3.4 - Reference Architecture
Engineering designs often fall into classes that share enough common needs that shared solutions are possible. Some examples from civil engineering include bridges, skyscrapers, and public roads. For bridges we have truss, arch, and suspension bridge types. Each of these has a repeatable design process, even though the details of a given location will be different. Bridges are relatively simple systems, mostly designed around carrying loads across their span safely. Skyscrapers are more complex, having to deal not only with load-bearing, but heating and cooling, lighting, water and sanitation, information technology, and other systems. The term Architecture first meant just the physical and esthetic design of a building, and the relation of the building's parts to the whole. In modern use, we apply the term System Architecture to the overall design of any complex system, and the relationships of the main elements to each other and to the outside world in which the system functions.
A Reference Architecture is then a high level design for a class of shared solutions, exhibiting their key concepts, relationships, and features. It is a starting point for later stages of design and becomes customized and more detailed for specific applications. A reference design saves effort because each application does not have to repeat the early stages of development. At the architecture level it is used to provide common language and understanding for Stakeholders, parties with an interest in a project. It is also used to identify technology risks and readiness level (TRL), and make early estimates of cost and schedule. It includes system level goals, design principles, an architecture description, high level interactions between elements and the system environment, general element requirements, and element descriptions. Supporting data for a reference architecture shows the reasoning for how it was arrived at. It includes data sources, analyses to support concept selection, and tracking from goals to lower elements. Reference architectures should be updated as the system concepts and specific applications become more detailed.
Design Goals and Principles
Design goals are the high level inputs for what we want the design to accomplish. Design principles are the high-level approaches, rules, and methods for how to reach the goals. When we get to specific applications and projects, the general goals are supplemented with specific design requirements, but that comes after we develop our reference architecture.
In setting our design goals, we start with the basic idea that a civilization which provides for the needs and desires of its members is better than one that doesn't. Physical needs include things like food, shelter, and utilities, that are necessary to support life and protect from the environment. Desires include things like personal choice in how to spend one's time, where to live, and what to wear. Having to spend all one's time working at a job you don't like, just to meet physical needs, is less desirable than a choice of jobs, or even not needing to work at all and still have your needs met. We call a civilization Post-Scarcity if it supplies more than enough resources to meet everyone's needs, while not forcing people to do things they don't want to do or make unsatisfactory choices.
History to date can be described as an era of forced labor and economic scarcity. People worked, not because they wanted to, but because they had to in order to gain the necessities of life. Early 21st century civilization has reached post-scarcity for a small portion of the developed world - the financially well off and some retirees. For the vast majority of people, there isn't enough of what they need and want. They must work longer and harder than they might want to, and compete for the scarce supply of the things they want.
Therefore we choose enabling a post-scarcity civilization as a worthy goal. Our approach to reach this goal is to develop self-expanding automation that uses abundant renewable energy and raw materials as inputs. Abundant sources ensures our approach can apply to the whole of civilization, and self-expansion reduces the initial work and cost to implement the approach. The productive outputs are designed to meet people's physical needs, and automation makes it possible to do so without burdening people with work they don't want to do. There are other things that people want besides physical needs, like personal happiness, but that falls outside the realm of engineering. At this point we cannot say if our approach is a better way to reach these goals than conventional production methods. The end goal is desirable enough, to this writer at least, to try and find out, and hence this book and the related design work we are doing.
Setting goals doesn't tell you how you can or should reach them. For that, you need to adopt design principles which seem most likely to lead to your goals. It is the difference between choosing a destination for a trip, and planning the detailed route to get there. The principles we have identified so far include:
- The self-expanding system architecture should be suitable for a wide range of applications and locations. One which is restricted to only certain uses or places is unlikely to have civilization-level impact.
- People have a wide range of needs, and automated production capable of meeting those needs will be complex. Therefore the design process should deal with complexity from the start. The Systems Engineering method has evolved for this purpose, so we will adopt it as a primary design approach. We will not exclude other methods if they are suitable. In particular, software and large scale construction projects deal with complexity, so we will consider adapting some of their methods.
- A civilization which stops meeting people's needs, on a time scale that we measure civilizations by, would be a failure. We want our systems to continue functioning indefinitely, or at least for a very long time. Therefore we will likely include features like sustainability and recycling, and exclude using items in limited supply where possible.
