|Thikness of the roof||3,5 m|
|Thikness of the walls ||2,4 m|
The 5 pens of K1 are identical. The interior of each is a chamber 71m long, 15m wide and 15m tall. There are two enormous armoured blast doors which seal the 12.5m wide, 11.5 m high entrance. The length of the cradle's tracks is 88m. Each pen is equipped with either one or two travelling bridges used as cranes.
The block was primarily used to store and repair type VII and type IX boats.