[ Freelance Traveller Home Page | Search Freelance Traveller | Site Index ]

*Freelance Traveller

The Electronic Fan-Supported Traveller® Resource

Starship Interiors

This article originally appeared in the July/August 2019 issue


Traveller starships span a wide variety of technology levels, with corresponding variations in construction techniques and standards. Some Traveller starship design sequences produce measurable differences for a ship built at different technology levels, and some do not. For example, Classic Traveller Book 2 or the Mongoose Traveller Core Rulebook provides a minimum technology level for a given design, but doesn’t specify any improvement for higher-tech starships. On the other hand, Classic Traveller Book 5: High Guard would allow the TL-15 design to take advantage of the increased technology level by using a smaller power plant and smaller fuel processors. Similarly, Mongoose Traveller Book 2: High Guard allows primitive and advanced spacecraft components to have differing costs, volumes, and benefits. It also clarifies that designs using the base rules are generic ships at approximately TL-12.

However, even using rules that provide for different results by technology level leads to the issue that we would need different starship designs and different deck plans for each class of ship at multiple TLs. Ideally, there should be a way of providing a distinct look and feel for each ship, even ships that are nominally equivalent, but built in different places and at different technology levels – without having to re-design the ship multiple times, and without having to draw and re-draw deck plans.

Describing Starship Interiors

Consider the following two descriptions, the first of a relatively low or early stellar starship:

The whooping klaxon and flashing master alarm light gets your attention – you need to be on the bridge, and fast. Ducking your head to avoid a low-hanging light fixture, you leave the crew’s common area and scramble forward through the narrow hallway linking it with the bridge. Sliding doors to the left and right lead to crew staterooms. All are currently closed, but you can hear cursing behind you as Gamaagin fumbles to get dressed. She’ll be right behind you – she’s always had a sense for trouble. The tangle of conduit, ductwork, and structural elements on the ceiling is punctuated by the occasional glow plate, which casts a harsh light on the surrounding area. You barely avoid knocking yourself senseless on a low-hanging pipe. Upon reaching the bridge, you activate the iris valve and step through, keeping your head down to avoid the top of the doorway. Inside, the cramped cockpit is filled with a myriad of read-outs, displays, buttons, and controls – all of which are in the red and clamoring for your attention.

Compare it with this one from a high technology starship:

The insistent tone of the master alarm gets your attention even before the ship’s emergency lighting starts to blink red. You leave the crew’s common area and rush forward through the hallway to the bridge. Sliding doors to the left and right along the hall lead to crew quarters. All are closed as you pass, but you can hear one open behind you. That must be Gamaagin; she’s always had a sense for trouble. The modern plasteel ceiling and wall panels that seem so clean and efficient in the ship’s standard ambient lighting become a surreal parody of themselves when the lights go emergency-red. Upon reaching the bridge, the iris valve smoothly cycles open in front of you. As you step inside, the computer recognizes you and brings up your control console even before you have a chance to sit down. To your dismay, almost all of the indicators are in the danger zone and need attention fast.

Despite the differences in the description, these two ships are both standard Subsidized Merchants, with the same performance specifications and same deck plan. The differences are merely descriptive, designed to lend an appropriate “feel” to each ship.

Technological Progression

The progression of starship technology can be used as a rough guide to the interiors of different Traveller starships. At early TLs, use descriptions such as “small”, “cramped”, and “Spartan”; consider referring to the bridge as the “cockpit” instead. Mention characters hitting their heads on piping or fixtures, particularly as comic relief. These ships should have the overall “feel” of movie starships like Firefly’s Serenity and the Millennium Falcon from the Star Wars franchise. At higher TLs, there should be a sense of more space, better lighting, and better décor; use words like “spacious”, “well-lit”, “sleek”, “smooth”, “clean” and “modern”. These ships should be described like Star Trek’s Enterprise. Consider the following suggestions by technology level:

TL-9: Early starships and spacecraft are cramped because ships can afford little spare mass or volume. Ceilings and bulkheads will be unfinished, with visible structural members, equipment, conduits, pipes, ductwork, and fittings. The overhead clearance in most sections of the ship will be uneven, as these items will protrude from the ceiling. Overhead clearance will vary between 1.70m and 2.00m, with an average of about 1.85m (6′ 1″). This is low enough that even moderately tall people will have to remember avoid light fixtures and fittings. Some tall people will be unable to stand upright. Some decoration may be present in passenger areas, selected for low mass and little volume, but otherwise these ships will be very Spartan. Interior partitions will be lightweight and offer little in the way of sound insulation. Unpowered pocket doors are used in place of sliding doors. Passengers and even some crew who have experienced better will complain about the primitive conditions.

