September 28, 2016

Comparing Borei/Boreys with Ohios & Columbias - SSBN Program 2

Diagram 1. Displacements are submerged.

Diagram 2. Columbia class SSBN-X features.

It is difficult, but not impossible, to compare Boreis/Boreys with Ohios and Columbia class (SSBN-X).

The respective Russian and US SSBN programs are out of phase instead of being of the same generation.
-  Ohios were built 1976-1997 lasting until 2040s.
-  Boreis entered/entering service 2013-2023, lasting until 2050s.
-  Columbias entering service 2031-2050, lasting until 2080s.

Secrecy often makes specifications, like diving depth and submerged speed, ballpark figures rather than actual.

Quietness, discretion and efficiency of combat systems (including sonars, other sensors, databases and weapons), drives and crew quality are also impossible to compare with open sources or even in a technical sense. The will be more about Russian sonar and other equipment makers on September 30, 2016.

The Borei class are built by Sevmash, the largest shipbuilding complex in Russia.

Russia’s SSBN force consists of:

-  3 Boreis with further commissioning exercises and technical upgrades yet to be completed. One
   Borei is deployed in Russia's Northern Fleet and two are in the Pacific Fleet. A fourth Borei is due
   to be commissioned later in 2016.
-  6 Delta IVs (all near end of service life at 26 to 32 years old) and
-  4 Delta IIIs (on extended service life of 34+ years)

At least two Deltas are under long term maintenance at any one time.


SLBM Numbers

Boreis can deploy only 16 SLBMs currently (on the first 4 Borei Is, 64 total), perhaps 20 SLBMS for the 4 to 6 future build Borei IIs in the 2020s (up to 20 total) (64 + 120 = 184 all up). This is less than the 14 Ohio SSBNs, each capable of deploying 24 SLBMs = 336 total.

Variables make precise SLBM counts very uncertain. Numbers of MIRVs per SLBM, empty missile containers, future introduction of 16 SLBM US Columbia (SSBN-X)) class and New START regulations may mean eventual parity at 336 SLBMs each by the 2040s.

Submerged Speed/Noise

According to submerged speed for the Borei may be up to 30 knots (good for fleeing from danger and faster redeployments but noisy). Boreis also have pump jets for relatively quiet operation at 20+ knots. No quieter electric drive known.

Ohios have a quiet standard official figure of 20 knots. Keeping at 20 knots or below may be sensible for Ohios as they were built in the era of no pump jets. Their bare propellers are assumed to be noisy at over 20 knots. No quieter electric drive.

Columbia's are expected to have pump jets and quieter electric drive.


The Borei has two ОК-650 nuclear reactors of a 1970s design and only up to 45% HEU which means 3 or 4 refuels are likely needed (perhaps every 10 years) over a 40 year Borei service life.

The Ohio class's S8G reactor last about 19 years between HEU refueling. See page 3 of Ronald O'Rourke’s Navy Columbia Class (Ohio Replacement) Ballistic Missile Submarine (SSBN[X]) Program: Background and Issues for Congress, of August 18, 2016 CRS 7-5700 R41129

The S1B reactor for the Columbia class does not need HEU refueling. The reactor meant to last the 42 year service life (see page 8

Crew size

Boreis have a smaller crew (probably Blue/Gold exchange system) of 107. Blue/Gold crews for Ohios and in future Columbias are/will be 155. This gives Ohios/Columbias an advantage in reducing crew exhaustion, decreased errors, increased attention, more coverage if crew members become ill, increased resources for damage control/safety.

Diving Depth

Boreis have a listed operational depth of 450m while Ohios are 240m. This may give Boreis a tactical advantage for evasion from SSNs, torpedos and depth bombs, and less chance of detection from the surface. But Boreis are still vulnerable to seafloor sensors and bottom rising mines. As Borei's main goal is being effective SSBNs their deep diving ability will be of little help to place them just below the surface to launch their SLBMs.

Protection of SSBNs

Russia has far weaker air and naval forces overall including: 9 mainly older Akula SSNs, 1 modern Yasen SSN, 5 Oscar class SSGNs (not specifically built to defend SSBNs) and 26 Kilo SSKs (probably too slow, and noisy when snorting, to guard SSBNs).

The US Navy has far larger naval and air forces to defend its SSBN force, including (at March 8, 2016) 55 high quality SSNs,


There has been a sharp drop in Russian SSBN deterrent patrols since the fall of the Soviet Union around 1991. Patrols by selected year have dropped from:

1984       102
2002           0
2008         10
2011           5
2015           5

The 14 US Ohios might each average about 2.5 patrols to 3 patrols a year. Hence about 35 to 42 patrols per year total for the force. 

