A Prediction About the BOREY Class Russian Ballistic Missile Nuclear Submarine (SSBN)
By Bruce Rule - Mar 8, 2014
Emily Lakdawalla, who writes very knowledgeably for the Planetary Society about NASA's planetary programs, published the following on her blog:
"It's an irony that is central to pretty much all of science that you usually have to predict the possibility of something new before you can discover it. For the most part, science is advanced in very small steps by people who master the stuff that we know, and use that mastery to predict something we didn't know before, then go looking for evidence. In that way scientific discovery is an act of creative imagination."
With that perspective in mind (thank you Emily), and based on information in the public domain, the writer makes the following prediction about the new BOREY Class Russian SSBN.
The BOREY has a hybrid propulsion system: turbo-electric (TE) for patrol mode speeds and turbine-reduction (TR) for higher speeds.
During TE operations, a large, propeller-shaft-connected dc motor (5,576 hp) is powered by the rectified output of two 3200 kW Ship's Service Turbo-Generators (SSTGs).
The GTZA OK-9VM main propulsion geared-turbine assembly, declutched from the propeller shaft, is in a stand-by (ready status to use the Russian term) for use in the TR mode if higher speeds are required.
A patrol-mode TE capability with the main propulsion geared-turbine assembly in stand-by would eliminate noise produced by the gear system when reduced noise levels are most critical. (See the writer's posting of 2 Mar 14 entitled: "A Russian Discussion of Submarine Gear Noise" which discusses gear noise produced at low speeds.)
It would also provide a "robust" (up to at least eight knots) emergency battery-powered propulsion capability should nuclear power be lost with the resulting loss of steam to power the main propulsion turbine and the SSTGs. Since the BOREY is the first SSBN built by the Soviet Union/Russia with a single main propulsion power train, it makes sense to provide a back-up capability that, in earlier SSBNs, was provided by the second power train.
The open-source listed value of 5,576 hp for the BOREY motor is an excellent match for the PG-141 extensively discussed in the writer's posting of 8 Mar 14 entitled: "Example of the Soviet/Russian Axiom: 'Better is the Enemy of Good Enough. "