost flotillas. There they would remain as the various groups folded to them, for several weeks of refit, repair and crew rest. The occasional supply ship from the rear bases also arrived with personnel and more supplies. Occasionally the ship would fold to a new location, as the fleets advanced. After a tour of typically two or three years, the tender would fold back to the large bases for its own refit and maintenance.

If necessary, the tenders could also fold towards damaged ships, if the battle had died down, and make on-site repairs. This was shown for example UES Bleriot rendezvoused with the Ikazuchi-class cruiser Valiant after she was severely damaged by Invid kamikazes. The Bleriot stabilized the Valiant’s main engines, which had become dangerously irregular, closed up many of the breaches in her hull and repaired the badly-damaged life-support system. After a week in this improvised space dock, the Bleriot fold-towed Valiant to Space Station Equality, were she was repaired and refitted.

Montgolfier-class Super Dimensional Tender 2History:

Five of these ships were built by the Expeditionary Forces on board the Robotech Factory Satellite Equality. They served throughout the existence of the Expeditionary Forces without ever coming under attack, or even seeing an enemy. Many of the space-born children drew their first breaths in the hospitals of a Montgolfier-class vessel in deep space.

Until 2043, they followed the described operational pattern. After that, the Expeditionary Forces decided to rebuild the old Joint-Moonbase Luna into a strongpoint and supply base, capable of housing most of the Expeditionary Forces fleet in underground docks. In order to carry this intent out, the entire class, with a large escort fleet, assembled and folded to dark side of the moon, where they then served as the base ships for the moon bases’ reconstruction. They continued to do this during the Reflex Point attack and for some years after, and this base still remains the main fleet base in the Terran system. This work later ensured the fast build-up of the post war space forces.

This class is still serving in the Terran Navy as tenders and supply ships, and are usually stationed, as before, in deep space, supporting long range sensor stations and scout vessels looking for remaining forces of the past three Robotech wars’ belligerents. Three enlarged and improved tenders have since been produced to strengthen the fleet support train, the UES SAD-6 Armstrong, UES SAD-7 Scobee and UES SAD-8 Chandrakant. These ships are known as the Armstrong-class.



Robotech (R) is the property of Harmony Gold. This document is in no way intended to infringe upon their rights.

Original artwork by: Harvey Neil Johnston

Acknowledgement is extended to Peter Walker, Pieter Thomassen and Robert Morgenstern of the unofficial Robotech Reference Guide. Peter Walker, Pieter Thomassen and Robert Morgenstern are given credit for all quotes and paraphrasing of the unofficial Robotech Reference Guide that has been utilized in this publication. 

Images from – N/A

Content by Pieter Thomassen and Peter Walker, edited by Tim Wing

Copyright © 2001, 1999, 1997 Robert Morgenstern, Pieter Thomassen, Peter Walker; 2016 Tim Wing







Leave a Reply

Your email address will not be published. Required fields are marked *