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diff --git a/technic/manual.md b/technic/manual.md new file mode 100644 index 0000000..9031792 --- /dev/null +++ b/technic/manual.md @@ -0,0 +1,1488 @@ +Minetest technic modpack user manual +==================================== + +The technic modpack extends the Minetest game with many new elements, +mainly constructable machines and tools. It is a large modpack, and +tends to dominate gameplay when it is used. This manual describes how +to use the technic modpack, mainly from a player's perspective. + +The technic modpack depends on some other modpacks: + +* the basic Minetest game +* mesecons, which supports the construction of logic systems based on + signalling elements +* pipeworks, which supports the automation of item transport +* moreores, which provides some additional ore types + +This manual doesn't explain how to use these other modpacks, which ought +to (but actually don't) have their own manuals. + +Recipes for constructable items in technic are generally not guessable, +and are also not specifically documented here. You should use a +craft guide mod to look up the recipes in-game. For the best possible +guidance, use the unified\_inventory mod, with which technic registers +its specialised recipe types. + +substances +---------- + +### ore ### + +The technic mod makes extensive use of not just the default ores but also +some that are added by mods. You will need to mine for all the ore types +in the course of the game. Each ore type is found at a specific range of +elevations, and while the ranges mostly overlap, some have non-overlapping +ranges, so you will ultimately need to mine at more than one elevation +to find all the ores. Also, because one of the best elevations to mine +at is very deep, you will be unable to mine there early in the game. + +Elevation is measured in meters, relative to a reference plane that +is not quite sea level. (The standard sea level is at an elevation +of about +1.4.) Positive elevations are above the reference plane and +negative elevations below. Because elevations are always described this +way round, greater numbers when higher, we avoid the word "depth". + +The ores that matter in technic are coal, iron, copper, tin, zinc, +chromium, uranium, silver, gold, mithril, mese, and diamond. + +Coal is part of the basic Minetest game. It is found from elevation ++64 downwards, so is available right on the surface at the start of +the game, but it is far less abundant above elevation 0 than below. +It is initially used as a fuel, driving important machines in the early +part of the game. It becomes less important as a fuel once most of your +machines are electrically powered, but burning fuel remains a way to +generate electrical power. Coal is also used, usually in dust form, as +an ingredient in alloying recipes, wherever elemental carbon is required. + +Iron is part of the basic Minetest game. It is found from elevation ++2 downwards, and its abundance increases in stages as one descends, +reaching its maximum from elevation -64 downwards. It is a common metal, +used frequently as a structural component. In technic, unlike the basic +game, iron is used in multiple forms, mainly alloys based on iron and +including carbon (coal). + +Copper is part of the basic Minetest game (having migrated there from +moreores). It is found from elevation -16 downwards, but is more abundant +from elevation -64 downwards. It is a common metal, used either on its +own for its electrical conductivity, or as the base component of alloys. +Although common, it is very heavily used, and most of the time it will +be the material that most limits your activity. + +Tin is supplied by the moreores mod. It is found from elevation +8 +downwards, with no elevation-dependent variations in abundance beyond +that point. It is a common metal. Its main use in pure form is as a +component of electrical batteries. Apart from that its main purpose is +as the secondary ingredient in bronze (the base being copper), but bronze +is itself little used. Its abundance is well in excess of its usage, +so you will usually have a surplus of it. + +Zinc is supplied by technic. It is found from elevation +2 downwards, +with no elevation-dependent variations in abundance beyond that point. +It is a common metal. Its main use is as the secondary ingredient +in brass (the base being copper), but brass is itself little used. +Its abundance is well in excess of its usage, so you will usually have +a surplus of it. + +Chromium is supplied by technic. It is found from elevation -100 +downwards, with no elevation-dependent variations in abundance beyond +that point. It is a moderately common metal. Its main use is as the +secondary ingredient in stainless steel (the base being iron). + +Uranium is supplied by technic. It is found only from elevation -80 down +to -300; using it therefore requires one to mine above elevation -300 even +though deeper mining is otherwise more productive. It is a moderately +common metal, useful only for reasons related to radioactivity: it forms +the fuel for nuclear reactors, and is also one of the best radiation +shielding materials available. It is not difficult to find enough uranium +ore to satisfy these uses. Beware that the ore is slightly radioactive: +it will slightly harm you if you stand as close as possible to it. +It is safe when more than a meter away or when mined. + +Silver is supplied by the moreores mod. It is found from elevation -2 +downwards, with no elevation-dependent variations in abundance beyond +that point. It is a semi-precious metal. It is little used, being most +notably used in electrical items due to its conductivity, being the best +conductor of all the pure elements. + +Gold is part of the basic Minetest game (having migrated there from +moreores). It is found from elevation -64 downwards, but is more +abundant from elevation -256 downwards. It is a precious metal. It is +little used, being most notably used in electrical items due to its +combination of good conductivity (third best of all the pure elements) +and corrosion resistance. + +Mithril is supplied by the moreores mod. It is found from elevation +-512 downwards, the deepest ceiling of any minable substance, with +no elevation-dependent variations in abundance beyond that point. +It is a rare precious metal, and unlike all the other metals described +here it is entirely fictional, being derived from J. R. R. Tolkien's +Middle-Earth setting. It is little used. + +Mese is part of the basic Minetest game. It is found from elevation +-64 downwards. The ore is more abundant from elevation -256 downwards, +and from elevation -1024 downwards there are also occasional blocks of +solid mese (each yielding as much mese as nine blocks of ore). It is a +precious gemstone, and unlike diamond it is entirely fictional. It is +used in many recipes, though mainly not in large quantities, wherever +some magical quality needs to be imparted. + +Diamond is part of the basic Minetest game (having migrated there from +technic). It is found from elevation -128 downwards, but is more abundant +from elevation -256 downwards. It is a precious gemstone. It is used +moderately, mainly for reasons connected to its extreme hardness. + +### rock ### + +In addition to the ores, there are multiple kinds of rock that need to be +mined in their own right, rather than for minerals. The rock types that +matter in technic are standard stone, desert stone, marble, and granite. + +Standard stone is part of the basic Minetest game. It is extremely +common. As in the basic game, when dug it yields cobblestone, which can +be cooked to turn it back into standard stone. Cobblestone is used in +recipes only for some relatively primitive machines. Standard stone is +used in a couple of machine recipes. These rock types gain additional +significance with technic because the grinder can be used to turn them +into dirt and sand. This, especially when combined with an automated +cobblestone generator, can be an easier way to acquire sand than +collecting it where it occurs naturally. + +Desert stone is part of the basic Minetest game. It is found specifically +in desert biomes, and only from elevation +2 upwards. Although it is +easily accessible, therefore, its quantity is ultimately quite limited. +It is used in a few recipes. + +Marble is supplied by technic. It is found in dense clusters from +elevation -50 downwards. It has mainly decorative use, but also appears +in one machine recipe. + +Granite is supplied by technic. It is found in dense clusters from +elevation -150 downwards. It is much harder to dig than standard stone, +so impedes mining when it is encountered. It has mainly decorative use, +but also appears in a couple of machine recipes. + +### rubber ### + +Rubber is a biologically-derived material that has industrial uses due +to its electrical resistivity and its impermeability. In technic, it +is used in a few recipes, and it must be acquired by tapping rubber trees. + +If you have the moretrees mod installed, the rubber trees you need +are those defined by that mod. If not, technic supplies a copy of the +moretrees rubber tree. + +Extracting rubber requires a specific tool, a tree tap. Using the tree +tap (by left-clicking) on a rubber tree trunk block extracts a lump of +raw latex from the trunk. Each trunk block can be repeatedly tapped for +latex, at intervals of several minutes; its appearance changes to show +whether it is currently ripe for tapping. Each tree has several trunk +blocks, so several latex lumps can be extracted from a tree in one visit. + +Raw latex isn't used directly. It must be vulcanized to produce finished +rubber. This can be performed by alloying the latex with coal dust. + +### metal ### + +Many of the substances important in technic are metals, and there is +a common pattern in how metals are handled. Generally, each metal can +exist in five forms: ore, lump, dust, ingot, and block. With a couple of +tricky exceptions in mods outside technic, metals are only *used* in dust, +ingot, and block forms. Metals can be readily converted between these +three forms, but can't be converted from them back to ore or lump forms. + +As in the basic Minetest game, a "lump" of metal is acquired directly by +digging ore, and will then be processed into some other form for use. +A lump is thus more akin to ore than to refined metal. (In real life, +metal ore rarely yields lumps ("nuggets") of pure metal