Friday, 25 March 2016

Dynamic Amplification and Extrapolation of Fundamental Laws


Study of the unpredictability of wave based phenomenon is of great importance in seakeeping.






We are accustomed to apply Newton’s Equations every now and then. But how much do we know its validity? If we seek the answer to this question, even the masterminds have to rack their brains! It is a universal and harsh truth that these are applicable to only a meager number of bodies around us.

Coming to the context of ships, Newton’s ‘linear’ postulates falter in front of the large diabolical forces and unpredictable rapidly-varying disturbances, it is subject to. If we take the pain to estimate the forces over a stipulated span of time on a side shell plating of the outer hull, we could notice that neither the strength, intensity, distribution nor the fetch of the generated stress can be estimated by our conventional methods. Dramatically enough, every single physical parameters associated with the region wields as an abrupt time-varying function. For example, the stress distribution would be following abrupt frequency response changes of intensity. This is where we introduce a non-dimensional parameter known as the Dynamic Amplification Factor. Mathematically, it can be expressed as the ratio of the maximum permissible load, Um to the static load applied to the same body, Us. Or in other words, it takes into account the “static-equivalent load” under the same conditions.



Rarely, in ships do we find static loads acting. The loading like that of storms, rain, earthquakes, floods or calmer ones like live traffic loads on a bridge, the loads encountered by a ship under all abrupt sea states are essentially highly accelerated and variant, viz. Dynamic loads. Have you ever wondered at the rogue deep sea waves lashing out at a ship? Do you think that the aggregate stresses embarked upon the ship at its multitude of structural locations could be simply assessed by a petty Newtonian Load equation? The answer is a big no. A lot of tedious work has to done by designers/naval architects, engineers, seafarers to analyse the nature of the loading at all strategic locations of any structure to execute its probabilistic failure computations.



The most preliminary application of Dynamic Amplification Factor on a ship would be to study the forces enacting on a single isolated object on board while a ship hurls above a big sea wave. This situation is analogous to the case of a simple elevator! We know that whenever an elevator goes upward with a certain acceleration, weight experienced by an object in it increases. Similarly, when a ship is aloft a wave, any object on board experiences an “added pseudo force”. 

Hence, the classical equation, F=mg gets modified in the form of

 F= m*g*(DYNAMIC AMPLIFICATION FACTOR)

The basic concept lies in the fact that when a body is subject to dynamic force, its effects are more pronounced due to the materials inability to promptly react to the sudden disturbance. This is where the induction of the DAF equalizes the effects of static and dynamic loading under the given conditions. 

The determination of the Dynamic Amplification Factor, however is a cumbersome task where it involves a compact knowledge of the nature of the frequency response curves.



Some of the methods involved are complicated and require high levels of expertise. Averaging of the stress variations from time-to-time in a system like that of a ship to deduce the DAF is a challenge to a naval architect. The designer/builder hones his skills again in turn to implement this in the detailed structural design and material analysis. Thus this simple ‘extrapolation’ of the fundamental laws have pronounced implications in the ship structure analysis.

By: Subhodeep Ghosh (Originally posted on our page)

Sunday, 6 March 2016

Under the Skin: Part 1


Have you ever wondered what lies within the skin of the prodigious engineering marvels such like ships? You may be surprised to learn that ships or vessels like we humans and other living creatures have an intricate 'skeleton' underneath! Analogous to the complex network of bones and ligaments in living beings, they have a well-engineered arrangement of structural members in varying attributes.



Fig. 1 A high-definition picture of Queen Mary 2 (Courtesy: www.largestships.com Archives)


You may still be in some doubt!

Large number of big and small components make up the hull structure which is the primary phase of manufacturing of any vessel and is the most tedious task. It is believed that the safety and sustainability of the vessel during its service is a chunk dependent on the ingenuity of the structural members and thereby the entire structure. Failure of any single component leads to disastrous results. So, it is a challenging task to undergo detailed selection, arrangement, analysis and testing methods to these structures.With due respect to the traditional mechanical analysis methods of materials along with empirical probabilistic methods,modern computational testing methods accompanied by Finite Element Analysis and other precision software have eased the cumber of the olden days providing a wider scope of accuracy and precision. 