Columbias are expected to have a higher number of patrols over their service lives due to less overhaul/refueling periods. For the 12 Columbias this may also average a total of 35 to 42 patrols.

These are just a few imprecise types of comparison.

Pete and Anonymous


Josh said...


And important attribute of the S8G fitted to Ohios is that it is a natural circulation reactor (at least at low power), relatively revolutionary at the time. The core is placed low and the heat exchanger placed high in the primary coolant loop such that the hot coolant rises to the exchanger then falls back down the other side of the loop once cooled off without the use of a pump. This eliminates an entire type of noise from plant, at the cost of size and weight apparently. The wider hull of a boomer makes this more practical to do in an SSBN than an SSN. Its not clear if the practice carried through to the Seawolf or Virginia's reactors; in might well not have been for size reasons or because more cost effective means of quieting coolant pumps became available (turbopumps, electrical systems that remove the 'snap' noise of pump engagement, etc).

Its also worth noting that any SSBN would spend its patrol at 5knts unless it was fired upon. The pump jet arrangement would only be advantageous getting to station. The Russians likely have much more reason to worry about being tracked during transit than the Americans due to their base geography and possibility of USN SSNs off their SSBN bases at any given moment. The USN keeps boats deployed off Russian coasts at much more often than the reverse case, even during the cold war. I suspect its quite the rarity for an Akula to appear off Maine or Washington these days.


Josh said...


Also worth noting that the USN doesn't escort its boomers on patrols. The Russians used to set up bastions to defend theirs; not sure what their current practice is.


Ztev Konrad said...

Regarding the reactors for the Borei class, normal Russian practice was to use two for its later ballistic missile submarines ( Yankee, Deltas I -IV) with two shafts. In Norman Polmars excellent book , Cold War Submarines, he indicates that the Borei class would have two OKB 650B reactors with a single shaft, I think the assumption is that with a single propeller it has the same single reactor as smaller displacement Akula etc.

Anonymous said...

Hi Pete

At the launching of SLBM, the launching order of SLBM must be adequately communicate to SSBN in the sea water. However, communication with submarines is difficult because radio waves do not travel well through good electrical conductors like salt water. The short frequency waves rapidly decay with increase in depth [1].

Electromagnetic waves in the ELF (3–300Hz) and VLF frequency ranges (3–30Hz) can penetrate seawater to depths of hundreds of meters, allowing communication with submarines at their operating depths. These ELF and VLF systems need huge horizontal grounded antennas (ex 60km long). The Russian ELF (82Hz) transmitter, “Zevs” exists at the base at Arrival Height in Antarctic (78°S 167°W) [2]. Moscow’s SLBM launching order will be communicate to SSBN via Zevs.



Pete said...

Hi Ztev

Yes, I think you're right.

An 8,000 t Akula needs one OK-650 reactor to drive it just over 30 knots

so a 24,000 t (submerged) Borei would need at least two OK-650 reactors to also drive it at 30 knots.

Also indicates that 19,000 t (submerged) Oscars have two OK-650 reactors.

I'll change text accordingly.



Pete said...

Hi S [at 29/9/16 1:16 PM]

[1] particularly interested me when it said:

"Apparently, both the American (SOSUS) and the Russian Navy have placed sonic communication equipment in the seabed of areas frequently traveled by their submarines and connected it by underwater communications cables to their land stations. If a submarine hides near such a device, it can stay in contact with its headquarters. An underwater telephone sometimes called Gertrude is also used to communicate with submersibles."

It sounds like Gertrude may have been a viable two-way means of communication permitting the submarine to talk to base?

But I'm assuming "Gertrude" technology is not used anymore? Because it is insecure?



Pete said...

Hi Josh

Thanks for your comments at 29/9/16 12:23 AM and 29/9/16 5:57 AM.

I'll integrate them into the text tomorrow.

The S8G non-moving parts heat exchanger method is interesting. As well as having electric drive in the overall powerplant I wonder if the heat exchanger aspect will be carried over to the Columbia's S1B reactor ?



Josh said...


"Gertrude" is old tech and involves acoustic signals. Typically it would be something used between boats or between a boat and the ships it was working with for ASW, like in a CVBG. I believe it was an analog arrangement and the modern equiv would be acoustical modem as in SeaWeb. It would have the liability of being an active acoustic signal.

