Hydrax

The Hydrax was a human-crewed ship from the 22nd century. It later became a permanent fixture on a planet in E-Space and was known as the Tower.

Technology
The Hydrax was equipped with a complex computer system that had features such as scanners which could present views of a target. They were capable of seeing through surfaces like an x-ray machine. The ship had three scout ships, each with a steel bolt on top. (DW: State of Decay, NA: Lucifer Rising)

Crew
Three of the Hydrax's crew members, Captain Miles Sharkey, Navigation Officer Lauren MacMillan and Science Officer Anthony O'Connor were turned into Vampires by the Great Vampire to prepare for rising. (DW: State of Decay)

History
In 2127, en route to Beta Two in the Perugellis sector, the Hydrax was drawn into a CVE and through into E-space by the King Vampire. He placed it on a planet and went into hiding beneath it.

The Hydrax became a castle as it stood upright for a thousand years and rock built up around it, making it appear it was on a hill. The detached computer system was taken by the rebels. Kalmar managed to get it working and used its scanner function to watch the Hydrax and the surrounding area. The Doctor fired off one of the scout ships and used its descent to impale the king with its steel frontage. The King's death resulted in the death of the former crew, whose lives was dependent on him. (DW: State of Decay)

Design
The Hydrax designs were drawn up by Christine Ruscoe. The original concept showed a greater link between the various sections. Filming for the Hydrax's exterior took place at Mont Saint Michel. This location was chosen by Ruscoe as she believed that it looked like a spaceship. Once this was decided upon, the period design had to be chosen. Ruscoe looked into Romanesque and medieval castles, and features from both found their way into the final design. These designs were intended to be pre-gothic to give a greater feeling of age.

Designs for the interior came from the BBC library. Ruscoe found an already existent piece with a decorative door. This was chosen for the throne room of the Hyrdrax.