: August 14, 2011: Three months ago, Russia announced that one of its older Delta IV SSBN (nuclear submarine carrying SLBMs) had test fired two of its Sineva SLBMs (Sea Launched Ballistic Missile). Now it’s been revealed that one of those missiles was not a Sineva, but a new design called Liner. Apparently the Liner is a solid fuel missile that will fit into the silos on the Delta boats.

The R-29RM Sineva is the last liquid fuel Russian SLBM in service, and is used in the Delta class SSBNs.  The Cold War era Delta IVs are getting old, and have only about a decade of useful service left. That’s the reason only eight of the twelve Delta IVs are available for service. Two of the new Borei boats are now in service, and its missile tubes are designed to hold the Bulava (which is 12.1 meters long and two meters in diameter.) The 40 ton Sineva is 14.8 meters long and 1.8 meters in diameter. Since little information has been released on the Liner, it’s unclear if it is short enough fit into the Bulava Silo.

SLBMs are one of the few weapons that Russia does not export, thus they tend to be very secretive about these missiles. The Liner appears to have been a long-shot backup design for the troubled Bulava. But now the Bulava appears to have overcome its problems, and the Liner is not needed. Then again, maybe not. It’s also possible that the Liner is an improved version of Sineva, for there was an earlier Sineva design that featured more warhead capacity (which the new Liner is supposed to have). Thus Liner, for the moment, is something of a riddle, wrapped in a mystery, inside an enigma.