Top Level Architecture and Functions
To develop a system architecture, we use the functional approach drawn from Systems Engineering. This involves first identifying what we need to do (functions), without locking in how it is to be done (a design). By breaking the architecture into smaller pieces, we can consider alternative ways of doing each piece, how they interact with each other, and optimizing the total design. A complex design is also too hard to do all at once. Smaller pieces, and the linkages between them, are easier to design individually.
Meeting people's needs can be divided into three top-level tasks. These are making what they need (production), delivering to the point of use (transport), and finally using these items where people are (habitation). We can assign a top-level function to each of these tasks, and then derive numerical values for them (e.g. how much production, how far to transport, and how many people?). The three top-level functions can then be broken down into successive levels of detail to the point that each task is simple enough to design. As this is done, the specific goals and numerical values for each function, which are called Requirements, are divided up and passed down to each sub-function. The intent is that the pieces of any given function, and their interactions with each other, add up to meet the parent-level requirements.
People live in many places, and the resources to make things are also found in many places. We therefore introduce the idea of Locations where some subset of the Production, Transport, and Habitation functions occur. To reach our post-scarcity goal, we then design, build, and operate a series of Locations, each of which can grow and evolve over time. They do this by collectively using all the new automation and other technologies. Existing civilization already provides production, transport, and habitation at numerous locations, but it is not highly automated, self-expanding, or integrated as a system. Nonetheless we must use and interact with elements of the already existing civilization because there is no alternative. We design and build our new Locations as additions, upgrades, or replacements to parts of civilization. They function as distributed networks, because civilization is physically distributed. Although the network consists of nodes under separate ownership and control, it follows agreed rules (protocols) to interact among its parts and the rest of the world. This allows better coordination and more automation across the whole network.
The examples in later sections of this book are specialized applications of the general produce-deliver-use sequence. The Community Factory has all three, but on a relatively small scale, for the direct use of the owners. The Industrial Factory concentrates on the production step, and is on a larger scale. The Distributed Production Network assumes multiple smaller production locations with different owners. The Remote Locations example uses all three main tasks, but considers difficult and remote environments. That places more emphasis on building transport and local self-use. At a civilization level, we would apply some combination of all the examples. That is far too complex to design for as a whole. Instead we would apply common standards and interfaces to individual projects. We can then take a modular approach, so that each piece can connect more easily to the others, and use each others outputs.
Deriving the Production Functions
The core of the factory production flow is taking raw materials and turning them into completed elements. This is divided into four steps, each of which is assigned a major function, because the nature of the tasks are very different. Extracting materials from the environment (mining) is generally done outside a fixed production location, and frequently changes locations. It is often a batch process, where loads of material are extracted and transported. Processing takes the raw materials and converts it into finished materials by chemical, electrical, mechanical, or other methods. The processing equipment is often flow-oriented rather than batch-oriented, and uses stationary equipment in controlled environments. Finished materials exist in bulk or generic shapes which can be used for a variety of end items. Fabrication converts finished materials into completed parts which meet a particular design. A number of different machine types and processes can be applied to the same material, depending on the end use. Assembly then combines separate parts into completed elements, but does not significantly change the details of the already fabricated parts.
These four major functions are supported by three others which enable the core to function. These include control of the location, which instructs and monitors the other functions so they know what to make, and how much of it. Supplying power is necessary, because without it none of the equipment would operate. Inventory storage is needed because inputs and outputs are not perfectly timed across the system. Outside supplies typically arrive in batches which are somewhat variable in time. Outputs from one production step are not perfectly matched to needs of the next. For example, assembly of a new machine may have to wait until all the parts are fabricated. In the interim they are temporarily stored. The last major function, growing organics, is separate from the rest because living things generate wood, plant oils, fibers, and other products by themselves. They incorporate the various production steps internally as a living organism.
These eight functions cover the main operations needed for useful outputs and internal growth at a given location. When more detailed designs are developed, some added secondary functions may be required, but we don't anticipate more at this top level. These functions also do not include transport between locations or outside destinations, or end use of products. A particular project that includes more than just production would then have additional top level functions.
Deriving the Transport Functions
In addition to the production activity at a given node, a network requires transport between nodes and to outside sources and destinations. We can define the main transport functions according to the types of entities flowing between these locations. These include delivering:
- Energy, either electrical, chemical, or other forms
- Food, for people and animals
- Water and other fluids and gases, both for people and production processes
- Parts and Materials for production
- Tools and Machines for production
- Completed Items for people
- Legal Rights, to land and other assets. Land itself isn't transported, but it must be acquired or rights to use it obtained.
