A hydraulic device having: - a motor, which is arranged in a motor housing, - a compensating tank for accommodating hydraulic fluid, - a hydraulic pump, which is arranged in a pump housing and is driven by the motor, - an actuator to be hydraulically controlled or actuated, - wherein the hydraulic pump is designed such that it allows hydraulic fluid to be delivered in two directions, namely in the forward and rearward directions, wherein - the hydraulic actuator comprises a drive cylinder with a first and a second cylinder chamber and a drive piston, which is arranged between said chambers and to which is fitted a longitudinally displaceable drive axle, characterized in that - the device comprises a bracing cylinder for an emergency closing spring, - the bracing cylinder has arranged in it a bracing-cylinder chamber and a bracing piston, which can be coupled to the drive axle, - wherein the bracing piston can brace the emergency closing spring in a bracing or emergency triggering standby position, - wherein the bracing-cylinder chamber is connected to an outlet of the hydraulic pump such that, as a result of the hydraulic pressure of the hydraulic pump, the bracing-cylinder chamber can be filled with hydraulic fluid, and the bracing piston upon compression of the emergency closing spring can be transferred into a bracing position and can be locked there hydraulically by check valves (36, 37), - and wherein a controlled seat valve is connected to an inflow/outflow opening of the bracing-cylinder chamber, - said seat valve being capable of transferring the emergency closing spring from the braced standby position into an emergency triggering open position, wherein it is possible both for hydraulic fluid which keeps the emergency closing spring in the standby position, and is located in the bracing-cylinder chamber, and for the hydraulic fluid which is located in the first cylinder chamber to be discharged via the controlled seat valve. - a motor, which is arranged in a motor housing, - a compensating tank for accommodating hydraulic fluid, - a hydraulic pump, which is arranged in a pump housing and is driven by the motor, - an actuator to be hydraulically controlled or actuated, - wherein the hydraulic pump is designed such that it allows hydraulic fluid to be delivered in two directions, namely in the forward and rearward directions, wherein - the hydraulic actuator comprises a drive cylinder with a first and a second cylinder chamber and a drive piston, which is arranged between said chambers and to which is fitted a longitudinally displaceable drive axle, characterized in that - the device comprises a bracing cylinder for an emergency closing spring, - the bracing cylinder has arranged in it a bracing-cylinder chamber and a bracing piston, which can be coupled to the drive axle, - wherein the bracing piston can brace the emergency closing spring in a bracing or emergency triggering standby position, - wherein the bracing-cylinder chamber is connected to an outlet of the hydraulic pump such that, as a result of the hydraulic pressure of the hydraulic pump, the bracing-cylinder chamber can be filled with hydraulic fluid, and the bracing piston upon compression of the emergency closing spring can be transferred into a bracing position and can be locked there hydraulically by check valves (36, 37), - and wherein a controlled seat valve is connected to an inflow/outflow opening of the bracing-cylinder chamber, - said seat valve being capable of transferring the emergency closing spring from the braced standby position into an emergency triggering open position,