him. The commander was provided with a periscope and a clear acrylic dome for navigational purposes. On 18 January 1944, Dönitz discussed the new design with Adolf Hitler who expressed his approval, and on 9 March contracts were placed with Germaniawerft of Kiel for construction of a prototype, followed by a further contract for 52 submarines on 28 March. The 53 Hechts were constructed between May and August 1944: in the event, none saw active service but were instead used to train Seehund crews. Type XXVIIB As the orders were being placed, Hecht variants were under construction. The first was the Type XXVIIB, which had a greater range, could carry two G7e torpedoes, and had diesel/electric propulsion. The design was completed at the end of June 1944 and resembled Hecht but had a better boat-shaped external casing for improved seakeeping while surfaced, and saddle tanks. Additional room had been made inside the pressure hull by moving the batteries to the keel, while the two torpedoes were mounted externally in recesses in the lower hull. A diesel engine was fitted for surface use and was estimated to give a surfaced speed of , with a electric motor providing a submerged speed of . The final variant of the Type XXVII was the Type XXVIIB5, better known as the Seehund ("Seal") or Type 27. Seehund had a small sail midships with the air-intake mast, magnetic compass, periscope, and a clear dome which could survive depths of . The submarine's fixed periscope incorporated lenses which let the commander check the sky above for aircraft before surfacing. Production The first contract for Seehund construction was placed on 30 July 1944, before the design was completed. A total of 1,000 boats were ordered, of which Germaniawerft and Schichau-Werke were to build 25 and 45 boats per month respectively. Other shipyards that were intended to participate in Seehund production were Cantieri Riuniti dell'Adriatico at Monfalcone, Italy, and Klöckner-Humboldt-Deutz at Ulm. However, Dönitz would not consent to the production of the Type XXIII submarine being held up for Seehund construction, while shortages of raw material, labor and transport problems, and conflicting priorities in Germany's economy all combined to reduce Seehund production. In the end Seehund production was undertaken by Germaniawerft at Kiel in the Konrad bunker which was no longer needed for production of Type XXI or Type XXIII submarines. A total of 285 Seehunds were constructed