---
title: "Veteran Sonarman Explains Why Pump-jets Are Superior To Props On Modern Submarines"
description: "The propeller is increasingly giving way to the more complex pump-jet propulsor on larger submarines. Here's why."
date: "2020-01-03"
modified: "2020-01-03"
authors:
  - name: "Tyler Rogoway"
    job_title: "Editor-in-Chief"
    link: "https://www.twz.com/authors/tyler-rogoway"
url: "https://www.twz.com/31708/veteran-sonarman-explains-why-pump-jets-are-superior-to-props-on-modern-submarines"
categories:
  - "Sea"
  - "Submarines"
tags:
  - "Borei"
  - "Explainer"
  - "Jive Turkey"
  - "Prop"
  - "Propeller"
  - "Propulsor"
  - "Pump-Jet"
  - "sonar"
  - "Submarine"
  - "Submarine prop"
---

# Veteran Sonarman Explains Why Pump-jets Are Superior To Props On Modern Submarines

![](<https://www.twz.com/wp-content/uploads/images-by-url-twz/content/2020/01/werw.jpg>)
*www.twz.com*

Our good friend and highly experienced sonarman, Jive Turkey, continues to run one of the [most interesting YouTube channels](<https://www.youtube.com/channel/UC9bMgCQyFNaMPsK9GtzM5dQ>) for anyone who is fascinated with the art of undersea warfare. A year ago, we [featured an interview with Jive](<https://www.twz.com/24638/retired-submariner-turned-gamer-gives-amazing-video-explainers-on-sub-tactics-and-tech>) and posted some of the incredible "whiteboard" explainer videos he produces on everything submarines. Just last summer, he filled us in on the [unique danger fire poses](<https://www.twz.com/28852/retired-u-s-navy-submariners-detail-why-fire-is-so-deadly-aboard-a-submarine>) to submariners and has lent his expertise to us even on some of the more ["exotic" underwater issues](<https://www.twz.com/25784/what-u-s-submariners-actually-say-about-detection-of-so-called-unidentified-submerged-objects>). Now he has posted a fascinating explainer of the differences between propellers and pump-jet propulsors used for propulsion on submarines and how detecting them on sonar differs, as well.

Propellers and pump-jets are among the most important and sometimes sensitive components of a submarine class. The highly intricate design art that gives birth to these systems balances efficiency and speed, and even weight, against acoustic signature. It's a fascinating mix of material science, mechanical engineering, and hydrodynamics.

Elaborate propeller configurations, some of which include unique vortex diffusers that you can [read all about here](<https://www.twz.com/26281/german-type-212-sub-has-this-propeller-boss-vortex-diffuser-to-reduce-its-acoustic-signature>), are still commonplace on many submarines, but the pump-jet, with its unique advantages, has become increasingly in demand on larger submarines. Most importantly, they allow for higher speeds without [noisy cavitation](<https://www.twz.com/26281/german-type-212-sub-has-this-propeller-boss-vortex-diffuser-to-reduce-its-acoustic-signature>)—which is a huge advantage when it comes to keeping from being detected while traversing vast swathes of ocean.

![message-editor%2F1578097100494-https\_\_\_api.thedrive.com\_wp-content\_uploads\_2019\_01\_sdadadvb.jpeg](<https://www.twz.com/wp-content/uploads/content-b/message-editor%2F1578097100494-https___api.thedrive.com_wp-content_uploads_2019_01_sdadadvb.jpeg>)
*German Type 212 screw with its boss vortex diffuser., *AP**

Pump-jet propulsors also feature better efficiency across most all but the low-end of a submarine's performance envelope. They protect the blade elements contained within them. They can also be handy in shallow water, especially if they have a nozzle or deflecting surfaces for thrust vectoring. There are drawbacks, as well. They are heavy, making them ill-suited for many smaller submarine designs, and they are costlier and more complex than a propeller.

![message-editor%2F1578094458493-32424242.jpg](<https://www.twz.com/wp-content/uploads/content-b/message-editor%2F1578094458493-32424242.jpg>)
*Russia modified a single *Kilo* class diesel-electric submarine, B-871 *Alrosa*, with a fairly advanced pump-jet design. , *Uncredited**

![message-editor%2F1578097039666-wrwerwrw.jpg](<https://www.twz.com/wp-content/uploads/content-b/message-editor%2F1578097039666-wrwerwrw.jpg>)
**Uncredited**

Regardless, the pump-jet has come into its own after decades of far less widespread, but often experimental use. The two-thirds of the Royal Navy's [*Trafalgar* class](<https://en.wikipedia.org/wiki/Trafalgar-class_submarine>) and later the U.S. Navy's [*Seawolf* class](<https://www.twz.com/14309/why-the-navys-top-spy-submarine-flew-a-pirate-flag-while-pulling-into-port>) were among the first standard production submarine designs to rely on the pump-jet propulsor configuration. Today, many other classes have followed suit.

The U.S. Navy's [*Virginia* class](<https://www.twz.com/24363/navy-wants-a-new-seawolf-like-attack-submarines-to-challenge-russian-chinese-threats>) uses a similar arrangement as will the upcoming [*Columbia* class](<https://www.twz.com/24804/navy-plans-for-large-payload-subs-based-on-new-columbia-class-to-take-on-ssgn-role-and-more>) nuclear ballistic missile submarine that is currently in development. Overseas, the feature is becoming far more commonplace among allied and non-allied designs, with pump-jets being found of boats like the [Russian *Borei*](<https://www.twz.com/21073/watch-one-of-russias-newest-ballistic-missile-subs-launch-a-rare-four-missile-salvo>) class and French [*Barracuda* class](<https://www.twz.com/28949/france-launches-the-first-of-its-new-class-of-super-quiet-barracuda-attack-submarines>).

![message-editor%2F1578100142694-tk5iammwhvgnvr3bhno9.jpg](<https://www.twz.com/wp-content/uploads/content-b/message-editor%2F1578100142694-tk5iammwhvgnvr3bhno9.jpg>)
*The Royal Navy's *Astute* class is equipped with a pumpjet., *Crown Copyright**

With that being said, I'll let Jive better explain the differences between the propulsion types, especially in regards to their tell-tail sound signature, in this awesome explainer video:

https://youtube.com/embed/mv0RjBfs-7c

Make sure to follow Jive Turkey on [Twitter](<https://twitter.com/JivTurky>) and at his [Patreon site.](<https://www.patreon.com/jivturky>)

*Contact the author: Tyler@thedrive.com*

## Author
Tyler’s passion is the study of military technology, strategy, as well as foreign policy, and he has fostered a dominant voice on those topics in the defense and national security space. Tyler was the creator of the hugely popular defense site *Foxtrot Alpha* before developing *TWZ*, which he continues to lead as the Editor-In-Chief to this day.

### Author social links  
[Twitter](<https://twitter.com/Aviation_Intel>)