directly. +More often the desired metal is chemically bound into the rock as an +oxide or some other compound, and the ore must be chemically processed +to yield pure metal.) + +Not all metals occur directly as ore. Generally, elemental metals (those +consisting of a single chemical element) occur as ore, and alloys (those +consisting of a mixture of multiple elements) do not. In fact, if the +fictional mithril is taken to be elemental, this pattern is currently +followed perfectly. (It is not clear in the Middle-Earth setting whether +mithril is elemental or an alloy.) This might change in the future: +in real life some alloys do occur as ore, and some elemental metals +rarely occur naturally outside such alloys. Metals that do not occur +as ore also lack the "lump" form. + +The basic Minetest game offers a single way to refine metals: cook a lump +in a furnace to produce an ingot. With technic this refinement method +still exists, but is rarely used outside the early part of the game, +because technic offers a more efficient method once some machines have +been built. The grinder, available only in electrically-powered forms, +can grind a metal lump into two piles of metal dust. Each dust pile +can then be cooked into an ingot, yielding two ingots from one lump. +This doubling of material value means that you should only cook a lump +directly when you have no choice, mainly early in the game when you +haven't yet built a grinder. + +An ingot can also be ground back to (one pile of) dust. Thus it is always +possible to convert metal between ingot and dust forms, at the expense +of some energy consumption. Nine ingots of a metal can be crafted into +a block, which can be used for building. The block can also be crafted +back to nine ingots. Thus it is possible to freely convert metal between +ingot and block forms, which is convenient to store the metal compactly. +Every metal has dust, ingot, and block forms. + +Alloying recipes in which a metal is the base ingredient, to produce a +metal alloy, always come in two forms, using the metal either as dust +or as an ingot. If the secondary ingredient is also a metal, it must +be supplied in the same form as the base ingredient. The output alloy +is also returned in the same form. For example, brass can be produced +by alloying two copper ingots with one zinc ingot to make three brass +ingots, or by alloying two piles of copper dust with one pile of zinc +dust to make three piles of brass dust. The two ways of alloying produce +equivalent results. + +### iron and its alloys ### + +Iron forms several important alloys. In real-life history, iron was the +second metal to be used as the base component of deliberately-constructed +alloys (the first was copper), and it was the first metal whose working +required processes of any metallurgical sophistication. The game +mechanics around iron broadly imitate the historical progression of +processes around it, rather than the less-varied modern processes. + +The two-component alloying system of iron with carbon is of huge +importance, both in the game and in real life. The basic Minetest game +doesn't distinguish between these pure iron and these alloys at all, +but technic introduces a distinction based on the carbon content, and +renames some items of the basic game accordingly. + +The iron/carbon spectrum is represented in the game by three metal +substances: wrought iron, carbon steel, and cast iron. Wrought iron +has low carbon content (less than 0.25%), resists shattering, and +is easily welded, but is relatively soft and susceptible to rusting. +In real-life history it was used for rails, gates, chains, wire, pipes, +fasteners, and other purposes. Cast iron has high carbon content +(2.1% to 4%), is especially hard, and resists corrosion, but is +relatively brittle, and difficult to work. Historically it was used +to build large structures such as bridges, and for cannons, cookware, +and engine cylinders. Carbon steel has medium carbon content (0.25% +to 2.1%), and intermediate properties: moderately hard and also tough, +somewhat resistant to corrosion. In real life it is now used for most +of the purposes previously satisfied by wrought iron and many of those +of cast iron, but has historically been especially important for its +use in swords, armor, skyscrapers, large bridges, and machines. + +In real-life history, the first form of iron to be refined was +wrought iron, which is nearly pure iron, having low carbon content. +It was produced from ore by a low-temperature furnace process (the +"bloomery") in which the ore/iron remains solid and impurities (slag) +are progressively removed by hammering ("working", hence "wrought"). +This began in the middle East, around 1800 BCE. + +Historically, the next forms of iron to be refined were those of high +carbon content. This was the result of the development of a more +sophisticated kind of furnace, the blast furnace, capable of reaching +higher temperatures. The real advantage of the blast furnace is that it +melts the metal, allowing it to be cast straight into a shape supplied by +a mould, rather than having to be gradually beaten into the desired shape. +A side effect of the blast furnace is that carbon from the furnace's fuel +is unavoidably incorporated into the metal. Normally iron is processed +twice through the blast furnace: once producing "pig iron", which has +very high carbon content and lots of impurities but lower melting point, +casting it into rough ingots, then remelting the pig iron and casting it +into the final moulds. The result is called "cast iron". Pig iron was +first produced in China around 1200 BCE, and cast iron later in the 5th +century BCE. Incidentally, the Chinese did not have the bloomery process, +so this was their first iron refining process, and, unlike the rest of +the world, their first wrought iron was made from pig iron rather than +directly from ore. + +Carbon steel, with intermediate carbon content, was developed much later, +in Europe in the 17th century CE. It required a more sophisticated +process, because the blast furnace made it extremely difficult to achieve +a controlled carbon content. Tweaks of the blast furnace would sometimes +produce an intermediate carbon content by luck, but the first processes to +reliably produce steel were based on removing almost all the carbon from +pig iron and then explicitly mixing a controlled amount of carbon back in. + +In the game, the bloomery process is represented by ordinary cooking +or grinding of an iron lump. The lump represents unprocessed ore, +and is identified only as "iron", not specifically as wrought iron. +This standard refining process produces dust or an ingot which is +specifically identified as wrought iron. Thus the standard refining +process produces the (nearly) pure metal. + +Cast iron is trickier. You might expect from the real-life notes above +that cooking an iron lump (representing ore) would produce pig iron that +can then be cooked again to produce cast iron. This is kind of the case, +but not exactly, because as already noted cooking an iron lump produces +wrought iron. The game doesn't distinguish between low-temperature +and high-temperature cooking processes: the same furnace is used not +just to cast all kinds of metal but also to cook food. So there is no +distinction between cooking processes to produce distinct wrought iron +and pig iron. But repeated cooking *is* available as a game mechanic, +and is indeed used to produce cast iron: re-cooking a wrought iron ingot +produces a cast iron ingot. So pig iron isn't represented in the game as +a distinct item; instead wrought iron stands in for pig iron in addition +to its realistic uses as wrought iron. + +Carbon steel is produced by a more regular in-game process: alloying +wrought iron with coal dust (which is essentially carbon). This bears +a fair resemblance to the historical development of carbon steel. +This alloying recipe is relatively time-consuming for the amount of +material processed, when compared against other alloying recipes, and +carbon steel is heavily used, so it is wise to alloy it in advance, +when you're not waiting for it. + +There are additional recipes that permit all three of these types of iron +to be converted into each other. Alloying carbon steel again with coal +dust produces cast iron, with its higher carbon content. Cooking carbon +steel or cast iron produces wrought iron, in an abbreviated form of the +bloomery process. + +There's one more iron alloy in the game: stainless steel. It is managed +in a completely regular manner, created by alloying carbon steel with +chromium. + +### uranium enrichment ### + +When uranium is to be used to fuel a nuclear reactor, it is not +sufficient to merely isolate and refine uranium metal. It is necessary +to control its isotopic composition, because the different isotopes +behave differently in nuclear processes. + +The main isotopes of interest are U-235 and U-238. U-235 is good at +sustaining a nuclear chain reaction, because when a U-235 nucleus is +bombarded with a neutron it will usually fission (split) into fragments. +It is therefore described as "fissile". U-238, on the other hand, +is not fissile: if bombarded with a neutron it will usually capture it, +becoming U-239, which is very unstable and quickly decays into semi-stable +(and fissile) plutonium-239. + +Inconveniently, the fissile U-235 makes up only about 0.7% of natural +uranium, almost all of the other 99.3% being U-238. Natural uranium +therefore doesn't make a great nuclear fuel. (In real life there are +a small number of reactor types that can use it, but technic doesn't +have such a reactor.) Better nuclear fuel needs to contain a higher +proportion of U-235. + +Achieving a higher U-235 content isn't as simple as separating the U-235 +from the U-238 and just using the required amount of U-235. Because +U-235 and U-238 are both uranium, and therefore chemically identical, +they cannot be chemically separated, in the way that different elements +are separated from each other when refining metal. They do differ +in atomic mass, so they can be separated by centrifuging, but because +their atomic masses are very close, centrifuging doesn't separate them +very well. They cannot be separated completely, but it is possible to +produce uranium that has the isotopes mixed in different proportions. +Uranium with a significantly larger fissile U-235 fraction than natural +uranium is called "enriched", and that