- Humans, as workers or passengers
- Money, or other financial resources
- Information, including design data, operating commands, and numerous other types.
- Wastes, including scrap, which can be recycled by others, and waste materials and energy that cannot be recycled.
The particular quantities and types of flows from the above list become design requirements for the elements which will perform them. For distributed locations, this can start with existing systems, and add custom ones over time. Our reference architecture groups these into the following functions:
- Transport Energy - conventionally distributed by an electric utility.
- Transport Discrete Cargo - includes food, parts, materials, tools, machines, and wastes that require environmental/handling protection and completed products for delivery.
- Transport Bulk Cargo - includes items which do not require environmental protection, such as some raw materials and wastes.
- Transport Fluids and Gases - includes piped and tanked delivery, such as water, natural gas, and propane.
- Transport Humans - combines habitation elements and increased safety with delicate cargo transport.
- Transport Data - includes legal rights, money, and other information types. Traditionally via paper, but now mostly electronic.
Deriving the Habitation Functions
This function is called Habitation because it involves places that people occupy or inhabit. This includes both residential non-working locations and work and transit locations, because people still have the same needs in all of them. If we consider the most basic needs that people have, they include shelter from the natural environment, and food and care of their bodies. Beyond these basics, most people desire personal space, a variety of physical items, interaction with other people, entertainment, and other services. We group these needs into a half dozen functions as follows:
- Protection from the natural outdoor environment
- Control of the internal environment
- Supplying food and drink
- Maintaining health and care of other bodily needs
- Supplying personal space and physical items
- Providing non-physical items like communications, information, entertainment, and other services.
Each of these will be divided into more detailed sub-functions
Applying the Design Concepts
In the preceding parts of Section 3.0 we identified a number of design concepts. These concepts are applied to various parts of the architecture and the design process as the details of a particular project are developed:
Project Phases - The functional breakdown we have developed only divides the system architecture by task, and not by time. However time is a strong element of both our high level goal and the evolution of locations and networks. Most people today are still in a condition of scarcity, while our chosen goal is to enable post-scarcity. Thus there will be a transition across time, as increasing numbers of people and locations reach post-scarcity levels. At the individual project level, we start with tools and equipment that exist today. To this we add some amount of automated starter equipment (i.e. a Seed Factory). We then start making parts for more equipment, based on factors like fastest growth rate or which machines are necessary before you can make certain other machines. Along with expanding production, we also output some level of non-consumable end-use items, such as houses. We start with zero such end items, and they accumulate over time.
In addition to the growth of locations, technology levels are not stationary in time. Within our projects, the automated systems and particular hardware designs we want to use are not developed all at once. Technology development takes a finite amount of time, and we may spread out the pieces of new technology and hardware due to budget and staff limits within the projects. Outside of specific projects, the available technology across human civilization also improves over time.
For such reasons of long-term goals, internal project evolution, and technology development it makes sense to divide a system architecture into time-based Phases. Each phase is then a smaller and simpler piece to design and build for the same reason we divide the architecture by functional tasks. Phases can in turn be divided into smaller sub-phases, and ultimately to a time sequence of tasks with a schedule. Phases are a useful way to organize a project on the time axis, but they are not required to be in strict time order, they can overlap partially or entirely. Inputs and outputs connect phases to each other and to outside the project in the same way as between functions. Since a phase, or individual tasks within it, cannot start until the necessary inputs are available, this drives the time relationships of phases and their internal schedules.
Other Design Concepts -
- System measures such as closure ratios and growth rates are applied to all parts of architecture as requirements and for evaluating designs.
- Standard economics concepts like margins, operating costs, and productivity are generalized beyond just monetary units to consider all types of resource flows, then applied across architectures, projects, and designs.
- Engineering concepts, such as a systems approach and modular design, are applied to all parts of the design.
- New concepts are applied as follows:
- - Resource accounting is used at all levels of the design to ensure all flows and resources are accounted for.
- - New software tools like process compilers are used in production across project stages, from research to operations.
- - Growth ideas and patterns such as starter and expansion sets, scaling and complexity, universality and location distribution, are used to define different examples and applications of the architectures.
