A self-closing gate for an electrified enclosure consists of an electrically conductive barrier (2) for closing a gateway in the enclosure, and a hinge (1) to which the barrier (2) is connected which allows the gate to open and close when a vehicle pushes past the barrier (2), the hinge (1) consisting of a first tube (4) connected to the barrier (2) and a second tube (3) telescopically engaged with the first tube (4) and for securing the hinge (1) to a rigid object, the first and second tubes (3, 4) further including cam surfaces (8) whereby rotation of the tubes (3, 4) relative to each other when the barrier (2) is opened and closed causes the first tube (4) to rise and fall axially of the second tube (3), a tension spring (11) within the tubes (3, 4) serving to urge said cam surfaces into engagement and close the gate.