This is NOT how a missile boat would be ordered to launch; in the USN I believe that would be by ELF/VLF* signal to get orders via satellite (as far as my chairborn knowledge goes). The US retired its ELF site, so this would fall on E-6 TACAMO aircraft (which have also taken over the 'Looking Glass' role at this point) to trail a long VLF wire to signal a sub. Depending on the patrol area I assume acoustical calls could also be made if infrastructure was available but I suspect those would still be prompts to initiate SATCOMs and not direct fire orders, which I suspect would come from MILSTAR. Russians I assume are similar?**

*Both of those methods of communication involve VERY low bandwidth such that only a few characters could be sent, and not reliably, and no acknowledgement can be sent by the sub via the same freq: it would have to go to periscope and communicate on some other wavelength.

**In the case of the RN, I believe their boats as a last resort are/were told to listen for the BBC global broadcast at peri depth, and if it was not on the air and no other communication was forthcoming, assume that the worst had happened and there was no British government to give them orders. At that point the captain was to open a safe with a letter directly from the standing Prime Minster that gave instructions for how to Stay Calm And Carry On. Which could mean a counter strike on Moscow or just contacting the USN and working for them; no RN letters have ever been revealed.


Anonymous said...

Hi Pete

The underwater telephone also known as UQC, AN/WQC-2, or Gertrude was developed by the U.S. Navy in 1945. The UQC underwater telephone is used on all manned submersibles and many Naval surface ships in operation. Voice or an audio tone (morse code) communicated through the UQC are heterodyned to a high pitch for acoustic transmission through water [1].

WQC-2of US Navy directly produces a sound in the sea water by speaker with power of 200W and talking range of 20,000 yards [2].

Though use of underwater telephone obviously results in significant loss of stealth of submarine, it is used for Virginia and Seawolf as shown in pictures of [2] and for Soryu submarine, because it is most reliable underwater communication method.

(ITT, Model 5400 Underwater Telephone, Underwater Communications)


Ztev Konrad said...

The appearance of shrouded propellor designs for missile submarines ( which some say dont need them unless its for the higher speeds ) indicates specific design for a slower moving and quieter variation for ballistic and even diesel electric ( RAN) submarines.
And interesting story about US submarine propellers history

Anonymous said...

Hi Pete

RSM-56 Bulava launched from Borei-Class, Yuri Dolgoruky has exploded yesterday.


Ztev Konrad said...

Further from my eelier link from the Smithsonian about US submarine propeller exhibit, there was a good link which deserves highlighting

What is known about the character of noise created by submarines?
the fascinating detail is at this sort of level (on a Russian submarine)-
'according to specialists' testimony, improving the tolerance for the size of a tooth gear on the submarine's main turbine gear assembly (GTZA) by 0.1 to 0.01 mm permitted a reduction of the submarine's SL by 3-4 orders of magnitude (30-40 dB)'

and this
'Discrete lines in the 0.1-10 Hz band are caused by rotation of the propellers. This noise is difficult to suppress. Moreover, the noise from the propeller may be heard in the ocean at a distance of up to several thousand kilometers since absorption by ocean waters at this low frequency is negligible.'

'The most characteristic line in the SL spectrum is the peak at frequencies of 50 and 60 Hz for Russian and American submarines respectively, i.e., the lines which correspond to the basic frequencies of the submarines electric generators.'

Pete said...

Hi Everyone

I need to delay specific replies to your comments for a few days while I write about the Australian Government's two big submarine announcements (Combat System Integrator and (separatly) signing a Contract With DCNS) today.



Josh said...

@Ztev Konrad

I suspect at this point the 50/60Hz lines are suppressed by active noise cancellation now adays. Active cancellation works best when it can employed against a known frequency and the turbine generators precise frequency would be a natural fit to that tech.

I wonder however to what degree shrouded propulsors suprress propeller noise? I think their primary role is cavitation supression but they might fulfill some role in the 0.1-10Hz band.


Anonymous said...


You mentioned that a larger crew provides lower workload/redundancy/damage control etc. It also provides higher cost. One key variable here is degree of automation.

Certain sites claim that some Russian designs have tried for higher automation (especially due to the difficulty they have in staffing, training and their need for permanent officers for sonar etc)


Pete said...

Kyle Mizokami has written a fine article in The National Interest, "Russia's Typhoon-Class Submarines Had Enough Nuclear Firepower to Kill Entire Countries" of 11 Nov 2016,
[Pete has used the term "Typhoon" rather than "Akula" because Russia currently operates Akula SSNs]

"...The [Typhoon] or Project 941 as it was known during development, was designed to form the basis of the Soviet Union’s nuclear deterrent forces at sea. The Soviet Union had gotten wind of the U.S. Navy’s impending Ohio-class fleet ballistic-missile submarines, which would be 564 feet long and pack 192 nuclear warheads. The Soviet leadership decided it needed a submarine of its own to respond to the looming threat, and the [Typhoon] class was born.

