Archive access limits Russian warship history

Why is so little known about some Russian warship classes?

Probably because few historians gained access before Russian archives became harder to use again, and fewer still were naval specialists looking for those records.

Limited archive access probably helps explain why some Russian warship designs remain poorly documented. The period of greater access ended before many naval historians could use it. Of the historians who did work in those collections, few were pursuing this particular naval information. This is a proposed explanation for the gap, rather than confirmation that no relevant records survive.