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Pim Rozendaal served in the Royal Netherlands Navy (RNlN) from 1975 until 2013. He sailed as a WEO (weapon electronics officer) on submarines and frigates. He has been involved in several Dutch naval ship building programs such as the Walrus class submarine and the Air Defense Frigate. He was Program manager of the Walrus Life Extension Program (LEP) from 2009-2013. Carel Prins was general manager for design and engineering at RDM Submarines in Rotterdam until 2000, when he retired from the company. He holds a Masters in mechanical engineering and a Ph.D. in nuclear power engineering. He is secretary of the Dutch Underwater Knowledge Center (DUKC).

The Walrus lineage
Ask a Dutch submariner who first invented a submarine and he will name Cornelius Drebbel of Alkmaar, the Netherlands (1572-1633), who is rumored to have demonstrated his submersible to the English King James I in the 1620’s. Ask a British submariner the same question and he will tell you that Drebbel borrowed the idea from the drawings of the Englishman William Bourne (1535-1583). In truth the designer of the first functional submarine is John Philip Holland from Ireland (1841-1914). The story of the early endeavors to navigate below the surface up to Holland’s success is filled with heroic exploits, half truths and hearsay if not fiction. The story of the submarine service of the RNlN begins when the Koninklijke Maatschappij de Schelde2 took the initiative in 1904 to built a type Holland-9 submarine “Luctor et Emergo” for its own account. On demonstrating the submarine to the RNlN the submarine was purchased and commissioned in 1906 as Hr. Ms. O-1.

This short history tells us not only of the pride of submariners and designers alike in their own boats but also that new submarine designs always ‘stand on the shoulders’ of previous designs. Since the O-1 the RNlN operated 63 boats. Of these 56 were build in the Netherlands. Between 1942 and 1969 one U-Class and two TClass boats were transferred from the RN and two Guppies from the USN. The Dutch designs, in the early years, were based on concepts of the Electric Boat Company and other foreign submarine builders. After WWII the first domestic design was of the so called triple hull type, with three pressure hulls arranged in a triangle (the Dolfijn Class of which four were build). But when USN NAUTILUS reached the North Pole in 1957 the nuclear promise brought the RNlN back to the US to request nuclear technology transfer for a Dutch SSN. This was denied by the US Administration in 1960, but the RNlN had already obtained the drawings of the diesel electric Barbel Class as a possible future platform. So, as it turned out, the submarine based on this US design the – Zwaardvis Class – became a diesel boat. Two were build and operated until 1994 when the next generation, the Walrus Class, had come into service. Their design proved to be successful both for open ocean and littoral environments. The latter has been recognized to be one of the advantages of a diesel boat.
Operational concept shift
The Walrus Class ocean going submarines were designed for Cold War missions. With a displacement of 2800 ton and a 10.000 NM range their strategic, NATO based, operational area was the North Atlantic. Already during the building phase of the Walrus Class, the end of the Cold war altered the political scene. Fortunately for the RNlN, the use of a diesel electric submarine is easily adjustable to the new circumstances without major technical changes.
With these political changes the setting for Naval operations for the whole western world entered a new era. It meant a shift from blue to brown water operations. This was also true for submarines and history shows that the four Walrus boats have been active in many different areas and with new missions. They have participated in many international operations, including peace keeping, anti drugs and anti piracy operations with ISR as the prime task. Experience has been gained during missions in the North Atlantic, the Caribbean, the Mediterranean and the Indian Ocean.

Life extension and technology update New lease on life In 2003, a Defense white paper announcing several changes for the Defense organization made clear that the Netherlands government acknowledged the importance of keeping a Dutch Submarine capability. Following this White paper the Naval Force has been reorganized preparing the fleet for the future. New capabilities had to be developed for Operations other than war. As part of this process it was decided that the operational life of the Walrus Class had to be extended from 25 to 35-40 years. To live up to this requirement several operational systems had to be updated and functionality had to be added. As a first step to enhance the Submarine’s capabilities, a Sonar safety project was initiated by adding a Mine and Obstacle Avoidance Sonar (MOAS) in the submarine’s bow, updating the Acoustic analysis capability and improving the intercept Sonar capability.

This was, however, certainly not enough to realize the envisioned life extension. More functional and even fundamental improvements and updates were considered necessary in order to ensure the operational performance until 2025-2030. It should be kept in mind that all the Walrus Combat Systems were designed and build before the appearance of the Personal Computer. Processing power and memory capacity of the boat’s current systems are limited and block future functional updates of the Combat Management System (CMS). As for now, for instance, several Lap-top computers are used for (operational) support functionalities. Furthermore several systems suffer from obsolescence and cannot be maintained any longer resulting in a high failure rate of aging equipment parts.