with a significantly lower fissile +fraction is called "depleted". + +A single pass through a centrifuge produces two output streams, one with +a fractionally higher fissile proportion than the input, and one with a +fractionally lower fissile proportion. To alter the fissile proportion +by a significant amount, these output streams must be centrifuged again, +repeatedly. The usual arrangement is a "cascade", a linear arrangement +of many centrifuges. Each centrifuge takes as input uranium with some +specific fissile proportion, and passes its two output streams to the +two adjacent centrifuges. Natural uranium is input somewhere in the +middle of the cascade, and the two ends of the cascade produce properly +enriched and depleted uranium. + +Fuel for technic's nuclear reactor consists of enriched uranium of which +3.5% is fissile. (This is a typical value for a real-life light water +reactor, a common type for power generation.) To enrich uranium in the +game, it must first be in dust form: the centrifuge will not operate +on ingots. (In real life uranium enrichment is done with the uranium +in the form of a gas.) It is best to grind uranium lumps directly to +dust, rather than cook them to ingots first, because this yields twice +as much metal dust. When uranium is in refined form (dust, ingot, or +block), the name of the inventory item indicates its fissile proportion. +Uranium of any available fissile proportion can be put through all the +usual processes for metal. + +A single centrifuge operation takes two uranium dust piles, and produces +as output one dust pile with a fissile proportion 0.1% higher and one with +a fissile proportion 0.1% lower. Uranium can be enriched up to the 3.5% +required for nuclear fuel, and depleted down to 0.0%. Thus a cascade +covering the full range of fissile fractions requires 34 cascade stages. +(In real life, enriching to 3.5% uses thousands of cascade stages. +Also, centrifuging is less effective when the input isotope ratio +is more skewed, so the steps in fissile proportion are smaller for +relatively depleted uranium. Zero fissile content is only asymptotically +approachable, and natural uranium relatively cheap, so uranium is normally +only depleted to around 0.3%. On the other hand, much higher enrichment +than 3.5% isn't much more difficult than enriching that far.) + +Although centrifuges can be used manually, it is not feasible to perform +uranium enrichment by hand. It is a practical necessity to set up +an automated cascade, using pneumatic tubes to transfer uranium dust +piles between centrifuges. Because both outputs from a centrifuge are +ejected into the same tube, sorting tubes are needed to send the outputs +in different directions along the cascade. It is possible to send items +into the centrifuges through the same tubes that take the outputs, so the +simplest version of the cascade structure has a line of 34 centrifuges +linked by a line of 34 sorting tube segments. + +Assuming that the cascade depletes uranium all the way to 0.0%, +producing one unit of 3.5%-fissile uranium requires the input of five +units of 0.7%-fissile (natural) uranium, takes 490 centrifuge operations, +and produces four units of 0.0%-fissile (fully depleted) uranium as a +byproduct. It is possible to reduce the number of required centrifuge +operations by using more natural uranium input and outputting only +partially depleted uranium, but (unlike in real life) this isn't usually +an economical approach. The 490 operations are not spread equally over +the cascade stages: the busiest stage is the one taking 0.7%-fissile +uranium, which performs 28 of the 490 operations. The least busy is the +one taking 3.4%-fissile uranium, which performs 1 of the 490 operations. + +A centrifuge cascade will consume quite a lot of energy. It is +worth putting a battery upgrade in each centrifuge. (Only one can be +accommodated, because a control logic unit upgrade is also required for +tube operation.) An MV centrifuge, the only type presently available, +draws 7 kEU/s in this state, and takes 5 s for each uranium centrifuging +operation. It thus takes 35 kEU per operation, and the cascade requires +17.15 MEU to produce each unit of enriched uranium. It takes five units +of enriched uranium to make each fuel rod, and six rods to fuel a reactor, +so the enrichment cascade requires 514.5 MEU to process a full set of +reactor fuel. This is about 0.85% of the 6.048 GEU that the reactor +will generate from that fuel. + +If there is enough power available, and enough natural uranium input, +to keep the cascade running continuously, and exactly one centrifuge +at each stage, then the overall speed of the cascade is determined by +the busiest stage, the 0.7% stage. It can perform its 28 operations +towards the enrichment of a single uranium unit in 140 s, so that is +the overall cycle time of the cascade. It thus takes 70 min to enrich +a full set of reactor fuel. While the cascade is running at this full +speed, its average power consumption is 122.5 kEU/s. The instantaneous +power consumption varies from second to second over the 140 s cycle, +and the maximum possible instantaneous power consumption (with all 34 +centrifuges active simultaneously) is 238 kEU/s. It is recommended to +have some battery boxes to smooth out these variations. + +If the power supplied to the centrifuge cascade averages less than +122.5 kEU/s, then the cascade can't run continuously. (Also, if the +power supply is intermittent, such as solar, then continuous operation +requires more battery boxes to smooth out the supply variations, even if +the average power is high enough.) Because it's automated and doesn't +require continuous player attention, having the cascade run at less +than full speed shouldn't be a major problem. The enrichment work will +consume the same energy overall regardless of how quickly it's performed, +and the speed will vary in direct proportion to the average power supply +(minus any supply lost because battery boxes filled completely). + +If there is insufficient power to run both the centrifuge cascade at +full speed and whatever other machines require power, all machines on +the same power network as the centrifuge will be forced to run at the +same fractional speed. This can be inconvenient, especially if use +of the other machines is less automated than the centrifuge cascade. +It can be avoided by putting the centrifuge cascade on a separate power +network from other machines, and limiting the proportion of the generated +power that goes to it. + +If there is sufficient power and it is desired to enrich uranium faster +than a single cascade can, the process can be speeded up more economically +than by building an entire second cascade. Because the stages of the +cascade do different proportions of the work, it is possible to add a +second and subsequent centrifuges to only the busiest stages, and have +the less busy stages still keep up with only a single centrifuge each. + +Another possible approach to uranium enrichment is to have no fixed +assignment of fissile proportions to centrifuges, dynamically putting +whatever uranium is available into whichever centrifuges are available. +Theoretically all of the centrifuges can be kept almost totally busy all +the time, making more efficient use of capital resources, and the number +of centrifuges used can be as little (down to one) or as large as desired. +The difficult part is that it is not sufficient to put each uranium dust +pile individually into whatever centrifuge is available: they must be +input in matched pairs. Any odd dust pile in a centrifuge will not be +processed and will prevent that centrifuge from accepting any other input. + +### concrete ### + +Concrete is a synthetic building material. The technic modpack implements +it in the game. + +Two forms of concrete are available as building blocks: ordinary +"concrete" and more advanced "blast-resistant concrete". Despite its +name, the latter has no special resistance to explosions or to any other +means of destruction. + +Concrete can also be used to make fences. They act just like wooden +fences, but aren't flammable. Confusingly, the item that corresponds +to a wooden "fence" is called "concrete post". Posts placed adjacently +will implicitly create fence between them. Fencing also appears between +a post and adjacent concrete block. + +industrial processes +-------------------- + +### alloying ### + +In technic, alloying is a way of combining items to create other items, +distinct from standard crafting. Alloying always uses inputs of exactly +two distinct types, and produces a single output. Like cooking, which +takes a single input, it is performed using a powered machine, known +generically as an "alloy furnace". An alloy furnace always has two +input slots, and it doesn't matter which way round the two ingredients +are placed in the slots. Many alloying recipes require one or both +slots to contain a stack of more than one of the ingredient item: the +quantity required of each ingredient is part of the recipe. + +As with the furnaces used for cooking, there are multiple kinds of alloy +furnace, powered in different ways. The most-used alloy furnaces are +electrically powered. There is also an alloy furnace that is powered +by directly burning fuel, just like the basic cooking furnace. Building +almost any electrical machine, including the electrically-powered alloy +furnaces, requires a machine casing component, one ingredient of which +is brass, an alloy. It is therefore necessary to use the fuel-fired +alloy furnace in the early part of the game, on the way to building +electrical machinery. + +Alloying recipes are mainly concerned with metals. These recipes +combine a base metal with some other element, most often another metal, +to produce a new metal. This is discussed in the section on metal. +There are also a few alloying recipes in which the base ingredient is +non-metallic, such as the recipe for the silicon wafer. + +### grinding, extracting, and compressing ### + +Grinding, extracting, and compressing are three distinct, but very +similar, ways of converting one item into another. They are all quite +similar to the cooking found in the basic Minetest game. Each uses +an input consisting of a single item type, and produces a single +output. They are all performed using powered machines, respectively +known generically as a "grinder", "extractor", and "compressor". +Some compressing recipes require the input