General Architecture Description
The reference architecture can be described from several points of view. Functions describe what needs to done as tasks or steps, and their connections to each other and to the outside. They do not specify how it should be done as far as process details, or the physical implementation as far as what equipment is used. System elements are then the design solutions which implement the functions, and incorporate the process and equipment choices. We derived the main functions in the previous paragraphs. The next step is then to show how they connect to form a complete architecture. The details of the system elements, or even their presence at all, will depend on the particular project application. We will give some examples in our reference description, but it should be remembered they can differ greatly in a given case.
Another point of view is the evolution of an architecture with time. A given project typically requires a sequence of design, production, and operation. Inputs of preexisting resources must precede each of these steps, and outputs of finished items and waste products follow them. It is difficult to display the functional and time relationships in the same diagram without three-dimensional displays. For two dimensional diagrams we display the relationships on different axes. Project phases with plans and schedules organize tasks along the time dimension, while functional diagrams show the logical connections among them at a specific time or at all times in the project. The combined set of diagrams represent the whole project.
A Single Location - For the self-expanding designs we describe in this book, the production portion includes two levels of functional interaction. The first is how the main functions of a single location interact with each other and outside elements. The second is how multiple production nodes interact in a network. This generic architecture will be be developed in more detailed examples later in the book. Figure 3.4-1 illustrates the reference architecture for a full self-expanding factory location. By full location we mean it has all eight of the major functions that enable it to be self-expanding. These are Control, Power, Extraction, Processing, Fabrication, Storage, Assembly, and Organics. A small production node or a new Seed Factory before it expands may not have all of these functional activities. Each function will change over time by upgrades and new equipment, either supplied from outside, or produced internally. For clarity, this diagram only shows some of the key flows between functions. The green arrows are inputs or steps in the production flow from raw materials to completed elements. The blue arrows are outputs, either finished products delivered to outside users, or expansion elements delivered to each of the functions. The output from box F.4 Process Materials goes to F.5 Fabricate Parts. We use a broken arrow in this case and label the end points in parentheses like "(F.5)" to show where they connect, rather than having a large loop that crosses many lines.
A Network of Locations - Figure 3.4-2 illustrates how a distributed production network of multiple nodes can expand by collaborating. A node is a location with any amount of activities, from a single person doing design work or remote control of machines, up to a full factory. We only show two functioning nodes in the diagram, but a network can have any number of them. Each node can have different output products and capacities. Thus Nodes 1 and 2 exchange outputs, to supply whatever the other node can't supply for itself. The network interacts with outside civilization, and thus accepts various inputs and delivers various outputs as needed. The inputs will typically include labor, land, hard to make parts, and materials not found locally. Outputs include items for sale, and are used to help pay for needed inputs. Each node also produces items for its own self-expansion, and is shown delivering items to a new node location being built. Thus the network can grow in two ways: by expanding each node, and by building new nodes. The new node can be different than either of the older nodes. We expect a common growth pattern will be expanded full factories delivering starter kit parts to a new location, which then grows over time to another full factory.
Project Phases - A time sequenced growth plan for a single location or a network would consist of a series of phases. The first of these is Research and Development. This includes the design stages from initial concept through completed detailed designs for hardware elements and locations. Some items will require new component technology or software to be developed. New integrated hardware elements will also need prototypes built and tested. These are also included in the R&D phase. Later locations using the same basic hardware will have less R&D in total, focusing in the unique adaptions to a particular location.
Following the R&D phase will be an initial fabrication and installation phase for the first unit of production capacity, followed by one or more expansion phases. Each phase progresses through the production steps, delivering output products plus new items for self-expansion. A completed growth phase becomes an input to the next growth phase. The R&D for later phases can be deferred, and overlap production and installation of earlier phase equipment.
The first set of automated self-expanding machinery must be built with preexisting conventional equipment. So in general the first production and installation phase would be conventional equipment, followed by the first set of automated equipment as an expansion. Later locations or generations may begin with automated machinery made by already existing locations. Conventional equipment can also be used for self-expansion. For example manual woodworking or metalworking machines can make parts for more such machines. Automated machinery just does it more efficiently with less human labor. Thus the growth of conventional equipment can also be broken into phases, which may overlap the production and expansion of automated machinery.
Transport systems are needed as the delivery mechanisms between nodes and to outside locations. Since the inputs and outputs comprise a variety of resource types, they require a corresponding variety of transport types. In early phases of a project, or growth of a network, existing transport systems must be used, since new elements can not be built until production is functioning. As new transport systems are built and maintained by the production tasks, they can add to or replace the existing systems.