To execute the Life Extension Program as required on a limited budget the Naval Staff carried out a study involving the Operators (Submarine Service) and Maintainers (Naval Dockyard). The outcome of the study formed the input for the Operational Requirements for the LEP. The essential items in the Operational Requirements are:

 Replacement of the Combat Management System including the Operator consoles
 Concentration of all Sonar processing in a Sonar suite
 An Optronic sensor to replace the navigation periscope
 Addition of a SHF SATCOM high data rate
 The implementation of Electronic Maps (WECDIS)
 Introduction of the MK48 7AT capabilities (upgrade
existing MK 48)
 Replacement of the Weapon Interface Unit (including FC
for the MK48 torpedo)

Operation & Support experience
All shore based maintenance of RNlN submarines is carried out at the Naval Dockyard. Over the years much experience has been accumulated with the result that the maintenance cost of the Walrus Class is markedly lower than has been reported by various navies operating (ocean going) diesel subs. Also the availability (per ship/year) is proportionally higher. With the in house expertise several upgrades and adaptations could successfully be implemented over the years.

Managing the LEP
A “menu” at the start
The Defense Materiel Organization (DMO) made the LEP conditional to some strict requirements. The modifications ought not exceed the DMO imposed budget which made it a design to cost project. The modifications had to comply with the original Walrus technical requirements and the overall LEP design must be both functional and safety driven.

The governing documents were the original Walrus build specification, a CONOPS prepared by the submarine service and a SEWACO (sensor, weapons and command system) development plan prepared by DMO’s Joint IV Command3.

Prior to the initiation of the LEP the Wet Ends of the mine avoidance sonar had been mounted on the bow and the Intercept Array had been replaced. Some processing algorithms were developed for the MOAS and Intercept sonar by the TNO D&V research institute and implemented by the supplier. The Sonar Safety project was installed on 2 Submarines in a Stand Alone configuration. Under the LEP, the new functionality will be fully integrated in the Combat Management System (CMS) of all submarines. The existing Sonars, i.e. the Long Range Sonar (LRS) (Towed Array and Flank Array), the Medium Range (MRS) and the Passive Ranging Sonar (PRS) will be replaced by one Sonar suite taking care of LRS, MRS and PRS processing. For budgetary reasons the existing wet ends will not be changed (except for signal digitizing and front end conditioning), but there are high expectations that the overall performance will be much improved by the new processing and the fact that the Sonar suite integrates all sonar functions enabling Sensor fusion at several levels.

The menu of the LEP requirements globally consists of:
1. A new functional software package for the Combat Management System will be developed “in house” by DMO’s
Joint IV Command. The Hardware will consist of COTS processing and memory devices and specifically designed Multi Function Control Consoles carrying COTS HW components and processors. The successful Guardion system and its proven functionality of the surface fleet is earmarked to be the basis of the new submarine CMS. This concept allows for fully multifunctional consoles and ensures commonality with the surface fleet.
2. Implementation of the modified MK 48 torpedo in combination with a new CMS requires a new Weapon Interface
Unit. This Interface Unit contains the Fire Control functionality for the modified MK 48, a newly defined CMS
interface and the interface with the Torpedo launching systems. This interface is partly created by reverse engineering for the control of the Launching Tube system, the Turbine Ejection pumps and to establish a Fire control sequence.
3. The current conventional Navigation Table needed to be modified to accept an IMO certified WECDIS system.
The WECDIS chart and track information will be interfaced with the CMS to provide consistent and reliable information for both Navigation and tactical Operations.
4. An Optronic mast shall replace the conventional Navigation periscope and will be fully integrated in the CMS.
Two of the MFCC’s will have facilities for hands on control by means of a joystick. The video information from
the cameras will be shared with the CMS on multiple levels in order to enhance this video information both within
the Optronic system and the CMS Video processing.
5. The required information turn-around time including CMS track data, sonar data and data from the Optronic mast has to be substantially shortened. It has to be shared with other assets and headquarters in preferably (near) real time. To achieve this, the SHF SATCOM will provide for a high data rate data channel.
6. The Central Control Room will undergo a major upgrade because of the replacement of the Navigation periscope, the new MFCCs and the modification of the Navigation console. In addition to that, several electronic equipment spaces will be rearranged where obsolete cabinets will be replaced by new hardware.

Limited human resources
The years of budget cut backs that the MoD has experienced effected the technical knowledge base in numbers and in capability. This was compensated partly through an industry initiative based on existing working methods. In fact there is a tradition in the Netherlands of collaboration of MoD, the research institutes and the industry, which is called the triple helix. Since the time the Walrus Class was introduced into the submarine service no new submarines have been build. Furthermore RDM, the submarine building yard, closed in 2004. Shortly before that closure several companies and research institutes with submarine experience formed a platform to exchange information, support (mutual) marketing efforts and initiate and jointly carry out concept studies with the objective to maintain submarine technology. The name adopted for the platform is DUKC (Dutch Underwater Knowledge Center). The members aim to collaborate and meet periodically. The industry based DUKC invited the RNlN/DMO as observer.