SHIP'S HULL- AN OVERVIEW 

                    Fig.2 Cross-Sectional View of a General Cargo Carrier (Copyright:Learn Ship Design)                
                                

A ship's hull is comprised of a criss-cross network of perpendicularly placed plates or members which are fixated to each other at all possible degrees of freedom. Some crucial members include extensive varieties of plates, struts, columns, bars, beams, stanchions, angles, brackets, knees, elbows and so on.

Must be wondering the arrangement of all of these in a mere vessel? And that too which floats and treads in water for such a long span of time!


The answer is quite simple. There is a holistic placement of all of them in accordance to their capabilities which complies with their strength, scantlings, locations, loads/stresses and their utilities. A ship, as we know is a large structure aimed at overcoming all hindrances of distance, carriage and cargo, sea-states, environmental vagaries, titanic loads accompanied by the pressing issue of safety of life as well as property (cargo/machinery). Naval architects, shipbuilders and designers owe a considerable amount of showmanship regarding design, lines plan, materials, scantlings, strength and model testings, intricate architecture of each component, related calculations and final accuracy in materialization of the arduous job. An obvious question arises at this juncture: What should be the apt choice for material selection as far as the hull is concerned? 



What is the material used?


Mild steel and wrought iron has been a sought-after choice of shipbuilders around the globe after the departure of the yesteryear wooden/timber vessels.However, in the recent times, wrought iron is losing its popularity owing to its corrosive nature and being bulkier.Mild steel earns the reputation of its abundance, ease in assemblage, lightweight along with required strength, ductility and malleability. However it is prone to failure under high stresses and hull shocks. It also has a degree of unreliability when it comes to their service as girders, struts or internal supporting members, with due respect to larger ships of today having massive tonnage. Furthermore it is highly corrosive in nature and is also prone to other problems like fouling. So, another breed of steel, High Tensile Steel/High Strength Steel with increased yield points have stolen the limelight. They include grades of steel like AH,DH,EH. Their yield point lies in the range of 315-350 MPa!





Fig.3: A very rare pic of The Titanic in construction. Wrought iron and mild steel were the chief materials used along with rivet joining (Courtesy: www.amberonline.com)     



But as it is said, everything has its pros and cons. High Steel Strength, despite its high degree of toughness has poor response when it comes to the problem of flexural bending. As longitudinal bending is inevitable in most of the large ocean-going vessels, they often pose the risk of fracture due to intensive bending moments at uncongenial sea states. The advent of composite fabricated members in the modern shipbuilding has changed the scenario. Though the SOLAS requirements and a majority of classification societies were dubious about its utility in the superstructures or other deck areas, thanks to its reduced fire resistance, the mid-1980s saw a gradual upraise of composite fibers in the industry. As usual, supporting reasons existed!


  • Lightweight. This helped in easily meeting the critical dead-weight barrier assigned to a ship. So this, up to a certain extent  helped in greater "inclusion" of added mass on board which was a constraint if material was a bulky one like steel. 
  • It has a lower life cycle cost coupled with cheaper maintenance and durability.
  • Due to its light weight, it amounted to lower fuel consumption. 
  • Higher stiffness and accorded to greater flexural bending moments by the virtue of its elasticity.
  • Was tough and rigid with minimal scope of cracking. Offered greater resilience.
  • Often use of composite material allowed higher superstructure and more accommodation space in passenger vessels designed for a given displacement. 
  • Its resistance to corrosion and fouling when present as a component in the hull structure was a boon.
FRP-sandwich panels/GRP-sandwich panels and PVC enforced steel plating found great predominance. Polymeric and non-polymeric materials found equal importance. However, composite had disadvantages as well like being highly flammable or being difficult to manufacture along with yielding at very high temperatures. Thus the decisive step is being taken as to optimize between steel and composite materials in suitable proportions for the best results.


Fig. 4 (Copyright:Linkedin)


Apart from these, forged steel and cast steel are used in secondary structural components like rudder posts, stern frame and stem according to the specifications of the latest classification societies. Some classification rules even give higher adherence to the existing Aluminium Alloys as the principal material for the construction of deckhouses, superstructures, hatch openings, covers etc. over composite materials. 