to be a stack of more than +one of the input item: the quantity required is part of the recipe. +Grinding and extracting recipes never require such a stacked input. + +There are multiple kinds of grinder, extractor, and compressor. Unlike +cooking furnaces and alloy furnaces, there are none that directly burn +fuel; they are all electrically powered. + +Grinding recipes always produce some kind of dust, loosely speaking, +as output. The most important grinding recipes are concerned with metals: +every metal lump or ingot can be ground into metal dust. Coal can also +be ground into dust, and burning the dust as fuel produces much more +energy than burning the original coal lump. There are a few other +grinding recipes that make block types from the basic Minetest game +more interconvertible: standard stone can be ground to standard sand, +desert stone to desert sand, cobblestone to gravel, and gravel to dirt. + +Extracting is a miscellaneous category, used for a small group +of processes that just don't fit nicely anywhere else. (Its name is +notably vaguer than those of the other kinds of processing.) It is used +for recipes that produce dye, mainly from flowers. (However, for those +recipes using flowers, the basic Minetest game provides parallel crafting +recipes that are easier to use and produce more dye, and those recipes +are not suppressed by technic.) Its main use is to generate rubber from +raw latex, which it does three times as efficiently as merely cooking +the latex. Extracting was also formerly used for uranium enrichment for +use as nuclear fuel, but this use has been superseded by a new enrichment +system using the centrifuge. + +Compressing recipes are mainly used to produce a few relatively advanced +artificial item types, such as the copper and carbon plates used in +advanced machine recipes. There are also a couple of compressing recipes +making natural block types more interconvertible. + +### centrifuging ### + +Centrifuging is another way of using a machine to convert items. +Centrifuging takes an input of a single item type, and produces outputs +of two distinct types. The input may be required to be a stack of +more than one of the input item: the quantity required is part of +the recipe. Centrifuging is only performed by a single machine type, +the MV (electrically-powered) centrifuge. + +Currently, centrifuging recipes don't appear in the unified\_inventory +craft guide, because unified\_inventory can't yet handle recipes with +multiple outputs. + +Generally, centrifuging separates the input item into constituent +substances, but it can only work when the input is reasonably fluid, +and in marginal cases it is quite destructive to item structure. +(In real life, centrifuges require their input to be mainly fluid, that +is either liquid or gas. Few items in the game are described as liquid +or gas, so the concept of the centrifuge is stretched a bit to apply to +finely-divided solids.) + +The main use of centrifuging is in uranium enrichment, where it +separates the isotopes of uranium dust that otherwise appears uniform. +Enrichment is a necessary process before uranium can be used as nuclear +fuel, and the radioactivity of uranium blocks is also affected by its +isotopic composition. + +A secondary use of centrifuging is to separate the components of +metal alloys. This can only be done using the dust form of the alloy. +It recovers both components of binary metal/metal alloys. It can't +recover the carbon from steel or cast iron. + +chests +------ + +The technic mod replaces the basic Minetest game's single type of +chest with a range of chests that have different sizes and features. +The chest types are identified by the materials from which they are made; +the better chests are made from more exotic materials. The chest types +form a linear sequence, each being (with one exception noted below) +strictly more powerful than the preceding one. The sequence begins with +the wooden chest from the basic game, and each later chest type is built +by upgrading a chest of the preceding type. The chest types are: + +1. wooden chest: 8×4 (32) slots +2. iron chest: 9×5 (45) slots +3. copper chest: 12×5 (60) slots +4. silver chest: 12×6 (72) slots +5. gold chest: 15×6 (90) slots +6. mithril chest: 15×6 (90) slots + +The iron and later chests have the ability to sort their contents, +when commanded by a button in their interaction forms. Item types are +sorted in the same order used in the unified\_inventory craft guide. +The copper and later chests also have an auto-sorting facility that can +be enabled from the interaction form. An auto-sorting chest automatically +sorts its contents whenever a player closes the chest. The contents will +then usually be in a sorted state when the chest is opened, but may not +be if pneumatic tubes have operated on the chest while it was closed, +or if two players have the chest open simultaneously. + +The silver and gold chests, but not the mithril chest, have a built-in +sign-like capability. They can be given a textual label, which will +be visible when hovering over the chest. The gold chest, but again not +the mithril chest, can be further labelled with a colored patch that is +visible from a moderate distance. + +The mithril chest is currently an exception to the upgrading system. +It has only as many inventory slots as the preceding (gold) type, and has +fewer of the features. It has no feature that other chests don't have: +it is strictly weaker than the gold chest. It is planned that in the +future it will acquire some unique features, but for now the only reason +to use it is aesthetic. + +The size of the largest chests is dictated by the maximum size +of interaction form that the game engine can successfully display. +If in the future the engine becomes capable of handling larger forms, +by scaling them to fit the screen, the sequence of chest sizes will +likely be revised. + +As with the chest of the basic Minetest game, each chest type comes +in both locked and unlocked flavors. All of the chests work with the +pneumatic tubes of the pipeworks mod. + +radioactivity +------------- + +The technic mod adds radioactivity to the game, as a hazard that can +harm player characters. Certain substances in the game are radioactive, +and when placed as blocks in the game world will damage nearby players. +Conversely, some substances attenuate radiation, and so can be used +for shielding. The radioactivity system is based on reality, but is +not an attempt at serious simulation: like the rest of the game, it has +many simplifications and deliberate deviations from reality in the name +of game balance. + +In real life radiological hazards can be roughly divided into three +categories based on the time scale over which they act: prompt radiation +damage (such as radiation burns) that takes effect immediately; radiation +poisoning that becomes visible in hours and lasts weeks; and cumulative +effects such as increased cancer risk that operate over decades. +The game's version of radioactivity causes only prompt damage, not +any delayed effects. Damage comes in the abstracted form of removing +the player's hit points, and is immediately visible to the player. +As with all other kinds of damage in the game, the player can restore +the hit points by eating food items. High-nutrition foods, such as the +pie baskets supplied by the bushes\_classic mod, are a useful tool in +dealing with radiological hazards. + +Only a small range of items in the game are radioactive. From the technic +mod, the only radioactive items are uranium ore, refined uranium blocks, +nuclear reactor cores (when operating), and the materials released when +a nuclear reactor melts down. Other mods can plug into the technic +system to make their own block types radioactive. Radioactive items +are harmless when held in inventories. They only cause radiation damage +when placed as blocks in the game world. + +The rate at which damage is caused by a radioactive block depends on the +distance between the source and the player. Distance matters because the +damaging radiation is emitted equally in all directions by the source, +so with distance it spreads out, so less of it will strike a target +of any specific size. The amount of radiation absorbed by a target +thus varies in proportion to the inverse square of the distance from +the source. The game imitates this aspect of real-life radioactivity, +but with some simplifications. While in real life the inverse square law +is only really valid for sources and targets that are small relative to +the distance between them, in the game it is applied even when the source +and target are large and close together. Specifically, the distance is +measured from the center of the radioactive block to the abdomen of the +player character. For extremely close encounters, such as where the +player swims in a radioactive liquid, there is an enforced lower limit +on the effective distance. + +Different types of radioactive block emit different amounts of radiation. +The least radioactive of the radioactive block types is uranium ore, +which causes 0.25 HP/s damage to a player 1 m away. A block of refined +but unenriched uranium, as an example, is nine times as radioactive, +and so will cause 2.25 HP/s damage to a player 1 m away. By the inverse +square law, the damage caused by that uranium block reduces by a factor +of four at twice the distance, that is to 0.5625 HP/s at a distance of 2 +m, or by a factor of nine at three times the distance, that is to 0.25 +HP/s at a distance of 3 m. Other radioactive block types are far more +radioactive than these: the most radioactive of all, the result of a +nuclear reactor melting down, is 1024 times as radioactive as uranium ore. + +Uranium blocks are radioactive to varying degrees depending on their +isotopic composition. An isotope being fissile, and thus good as +reactor fuel, is essentially uncorrelated with it being radioactive. +The fissile U-235 is about six times as radioactive than the non-fissile +U-238 that makes up the bulk of natural uranium, so one might expect that +enriching from 0.7% fissile to 3.5% fissile (or depleting to 0.0%) would +only change the radioactivity of uranium by a few percent. But actually +the radioactivity of enriched uranium is dominated by the non-fissile +U-234, which makes up only about 50 parts per million of natural uranium +but is about 19000 times more radioactive than U-238. The radioactivity +of natural uranium