X-1: The Royal Navy’s Mystery Submarine

X.1: The Royal Navy’s Mystery Submarine grabs a reader’s attention from the start. The title indicates a dramatic read full of suspense and intrigue, but the book provides more with the truth about the often misrepresented boat. Branfill-Cook, a retired insurance writer and current translator of French books on historical and military subjects, seeks to clarify historical misinformation about X.1 and bring the story of the initially hidden, often ignored, and certainly ill-fated submarine to light.

To achieve this goal, the author delivers twelve chapters and three appendices. The first chapter provides a history of giant submarines that influenced X.1’s design and armament. These submarines range from early twentieth- century German-built Russian-owned versions to German U-boats that the British captured during World War I. Although the author is thorough in his discussion of the submarines, prior familiarization with the historical circumstances occurring in this period would be beneficial and make the reading experience more pleasurable for the reader.

Chapters two through six explore the design plans, armament, equipment and construction of X.1. These five chapters include many plan drawings and renderings of the interior of the boat. Each portion of the boat is discussed, and the reader gains an extensive knowledge of X.1 from the keel to the exterior paint schemes., At no point would these be considered easy reading, but the chapters are integral to a full understanding of X.1.

Life aboard ship, trials, excursions and exercises fill the next five chapters. This is the section of the book that explores the intrigue and human element of X.1. The “secret” boat was announced by a newspaper at its launch, causing political upheaval. The unrest continued when copies of X.1’s design plans were found in the possession of a foreign spy. Not all of the stories are dramatic, and it is easy and enjoyable to be drawn into the stories of everyday life for the crew. 

The concluding chapter is Branfill-Cook’s interpretation and opinion regarding the life and eventual perceived failure of X.1. The author successfully brings together the prior eleven chapters to support his arguments. The reasons for the unfulfilled potential of X.1 and its tragic end are explored and possible explanations discussed. In the following appendices, the author provides extracts from X.1’s log book, copies of the plans and a comparison of gun types used on the boat.

Although a reader might be overwhelmed by the technical jargon of this book, any avid student of submarine or Royal Navy history would find themselves in familiar territory. The lack of in-text citation leaves the researcher with difficulties if trying to verify primary sources, but the author does provide a one-page bibliography and notes about specific details. The singular focus of the book allows for a range of subjects from exhaustive documentation of technical details to personal stories of life aboard X.1. Branfill-Cook successfully uses this focus to put to rest some of the myths surrounding X.1 and replace them with the true tale of “the Royal Navy’s mystery submarine.” 

Reviewed by Julie A. Powell, East Carolina University