TL-10: The situation improves somewhat at TL-10, and overheads increase to an average of 2.00m (6′ 4″). Ships are still cramped, but a noticeable improvement over the first generation. Unfinished ceilings and bulkheads are still the norm, but at least even the lowest-hanging fixtures and equipment are more than 6 feet off of the deck. Some tall people will still have to duck on occasion, and particularly tall individuals may not be able to stand upright. The furnishings for passenger areas will still be governed by mass and volume concerns, and complaints will be common. Military ships, and the engineering spaces of civilian ships, will be purely functional.

TL-11: As space travel technology matures, naval architects are able to allocate more mass and volume to crew and passenger comfort. Overheads increase again to an average of 2.15m (6′ ½″). Particularly tall individuals may risk hitting their heads on a few prominent fittings, and ships are noticeably more cramped than planet-based residences or workplaces. Passengers will often comment about how small or confined the ship seems to be. Bulkheads and ceilings remain unfinished with exposed conduits, ductwork, equipment, and fittings that may protrude downward by several inches. Passenger areas and interior partitions may have some sound insulation to increase privacy, and the use of powered sliding doors is universal.

TL-12: At average stellar technology levels, overhead clearance increases to an average of 2.30m (7′ 6″). Although lower than most residences and office buildings, this is high enough that the vast majority of the population doesn’t have to worry about hitting their heads. Bulkheads and ceilings remain unfinished in crew areas. Passenger areas now feature lightweight sound-insulating panels on the walls and ceilings, improved lighting, and individual temperature and gravity controls in each stateroom. These amenities, along with improved decorating options, significantly improve comfort and privacy.

TL-13: Overheads increase again to 2.5m (8′ 2½″), which is comparable to many residences. The increased volume and mass budgets allow the ceilings and bulkheads of all areas to be finished with lightweight panels, giving the interior of the ship a modern and finished look. Panels in maintenance-intensive areas such as the bridge and engineering are designed for easy removal, and military ships typically omit them entirely in these areas. Passenger areas are often carpeted. If well appointed and maintained they can be comparable to a planet-side budget hotel.

TL-14: At high stellar technology levels, overheads increase again to 2.7m (8′ 10″), which is comparable to many commercial buildings. Passenger and crew areas feature improved fit and finish, such as low-maintenance surfaces that reduce noise and improved lighting. Smart portals are used in passenger spaces, but some ships prefer standard portals for crew areas. Increased mass and volume capacity means that the comfort of passenger accommodations is often governed by cost: they can be equivalent to a planet-side mid-range hotel if the ship owner is willing to pay the expense.

TL-15: Overhead clearances do not increase at this stage of development, but further improvements in fit and finish, higher mass and volume budgets for décor, improved artificial gravity and life support systems often result in passengers being unable to tell if they are aboard ship or in a high-quality planet-side hotel. Use of smart portals is ubiquitous.

These descriptions assume an Imperial vessel designed for a typical mixed Solomani or Vilani crew. At TL-13 and above, the 2.5m to 2.7m ceiling heights will accommodate Aslan, Darrian, Droyne, Solomani, Vargr, Vilani, and Zhodani. At TL-12, only particularly tall members of the tallest species will have difficulty with the 2.3m clearances. Below TL-12, taller species will build their ships with higher minimum overhead clearances to suit their particular needs.

To determine if a passenger or NPC has an issue with the ceiling height without generating the character’s height in detail, roll 2d6. Apply a -1 DM for diminutive species such as Vargr. If the result is less than the technology level of the ship, there is no problem. If the roll equals the ship’s TL, that passenger or NPC will have to watch out for a few particularly low-hanging fixtures. A dice result greater than the TL indicates a character that encounters overhead height issues aboard the ship.

Down in the Hold

Starship deck plans typically show the ship’s cargo hold as a large empty space. However, aboard a working starship, empty space in the cargo hold represents lost revenue. In a role-playing context, the things that make the cargo hold an interesting setting for adventure are what it contains: the containers, pallets, boxes, and bales of goods that must be transported from one world to another.