comes just about half from U-238 and half from U-234, +and the uranium gets enriched in U-234 along with the U-235. This makes +3.5%-fissile uranium about three times as radioactive as natural uranium, +and 0.0%-fissile uranium about half as radioactive as natural uranium. + +Radiation is attenuated by the shielding effect of material along the +path between the radioactive block and the player. In general, only +blocks of homogeneous material contribute to the shielding effect: for +example, a block of solid metal has a shielding effect, but a machine +does not, even though the machine's ingredients include a metal case. +The shielding effect of each block type is based on the real-life +resistance of the material to ionising radiation, but for game balance +the effectiveness of shielding is scaled down from real life, more so +for stronger shield materials than for weaker ones. Also, whereas in +real life materials have different shielding effects against different +types of radiation, the game only has one type of damaging radiation, +and so only one set of shielding values. + +Almost any solid or liquid homogeneous material has some shielding value. +At the low end of the scale, 5 meters of wooden planks nearly halves +radiation, though in that case the planks probably contribute more +to safety by forcing the player to stay 5 m further away from the +source than by actual attenuation. Dirt halves radiation in 2.4 m, +and stone in 1.7 m. When a shield must be deliberately constructed, +the preferred materials are metals, the denser the better. Iron and +steel halve radiation in 1.1 m, copper in 1.0 m, and silver in 0.95 m. +Lead would halve in 0.69 m if it were in the game, but it's not, which +poses a bit of a problem due to the drawbacks of the three materials in +the game that are better shielding than silver. Gold halves radiation +in 0.53 m (factor of 3.7 per meter), but is a bit scarce to use for +this purpose. Uranium halves radiation in 0.31 m (factor of 9.4 per +meter), but is itself radioactive. The very best shielding in the game +is nyancat material (nyancats and their rainbow blocks), which halves +radiation in 0.22 m (factor of 24 per meter), but is extremely scarce. + +If the theoretical radiation damage from a particular source is +sufficiently small, due to distance and shielding, then no damage at all +will actually occur. This means that for any particular radiation source +and shielding arrangement there is a safe distance to which a player can +approach without harm. The safe distance is where the radiation damage +would theoretically be 0.25 HP/s. This damage threshold is applied +separately for each radiation source, so to be safe in a multi-source +situation it is only necessary to be safe from each source individually. + +The best way to use uranium as shielding is in a two-layer structure, +of uranium and some non-radioactive material. The uranium layer should +be nearer to the primary radiation source and the non-radioactive layer +nearer to the player. The uranium provides a great deal of shielding +against the primary source, and the other material shields against +the uranium layer. Due to the damage threshold mechanism, a meter of +dirt is sufficient to shield fully against a layer of fully-depleted +(0.0%-fissile) uranium. Obviously this is only worthwhile when the +primary radiation source is more radioactive than a uranium block. + +When constructing permanent radiation shielding, it is necessary to +pay attention to the geometry of the structure, and particularly to any +holes that have to be made in the shielding, for example to accommodate +power cables. Any hole that is aligned with the radiation source makes a +"shine path" through which a player may be irradiated when also aligned. +Shine paths can be avoided by using bent paths for cables, passing +through unaligned holes in multiple shield layers. If the desired +shielding effect depends on multiple layers, a hole in one layer still +produces a partial shine path, along which the shielding is reduced, +so the positioning of holes in each layer must still be considered. +Tricky shine paths can also be addressed by just keeping players out of +the dangerous area. + +electrical power +---------------- + +Most machines in technic are electrically powered. To operate them it is +necessary to construct an electrical power network. The network links +together power generators and power-consuming machines, connecting them +using power cables. + +There are three tiers of electrical networking: low voltage (LV), +medium voltage (MV), and high voltage (HV). Each network must operate +at a single voltage, and most electrical items are specific to a single +voltage. Generally, the machines of higher tiers are more powerful, +but consume more energy and are more expensive to build, than machines +of lower tiers. It is normal to build networks of all three tiers, +in ascending order as one progresses through the game, but it is not +strictly necessary to do this. Building HV equipment requires some parts +that can only be manufactured using electrical machines, either LV or MV, +so it is not possible to build an HV network first, but it is possible +to skip either LV or MV on the way to HV. + +Each voltage has its own cable type, with distinctive insulation. Cable +segments connect to each other and to compatible machines automatically. +Incompatible electrical items don't connect. All non-cable electrical +items must be connected via cable: they don't connect directly to each +other. Most electrical items can connect to cables in any direction, +but there are a couple of important exceptions noted below. + +To be useful, an electrical network must connect at least one power +generator to at least one power-consuming machine. In addition to these +items, the network must have a "switching station" in order to operate: +no energy will flow without one. Unlike most electrical items, the +switching station is not voltage-specific: the same item will manage +a network of any tier. However, also unlike most electrical items, +it is picky about the direction in which it is connected to the cable: +the cable must be directly below the switching station. + +Hovering over a network's switching station will show the aggregate energy +supply and demand, which is useful for troubleshooting. Electrical energy +is measured in "EU", and power (energy flow) in EU per second (EU/s). +Energy is shifted around a network instantaneously once per second. + +In a simple network with only generators and consumers, if total +demand exceeds total supply then no energy will flow, the machines +will do nothing, and the generators' output will be lost. To handle +this situation, it is recommended to add a battery box to the network. +A battery box will store generated energy, and when enough has been +stored to run the consumers for one second it will deliver it to the +consumers, letting them run part-time. It also stores spare energy +when supply exceeds demand, to let consumers run full-time when their +demand occasionally peaks above the supply. More battery boxes can +be added to cope with larger periods of mismatched supply and demand, +such as those resulting from using solar generators (which only produce +energy in the daytime). + +When there are electrical networks of multiple tiers, it can be appealing +to generate energy on one tier and transfer it to another. The most +direct way to do this is with the "supply converter", which can be +directly wired into two networks. It is another tier-independent item, +and also particular about the direction of cable connections: it must +have the cable of one network directly above, and the cable of another +network directly below. The supply converter demands 10000 EU/s from +the network above, and when this network gives it power it supplies 9000 +EU/s to the network below. Thus it is only 90% efficient, unlike most of +the electrical system which is 100% efficient in moving energy around. +To transfer more than 10000 EU/s between networks, connect multiple +supply converters in parallel. + +powered machines +---------------- + +### powered machine tiers ### + +Each powered machine takes its power in some specific form, being +either fuel-fired (burning fuel directly) or electrically powered at +some specific voltage. There is a general progression through the +game from using fuel-fired machines to electrical machines, and to +higher electrical voltages. The most important kinds of machine come +in multiple variants that are powered in different ways, so the earlier +ones can be superseded. However, some machines are only available for +a specific power tier, so the tier can't be entirely superseded. + +### powered machine upgrades ### + +Some machines have inventory slots that are used to upgrade them in +some way. Generally, machines of MV and HV tiers have two upgrade slots, +and machines of lower tiers (fuel-fired and LV) do not. Any item can +be placed in an upgrade slot, but only specific items will have any +upgrading effect. It is possible to have multiple upgrades of the same +type, but this can't be achieved by stacking more than one upgrade item +in one slot: it is necessary to put the same kind of item in more than one +upgrade slot. The ability to upgrade machines is therefore very limited. +Two kinds of upgrade are currently possible: an energy upgrade and a +tube upgrade. + +An energy upgrade consists of a battery item, the same kind of battery +that serves as a mobile energy store. The effect of an energy upgrade +is to improve in some way the machine's use of electrical energy, most +often by making it use less energy. The upgrade effect has no relation +to energy stored in the battery: the battery's charge level is irrelevant +and will not be affected. + +A tube upgrade consists of a control logic unit item. The effect of a +tube upgrade is to make the machine able, or more able, to eject items +it has finished with into pneumatic tubes. The machines that can take +this kind of upgrade are in any case capable of accepting inputs from +pneumatic tubes. These upgrades are essential in using powered machines +as components in larger automated systems. + +### tubes with powered machines ### + +Generally, powered machines of MV and HV tiers can work with pneumatic +tubes, and those of lower tiers cannot. (As an exception, the fuel-fired +furnace from the basic Minetest game can accept inputs through tubes, +but can't output into