Living with preliminary technical requirements
The LEP planning recognized three phases: an engineering study phase aimed to provide well researched grounds for selecting the new components and defining new arrangements, a detailed design phase and an implementation phase. The Naval Dockyard would be responsible for the LEP related shipyard work to remove, modify and install all equipment and systems. When DMO planned the LEP, it was found they needed outside assistance. In response, based on their philosophy, DUKC proposed to provide support for the engineering phase of the LEP. Subsequently five members formed a joint design team and presented a generic plan to DMO. The proposal was a novelty in the sense that all five participating industries would work under one contract with standard conditions identical for them all. One company would be the acting legal and financial administrator for the group. A project manager was given the task of integrating the design work and overall project management. The participating companies agreed and accepted that they would form a team of independent consulting engineers with no preferred position for equipment choices by DMO and during the implementation phase. The contract would be on a price not to exceed basis. This was an important condition for cost control because initially there were only limited and general technical requirements as mentioned above. The project named WESP (Walrus Engineering Support Project) was contracted and set in motion by DMO. WESP performed tasks for which DMO lacked the capacity at the time.

One of these tasks was to generate a Basic Design and define technical solutions for the modification of the submarine itself. The WESP terms of contract were formulated around four separate one page functional work assignments. DMO remained responsible for functional and technical (procurement) specifications for the new systems and equipment. In addition to that, existing general design specifications for the submarine had to be
supplemented taking the new equipment into account. The integrated approach of WESP was aimed at keeping to an otherwise slipping planning.

The menu items of the requirement and the WESP project plan were functionally clustered into four engineering work assignments. (Major) changes or additions to the WESP assignment would require a Change Order form. This was necessary only once.

The way of contracting WESP had the advantage that the terms and conditions were identical for all participants giving them the same responsibilities with respect to their work packages. This made the formation of an integrated project team in fact more easy than when entering into a conventional contract with a main contractor and subcontractors.

The second novel aspect was the interaction between the WESP team and the various navy departments involved. WESP had direct interaction not only with the DMO project organization but also with the Naval Shipyard, the Joint IV Command, the Submarine Service and the Operational-school. The DMO team gladly reciprocated, making an effective communication scheme possible. This was necessary to design, propose and select technical solutions for the desired new functions following from the CONOPS and SEWACO plan. To avoid a cacophony of discussions between the actors of the WESP team, with members working on their particular items of the menu items and their counterparts in the various DMO departments, a strict but flexible form of communication was established. Technical meetings on (isolated) topics could be scheduled involving WESP team members and DMO representatives and the meeting results were communicated project wide. These could concern straightforward issues as agreeing on the outcome of a shock calculation or
elaborate design solutions when alternatives were presented for the rearrangement of the central control room. The advantage was direct interaction between the relevant players and specialists with (parallel) identified lines of communication on technical issues. This was called consultation. The other important line of communication was the formal line involving acceptance of performance, progress and results.

Acceptance included the major technical decisions. This acceptance of results and the fundamental decision making was the prime responsibility of the DMO program manager and the WESP project manager and was organized with informal and formal reviews.
The functional and commercial choice for selecting a component or system supplier was the sole responsibility of DMO. WESP however was involved in the selection process several times for direct technical advice on feasibility of proposed solutions and interfaces. This involvement continued until (contractual) technical interfaces were completed. In this way procurement work for the major components went on in parallel with the engineering of (ship) interfaces with these components. Due to the complexity this was accepted by all parties involved, including (potential) suppliers (OEMs). In the execution it proved to be an effective way to reduce the technical risks.

In practice the communication within WESP worked out very well. One reason was that fairly soon the WESP team members, although coming from different companies and a research institute, understood that interdependency was essential to draft an integrated WESP proposal and to perform accordingly. It proved to be an effective framework to identify and evaluate alternatives and to submit technical solutions to DMO. At the same time the representatives of DMO saw immediate progress. They could make use of appropriate technical expertise helping to come to decisions while they received (pre-)engineered data to set up and improve the interface requirements with OEMs. It also offered similar advantages for the OEMs reducing program risks and as a result enable them to compose competitive offers.

