Abstract: Apparatus for containing a pressurized fluid jet, for example a "blow-out" of oil, comprises a receptacle of preferably frusto-conical form for holding a body of liquid such as water, and means whereby the jet can enter the receptacle, the arrangement being such that, with the body of liquid in the receptacle, sufficient energy is absorbed by movement of liquid to contain the jet. The energy may be absorbed by creation of vortices, and wall parts of the receptacle, when viewed in side elevation, preferably define an included angle of less than 25.degree.. The apparatus may be used as part of an oil-production installation on an oil-rig.