tubes.) + +If a machine can accept inputs through tubes at all, then this +is a capability of the basic machine, not requiring any upgrade. +Most item-processing machines take only one kind of input, and in that +case they will accept that input from any direction. This doesn't match +how tubes visually connect to the machines: generally tubes will visually +connect to any face except the front, but an item passing through a tube +in front of the machine will actually be accepted into the machine. + +A minority of machines take more than one kind of input, and in that +case the input slot into which an arriving item goes is determined by the +direction from which it arrives. In this case the machine may be picky +about the direction of arriving items, associating each input type with +a single face of the machine and not accepting inputs at all through the +remaining faces. Again, the visual connection of tubes doesn't match: +generally tubes will still visually connect to any face except the front, +thus connecting to faces that neither accept inputs nor emit outputs. + +Machines do not accept items from tubes into non-input inventory slots: +the output slots or upgrade slots. Output slots are normally filled +only by the processing operation of the machine, and upgrade slots must +be filled manually. + +Powered machines generally do not eject outputs into tubes without +an upgrade. One tube upgrade will make them eject outputs at a slow +rate; a second tube upgrade will increase the rate. Whether the slower +rate is adequate depends on how it compares to the rate at which the +machine produces outputs, and on how the machine is being used as part +of a larger construct. The machine always ejects its outputs through a +particular face, usually a side. Due to a bug, the side through which +outputs are ejected is not consistent: when the machine is rotated one +way, the direction of ejection is rotated the other way. This will +probably be fixed some day, but because a straightforward fix would +break half the machines already in use, the fix may be tied to some +larger change such as free selection of the direction of ejection. + +### battery boxes ### + +The primary purpose of battery boxes is to temporarily store electrical +energy to let an electrical network cope with mismatched supply and +demand. They have a secondary purpose of charging and discharging +powered tools. They are thus a mixture of electrical infrastructure, +powered machine, and generator. + +MV and HV battery boxes have upgrade slots. Energy upgrades increase +the capacity of a battery box, each by 10% of the un-upgraded capacity. +This increase is far in excess of the capacity of the battery that forms +the upgrade. + +For charging and discharging of power tools, rather than having input and +output slots, each battery box has a charging slot and a discharging slot. +A fully charged/discharged item stays in its slot. The rates at which a +battery box can charge and discharge increase with voltage, so it can +be worth building a battery box of higher tier before one has other +infrastructure of that tier, just to get access to faster charging. + +MV and HV battery boxes work with pneumatic tubes. An item can be input +to the charging slot through the bottom of the battery box, or to the +discharging slot through the top. Items are not accepted through the +front, back, or sides. With a tube upgrade, fully charged/discharged +tools (as appropriate for their slot) will be ejected through a side. + +### processing machines ### + +The furnace, alloy furnace, grinder, extractor, compressor, and centrifuge +have much in common. Each implements some industrial process that +transforms items into other items, and they manner in which they present +these processes as powered machines is essentially identical. + +Most of the processing machines operate on inputs of only a single type +at a time, and correspondingly have only a single input slot. The alloy +furnace is an exception: it operates on inputs of two distinct types at +once, and correspondingly has two input slots. It doesn't matter which +way round the alloy furnace's inputs are placed in the two slots. + +The processing machines are mostly available in variants for multiple +tiers. The furnace and alloy furnace are each available in fuel-fired, +LV, and MV forms. The grinder, extractor, and compressor are each +available in LV and MV forms. The centrifuge is the only single-tier +processing machine, being only available in MV form. The higher-tier +machines process items faster than the lower-tier ones, but also have +higher power consumption, usually taking more energy overall to perform +the same amount of processing. The MV machines have upgrade slots, +and energy upgrades reduce their energy consumption. + +The MV machines can work with pneumatic tubes. They accept inputs via +tubes from any direction. For most of the machines, having only a single +input slot, this is perfectly simple behavior. The alloy furnace is more +complex: it will put an arriving item in either input slot, preferring to +stack it with existing items of the same type. It doesn't matter which +slot each of the alloy furnace's inputs is in, so it doesn't matter that +there's no direct control ovar that, but there is a risk that supplying +a lot of one item type through tubes will result in both slots containing +the same type of item, leaving no room for the second input. + +The MV machines can be given a tube upgrade to make them automatically +eject output items into pneumatic tubes. The items are always ejected +through a side, though which side it is depends on the machine's +orientation, due to a bug. Output items are always ejected singly. +For some machines, such as the grinder, the ejection rate with a +single tube upgrade doesn't keep up with the rate at which items can +be processed. A second tube upgrade increases the ejection rate. + +The LV and fuel-fired machines do not work with pneumatic tubes, except +that the fuel-fired furnace (actually part of the basic Minetest game) +can accept inputs from tubes. Items arriving through the bottom of +the furnace go into the fuel slot, and items arriving from all other +directions go into the input slot. + +### music player ### + +The music player is an LV powered machine that plays audio recordings. +It offers a selection of up to nine tracks. The technic modpack doesn't +include specific music tracks for this purpose; they have to be installed +separately. + +The music player gives the impression that the music is being played in +the Minetest world. The music only plays as long as the music player +is in place and is receiving electrical power, and the choice of music +is controlled by interaction with the machine. The sound also appears +to emanate specifically from the music player: the ability to hear it +depends on the player's distance from the music player. However, the +game engine doesn't currently support any other positional cues for +sound, such as attenuation, panning, or HRTF. The impression of the +sound being located in the Minetest world is also compromised by the +subjective nature of track choice: the specific music that is played to +a player depends on what media the player has installed. + +### CNC machine ### + +The CNC machine is an LV powered machine that cuts building blocks into a +variety of sub-block shapes that are not covered by the crafting recipes +of the stairs mod and its variants. Most of the target shapes are not +rectilinear, involving diagonal or curved surfaces. + +Only certain kinds of building material can be processed in the CNC +machine. + +### tool workshop ### + +The tool workshop is an MV powered machine that repairs mechanically-worn +tools, such as pickaxes and the other ordinary digging tools. It has +a single slot for a tool to be repaired, and gradually repairs the +tool while it is powered. For any single tool, equal amounts of tool +wear, resulting from equal amounts of tool use, take equal amounts of +repair effort. Also, all repairable tools currently take equal effort +to repair equal percentages of wear. The amount of tool use enabled by +equal amounts of repair therefore depends on the tool type. + +The mechanical wear that the tool workshop repairs is always indicated in +inventory displays by a colored bar overlaid on the tool image. The bar +can be seen to fill and change color as the tool workshop operates, +eventually disappearing when the repair is complete. However, not every +item that shows such a wear bar is using it to show mechanical wear. +A wear bar can also be used to indicate charging of a power tool with +stored electrical energy, or filling of a container, or potentially for +all sorts of other uses. The tool workshop won't affect items that use +wear bars to indicate anything other than mechanical wear. + +The tool workshop has upgrade slots. Energy upgrades reduce its power +consumption. + +It can work with pneumatic tubes. Tools to be repaired are accepted +via tubes from any direction. With a tube upgrade, the tool workshop +will also eject fully-repaired tools via one side, the choice of side +depending on the machine's orientation, as for processing machines. It is +safe to put into the tool workshop a tool that is already fully repaired: +assuming the presence of a tube upgrade, the tool will be quickly ejected. +Furthermore, any item of unrepairable type will also be ejected as if +fully repaired. (Due to a historical limitation of the basic Minetest +game, it is impossible for the tool workshop to distinguish between a +fully-repaired tool and any item type that never displays a wear bar.) + +### quarry ### + +The quarry is an HV powered machine that automatically digs out a +large area. The region that it digs out is a cuboid with a square +horizontal cross section, located immediately behind the quarry machine. +The quarry's action is slow and energy-intensive, but requires little +player effort. + +The size of the quarry's horizontal cross section is configurable through +the machine's interaction form. A setting referred to as "radius" +is an integer number of meters which can vary from 2 to 8 inclusive. +The horizontal cross section is a square with side length of twice the +radius plus one meter, thus varying from 5 to 17 inclusive. Vertically, +the quarry always digs from 3 m above the machine to 100 m below it, +inclusive, a total vertical height of 104 m. + +Whatever the quarry digs up is ejected