The 21st century will be the century of saving resources — energy, raw materials, minerals, spatial, financial, labor, food, etc. And it has a direct relationship to transport communications. They should be only on the "second" level above the ground, which has been long before occupied by flora and fauna, where the SkyWay will be out of competition.
In the 20th century the world population grew up by 4 times, with the GDP growth by 20 times, which increased the demand for some natural resources by 2,000%. However, the world has entered the era of expensive resources — the era of low prices remained in the past. The growth of the middle class by 3 billion people over the next 20 years will dramatically increase the demand for new resources, and the search of new sources of raw materials, energy, water and food is complicated and expensive. The jump in demand will occur at precisely the moment when the search of new sources of resources becomes difficult or expensive, and we shall face the "resource revolution". The deficit or price rise on one type of resources can spread over to other ones. An attempt to satisfy the growing demand with proportional increase in production will require in future additional investment of up to USD 10 trillion a year and shall be of serious risks for the civilization.
The SkyWay will be able to provide double saving for the humanity.
First, string cargo routes will provide cheap access to mineral resources that are not accessible currently. It is because they are located, for example, high in the mountains, in the tundra and on the Arctic ocean shelf, deep in the vast deserts, in the heart of continents, such as Australia. Accessible mineral resources will allow the global economy to continue to develop dynamically.
Secondly, the passenger string tracks will allow creating an extensive global network of transport and communication infrastructure at much lower cost and with less spending of raw materials, energy and other resources. It will be combined with information and power networks. Thus, during the 21st century, almost all the traffic will move up to the "second" level, leaving the "first" level to nature and people. This will allow to improve relationship within the terrestrial civilization — according to the UN the need for people to travel within the next 50 years should increase by 5-6 times, with considerable increase of speed and range of these travels.
The specific feature of any high-speed track structure is the required extremely high flatness of a route, due to needed conditions of comfort and safety. It is necessary not only because of irregularities in construction structures, but also static and dynamic deformations of flyovers under the load moving at high-speed. For example, at a span length of 50 m and a speed of 500 km/h, the maximum roughness, taking into account the construction of the (technological) errors and dynamic deformations of a flyover superstructure under load, should not exceed 10 mm (or 1/5.000 of the length of span).
A designed high-speed rail-string overpass meets the above requirements. A delicate track structure, arranged above the ground on the "second" level, has low material consumption and, consequently, low consumption of mineral resources for its construction: steel and steel structures, nonferrous metals, reinforced concrete, concrete, cement, fittings, gravel, sand, soil, etc. Thus, due to the continuous (uncut) structure of the string rail (all over the length it has no deformation and other joints, as it is welded into a single whip), the bearing capacity of supporting poles increases by ten times. Moreover, since such supports are in the majority in the design of the "second level" tracks (one anchor support comprises about 100 intermediate supports), respectively, material consumption and cost of the supports become drastically lower.
The consumption of construction materials per 1 km of a double-track pre-stressed (stretched) high-speed (500 km/h) string-rail overpass is: bridge-type steel — up to 600 ton/km (among them: track structure— up to 350 ton/km; anchor and intermediate supports— up to 250 ton/km), concrete — up to 900 ton/km (among them: track structure — up to 300 ton/km; anchor and intermediate supports — up to 600 ton/km). Guaranteed durability of such overpasses will be 100 years. Its analogue was built at the test site of the first generation of string transport in 2001 (Town of Ozyory, Moscow region, Russia) with the consumption of steel on the overpass — up to 120 kg/m for a single track.
here is the main data on the high-speed railway of the elevated design built by Japanese technologies in 2000 and 2007 on the island of Taiwan for traffic at speeds up to 350 km/h. The basic resource features of this track with a length of 345 km and the cost, according to various estimates, from USD 15 to USD 18 billion (or USD 43.5—52.2 million/km in 2005 prices; in 2014 prices these figures should be increased approximately by 2 times):
— length of spans is 35 m;
— foundations of supermassive concrete poles installed on four reinforced concrete bored piles of 2m diameter and up to 60 m length each (weight of only pile foundation under each support can reach 1,800 tons, or more than 50 tons per linear meter of track!);
— powerful overpass superstructures in the form of two pre-stressed assembly concrete beams with 6 m width, 3 m height and weighing 800 tons each on an overpass;
— laid on the supporting beams is a pre-stressed reinforced concrete slab of 13 meter width and 500 ton weight on an overpass;
—placed on the slab is a rail-sleeper grid of a double-track high-speed railway.
Consumption of structural materials on this overpass is (including rail-sleeper grid): high-strength steel (mostly rebar in reinforced concrete structures) — 11,400 ton/km, reinforced concrete — 109,000 ton/km. About the same material consuming, as described, is the overpass for magnetic levitation trains "Transrapid" designed by "Siemens".
Thus, conditional savings of basic building and construction materials when using RSW technologies is: steel — 10,800 ton/km, reinforced concrete — 108,100 ton/km (or 45,000 m3/km). Therefore, on a high-speed network of SkyWay routes of length of 25 million kilometers to be built in the 21st century on the planet, conditional savings of mineral resources will be: steel 270 billion tons, reinforced concrete — 2.7 trillion tons (or 1.125 billion cubic meters).