BASIC/FUNDAMENTAL STRUCTURAL MEMBERS



After a brief insight into the material properties commonly used, let us have a glance at the big and small structural members that make up a ship's hull!



              Fig. 5 General steel plating arrangement of the ship's hull (Courtesy: wikipedia.org) 

Plating

They are the primary building blocks to any vessel just as bricks are to any house ! Right from the day when wooden vessels were made of wooden boards to the present day where steel/composite plating form the hull. Plates of varying dimensions or scantlings are used depending on the functionality, general arrangement and stress considerations. The final placement of the plates give rise to the structural truss which along with the outfitting and ancillary components give rise to the entire vessel form. Platings broadly referred to the outershell  plating as well as the inner walls of the hull. They may also be found in the modified form of bulkheads or as components in decks and other outfitting. Platings prove their versatility in the role of taking up any shape as per the criteria, like round or being curved.

Well, a question which is definitely going to arise in your minds at this juncture: How are these mere plates joined or concatenated to give rise to the final shape?



  Fig. 6 Ongoing welding jobs within a ship's hull (Courtesy: www.gettyimages.com)

The answer is quite simple. Joining is very catalytic component in shipbuilding not only a ship's production but also its subsequent productivity, performance and safety is highly dependent on the joining methods. The total length of structural joints in a large cruise ship is of the order of 400 -500 km! Even that too has an evolution like the ship itself. 

Earlier,the method of caulking was used to make the seams in wooden boats and ships watertight, by driving fibrous materials into the wedge-shaped seams between boards.Till the World War era, it's successor riveting was the chief technique employed which was the . The entire ship was exacted by joining cogs and nuts at every plate/board itself. This was a tedious task which made making of a ship very cumbersome and time-taking.

However, post-World War II, the modern techniques of Welding took over. Welding as we know is a safe,convenient and firm way of joining metals. Without delving into the details some of the various methods of welding involved are :

  1. Electric-Arc Welding
  2. Electro-Slag Welding                                    
  3.  Shielded Metal Arc Welding
  4. Submerged Metal Arc Welding
  5. Gas Metal Arc Welding
  6. Ceramic Welding
  7. Laser Welding
                            

 Fig. 7 Underwater welding repair of hull (Copyright: www.telegraph.co.uk)



While each of them have their own pros and cons, other methods of metal joining like Adhesive Bonding and Mechanical Joining Techniques are often used as well.

  Keel :




          Fig. 8 Typical closeup view of keel network (Courtesy: googleimages)


All of you must be familiar with this term. It is often referred to as the backbone of any ship. It is the chief structural member in the form of the center plane girder that runs longitudinally from fore to aft, generally a beam around which the entire hull is supported. This could be worth saying that the entire hull grows from strength to strength about the keel at the base. The structural strength and integrity of the keel, is a key determinant to the safety and the performance of the ship.

Maybe, this is why keel laying ceremony is celebrated in such an aura in any shipbuilding project!


The keel forms are divided into three principal types: 



  • Flat keel. The commonest form of every keel. A highly strengthened, flat beam is placed parallel to the ground. Most of the large ocean-going vessels and other bigger ships nowadays have this type of keel. This accounts for lower resistance, accurate draught; but is susceptible to grounding.
                

          Fig.9 Keel laying of an old design flat-plate keel (Courtesy: wikipedia.org)

  • Bar keel: An old design of keel, still used in many smaller vessels and boats involves a rectangular cross-section flange poised over the bottom-most part of the hull. They are becoming rarer these days, thanks to its added weight problems which increase draft without increasing the displacement. However, having the unique property of jutting out below the main hull form closure ,bar keels are still alluded as a ready-hand solution to excess rolling.
  • Duct keel is the hollow form of the keel floor in some ships, generally running from collision bulkhead to engine room bulkhead with the provision of allowing piping systems throughout its expanse.