The [Typhoons] were designed to launch their missiles from relatively close to the Soviet Union, allowing them to operate north of the Arctic Circle, where Soviet air and naval forces could protect them. As a result the submarines were designed with a reinforced hull that was capable of breaking through polar ice, a large reserve buoyancy to help it surface through ice and a pair of shielded propellers to protect them from collisions with ice...."

GClarkII said...

Yes I know it's old.
Someone mentioned about the possibility of tracking older subs due to the intrinsic noise of their props.

Trying to track any submarine, let alone an Ohio class by simple propeller noise in the 0.1 to 10 Hz band is effectively impossible. This is due to the multitude of other noise sources in this range. Some of which are going to be a much larger signal.
A couple of sources of noise in this range include:
*** Ice noise(grinding and breaking of ice) high intensity and easily detected 1000's of kilometers away. Both Arctic and Antarctic.
*** Seismic activity -- More local, but can be of high intensity
*** Whale calls -- Fin whales especially.
*** Surface ships -- These will be generating identical signals(think about it). These things will be pumping out the same noise as a prop driven sub, but at much greater levels.
There are others, see Sounds in the Ocean at 1 - 100 Hz for more information.

What all this means is that your NOT going to track any submarine by virtue of the intrinsic noise generated by a propeller down the weeds(i.e. 0.1 to 10 Hz). It's going to be washed out by everything else. And this is not even taking in to consideration how those acoustic signals are effected by everything from the thermocline to local salinity levels.

Pete said...

Hi GClarkII [your Sep 15, 2021 comment]

Thanks for your comment on sub sonar performance.

I would have thought the most well financed sonar suites would (with massive oceanic surveying super computer "dictionary" foundations)

be able to filter out ice noise, seismic activity noise, marine animal and surface ship noise.

Even filtering out frindly or non-target submarine sounds should be software/hardware possible?

Propeller noise is only one variable. Hydrodynamic hull noise, speed, "doppler effect?" etc might be additional variables considered by a sonar suite, broader combat system, and human judgement all working together?



GClarkII said...


First off, that appendix is not really of much value, some of the assumptions it made really don't hold up. The paragraph in question is an example:
Discrete lines in the 0.1-10 Hz band are caused by rotation of the propellers. This noise is difficult to suppress. Moreover, the noise from the propeller may be heard in the ocean at a distance of up to several thousand kilometers since absorption by ocean waters at this low frequency is negligible. The method of narrow-band filtration of the spectrum's discrete line at frequencies up to several Hz is the basic working principle for sonar systems for long-distance detection.
I'm a ET/EE not a sonar tech of any type, but there are problems here. For that prop to generate that 10 Hz signal would mean that it's rotating TEN TIMES A SECOND, or SIX HUNDERED TIMES A MINUTE! Sure, you might get 10 Hz harmonics from a lessor speed, but they are going to MUCH MUCH lower in magnitude, to say the least. The same applies to lower freq.

I would have thought the most well financed sonar suites would (with massive oceanic surveying super computer "dictionary" foundations) be able to filter out ice noise, seismic activity noise, marine animal and surface ship noise

The biggest problem your going to encounter with trying to filter out those other sources is the simple fact they are of a greater magnitude than the signals your trying to track. That sub prop, unless it's cavitating(at which point your going to have NO problem tracking it), is going to be one of the most quite sounds out there.

Another problem, and the reason why a "dictionary" is not going to be of much help here, is the fact that all of those sources are more or less of a random nature. Meaning that they are going to be hitting your sensors from various directions and times.

And that surface ship propeller noise is really going to be the killer. They are going to be generating more or less identical noise. There are also going to be a lot more of them. Trying to tell the difference between a single screw surface ship with a single screw submarine that is at let's say 100 feet is going to be almost impossible if they are both making identical turns. Sure for the most part surface ships are making more turns and most likely cavitating to boot, but if your trying to track that sub from long distances, well...

I'm a ET/EE by trade. The problem here is of the same type that noise in op-amps is. There is only a certain level that you can go to, before the other noise in the system makes it futile.

Hydrodynamic hull noise, speed, "doppler effect?" etc might be additional variables considered by a sonar suite, broader combat system, and human judgement all working together? Sure hull noise and speed are going to be other variables. I'm not exactly sure what you mean by "doppler effect" here. I know what it is, but I don't see how it could have any effect on tracking. If a signal source crosses a sensor, sure, but that is going to be more due to the fact that the signal source first came closer to that sensor.


GizUSN said...

Blade Rate (BR) = Prop Shaft Rate (PSR) x number of blades. No comment on what is in or out of band. Just sharing the correct math.