through the top of the machine, +as if from a pneumatic tube. Normally a tube should be placed there +to convey the material into a sorting system, processing machines, or +at least chests. A chest may be placed directly above the machine to +capture the output without sorting, but is liable to overflow. + +If the quarry encounters something that cannot be dug, such as a liquid, +a locked chest, or a protected area, it will skip past that and attempt +to continue digging. However, anything remaining in the quarry area +after the machine has attempted to dig there will prevent the machine +from digging anything directly below it, all the way to the bottom +of the quarry. An undiggable block therefore casts a shadow of undug +blocks below it. If liquid is encountered, it is quite likely to flow +across the entire cross section of the quarry, preventing all digging. +The depth at which the quarry is currently attempting to dig is reported +in its interaction form, and can be manually reset to the top of the +quarry, which is useful to do if an undiggable obstruction has been +manually removed. + +The quarry consumes 10 kEU per block dug, which is quite a lot of energy. +With most of what is dug being mere stone, it is usually not economically +favorable to power a quarry from anything other than solar power. +In particular, one cannot expect to power a quarry by burning the coal +that it digs up. + +Given sufficient power, the quarry digs at a rate of one block per second. +This is rather tedious to wait for. Unfortunately, leaving the quarry +unattended normally means that the Minetest server won't keep the machine +running: it needs a player nearby. This can be resolved by using a world +anchor. The digging is still quite slow, and independently of whether a +world anchor is used the digging can be speeded up by placing multiple +quarry machines with overlapping digging areas. Four can be placed to +dig identical areas, one on each side of the square cross section. + +### forcefield emitter ### + +The forcefield emitter is an HV powered machine that generates a +forcefield remeniscent of those seen in many science-fiction stories. + +The emitter can be configured to generate a forcefield of either +spherical or cubical shape, in either case centered on the emitter. +The size of the forcefield is configured using a radius parameter that +is an integer number of meters which can vary from 5 to 20 inclusive. +For a spherical forcefield this is simply the radius of the forcefield; +for a cubical forcefield it is the distance from the emitter to the +center of each square face. + +The power drawn by the emitter is proportional to the surface area of +the forcefield being generated. A spherical forcefield is therefore the +cheapest way to enclose a specified volume of space with a forcefield, +if the shape of the space doesn't matter. A cubical forcefield is less +efficient at enclosing volume, but is cheaper than the larger spherical +forcefield that would be required if it is necessary to enclose a +cubical space. + +The emitter is normally controlled merely through its interaction form, +which has an enable/disable toggle. However, it can also (via the form) +be placed in a mesecon-controlled mode. If mesecon control is enabled, +the emitter must be receiving a mesecon signal in addition to being +manually enabled, in order for it to generate the forcefield. + +The forcefield itself behaves largely as if solid, despite being +immaterial: it cannot be traversed, and prevents access to blocks behind +it. It is transparent, but not totally invisible. It cannot be dug. +Some effects can pass through it, however, such as the beam of a mining +laser, and explosions. In fact, explosions as currently implemented by +the tnt mod actually temporarily destroy the forcefield itself; the tnt +mod assumes too much about the regularity of node types. + +The forcefield occupies space that would otherwise have been air, but does +not replace or otherwise interfere with materials that are solid, liquid, +or otherwise not just air. If such an object blocking the forcefield is +removed, the forcefield will quickly extend into the now-available space, +but it does not do so instantly: there is a brief moment when the space +is air and can be traversed. + +It is possible to have a doorway in a forcefield, by placing in advance, +in space that the forcefield would otherwise occupy, some non-air blocks +that can be walked through. For example, a door suffices, and can be +opened and closed while the forcefield is in place. + +power generators +---------------- + +### fuel-fired generators ### + +The fiel-fired generators are electrical power generators that generate +power by the combustion of fuel. Versions of them are available for +all three voltages (LV, MV, and HV). These are all capable of burning +any type of combustible fuel, such as coal. They are relatively easy +to build, and so tend to be the first kind of generator used to power +electrical machines. In this role they form an intermediate step between +the directly fuel-fired machines and a more mature electrical network +powered by means other than fuel combustion. They are also, by virtue of +simplicity and controllability, a useful fallback or peak load generator +for electrical networks that normally use more sophisticated generators. + +The MV and HV fuel-fired generators can accept fuel via pneumatic tube, +from any direction. + +Keeping a fuel-fired generator fully fuelled is usually wasteful, because +it will burn fuel as long as it has any, even if there is no demand for +the electrical power that it generates. This is unlike the directly +fuel-fired machines, which only burn fuel when they have work to do. +To satisfy intermittent demand without waste, a fuel-fired generator must +only be given fuel when there is either demand for the energy or at least +sufficient battery capacity on the network to soak up the excess energy. + +The higher-tier fuel-fired generators get much more energy out of a +fuel item than the lower-tier ones. The difference is much more than +is needed to overcome the inefficiency of supply converters, so it is +worth operating fuel-fired generators at a higher tier than the machines +being powered. + +### solar generators ### + +The solar generators are electrical power generators that generate power +from sunlight. Versions of them are available for all three voltages +(LV, MV, and HV). There are four types in total, two LV and one each +of MV and HV, forming a sequence of four tiers. The higher-tier ones +are each built mainly from three solar generators of the next tier down, +and their outputs scale in rough accordance, tripling at each tier. + +To operate, an arrayed solar generator must be at elevation +1 or above +and have a transparent block (typically air) immediately above it. +It will generate power only when the block above is well lit during +daylight hours. It will generate more power at higher elevation, +reaching maximum output at elevation +36 or higher when sunlit. The small +solar generator has similar rules with slightly different thresholds. +These rules are an attempt to ensure that the generator will only operate +from sunlight, but it is actually possible to fool them to some extent +with light sources such as meselamps. + +### hydro generator ### + +The hydro generator is an LV power generator that generates a small amount +of power from the natural motion of water. To operate, the generator must +be horizontally adjacent to water. It doesn't matter whether the water +consists of source blocks or flowing blocks. Having water adjacent on +more than one side, up to the full four, increases the generator's output. +The water itself is unaffected by the generator. + +### geothermal generator ### + +The geothermal generator is an LV power generator that generates a small +amount of power from the temperature difference between lava and water. +To operate, the generator must be horizontally adjacent to both lava +and water. It doesn't matter whether the liquids consist of source +blocks or flowing blocks. + +Beware that if lava and water blocks are adjacent to each other then the +lava will be solidified into stone or obsidian. If the lava adjacent to +the generator is thus destroyed, the generator will stop producing power. +Currently, in the default Minetest game, lava is destroyed even if +it is only diagonally adjacent to water. Under these circumstances, +the only way to operate the geothermal generator is with it adjacent +to one lava block and one water block, which are on opposite sides of +the generator. If diagonal adjacency doesn't destroy lava, such as with +the gloopblocks mod, then it is possible to have more than one lava or +water block adjacent to the geothermal generator. This increases the +generator's output, with the maximum output achieved with two adjacent +blocks of each liquid. + +### wind generator ### + +The wind generator is an MV power generator that generates a moderate +amount of energy from wind. To operate, the generator must be placed +atop a column of at least 20 wind mill frame blocks, and must be at +an elevation of +30 or higher. It generates more at higher elevation, +reaching maximum output at elevation +50 or higher. Its surroundings +don't otherwise matter; it doesn't actually need to be in open air. + +### nuclear generator ### + +The nuclear generator (nuclear reactor) is an HV power generator that +generates a large amount of energy from the controlled fission of +uranium-235. It must be fuelled, with uranium fuel rods, but consumes +the fuel quite slowly in relation to the rate at which it is likely to +be mined. The operation of a nuclear reactor poses radiological hazards +to which some thought must be given. Economically, the use of nuclear +power requires a high capital investment, and a secure infrastructure, +but rewards the investment well. + +Nuclear fuel is made from uranium. Natural uranium doesn't have a +sufficiently high proportion of U-235, so it must first be enriched +via centrifuge. Producing one unit of 3.5%-fissile uranium requires +the input of five units of 0.7%-fissile (natural) uranium, and produces +four units of 0.0%-fissile (fully depleted) uranium as a byproduct. +It takes five ingots of 3.5%-fissile uranium to make each fuel rod, and +six rods to fuel a reactor. It thus takes the input of the equivalent +of 150 ingots of natural uranium, which can be obtained from the mining +of 75 blocks