                                  

 Fig. 10 Inside a duck keel passage of an LNG carrier (Courtesy: http://www.fsharris.co.uk/gallery/29.jpg)



Strakes

They specifically refer to the bottom and side shell plating which are the supposed points of maximum stresses. Strakes are categorized as Bottom Strake, bilge strake and Sheer Strake. The bottom shell plating follows a unique system of nomenclature in almost all ships,i.e. in the form of successive alphabets with the keel as reference (e.g. A strake, B strake etc.). 
The first stake in the order of appearance is also termed as Garboard Strake.
Similarly, the strake situated at the "turn of the bilge" is referred to as the Bilge Strake. 
The upper-most strake near the deck edge is the Sheer Strake. It may be worth saying that as these are the critical points of high stresses, additional strengthening is provided to these plating to sustain high amounts of unpredictable loads. 

Other members: Even if the ship looks complicated, its structural components are not that much complicated or massive as they might seem.The items are very basic like columns, struts, beams, flanges, angles, brackets and stanchions. Maybe these are not all. Small to negligible members exist in every minuscule of the vessel to give rise to the proper functionality of the structure. The nomenclature of all such members are different according to their role and location.Their role may be variant in the either of the following forms:

  • Construction
  • Support
  • Strengthening
  • Stiffening


            
          Fig. 11 Diagram of all the basic structural parts of an arbitrary hull section (Copyright: United States Naval Academy student archives)


Although strengthening and stiffening are not exactly same, we simplify our topic of discussion by the convenience that the corresponding structures employed in ship construction are one and the same. We next a brief insight into the stiffening members.





 STIFFENING AND STIFFENERS


The word 'stiffening' essentially suggests the purpose of providing extra stress-bearing capacity or rigidity to the existing structural member. 

Does simply erecting four successive plates in a mid-ship section, for instance serve the purpose?

The answer is a big no. Every structural member requires a stiffening in some form not only to be stable itself, but also to provide resistance to the various amount of internal and external causal agents leading to stress concentrations on the structure. These stress concentrations as you know are fatal, even if neglected once! Thus stiffening from grass root level is of utmost mandate for every single component irrespective of size, location, form and purpose. Stiffeners are these secondary structural components which conjoin with the principal members giving rise to the complete framework of stiffened panels.These panels in unison all throughout the designated length, beam and depth form the final structure of the ship's hull. The stiffeners also have their own classification: 


  • Longitudinal Stiffeners: As the name suggests, they provide longitudinal stiffening,viz., retain the rigidity against the longitudinal bending and buckling of the ship. As the waves in the open seas are unpredictable and maybe sometimes highly precarious, failure. Longitudinal stiffening mainly focuses on the length-wise stiffening parallel to the center line. The primary objective running through the mind of all designers and naval architects are the basic concepts of shear force and the resultant bending moment which may be given as:                                                         
       All of them are attributed to either of the three groups:                      
  1. Longitudinals- They are the stiffeners running longitudinally along the bottom of the ship (parallel to the baseline) from fore to aft. They stiffen the bottom-shell plating of the hull, hence preventing it from the external forces such as the wave loads and the internal forces such as loads of cargo or the other contents of the hull. Essentially they are girders of specified scantlings depending on the applicability of the vessel type.
  2. Stringers-If we concentrate on the longitudinal stiffening at the side shell girders, stringers are the answer. They are like longitudinals, sideshell plating strengthening members on the hull. Even as the sideshell platings are prone to high amount of transverse wave stresses, they are also reserved to the maximum degree of rigidity
  3. Deck Girders/ Longitudinals: Longitudinal stiffening underneath the main deck, i.e, in conjunction to the inner deck plating. They deck is prone to various types of loads, like passenger/crew, live loads, deck equipment, superstructure, green water etc. Thus deck girders running fore to aft serve the bulk of the purpose. However, they are not having high section modulus as lower bottom shell plating as the deck is considered relatively less affected by high stress as compared to the bottom.  

  • Transverse Stiffeners. They provide transverse stiffening across the breadth/beam of the ship. They are mutually orthogonal to the longitudinal stiffeners. Akin to their longitudinal counterparts, they too can be segregated into three forms based on their functionality.

