A subsurface safety valve comprising an assembly configured to convert rotary motion from an electrically controlled drive into linear motion of a member, the member configured to compress an elastic member, the assembly comprising a gear assembly comprising: a worm drive comprising a worm screw configured to be rotated by the drive and a worm gear associated with the worm screw, the worm gear configured to be rotated by the worm screw; a one-way clutch configured to allow drive and torque in one rotary direction and configured to freewheel in the other opposition rotary direction, the one-way clutch comprising a sprag clutch within a spur gear; and a retention mechanism comprising a ratchet configured to maintain the elastic member in a compressed state after linear motion of the member stops, the member comprising an elongate member comprising: a shaft having a toothed portion; and a flow tube connected to the shaft and configured to transfer linear motion of the shaft to actuate a valve, wherein the electrically controlled drive is configured to, upon receiving a signal to rotate the gear assembly, provide power to the drive to rotate the worm screw which is transferred to the worm gear via meshing of a threaded portion of the worm screw and teeth of the worm gear such that rotation of the worm screw results in rotation of the spur gear which is connected to the same axis as the worm gear, teeth of the spur gear meshing with the toothed portion of the shaft to cause linear motion of the shaft to actuate the valve via the flow tube and to compress an elastic member, and wherein the elastic member is ratcheted by the ratchet to maintain a compressed state after the linear motion of the shaft stops. a worm drive comprising a worm screw configured to be rotated by the drive and a worm gear associated with the worm screw, the worm gear configured to be rotated by the worm screw; a one-way clutch configured to allow drive and torque in one rotary direction and configured to freewheel in the other opposition rotary direction, the one-way clutch comprising a sprag clutch within a spur gear; and a retention mechanism comprising a ratchet configured to maintain the elastic member in a compressed state after linear motion of the member stops, the member comprising an elongate member comprising: a shaft having a toothed portion; and a flow tube connected to the shaft and configured to transfer linear motion of the shaft to actuate a valve, a shaft having a toothed portion; and a flow tube connected to the shaft and configured to transfer linear motion of the shaft to actuate a valve, wherein the electrically controlled drive is configured to, upon receiving a signal to rotate the gear assembly, provide power to the drive to rotate the worm screw which is transferred to the worm gear via meshing of a threaded portion of the worm screw and teeth of the worm gear such that rotation of the worm screw results in rotation of the spur gear which is connected to the same axis as the worm gear, teeth of the spur gear meshing with the toothed portion of the shaft to cause linear motion of the shaft to actuate the valve via the flow tube and to compress an elastic member, and wherein the elastic member is ratcheted by the ratchet to maintain a compressed state after the linear motion of the shaft stops.