Abstract: A disaster prevention apparatus is adapted to intercept and disperse gas leaking from a disaster ship offshore. The apparatus includes a marine mover and a water curtain forming device for forming a water curtain on the lee of the disaster ship. Pressurized water is supplied to the water curtain forming device by a water pump. The water thusly supplied is ejected from the water curtain forming device in a direction substantially perpendicular to the water surface, thereby creating a water curtain on the water.

Abstract: A method of controlling the position of an on-water water curtain device for building a water curtain on the water in order to stop or disperse dangerous gas leaking from a ship or to block flame and radiant heat due to the leaking gas. The method comprises the steps of detecting positions of the ship and the water curtain device, detecting wind direction and tidal current, and adjusting the position of the water curtain device to an optimal position in accordance with detected values so as to maintain the diaster prevention water curtain substantially perpendicular to the leaking gas.

Abstract: A screen forming apparatus and method comprises a long pipe of predetermined length floatable in the water, a pump for conveying the water through the pipe, a pipe connecting the pipe with the pump, an air-water device provided with the pipe for mixing the water with air, a number of nozzles disposed along the longitudinal direction of the pipe at predetermined intervals for injecting the water in the form of screen, and a device for producing air curtains flowing along the front and the rear surfaces of the screen in order to maintain the screen substantially uniform in thickness.

Abstract: A screen forming apparatus and method comprises a long pipe of predetermined length floatable in the water, a pump for conveying the water through the pipe, a pipe connecting the pipe with the pump, an air-water device provided with the pipe for mixing the water with air, a number of nozzles disposed along the longitudinal direction of the pipe at predetermined intervals for injecting the water in the form of screen, and a device for producing air curtains flowing along the front and the rear surfaces of the screen in order to maintain the screen substantially uniform in thickness.