Midlife Overhaul for Dutch Submarines - Operational to 2025

A Walrus class submarine moving quickly. At 2,450 short tons (surfaced), 2,800 tons (submerged), with a crew of 49 to 60 - in Europe the Walrus is a uniquely large SSK class.

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A 25 February 2017 comment from Kevin has prompted me to write two updates on:

-  Dutch Walrus class submarine overhauls (below), and
-  later this week Dutch submarine replacement issues and requirements.

The issue of overhaul or replacement of the Netherlands 4 Walrus class submarines, launched between 1985 and 1992, has been long discussed in Dutch naval and political circles. Originally the Walrus class were designed to operate for just 25 years (until around 2015). 

But the Walruses have operated mostly in shallow coastal waters (shallow immersion cycles). Hence the physical demands (contraction and expansion of the steel hulls causing metal fatigue) have been less than originally expected. Possibly the Walruses have been mainly used for signals monitoring as they are too slow for hunter-killer duties, chasing SSNs, SSGNs and SSBNs. The Walrus class  operating life has therefore been increased to 35 years, allowing the subs to remain in use until at least 2025.

The Walrus mid-life overhaul is known as the Capability Upkeep Program (CUP) [in Dutch 1]. The CUP overhaul program began in mid 2014 starting with His Netherland Majesty's Ship (HNLMS) Sealion [1]. Overhauls will continue until 2020. The CUP has also been called the Life Extension Program (LEP).

The overhaul includes:

-  modernising sensors, such as:
   = new sonars allowing the sub to draw closer to the coast (aka “near shore”) to gather intelligence.
      The suite includes a Mine and Obstacle Avoidance Sonar by ELAC Nautik.
   = New optronics masts [1] from L-3 KEO permitting sub to quickly see 360 degrees around itself,
      with less risk of discovery tan a periscope or older optronic. The new optronics suite includes a
      thermal imaging camera [1] providing HD footage both day and night. Optronics allow very sharp
      images to be visible on a screen for most in the sub's command center (not just one viewer's old
      periscope eyeball).

-  upgraded weapons including new software and other equipment for the Mark 48 torpedos, moving
   and them from current mod-4 standard to mod-7 CBASS.

-  command and combat systems and communications,
   = including a super high frequency (SHF) satellite communications system allowing messages to
      the submarine from Dutch naval headquarters or NATO Defense Networks, and
   = improved operating software for most systems (likely much work will be by Lockheed Martin).

-  refurbishing, strengthening and de-rusting the pressure hull

Later this week I’ll comment on the Walrus replacement program (yet to be approved by the Dutch Parliament) and on likely requirements and builders of a Dutch future submarine.

[1] these sites are in Dutch. For a PC mouse - right click mouse - then you will see Translate to English - translation may take 20 seconds. 

Pete