The case of the central control room and new processing

An example of the way how WESP operated, is the interactive redesign of the central control room. A specific (LEP) CONOPS outlined new operational procedures based on the perception of what the new sensors, Network Enabled Capabilities and a new CMS would offer. The important new technology offers potential for fusion of the information coming from independent sources, mostly from sonar and optronics. The CMS is designed to provide a common operational picture for the command team to decide on deployment of available means to suit the submarine’s mission. With the newly implemented SHF SATCOM the command team might have to face an avalanche of data. The requirement for the new CMS was to make all that information manageable and effective by incorporating a level of automation that is higher than was experienced on submarines up till now. The DMO Joint IV
Command, the in house IT developer of DMO, was tasked to customize the Guardion software for submarines. All relevant information flows from sensor-, communication-, and information systems are collected, fused, upgraded and distributed to support planning, decision making and data logging. The customized Guardion concept will bring in experience from CMS designs for AAW, ASUW and ASW tasks of the Guardion equipped surface vessels.
To improve safe navigation in a littoral, shallow area WECDIS and MOAS are added to the sonar suite of Medium Range sonar, Passive Ranging sonar, Flank array, Towed array and Intercept sonar. The objectives for new sonar processing concerned new digitized data acquisition, beam forming, signal and audio processing to get better detection, classification, Target Motion analysis, and recording of (audio) tracks. Already the high definition broadband mode of the Sonar suite processor has been tested with actual signals. This showed a better system performance for the tasks mentioned than the existing sonars. Some detection ranges have been doubled due to the new processing. The WESP team analyzed the procedures and basic routines of the CONOPS meaning to optimize the operational process and the design of new MFCC’s. It was also their task to design the rearrangement of the central control room in line with the MMI
required for the new CMS, the (partly new) functions and
paperless navigation.

For the new arrangement, the TNO participants of the WESP team were leading in setting up the dialogue with DMO, the submarine service and the Op-school. A number of work shops5 were used to generate concepts for the optimal design of MFCCs and their arrangement in the central control room. The workshop planning involved three phases: the establishing of functional demands, the concept design phase and a design definition to be the basis for the detailed design. The WESP team had made 3D computer models of the existing operational spaces. The new components and alternate re-arrangements were visualized using these computer models. The introduction of the non hull penetrating optronic periscope with displays for all operators to see, the integration of WECDIS and the introduction of SATCOM communication and NEC were an integral part of the conceptual design phase. Following the CONOPS about ten operational scenarios were formulated. For each scenario a link analysis on information flow and communication in the command team was carried out and confirmed during the interactive WESP–User workshops.

Following the analysis three different layouts of the central control room were generated and proposed to the Program manager as potential solutions. A conventional concept that stayed closest to the existing situation with one additional MFCC made use of an existing foundation/shock frame. In a revolutionary concept, the existing shock frame was removed placing MFCCs in an arrangement looking forward to the ship’s bow, instead of being aligned along the (starboard) side. The third, evolutionary, design concept was an intermediate arrangement making use of advantages of both concepts using the existing shock frame. An important difference with the existing design is a dedicated, simplified console for the CO facing to the forward bulkhead and giving access to both CMS data and NEC enabled (operational) networks For all three alternatives the human factor played an important role in the ergonomic design of the MFCCs, the overall arrangement and the positioning of additional displays for command team information. The workshop discussions led to well-founded concept proposals for the Program manager taking into account all relevant aspects including the budget. This enabled the Program manager to make a considered choice that was widely supported by his team, (future) operators and technicians. The conventional arrangement with some adaptations was finally chosen. An important reason for this selection was to keep consequences for actual outfitting within limitations of the current arrangement of the central control room. This was done to reduce risks and to prevent overstretching the actual building planning.

In the last, more detailed, design phase production issues of the arrangement were reviewed by WESP team members with production experience. They assisted in the process of drafting practical technical procurement specifications for the MFCCs. In fact the procurement specification came close to a preliminary design, giving DMO substantial money and time savings for the production contract of the MFCCs.

Overall effect of the interactive collaboration. The other assignments of the menu were carried out in a similar manner as described above for the Control room arrangement. The WESP engineering study was followed by a detailed design phase that was completed mid 2013. At present the implementation of the LEP on the first submarine is in progress at the Naval Dockyard. The first submarine undergoing the modifications is Zr. Ms. Zeeleeuw. The completion and start of sea trails is scheduled for 2015.


WESP proved that experienced professionals from (in this case four) industrial companies and a research institute, working as a team of independent consulting engineers interacting directly with DMO specialists has been a success factor for the engineering of the LEP. For the program it helped to control progress and expenditure.

The framework of a price not to exceed contract offered flexible control based on progress and actual costs. The contract ensured that the WESP project was transparent to all parties and could be carried out within the limited budget even when working with only preliminary technical requirements at the start. It provided MOD a no surprise Engineering Data Package without undue risks.

During the engineering phase WESP supported the procurement process for the equipment and services for the implementation phase. This has been beneficiary for DMO, but also for the suppliers in particular regarding proper technical interfacing resulting in risk mitigation for all concerned.

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