Not so long ago, in the category "Business Lynch" on the website of the design Studio Artyom Lebedev, there appeared of the SkyWay technology. The industrial designer of the Studio expressed in this review his doubts about the effectiveness of the string transport, although he noted that "the idea looks nice." As we see it, the author of the review has spent too little time studying the issue, and therefore, there are a lot of inaccuracies and misconceptions in his review. In order not to allow similar misconceptions to appear again in the future, and at the same time to detail and to explain in simple terms the main elements of the SkyWay concept, we will answer some of the questions posed in the critical review.
— How can the space between the supports of the string transport be used?
— And how is the space between the supports of the lighting poles used in the city now? And what about the space under ridgepoles between buildings and poles (trolleybus wires, advertising cross street banners)? Sidewalks, roadway, lawns can be easily marked under the track structure. And if the track structure and the vehicles passing on it are located at a sufficient height, the location of the complex can be combined with conventional urban facilities. Outside the city, this space will be occupied by a green area or agricultural land.
— What will happen in case of malfunction when the cabin with passengers is stuck at a height of 15 m? Probably, it should be reached somehow and, obviously, from the earth.
- First of all, the rails can be placed both at a height of 6-8 meters (if there is a task to rise transport above the ground, to free the surface, but there is no task to rise higher than required, as it increases the cost of the track); and at a height of 100 m (for example, if it is "a horizontal lift" between high buildings). You can get to the cabin from the ground at a low hight, but not at high one, as it is almost impossible. Therefore, all vehicles, firstly, have back up systems for minimizing the probability of an emergency halt on the way; secondly, the vehicles are equipped with towing devices---they can be seen in front and behind the unibus - with their help, a neighboring vehicle can take a unibus with a breakage in tow and deliver it to the depot, not blocking the track.
- Movement is possible on sufficiently smooth, almost straight trajectories, which does not add mobility and maneuverability.
- On the string sections of the track structure (i.e. pre-stressed sections), the trajectory "in plan" is indeed straight. However, this does not mean that the vehicles are not maneuverable, as they cannot turn. The track structure has also transitional non prestressed sections, where vehicles can turn – in other words, different types of tracks can be combined to perform different specific tasks.
The minimum radii of veering for the non prestressed sections are 15 m for passenger monorail unibuses (with the capacity for 15-30 people), and 24 m for the double-rail ( with the capacity for 25-60 people), which is comparable with the radii of veering on motor roads in the city: typical trajectories,depending on the road class, have radii from 10 to 30 m.
If you take light and super-light vehicles with a capacity for 1-4 people, the radii of their veering can be 5-10 m -- this maneuverability is enough for ride into every yard, relatively speaking.
- The declared high speed of 150 km/h on a flexible rail is possible between supports, on a support, the possible speed is 30 km/h. So, in fact, the vehicles will move with this speed.
-Let's take again a clear automobile analogy. If a car is in front of an intersection and is driving at 10 km/h on this section, does that mean that such speed is its actual moving speed around the city? Obviously, the average speed of movement is important, which will be much higher – about 70 kilometers per hour. It is also worth paying attention to the importance of flow continuity. The road transport has a lot of problems with that now. Cars that can drive freely at 180-200 km/h, go through the city at an average speed of 15-30 km/h (speed limits, traffic lights, traffic jams). Unibuses, like the metro, having no obstacles on the way and moving in a continuous flow, will provide a greater average speed and greater traffic capacity.
Trolleys are driven by electric motors powered by batteries, located at the top of the capsules. For the trains not to stand idle while charging, the battery package should be changed, which means, there should be special warehouses where the replacement batteries can be stored and charged.
- The specific solution for the energy supply of the vehicles depends on the specific conditions and requirements. The options for solving the problem of energy supply can be very different: electric drives, powered by a contact network, hybrid circuit (battery + contact network, battery + generator on board).
For vehicles with an electric drive, recharging is possible at night, between peak hours, during stops for boarding passengers (especially for energy accumulators on supercapacitors) - with a certain combination of parameters, the unibus can work all day even with an electric drive.
Moreover, we should not forget about the practically unique unibuses' ability to use a "gravity engine" on the sagging structure. The same principle has long been used in the metro. When moving away from the station, the train moves slightly down, and gravity helps it to accelerate. After the middle of the road, on the rise, gravity on the contrary, begins to slow down the train, reducing the necessary energy consumption for the braking. This principle, coupled with the low rolling resistance of the wheel and good aerodynamic shape, allows to get a very low energy consumption, and, accordingly, to eliminate the need for a large battery or frequent recharging.
- The tracks are located high enough, which means that for loading, the cargo must be lifted to the height of the cargo capsule, and at the destination-- lowered back to the ground.
— There's even no need to explain something: containers are always lifted and lowered by cranes. Bulk cargo is poured from the conveyor or cargo ramp into the unitruck bunker, and then, in the right place, is just poured out.
If we talk about passengers, they really need to go up and down using stairs, escalators, or elevators-- exactly the same as in the metro. However, the city SkyWay line, is much cheaper than the analogous metro line.