How does a Marine gearbox work?, PRM DELTA 20

Here I try to share the wonder of modern finesse that is the PRM hydraulically actuated boxes. This is the small delta 20 but the principle is the same with many gearboxes that use hydraulic force. Any advice or suggestions here are taken at your own risk, no liability for your own actions can be taken. If in doubt seek professional advice either with us directly or independently. Thank you.