Specification :

This VWT-FFS-4372 Double Loop tunnel construction and its technology equipment are optimized for a professional use of sportsmen, army troop as well as general public and schools. Optimization of the fan can be performed on any other scenario of the use of the tunnel ( like only sport tunnel utilization, or only to tourism utilization, military and special training purposes, or eventual their combination...) . Optimization means a proper selection of tunnel dimensions, fans and engines parameters for proposed purposes to gain an optimal ratio between desired performance and operational costs.
Dimensions and technical parameters of this tunnel offer the best conditions for the professional requirements on speed, space and height. Its size provides ample space for the entire training even of group formations of eight skydivers. Tunnel with 4, 3 m of flying chamber diameter is the perfect place for training of army parachutes and special troops with their specific equipment. From tourist' s point of view, the tunnel offers comfortable space even for flying couples with instructors or other smaller groups.
Thanks to a comprehensive fan optimization the, tunnel allows operation of profi-flights as well as fun-flights at very low operation costs.
Materials and Dimensions
Air conductors in the aboveground part of the tunnel are made of sheet steel.
All steel elements are provided with corrosion protection.
Tunnel skin is made by sound-insulation panels KINGSPAN.
Net dimensions of the tunnel are:
width 30 m
depth 10 m
height 32 m
The typical depth of foundation of ground concrete structure is 7, 5 m.
The typical height of the tunnel above the ground is 24 m.
Flight chamber
Flight chamber consists of a glass part, which is on its top connected to a steel construction of tunnel shell. Lower part of the flight chamber is purely cylindrical with a diameter of 4, 3 m and a height of 5 m. The upper part of a flight chamber is made from steel and its height is 9 m. The shape of this part of flight chamber is gradually changing from a circular diameter of 4, 3 meters to circular diameter 4, 3 x 4, 3 m.
The overall maximum height of flight chamber 14 m
The height of the glass part of flight chamber 5 m
Diameter of flight chamber 4, 3 m
Maximum speed
Maximum air speed at which the tunnel can be operated continuously is 80+ m/ s ( 300+ km/ h) .
Motors, fans and electronic equipment
The air stream is formed by four vertically stored fans, each of 3.15 m in diameter, which are powered by a 4 electro-motors, each rated at 355 kW. RPM are controlled and regulated by 4 frequency changers from ABB. Control and monitoring system of the tunnel is realized using SIEMNS technology.
Cooling
Tunnel cooling is provided by an active cooling unit with a maximum power consumption of 330 kW, which corresponds to a maximum cooling performance of 1 000kW. Cooling compressor unit is located outside the tunnel and two pairs of optimized coolers installed in the tunnel design ensures a comfortable temperature in the flight chamber even during very warm summer period. During cold seasons, from the certain threshold temperature, the compressor unit is automatically switched to dry coolers, which maximize utilization of outside cold air and rapidly decrease the power consumption ( up to 30 kW) .