of uranium ore, to make a full set of reactor fuel. + +The nuclear reactor is a large multi-block structure. Only one block in +the structure, the reactor core, is of a type that is truly specific to +the reactor; the rest of the structure consists of blocks that have mainly +non-nuclear uses. The reactor core is where all the generator-specific +action happens: it is where the fuel rods are inserted, and where the +power cable must connect to draw off the generated power. + +The reactor structure consists of concentric layers, each a cubical +shell, around the core. Immediately around the core is a layer of water, +representing the reactor coolant; water blocks may be either source blocks +or flowing blocks. Around that is a layer of stainless steel blocks, +representing the reactor pressure vessel, and around that a layer of +blast-resistant concrete blocks, representing a containment structure. +It is customary, though no longer mandatory, to surround this with a +layer of ordinary concrete blocks. The mandatory reactor structure +makes a 7×7×7 cube, and the full customary structure a +9×9×9 cube. + +The layers surrounding the core don't have to be absolutely complete. +Indeed, if they were complete, it would be impossible to cable the core to +a power network. The cable makes it necessary to have at least one block +missing from each surrounding layer. The water layer is only permitted +to have one water block missing of the 26 possible. The steel layer may +have up to two blocks missing of the 98 possible, and the blast-resistant +concrete layer may have up to two blocks missing of the 218 possible. +Thus it is possible to have not only a cable duct, but also a separate +inspection hole through the solid layers. The separate inspection hole +is of limited use: the cable duct can serve double duty. + +Once running, the reactor core is significantly radioactive. The layers +of reactor structure provide quite a lot of shielding, but not enough +to make the reactor safe to be around, in two respects. Firstly, the +shortest possible path from the core to a player outside the reactor +is sufficiently short, and has sufficiently little shielding material, +that it will damage the player. This only affects a player who is +extremely close to the reactor, and close to a face rather than a vertex. +The customary additional layer of ordinary concrete around the reactor +adds sufficient distance and shielding to negate this risk, but it can +also be addressed by just keeping extra distance (a little over two +meters of air). + +The second radiological hazard of a running reactor arises from shine +paths; that is, specific paths from the core that lack sufficient +shielding. The necessary cable duct, if straight, forms a perfect +shine path, because the cable itself has no radiation shielding effect. +Any secondary inspection hole also makes a shine path, along which the +only shielding material is the water of the reactor coolant. The shine +path aspect of the cable duct can be ameliorated by adding a kink in the +cable, but this still yields paths with reduced shielding. Ultimately, +shine paths must be managed either with specific shielding outside the +mandatory structure, or with additional no-go areas. + +The radioactivity of an operating reactor core makes starting up a reactor +hazardous, and can come as a surprise because the non-operating core +isn't radioactive at all. The radioactive damage is survivable, but it is +normally preferable to avoid it by some care around the startup sequence. +To start up, the reactor must have a full set of fuel inserted, have all +the mandatory structure around it, and be cabled to a switching station. +Only the fuel insertion requires direct access to the core, so irradiation +of the player can be avoided by making one of the other two criteria be +the last one satisfied. Completing the cabling to a switching station +is the easiest to do from a safe distance. + +Once running, the reactor will generate 100 kEU/s for a week (168 hours, +604800 seconds), a total of 6.048 GEU from one set of fuel. After the +week is up, it will stop generating and no longer be radioactive. It can +then be refuelled to run for another week. It is not really intended +to be possible to pause a running reactor, but actually disconnecting +it from a switching station will have the effect of pausing the week. +This will probably change in the future. A paused reactor is still +radioactive, just not generating electrical power. + +A running reactor can't be safely dismantled, and not only because +dismantling the reactor implies removing the shielding that makes +it safe to be close to the core. The mandatory parts of the reactor +structure are not just mandatory in order to start the reactor; they're +mandatory in order to keep it intact. If the structure around the core +gets damaged, and remains damaged, the core will eventually melt down. +How long there is before meltdown depends on the extent of the damage; +if only one mandatory block is missing, meltdown will follow in 100 +seconds. While the structure of a running reactor is in a damaged state, +heading towards meltdown, a siren built into the reactor core will sound. +If the structure is rectified, the siren will signal all-clear. If the +siren stops sounding without signalling all-clear, then it was stopped +by meltdown. + +If meltdown is imminent because of damaged reactor structure, digging the +reactor core is not a way to avert it. Digging the core of a running +reactor causes instant meltdown. The only way to dismantle a reactor +without causing meltdown is to start by waiting for it to finish the +week-long burning of its current set of fuel. Once a reactor is no longer +operating, it can be dismantled by ordinary means, with no special risks. + +Meltdown, if it occurs, destroys the reactor and poses a major +environmental hazard. The reactor core melts, becoming a hot, highly +radioactive liquid known as "corium". A single meltdown yields a single +corium source block, where the core used to be. Corium flows, and the +flowing corium is very destructive to whatever it comes into contact with. +Flowing corium also randomly solidifies into a radioactive solid called +"Chernobylite". The random solidification and random destruction of +solid blocks means that the flow of corium is constantly changing. +This combined with the severe radioactivity makes corium much more +challenging to deal with than lava. If a meltdown is left to its own +devices, it gets worse over time, as the corium works its way through +the reactor structure and starts to flow over a variety of paths. +It is best to tackle a meltdown quickly; the priority is to extinguish +the corium source block, normally by dropping gravel into it. Only the +most motivated should attempt to pick up the corium in a bucket. + +administrative world anchor +--------------------------- + +A world anchor is an object in the Minetest world that causes the server +to keep surrounding parts of the world running even when no players +are nearby. It is mainly used to allow machines to run unattended: +normally machines are suspended when not near a player. The technic +mod supplies a form of world anchor, as a placable block, but it is not +straightforwardly available to players. There is no recipe for it, so it +is only available if explicitly spawned into existence by someone with +administrative privileges. In a single-player world, the single player +normally has administrative privileges, and can obtain a world anchor +by entering the chat command "/give singleplayer technic:admin\_anchor". + +The world anchor tries to force a cubical area, centered upon the anchor, +to stay loaded. The distance from the anchor to the most distant map +nodes that it will keep loaded is referred to as the "radius", and can be +set in the world anchor's interaction form. The radius can be set as low +as 0, meaning that the anchor only tries to keep itself loaded, or as high +as 255, meaning that it will operate on a 511×511×511 cube. +Larger radii are forbidden, to avoid typos causing the server excessive +work; to keep a larger area loaded, use multiple anchors. Also use +multiple anchors if the area to be kept loaded is not well approximated +by a cube. + +The world is always kept loaded in units of 16×16×16 cubes, +confusingly known as "map blocks". The anchor's configured radius takes +no account of map block boundaries, but the anchor's effect is actually to +keep loaded each map block that contains any part of the configured cube. +The anchor's interaction form includes a status note showing how many map +blocks this is, and how many of those it is successfully keeping loaded. +When the anchor is disabled, as it is upon placement, it will always +show that it is keeping no map blocks loaded; this does not indicate +any kind of failure. + +The world anchor can optionally be locked. When it is locked, only +the anchor's owner, the player who placed it, can reconfigure it or +remove it. Only the owner can lock it. Locking an anchor is useful +if the use of anchors is being tightly controlled by administrators: +an administrator can set up a locked anchor and be sure that it will +not be set by ordinary players to an unapproved configuration. + +The server limits the ability of world anchors to keep parts of the world +loaded, to avoid overloading the server. The total number of map blocks +that can be kept loaded in this way is set by the server configuration +item "max\_forceloaded\_blocks" (in minetest.conf), which defaults to +only 16. For comparison, each player normally keeps 125 map blocks loaded +(a radius of 32). If an enabled world anchor shows that it is failing to +keep all the map blocks loaded that it would like to, this can be fixed +by increasing max\_forceloaded\_blocks by the amount of the shortfall. + +The tight limit on force-loading is the reason why the world anchor is +not directly available to players. With the limit so low both by default +and in common practice, the only feasible way to determine where world +anchors should be used is for administrators to decide it directly. + +subjects missing from this manual +--------------------------------- + +This manual needs to be extended with sections on: + +* powered tools + * tool charging + * battery and energy crystals + * chainsaw + * flashlight + * mining lasers + * mining drills + * prospector + * sonic screwdriver +* liquid cans +* wrench +* frames +* templates |