A confirmation that China is currently developing X-tail rudders for submarines. Images below show a procurement document from the
China Ship Design & Research Center (a.k.a. 701 Institute). The document asks manufacturers to submit bids for a set of 55kN-m electro-hydraulic steering gear (with
), to be used to actuate X-shaped stern rudders. The steering gear must be able to deflect all four rubbers at the same time up to 35 degrees to either side (i.e. 70 degrees total). The steering gear must weigh ≤1350kg.