  1.  Frames are the larger portions of these transverse stiffeners which run from the keel to the main deck uninterrupted. Frames occur at specified intervals throughout the length of the ship. The spacing between the frames is dependent upon the dimensions and the operation of the vessel along with its type. One crucial thing that must be kept in mind is that they are not to be confused with Stations nor Bulkheads. While the former is an imaginary hypothesis assumed by naval architects while shaping up their lines plan, the latter is a composite structural feature. But frames only align themselves with the side shell and the bottom shell plating without interfering with the inner aspects providing an integral contribution in stiffening plating transversely.
  2. Floors assumed to be the continuation of the frames at the base. In general, they can be simply interpreted as the transverse stiffening of the bottom-shell plating. In the case of a single bottom ship, frames are sometimes connected directly to floor plates. The lower ends of tween deck frames are connected directly to the deck plating or are extended beyond deck-head and fixed at brackets.
    However, in most of today's ships, the concept of double hull has been imbibed. Hopefully, all of you know what a double hull represent? For the novice, it is just enough to know that they are two-layered system of bottom plating, i.e an outer shell plate and another inner bottom shell plate with some clearance. Floors are generally sandwiched between the inner and outer shell plating to provide sturdiness to the bottom hull. Floors even have their type like solid floors and bottom floors, about which we refrain to comprehend at this juncture.
     
  3. Deck Transverse They, like deck girders stiffen the deck-shell plating, but across the allowable beam. However, their strength and spacing depends on the type of the vessel and the 'superstructure loads'. 




                  Fig. 12 A typical cross-section of a 5000 DWT coastal tanker showing all the essential stiffeners and resultant stiffened panels ( Courtesy: Ship construction by D.J. Eyres)



Reiterating the last point on Deck Transverses, it may be worthwhile to say that the placement and the number of the longitudinal or stiffener framing system is solely dependent on the type of vessel, capacity, service, sea-states, cargo optimizing the owner's economical constraints with due adherence to the Factors of Safety. 
It may be suffice to know that in most of the smaller ships having Length-to-Breadth ratio not very high, the number of transverses are more than the number of longitudinals. The spacing inbetween the transverse stiffening members are also very less; they are crowded! This type of framing system known as Transverse Framing System is mostly deployed in the smaller vessels where longitudinal bending is not much of an issue. Transverse stiffeners provide resilience against transverse forces such as those induced by the side waves which can cause unwanted Racking and Torsional motions in the ship. 




                           Fig. 13  Profile of the sideways wave forces and the transverse deflection/deformation inducing racking motions (Courtesy: United Stated Naval Academy student archives)

On the contrary, in large/lengthy vessels such as general cargo ships or the majority of the passenger liners which are prone to longitudinal bending, buckling, flexure, there is more number of longitudinal stiffening induced in all along its length. The spacing between the longitudinals are reduced considerably. A ship of this type may be reckoned as a 'Longitudinally Stiffened Ship'. 


TO BE CONTINUED

      Fig. 14 Ongoing Ship Construction (Courtesy :www.wikipedia.org)


So far we had talked about the basic components of the hull in brief. Maybe that is not enough. Similar to the universal process of concatenation, the basic structural elements join in various forms and types to form what is known as the 'Grillage'. The hierarchy of evolution from simple elements to complex ones follows a definite algorithm of assemblage. One thing that must be kept in mind is that the composite form of the ship's hull is basically a resultant of three different kinds of formation, regardless of the modern designs as well as evolution of the composing materials.                                                                                                                                                                              
                  
  • Stiffened Panels 
  • Frameworks
  • Blocks


All of you will be provided an insight to the more detailed process of assemblage of individual materials in a well-defined hierarchy in the next article. For the time being, it is just the idea that the ship's hull is just like any other indigenous engineering output where basic elements of given material composition are arrayed in a predefined manner, of course keeping in mind the strength, reliability, utility, safety and economy into consideration.LSD   



Fig. 16 Freedom of The Seas (Courtesy: www.usatoday.com)  


Article By: Subhodeep Ghosh

Saturday, 31 October 2015

Ballast Free Ship Design

INTRODUCTION:


Ballast water is fresh or seawater, held in tanks and cargo holds of ships to increase stability and manoeuvrability during transit. Ballast water is essential to the safe and efficient operation of modern ships, providing balance and stability to un-laden ships (often returning empty during return voyages) as well as loaded ships. Its superb operational advantages, however come at a cost. 

