The first three boats of the class were financed by Denmark.

U-30 was also the only boat of the class to be lost during the war.

Three boats of the class were lost in action.

U-11 was laid down on 11 February 1914, the final boat of the class begun.

Of the three boats of the class, only U-5 survived the war intact.

All four boats of the class quickly became obsolete, and before 1900 had fallen out of use.

The Navy ordered the first six boats of the class on 12 October 1915.

There is a single boat of the class, the Sarov itself.

Nevertheless 14 more boats of the class were ordered on 29 June 1918 for delivery in 1919.

It also appears that the boats of the middle class rose on the high tide of the 1980's.