"Repeat Job 9" in No. 13 Dry Dock, Portsmouth Dockyard, Hampshire

A submersible structure under construction in No. 13 Dry Dock, Portsmouth Dockyard, taken from the top of the dock off the port bow. The Portsmouth Dockyard negative register refers to this structure as Repeat Job 9 but no details of this experimental vessel have been traced. The structure consists of a part welded, part riveted cylindrical hull, sealed at both ends, with a vertical hatch opening amidships and an angled hatch, possibly representing a torpedo loading hatch, near the bow. Side frames have been fitted amidships, numbering from 10 to 35, and written on the end plate is Ext Tank, possibly indicating external ballast tanks. The sterns of the two submarines Thor and Tiara can be seen in the left foreground. The Portsmouth Dockyard negative register number P50/44 has been written near the bottom left corner of the negative.