It is mentioned in the book “Cold War Submarines” (Polmar & Moore, 2004) that in 1990, Russians tried to fit a pump-jet of 5,500 hp to one of the Kilos of Black Sea fleet, with the designation 877V. No further information is given in the book besides that the Kilo did not return to sea until 2000. Anyone has heard of this story before ? It seems to me that the Russians are not very enthusiastic about pump-jets, otherwise how do you explain that not a single Russian submarine has pump-jet ? Or the pump-jet propulsion system is really this hard to develop (I know the Typhoon class has shrouded propellors for arctic ice-breaking operations, but they are not real pump-jets) ?
Also, the Amur class seems no longer has the two small internal auxiliary propellors like those in the Kilo class. I am wondering if this is a good decision ?
By: Woodie - 2nd December 2006 at 06:36
The Russians appreciate the design advantages of pump jet propulsors. The same math and physics work in both the former east as well as the west. Pump jets are indeed heavier, but so much quieter. The big advantage pump jets offer is providing the submarine with a higher tactical ‘silent speed’. A conventional propeller submarine may have a silent speed of 7 to 9 knots, the pump jet submarine much higher – speculating in the ‘teen’ speeds or more. On the new American Seawolf, the British Trafalgar and Swifture SSN’s – the reactor power plant cooling circulation pumps, a potential source of radiated noise can be switched off. Water sea suction intakes in the leading edges of the horizontal sternplanes on the SSN’s then can provide cooling circulation by the forward motion of the vessel through the water.
Pump jets are very impractical on diesel conventional powered submarines. The added weight and cost is worthless if the batteries (or even present day fuel cells) of a conventional powered submarine cannot sustain those higher silent speeds a pump jet could exploit for very long. Nuclear power you can sustain those speeds for literally years. This is why you see pump jets only on nuclear powered combatants, and if ever on diesel submarines at all, it is for experimental tests of short duration runs only. Hence the Kilo test boat – 877V project design.
All pump jet submarines also have little reversing backing power astern too. Usually tugs for docking are manditory. But the operational advantages of the lamp shade on the stern seem to out weigh this.
The new generation Russian ballistic missile submarines of the Borei class (officially designated Project 935). Builders Models of these submarines show a Russian pump jet design. These new submarines have been named: Yury Dolgoruky, Alexander Nevsky, and Vladimir Monomakh. The Russian planned contingent is for 10 strategic submarines expected to be commissioned within the next decade (5 will be project 935, and 5 will be a more advanced project 955 in service by 2015.
Model of Yury Dolgorruky below.
http://upload4.postimage.org/1165683/photo_hosting.html
http://upload4.postimage.org/1165676/photo_hosting.html
Woodie
By: sealion - 8th July 2004 at 02:08
Thanks for the link. As Trident mentioned, pump-jet can be quite heavy and bulky, especially on a disesel-electric submarine.
By: Klingsor - 7th July 2004 at 11:09
Here is a picture of the project 877V boat (B-871):
http://submarine.id.ru/galery/t269.shtml
note the control planes mounted on the pumpjet shroud, unlike western designs
AFAIK there is no confirmation one way or the other if project 885
(Yasen, Severodvinsk, Graney, or what the hell it is called!) makes use
of this technology (“artist” models and drawings show a conventional propeller,
but it is questionable how accurate they are) or if later boats of
that calss will use it.
By: Arabella-Cox - 6th July 2004 at 23:01
Pump jets come with a significant weight increase, AFAIK. No idea why exactly they chose not to field such a system (or indeed if they did choose rather than being forced to abandon it due to financial difficulties) or if this drawback can be considered to be large enough vs. the decrease in noise signature to discard the technology.
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July 6, 2004 at 9:32 pm