Tuesday, 17 September 2013
IP-W Project Provides Extra Service Life for “Walrus” Class Submarines
The Royal Netherlands Navy is upgrading its four indigenously built “Walrus” class diesel-electric submarines under an approximately €200M (US$155M) modernisation programme called the Walrus Engineering Support Programme (WESP). Part of the programme is a new anti-corrosion treatment of the submarines’ hulls, since the original protection has worn off and the hulls are now vulnerable to corrosion, said State Secretary for Defence Procurement Jack de Vries. Also of significance will be the integration of the SCOUT mine and obstacle avoidance sonar received from Germany’s L-3 ELAC Nautik GmbH and the upgrading of the submarines’ Mk48 Mod 7AT torpedo weapon. This wok will allow the Royal Netherlands Navy to postpone to think about a replacement project for another five to seven years.
Cdr. (E) E.P.M. van der Klip, Programme Manager, Heavyweight Torpedoes and Submarine Sonar Systems, at the Defence Materiel Organisation, said to NAVAL FORCES in Hamburg that several systems aboard the four “Walrus” class submarines, within the scope of the Life Extension Programme (called IP-W Project), need modifications, replacements or have to be added to the submarine in order to meet these requirements. Examples are the update of the Mk48 torpedoes, the replacement of one periscope by an optronic mast, and the installation of a Super High Frequency SatCom system. The upgrade of the sonar system is split into a two-way approach. Already prior to the LEP programme, a sonar pre-LEP contract was signed in 2008 for several sonar safety functionalities. It was anticipated that, due to obsolescence problems, essential sonar safety functionalities would not be serviceable until the submarines would enter their LEP. The other sonar functionalities would be upgraded during the LEP.
Cdr. van der Klip noted that WESP is the cooperation of three companies (Imtech, Nevesbu and Verebus) with the task to carry out the necessary engineering to allow embedding of all modifications (including the new systems) on-board of the submarines. The WESP group is tasked for making an inventory of systems for decommissioning. Further steps in the process include the design of the new arrangement, allocating space for the new hardware and (as an architect) give all new and existing equipment a place in the submarine. WESP is further responsible for designing the foundations of the equipment, cable ducts, piping and suspensions, electrical systems, the cooling system, including monitoring aspects like power distribution, heat balance, and the vessels’ weight/volume/stability and strength.
The pre-LEP sonar safety programme is called the MANTA project. “The contract was awarded in 2008 to ELAC (Kiel) with ISL (San Diego) as sub-contractor”, he said. “The first system is operational on the submarine HrMs “Bruinvis” since 2011 and performed well during Operation OCEAN SHIELD in 2012. The second system will enter operational service later this year. The remaining two systems will be installed during the LEP programme.”
The LEP sonar programme is called the Sonar Suite Project. “Within this sonar suite project, the three existing sonar systems (LRS, MRS and PRS) will be integrated into one sonar suite system”, Cdr. van der Klip said. “The upgrade comprises replacement of the complete set of signal processing for the long-range, medium-range, and passive range sonars. This includes software and hardware, but does not include the replacement of the various sonar wet-ends. The new combat management system will integrate all sonar data and display the results to the operator.”
Regarding the upgrading of the Mk48 Mod 7AT torpedo weapon, Cdr. van der Klip said that the main reasons to update the torpedo weapon are obsolescence and improvement of performance in shallow water. “The Mk48 update mainly features a hardware upgrade of the front section of the torpedo. The aft section will not be replaced but only slightly modified. The guidance and control upgrade replaces the obsolescent guidance and control unit with current technology, improves the acoustic receiver, and adds additional memory and improves processor throughput. Included in the upgrade is a Common Broadband Advanced Sonar System (CBASS) programme, which will develop a fully digital wideband sonar capability to enable the torpedo to operate effectively both in shallow water and deep water environments”, he concluded.