The habitation locations which people occupy as private living, work, recreation, and social spaces, will comprise a wide variety of detailed designs. We cannot predict these designs in advance, because we will not know individual desires, or what changes a particular location will require. However, people share common physical needs, so we can design shared pieces from which complete habitable locations can be built. We can also design the pieces to integrate with production and transport, and include features like recycling and long term maintenance. Like production and transport, the first phase of habitation can use existing locations, and then start adding to or replacing them in a series of expansions once new production is available.
Whether a phase involves existing or new elements, or they are manual or automated, similar functions need to be performed for production, transportation, and living space. Therefore we can use a shared framework for the functional divisions of a project, regardless of type or state. A shared framework helps maintain consistency and reuse of designs across projects. However, a given project may not include all the functions, or use them all the time. It may rely on outside elements to perform a given task, or a given function may not occur at all in the project.
General Function Descriptions
The descriptions that follow are in terms of a generic project involving one or more locations, with all parts of the produce-deliver-use architecture present. A particular project may not have all these functions present.
1.0 Production Descriptions
1.1 Control Location - This function provides overall control of project operations, including habitation, transport, and external flows, as well as controlling the production tasks at the locations. Individual production elements, such as a CNC machine, can also have their own local controls as needed. This function operates at a higher level where coordination across the entire project is important. It includes a mix of human-operated, automated, and software generated commands, issued locally or remotely, and transmitted to individual elements. The hardware elements for control will include computers, networking, displays, observation, measurement, and data collection equipment. Software elements include existing and custom written operations and control software. Control tasks include future planning, real-time operation, and retrospective analysis. The control function takes designs for the locations and the products it makes as input from a previous research and development phase.
1.2 Supply Power - This function is to supply all forms of power to the project, and converting it to the needed forms, including electrical, thermal, hydraulic, stored energy, and others. It also includes providing a significant surplus as a goal. Power can be divided by demand class - residential and control power should be more reliable than some industrial tasks that can be interrupted. It can also be divided into fixed and portable power. Examples of power supply equipment include outside utility lines, solar cell panels, and wind turbines for electrical power. Solar furnaces can be used for direct heating, and thermal storage for additional electric generation.
1.3 Extract Materials - This includes excavation and mining, water and air collection, and harvest of plants, either directly at the location or nearby, using location equipment. The goal is to obtain the majority of total materials from local supply, or from recycled local or outside sources. This can be divided into extracting from project-owned land, and using extraction rights to other land. Delivery of bulk materials produced by others using their equipment is not part of this function, it is an external input. Typical mining and harvesting equipment includes a variety of hydraulic and mechanical attachments to a common tractor core. This equipment would be manufactured internally where possible.
1.4 Process Materials - This includes conversion of raw materials to finished materials inventory, ready for storage, parts making, or consumption. It can use chemical, mechanical, thermal, electrical, or other processes, and operate as a continuous flow or in separate batches. Outputs from this function can include the following categories: stone and concrete, metals, ceramics, glass, wood, fibers, electronics, organic and inorganic compounds, fertilizers, and clean water. Because of the wide range of materials and processes, a single location may start out with only one or a few of them, and add more over time, or build up a local network of locations doing different tasks.
1.5 Fabricate Parts - This takes finished materials from processing or storage, plus outside materials supply, and transforms them into finished parts ready for assembly. Historically a wide variety of production machines and processes have been used for this function. We can organize these diverse fabrication tasks by the same materials categories as the previous Process Materials function. We can also list parts types such as castings, structural and mechanical parts, electrical, and electronic parts.
1.6 Store Inventory - This task includes storage for materials, parts, and completed items not currently in use. It includes storage for other Production functions, Habitation, and Transport. It also includes environment protection and control (i.e. buildings) for the other production functions, and land for industrial tasks. Warehouse space for storage and building space for a factory floor are functionally similar, and in fact one will likely be transformed to the other as the factory expands. Rather than accounting for them under multiple headings, we collect all the environmental enclosures here.
1.7 Assemble Elements - This includes combining parts and materials into higher level assemblies (collections of parts), leading to completed elements. It also includes dis-assembly of elements for maintenance or modification, with any draining and cleaning added as necessary. It can use any combination of human labor, robots, or automated processes, with local or remote control. Assembly can be divided into movable elements such as production machines and vehicles, and construction of fixed elements such as buildings. The latter may require temporary structures, weather protection, and cleaning tasks. Fixed elements may use modules assembled indoors to reduce weather delays and increase automation.
