g, commutation and variable speed, and less impact on the ship's power plant; inertia, high precision position control; force and torque of the output can be large, but the line speed and the speed can be very low, very small size and weight; wide speed range. Therefore, the hydraulic drive is now widely used in all types of vessels. The issue is China's first aircraft carrier, the hydraulic design of the boarding ladder. Springboard (boarding ladder) is mainly used for warships to the pier and weight limit supplies through or migrate. The boarding ladder system to the electric can also be manually manually by hand pump, the use of the hand pump is designed to prevent the boarding ladder in case of power failure can not be used.Р Keywords: boarding ladder; hydraulic transmission; hand pump