Abstract: A helical field device that accelerates an object to high velocity by converting rotational kinetic energy in the device into linear kinetic energy in the object, and alternatively, that decelerates objects from high velocity by converting the linear kinetic energy in the object into rotational kinetic energy in the device. The device transfers kinetic energy between the device and an object through the use of a localized high pressure field in the form of a helix having a variable pitch along the length of the device, which couples the object to the device without the pressure field itself significantly contributing energy into the system. Instead, the energy that is used to accelerate the object comes from the kinetic energy imparted to the device by an outside source, such as an engine, or a potential energy storage device.