1.8 Grow Organics - This includes growing microorganisms, plants, and animals to the point of harvest to provide useful items. Pets and ornamental plants are placed under Personal Items in Habitation. It includes the land space to grow biological products, some of which may overlap with Habitation areas. Total land includes owned and leased land, and crop and timber harvest rights. The latter may be used to reduce costs during early construction. Some early timber may be obtained from construction site clearing if the land was well stocked.
2.0 Habitation Descriptions
2.1 Protect from External Environment - This includes passive protection of people and other habitation elements from weather, water, insects, and other outside factors. It also includes structural support of all habitation elements. This can be considered protection from gravity, uneven ground, and shifting subsoil, but stable support of the protective items is a necessary feature for them to work. In turn, the structural support requires underlying land for it to rest on, so we include all the habitation land under this function. We also include outdoor protection for humans in the form of protective clothing.
2.2 Control Internal Environment - This function covers actively managing the internal environment created by the protective shell in terms of temperature, humidity, lighting and other factors. It includes control inputs and sensors (such as thermostats), and active hardware which produces the desired changes, such as heating, ventilation, and air conditioning (HVAC) systems. Passive thermal insulation was included in the previous function, and lighting, windows, and window coverings are included here as active devices. Emergency systems are also included here.
2.3 Provide Food and Drink - This includes supply of food and drink materials at the point of use for residents and guests, local storage within Habitation areas, food preparation, serving and dining, and disposal of food and drink wastes. The latter does not include human wastes, which are covered under Maintain Health.
2.4 Maintain Health - We need to include the actual human residents and guests someplace in the architecture, because they have inputs and outputs, and this is the chosen location. The tasks include supporting basic needs for sleep, sanitation, exercise, cleaning of persons and the internal environment, and filtering the latter, health monitoring, first aid and emergency services, and local examination and treatment.
2.5 Provide Personal Items - This includes the internal volume for private living and storage space, public or community space such as meeting rooms and athletic areas, and commercial space such as offices and shops. It also includes the physical contents of these spaces such as furniture and decorations. Decorative/non-protective clothing is also included. The total enclosed space from functions 2.2 to 2.5 then becomes a design requirement for 2.1 Protect from External Environment.
2.6 Provide Information - This includes communications, storage, and processing in all forms (text, voice, and video) for personal or commercial purposes, teaching materials, entertainment, and general information like news and weather. It does not include operational information for production, although this function may share common hardware and software elements used across the location.
3.0 Transport Descriptions
Transport in general can involve movement to and from external locations, between locations of a given project, and internally within a single location or building. All the different destinations may use shared transport elements, thus we organize the functions by type of item transported rather than where they are going. Transport can involve both mobile and fixed elements. An example is delivery trucks and the roads they drive on. Transport elements also include lifting and conveying devices to move objects horizontally and vertically, and both enclosed and open pipes, channels and systems. Thus a drainage ditch is a transport element for storm water.
3.1 Transport Bulk Cargo - This includes bulk supplies, including items for sale or to build new locations. Bulk items have relatively large volumes, but low requirement for protection from the environment or the shocks and vibrations of vehicle transport. Typical examples would be gravel and raw logs.
3.2 Transport Discrete Cargo - This includes transport of individual items which need some protection from the environment, and the shocks and vibration of delivery. Environmental conditions which can cause damage or contamination include temperature, rain, insects, and dirt. Quantities are typically smaller than for bulk items, and thus multiple items may be delivered in one load. Separate containers then help keep the various items from mixing or reacting with each other. Finally, the vehicle or containers may use devices to reduce shocks and vibrations to acceptable levels.
3.3 Transport Humans - This includes the transport of humans to and from project locations, and internally within locations. Humans have many of the same needs as discrete cargo, but also some additional ones. These include a higher safety level, added comfort features, optional manual vehicle control, and schedule priority. Therefore habitation type features, like heating and air conditioning, are added to the transport systems when people are transported.
3.4 Transport Energy - This mostly involves wired and wireless distribution of electricity, although some energy may be delivered in battery or thermal form.
3.5 Transport Fluids and Gases - These items require closed containers or fixed piping to prevent contamination and leakage. Common examples for fixed piping are water and natural gas. Common examples for closed containers are propane and diesel fuel.
3.6 Transport Data - This includes all types of data in all forms, electronic and non-electronic. Legal rights and money are items needing data transport to function, so we include their delivery here.