Abstract: The improvement in a control circuit for the operation of pneumatically propelled vehicles consists of a propulsion duct formed by a guideway (1) and power propulsion units (3) with flow control valves (4) located at intervals along the guideway (1). Atmospheric valves (2) are located at specific points along the guideway (1), opening and closing the duct to the atmosphere, and the section isolation valves (6) are positioned in such a way as to isolate adjacent blocks of the guideway (1) and at the same time to maintain the functioning of the propulsion circuit in the other blocks. A secondary duct (7) can be provided to allow a propulsion unit installed at a vehicle station to propel a vehicle which is stopped at the station.

Abstract: The improvement in a control circuit for the operation of pneumatically propelled vehicles consists of a propulsion duct formed by a guideway (1) and power propulsion units (3) with flow control valves (4) located at intervals along the guideway (1). Atmospheric valves (2) are located at specific points along the guideway (1), opening and closing the duct to the atmosphere, and the section isolation valves (6) are positioned in such a way as to isolate adjacent blocks of the guideway (1) and at the same time to maintain the functioning of the propulsion circuit in the other blocks. The atmospheric valve (2) is coupled to an aperture (11) in the guideway (1) and consists of a butterfly valve.

Abstract: An improved system for sealing a slot (37) in the guideway (13) of a pneumatic transportation system includes two separate pairs of sealing flaps for producing two separate opposed seal interfaces (47, 49) through which a travelling pylon (18) connecting a propulsion plate (17) to a vehicle (15) on the guideway can pass. A first pair of sealing flaps (43a, 43b) provides a negative pressure seal and a second pair of sealing flaps (49a, 49b) provides a positive pressure seal. The sealing flaps contact the travelling pylons along their distal ends only, so as to produce minimum deflection of the seal and minimum mechanical resistance against the pylon. The slot seal system of the invention is relatively easy to install from outside the vehicle guideway and produces no cavities in the top of the guideway in which moisture and debris can accumulate.