Currently the world produces 1.5 billion tons of steel per year. To obtain additional saved 270 billion tons of steel and rolled products from it would be additionally released in the environment (in billion tons): dust — 32, Sulphur dioxide — above 17, carbon dioxide — above 38, nitrogen oxide — above 3.8, wastewater — above 50 trillion cubic meters (50 thousand cubic kilometers). To produce such amount of steel for 50 years there would be no need in 540 major steel plants with the capacity of 10 million ton per year, with lots of workshops and support services, which would occupy a territory of 500 hectares. Moreover, this would not require additionally allocated lands, disturbed by mining operations, occupied with dumps, ash- and slag collection points of the area of more than 62.5 million hectares (or more than 625 thousand km2 — almost 3 territories of such a country as the UK. More than 1.2 trillion tons of different exhaustible raw materials (including coking coal) would not be mined in quarries and mines. After processing this quantity, more than 120 billion tons of environmentally hazardous and carcinogenic substances would have appeared in the solid and ecologically hazardous waste.
Even more resources would have been required (including energy, land, human, financial, etc.), and there would be more global environmental problems during the production and fitting in constructions of an additional 1.125 trillion cubic meters (2.7 trillion tons) of reinforced concrete that can be saved when using RSW technologies on 25 million km of tracks of overpass type.
Thus it is necessary to emphasize the advantages of the overpass, as the support structure for a high-speed track structure, over the traditional earth embankment (the notch), and also over gravel-sand bed and rail-sleeper grid of a high-speed railway.
During the construction of a rail-string overpass, the point volume of earthworks will be reduced by more than 100 times in comparison to laying the same strip of railroad on a linear mound. Therefore, the terrain and biogeocenose in the construction zone will not suffer any damage and land reclamation will not be required. This is especially important when laying a route in permafrost and poor soils that are not capable of withstanding the additional load from the mound, not only weight, but also heat in summer time.
In addition, not only is the earth mound, but also the underlying soils on conventional high-speed railroads should be dense (optionally compacted by about 10%). This turns this railroad in a long, low-pressure dam, crossing the sources of the rivers, the movement of ground and surface waters, including, flood waters. Such extremely wasteful mound, sometimes reaching a height of 10 m or more (or about 500 thousand tons of soil for every kilometer of road length), disturbs the migration of animals, both domestic and wild, inhibits natural biodiversity, prevents the movement of agricultural and other machinery. In this case, because of the danger of entering the path by large animals (elk, cow, wild boar), which would lead to the collapse and derailing of high-speed rolling stock, railroaders have to fence such mound. Moreover, the cost of such conventional fencing and associated embankments of a conventional transport infrastructure (culverts, bridges, overpasses, and multilevel transport interchanges, etc.) will be much more expensive than the whole string-rail overpass of the same length.
Another advantage of RSW technologies is savings on the resources for mass production of rolling stock. For example, a modern aircraft transports up to one ton of its structure and fuel per passenger (rising to the height of 10-12 km, wasting enormous amounts of energy for it). Moreover, one seat in a modern Airbus stands up to USD 500—600 thousand. The whole aircraft fleet would cost the customer additional USD 75 trillion to perform the same transportation work as the SkyWay network of the length of 25 million kilometers performs. This surplus value is created by irrationally used, though limited, raw materials, labor, social, and financial resources of our civilization (and therefore not used for other more reasonable goals).
Modern rail cars do not carry fuel, but the "iron" in them is up to 1.8 tons per passenger of a compartment car, and including the weight of the locomotive — up to 2.5 ton/passenger, which is very inefficient from a resource point of view. And each passenger seat on the railway is quite expensive, too, and the higher is the design speed — the more expensive it is. For example, in high-speed trains "Sapsan", purchased by Russia in Germany and reaching the speed of 250 km/h only, each sitting place costs for the taxpayer almost USD 200 thousand.
A unibus, even a high-speed one (500 km/h), is structurally not more complicated than a modern passenger car (van) and is similar in weight, size and cost characteristics: "low iron" — up to 250-300 kg/passenger, the cost (at mass production) — up to USD 20-25 thousand/passenger.
Saving investment costs for the construction of one kilometer of a rail-string overpass, in comparison with the high-speed railway viaduct and the magnetic levitation trains, will be approximately USD 60 million/km — with the inevitable cost rise of traditional transport flyovers in difficult natural and climatic conditions for most of the routes. If at least 25 million km of high-speed, intercity and international routes of overpass type are built all over the world (so far on the planet built are more than 30 million km of motor roads and more than 1 million km of railways), humanity would save on building high-speed routes 1.5 quadrillion (or USD 1,500 trillion) of financial resources. Those savings would be formed by saving non-renewable resources. These are natural (ore, oil, coal, etc.) and labor ones. Unnecessary will become inefficient, giant work not only on construction itself but also in the extraction of ore and petroleum, smelting and rolling of steel, production of concrete as well as for their transportation to hundreds and thousands of kilometers, etc.
Earth embankments of railroads (including high-speed ones) and motor roads cover (take away from a land user), including infrastructure, minimum 4 ha of soil for every kilometer of distance. During the construction of the SkyWay track network of 25 million km length it will save from destruction approximately 1,000,000 square kilometers of soil, and this is the territory four times larger than that of Great Britain. At the averaged value of withdrawn land for the construction of USD 1 million/ha, the cost of saved land will amount to USD 100 trillion, at the cost of USD 10 million/ha (the land is constantly going up in price and by the end of the century may, at average, be even more expensive) — USD 1.000 trillion (or USD 1 quadrillion). Saved will be not just the land, but fertile soil. After all, the most valuable mineral resource on the planet is certainly the living soil, which, in fact, gives us all life. The humus in the soil was created by living organisms over millions of years not to make it "rolled up in asphalt".