You open the iris valve on the deck, and step down the ladder into the ship’s cargo hold. Despite the size of the space, the narrow aisles and alleys between containers feel claustrophobic, and the deck cargo with its tie-down straps looks like an ominous spider in the forward hold. The bad lighting and stale air don’t help your mood, either. It seems like you’re always down here after every visit to an overcrowded mudball, iron-fisted police state, or planet overrun by religious nutjobs. There’s someone hiding in the hold, and you have to deal with it before the ship lifts. Most of the time it’s some wet-behind-the-ears kid, who thinks that getting off world is their ticket to fame, fortune, and the Iridium Throne. You wouldn’t mind the kids so much – heck, you even remember being that eighteen-year-old kid, taking your first step on a journey that led to being an officer on a free trader – except for the times when it isn’t a kid. Those are the ones that you worry about, when the shadow between containers turns out to be a hijacker, a pirate, or some kind of Ine Givar terrorist. Those can go bad, fast.

Physical Description

The cargo hold is an empty deck or decks, generally clear of obstructions, designed to accommodate shipments of freight and cargo. The floor and walls contain tie-down fittings so that standard containers can be secured in the hold. There is at least one pressure-tight bay door that opens to the full height of the hold, and at least 4.5m wide. The bay doors are often 7.5m, 13.5m, or 15m wide or wider, to accommodate standard containers lengthwise. The doorway usually has a fold-down loading platform or ramp, and the ship’s internal cargo-handling equipment extends outward far enough to pick up containers and pallets placed near the door or on the platform. Environmentally, the hold is maintained at the same temperature, pressure, and gravity as the rest of the ship:

Environment Nominal Minimum Maximum
Atmospheric Pressure 100kPa (1.0 atm) 50kPa (0.5 atm) 150kPa (1.5 atm)
Temperature 20°C (293K, 68°F) 0°C (273K, 32°F) 40°C (313K, 104°F)
Gravity Field 10m/sec2 (1G) None 20m/sec2 (2G)

Given the large size and limited air circulation, heat and atmosphere can become concerns. Some types of containers have built-in support equipment that keeps the interior cold or frozen for shipping refrigerated or frozen goods. Higher-tech containers can also mount nuclear damper systems for safely shipping radioactive, or gravity systems for shipping goods that must be maintained in an environment of other than standard G. These systems all use power and produce heat, so must be loaded in spots with adequate power and ventilation. Live cargo, such as livestock, can be subject to similar concerns.

Mechanically, the overhead clearance in cargo holds must be at least 2.7m so that standard cargo containers can be accommodated, but is often higher – for example, the standard Type R Subsidized Merchant has a cargo hold that is two decks high. The table below shows minimum and maximum clearances as well as the standard container load-out for a given cargo bay height, in decks:

Height (decks) Overhead Clearance Container Loading (layers from bottom up)
Minimum Maximum
1 deck 2.7m (8′ 10″) 3.0m (9′ 10″) 1 standard
2 decks 5.6m (18′ 4″) 6.2m (20′ 2″) 1 high-cube + 1 standard
3 decks 8.5m (27′ 11″) 9.3m (30′ 6″) 2 high-cube + 1 standard
4 decks 11.4m (37′ 6″) 12.5m (40′ 10″) 3 high-cube + 1 standard
5 decks 14.3m (47′ 0″) 15.6m (51′ 2″) 4 high-cube + 1 standard
6 decks 17.2m (56′ 7″) 18.8m (61′ 6″) 5 high-cube + 1 standard

All cargo holds can accommodate cargo up to the minimum overhead clearance, and may be able to accommodate cargo up to the maximum. The ability of the cargo bay to accept over-height goods, including attempts to load high-cube containers instead of standard ones, depends on the technology level of the ship. Low-tech ships are often designed to the minimum standards, while higher technology ships are designed with generous clearances and flexibility in mind. The table below shows the maximum amount of cargoes that exceed the minimum overhead clearance that can be stowed in the bay, and the difficulty of doing so. Referees should treat loading over-height cargo as a task against Mechanical skill and/or Intelligence. If the task fails, the item will not fit, and the task may not be re-tried unless the cargo is modified to make it more likely to fit.