 It poses serious ecological and health threats due to transfer of a multitude of marine species (non- native species) into an altogether different host environment containing different native species. 

Didn’t quite get that?

e.g.- The ballast water is taken from coastal port areas(source point) and transported inside the ship to the next port of call(destination point) where it may be discharged, along with all the surviving organisms. This way, the ballast water may introduce organisms into the port of discharge which do not naturally belong there. These introduced species are called exotic species. Populations of exotic species may grow very quickly in the absence of natural predators. In this case they are called ‘invasive’. However, most species can’t survive in the new surroundings – temperature, salinity etc. (Remember, Survival of the fittest?) being less than optimal. Thus only a few species are ‘successful invaders’, however those that do survive, establish a population and have the potential to cause major harm! Aquatic invasions are considered the second greatest threat to global bio-diversity after habitat loss, are virtually irreversible, and increase in severity over time. If that is the case, then one can’t even imagine the damage, caused by transfer of 3 to 5 billion tons of ballast water each year.
  

SOLUTIONS:


NO BALLAST SHIP (NOBS) CONCEPTS:


There are mainly three projects in which the concept of a ship with zero ballast water has been developed:
  • Delft University of Technology (DUT)-‘Monomaran Hull’.
  • Det Norske Veritas(DNV)-‘Volume Cargo Ship’
  • Daewoo Shipbuilding and Marine Engineering(DSME)-‘ Solid Ballast Ship’
  1. ‘The Monomaran Hull’ – An unloaded rolling ship (without ballast water) requires adequate stability. DUT proposed a monomaran hull by adopting a catamaran shape to the base of the broad single hull.
  2. ‘Volume Cargo Ship’ - DNV proposed a design similar to DUT but with a trimaran hull shape thus imparting high level of stability.
  3. ‘Solid ballast ship’ – In this case, the ballast water is replaced by 25 tonne Solid ballast in standard containers. However the application of this method is limited to container ships only. The hull form (size) remains the same.
Another solution to this problem is the Yokohama buoyancy control compartment concept, which converts conventional ballast tanks into a series of buoyancy control compartments. 






(Fig. 1: Comparison between conventional ballasting and ballast free ship design. (Courtesy: www.nsdrc.com/Publications-"Development of a ballast free ship design" by Avinash Godey, Prof. S.C. Misra, Prof. O.P. Sha)


Each compartment is flooded to provide adequate draught in the unloaded condition then continuously flushed at normal voyage speeds to ensure efficient exchange without the need for pumps. Each compartment is fitted with intake and outlet valves that are optimally designed and positioned for each compartment so as to maximize its flushing rate during normal voyage speeds.

Although ballast water treatment is an effective way of tackling ballast water issues.
The details of it will not be discussed in this article.
   

The Ballast Free Ship (BFS):


When a ship moves forward it produces regions of increased water pressure near its bow and reduced water pressure at its stern. This pressure differential is utilised to drive water through a set of these below-waterline corridor (trunks) without the need for pumps. Although this leads to slight increase in the resistance of the ship, the discharge of the trunk flow into the upper half of the propeller disc tends to smooth out the inflow to the propeller, allowing the propeller to operate at higher propeller efficiency and thus compensate for the added resistance to some extent.


Fig.2:Rendition of the concept behind ballast free ship design (Copyright: Learn Ship Design)


Fig.2:Rendition of the buoyancy control compartments with provisions for flushing water at normal voyage speeds. (Copyright: Learn Ship Design)

However, it also has to overcome some other challenges like:

1.) Loss of cargo carrying capacity- due to ballast water volume restraint. As it’s quite difficult to sustain the cargo carrying capacity and also the same ballast water volume

2.) Loss of ship strength- There would be a total redesign of the double bottom. As the conventional transverse framing will create difficulty for ballast water to flow through the tunnels. Hence this elimination will enhance the flow of ballast water at the cost of ship’s strength.
Classification societies might not permit the elimination of all of these frames. Moreover, watertight trunk boundaries will be required at transverse locations. Longitudinal stiffeners could be replaced with sandwich panels, thereby improving the flow. Thus compensating for the loss of strength.