Ship TL Maximum Over-Height Difficulty
TL-9 1% of cargo bay volume Formidable (14+)
TL-10 5% of cargo bay volume Very Difficult (12+)
TL-11 10% of cargo bay volume Very Difficult (12+)
TL-12 20% of cargo bay volume Difficult (10+)
TL-13 30% of cargo bay volume Difficult (10+)
TL-14 40% of cargo bay volume Average (8+)
TL-15 50% of cargo bay volume Average (8+)

Fittings and Features

Just like the main areas of the ship, the fittings and features of the cargo hold itself will vary with the technology level of the starship. Use the following descriptions as a guide:

TL-9: Holds will have limited lighting and little or no air circulation – but at least there is pressure, although the temperature may vary widely. Ceilings and bulkheads will be unfinished, with visible structural members, equipment, conduits, pipes, ductwork, and fittings. Cargo handling equipment is mechanical, and loading or unloading the entire cargo hold can take several crewmembers the better part of two days. No provision is made for over-height loads.

TL-10: Power drops are placed at intervals throughout the hold to allow the ship to provide electrical power to up to 10% of the containers in the hold. This allows containers to have individual environmental-support units that keep the contents at a specified pressure, temperature, and gravity regardless of conditions in the hold. Minor provisions are made for loading over-height cargoes, but dealing with these types of loads remains difficult.

TL-11: Although physical conditions don’t change significantly, gravitic cargo-handling equipment is now built into the ship’s hold, which significantly improves the speed and ease of loading and unloading. Two crewmembers can now load or unload the entire cargo bay in less than a day.

TL-12: Starting at TL-12, cargo holds are designed to handle a limited amount of oversize freight, easing the difficulty of loading such cargoes. Cargo handling and power availability remains otherwise unchanged.

TL-13: The cargo hold remains unfinished, but improved power margins and air circulation in the hold allows it to provide electrical power to up to 20% of the containers in the hold. Increased automation of the gravitic cargo-handling equipment facilitates rapid loading and unloading. A single crewmember can completely load or unload the cargo hold in a matter of hours.

TL-14: At high stellar technology levels, cargo holds receive easily replicable floor, ceiling, and bulkhead paneling made of a durable and resilient plastic for improved maintainability. The ability to handle over-sized cargo improves again, but cargo handling and the availability of power drops remain unchanged.

TL-15: At this TL, further improvements allow power drops to supply up to 30% of the containers in the hold. Cargo handling remains unchanged.

Cargo and Containers

There are two general types of goods in interstellar transport: bulk and break-bulk. Bulk goods are transported unpackaged and in large quantity: grains, minerals, ores, fuels, cement, and chemicals. They are usually transported by purpose-designed bulk carrier or tanker starships. Small commercial starships typically carry break-bulk cargoes, such as trade goods, media, and manufactured items: anything from toys to tools and computers to handcrafts. The vast majority – over 90% – of break-bulk goods is shipped in a standard cargo container. Small quantities of bulk cargoes may also be shipped in containers. Most of the rest are deck cargoes – the general term for any large item that is secured in the hold. Vehicles, machinery, and other items that are too large to fit in a container are typically shipped as deck cargo.

Present-day Terran containers are based on a standard 20′ intermodal container that is 8′ 6″ (2.591m) high, 8′ 0″ (2.438m) wide, and 19′ 10.5″ (6.058m) long. These exterior dimensions make it about 2.9 dtons, and it can hold 33.1m3 of cargo (2.346 dtons). Standard containers come in 20′ and 40′ lengths, and also in “high-cube” variants that are 9′ 6″ (2.896m) tall and either 40′ or 45′ long. These dimensions are slightly inconvenient for our 1.5-meter floor grid, since the containers don’t line up exactly.

Imperial Containers

A more convenient size might be 2.6m high, 3m wide, and 6m long — this would occupy 8 deck grid squares, and fill the space from floor to ceiling while leaving enough space to support another deck above. This would be a “4-ton” container, not because it has a 4-ton capacity or is 4 dtons itself, but because it occupies 4 displacement tons worth of space in a ship’s cargo hold. The container is actually about 3.3 dtons, and can store about 2.66 dtons or 37.53m3 of cargo. These dimensions are the basis for a range of standardized containers:

4-Ton Standard Container: A standard interstellar shipping container, 3m wide, 6m long, and 2.6m high. It occupies 8 deck grid squares and 4 tons of capacity in a ship’s cargo hold, and accommodates 37.53m3 (2.66 dtons) of goods.

8-Ton Standard Container: A double-size container, 3m wide, 12m long, and 2.6m high. It occupies 16 deck grid squares and 8 tons of capacity in a ship’s cargo hold, and accommodates 76.54m3 (5.42 dtons) of goods.

8-Ton High-Cube Container: A high-capacity interstellar shipping container, 3m wide, 12m long, and 2.9m high. It occupies 16 deck grid squares and 8 tons of capacity in a ship’s cargo hold, and accommodates 85.38m3 (6.05 dtons) of goods.

9-Ton High-Cube Container: An extra-long, high-capacity container, 3m wide, 13.5m long, and 2.9m high. It occupies 18 deck grid squares and 9 tons of capacity in a ship’s cargo hold, and can contain 97.63m3 (6.92 dtons) of goods.

All containers have 8 twist-lock fastener sockets, one on each corner, so they can be secured in a cargo hold or stacked on other containers. The 9-ton high-cube has a second set of sockets 0.75m from each end so that it can be fastened to standard-length containers. Larger containers are used for less-dense items, since all containers are limited to a maximum of 32,000kg. Multiple container designs are available in the standard sizes, including box containers for general goods, tank containers, refrigerated containers for perishables, bins for bulk solids, as well as frames and pallets for a wide variety of unique or irregularly shaped objects.

Container Freight

Shipping rates for freight are based on the nominal size of the container, so the 2.66 tons of goods inside a “4-ton” container would get billed at the rate for 4 tons of freight. Larger containers, and particularly the high-cube containers made possible by the more generous space allocations in high-tech ships, offer a better value.

As the hold is loaded, the cargo officer must ensure that the hold is packed efficiently, loads are secured firmly, the mass of the load is distributed evenly, and that sufficient space remains for access to the hold. At minimum, a 1.5m corridor should remain clear to link all of the iris valves, hatches, or airlocks that open into the cargo hold. As goods arrive for shipment, the cargo officer enters them into a manifest maintained by the ship’s computer. The computer then calculates the optimum loading for the hold based on size, mass, and destination. Shipments that arrive late can change the loading plan, forcing the ship to unload and re-pack some or all of the items already stowed.

Traditional Vilani Length Measures

Few Terrans are aware of the traditional Vilani units of length, because the Third Imperium uses the Terran SI (“metric”) system. The Second Imperium officially imposed the SI system on all worlds, but adoption varied in practice. Unofficial use of traditional Vilani units has continued on many worlds with a Vilani cultural heritage, even into the Third Imperium.

The primary unit of length on Vland was the ashesh (commonly translated as “pace” or “stride” in Galanglic). In antiquity, this distance was based on an adult woman’s walking pace, and measurements could vary considerably depending on whose stride was used. It was eventually standardized around 11,000 years ago at the 47th semi-annual meeting of the Grand Committee to Promote Uniform Weights and Measures for Trade at a length of 750.47mm by current Imperial measures. Traditional measurements of short distances are based on a shiashesh (“half-pace”, commonly but incorrectly translated as “Vilani cubit”), which was then broken down into 4 “hands”. Each hand was further subdivided into 4 “fingers”. Traditional measurement of longer distances is based on multiples of the ashesh, with the giashesh (“double-pace”, sometimes called a “Vilani fathom”) as the starting point. Larger units included 10, 100, and 1000 of these double-paces, though only the largest of these, the milakha or “Vilani mile”, was used frequently.

Unit Translation Measure Equivalent
Ugish Finger, “Vilani inch” ¼ ushalar 2.34cm, 0.923 in
Ushalar Hand ¼ shiashesh 9.375cm, 3.69 in
Shiashesh Half-pace, “Vilani cubit” ½ ashesh 37.5cm, 1.23 ft
Ashesh Pace, “Vilani yard” basic unit 0.75m
Giashesh Double-pace, “Vilani fathom” 2 ashesh 1.50m
Milakha “Vilani mile” 1000 giashesh 1500m, 0.93 mi

Despite Imperial standardization on SI units, the Vilani ashesh lives on in two significant ways:

When the 531st semi-annual meeting of the Grand Committee to Promote Uniform Weights and Measures, Establish Standards for Intercontinental Trade and Improve Transportation Efficiency standardized intermodal container sizes on Vland, they established 4 ashesh as the width for transport containers. This was practical because early Vilani roads were typically wider than ancient Terran roads, since the riding beasts of Vland were larger than horses or oxen (see Vilani and Vargr, p.17). This standard survives to this day as the 3-meter basic width for interstellar shipping containers in the Third Imperium.

Secondly, Vilani dwellings were typically measured in giashesh, so building and starship interiors often have a 1-giashesh grid superimposed on them to provide an easy and convenient sense of scale.