3.) Increase in ship’s resistance- due to disturbance from discharge of ballast water into the flow around the propeller – The introduction of a plenum at the bow and stern of the ship, as well as the location of the plenums will affect the resistance of the ship, increasing fuel consumption.

Also, the increased ballast water flow velocity at discharge location will increase resistance as shown experimentally

Equipped with such technology, we can hope to minimize our environmental footprint to the greatest possible extent in the different spheres of conflict with the marine ecosystem.LSD

Article By: Vishal Kumar Jha

Saturday, 19 September 2015

An Interview with Dr. Jan Emblemsvåg

Jan Emblemsvag
(Image Courtesy: www.emblemsvag.com)
"The dichotomy of theory versus practice is an artificial one – all practice is based on theory whereas not all theory is based on practice, which is why this dichotomy arose. The difference between modern approaches to leadership and management and other approaches lies in their relation to reality. Modern approaches are fact-based and driven by reality, and so am I." says a note on his website

Jan Emblemsvåg is the SVP of Ship Design and Systems at Rolls-Royce Marine. The acclaimed corporation which has delivered the most ship designs over the years for the world offshore market, major designs in fishing vessel technology and merchant vessels. The corporation has also ventured into special purpose vessels and ship conversion projects.

In this interview with Learn Ship Design, we get to know about Rolls Royce Marine and it's operations. He speaks about Managerial challenges, his work on the Life Cycle Costing Approach, keeping pace with changing trends and what makes Rolls Royce Marine a leader in it's game.

Rolls Royce Marine seems to provide top notch solutions, be it with regard to pure raw power of drill-ships or the demanding precision of research vessels. But, it also amazes to witness the prowess in mainstream application of alternate fuels and the proposed mass automation (drone ships) in ship design. What drives this immense initiative? Please tell us about your experience.

Rolls-Royce Marine (RRM) has a large network in the market so we quickly hear about new ideas, new needs or new trends in general.  This, in combination with highly skilled employees, we have a very good breeding ground for innovation.  Why there are so many, is a good question. It is probably a mix of a willingness to try out new things and the fact that RRM indeed has very wide product portfolio so that there is a large opportunity for innovation.

Would you like to comment on how your work at Rolls Royce Marine and the unique challenges faced in the shipbuilding industry is honing your managerial skills in its own unique way?

The shipbuilding industry, for which we deliver ship design and equipment, is a volatile industry with focus on personal relations (due to the risk level – do you trust your business partner to deliver?) and complex projects with significant risks. RRM is a wholly owned subsidiary of Rolls-Royce plc which is traded at the Financial Times index in London. Stock markets typically want steady growth etc. This creates a unique mixture of apparent contradictions, which I personally believe is a great opportunity of innovations.  As a manager I must therefore try to handle a very large variety of issues – something I find very challenging, interesting and stimulating personally.  My level of performance must someone else talk about. 

Can you give our readers a brief jest about the Life-cycle costing approach and the Monte Carlo method and how we can use them in the maritime industry?

Activity-Based Life-Cycle Costing builds on Activity-Based Costing (ABC) and Life-Cycle Costing (LCC) and it uses Monte Carlo methods to power the approach, so to speak.  From ABC we get the focus on process, correct cost assignment, correct handling of overhead costs and more, from LCC we get the life-cycle perspective and the importance of handling risk and uncertainty and the Monte Carlo methods allow us to make huge models and realistically model risk and uncertainty as well as tracing key success factors.  The approach can be used for all kind of applications to calculate costs, profitability and so on.  Concrete examples can be to calculate the profitability of a contract for a ship owner, use the model and tie it to design changes so that design can be improved before they are built.  This can concern ships, oil rigs and any asset expensive enough for the cost of creating such a model.  The most important aspect of what it can be used for, however, is the availability of data.  This said, the Monte Carlo methods reduce the need for accurate data as long as the data is somewhat consistent. 

What are the main aspects one should keep in mind while evaluating the profitability of a ship/offshore design?

The single most important element in this industry is risk due to its volatility, and therefore flexibility/robustness is critical in the design particularly for offshore- and special purpose vessels.  The risk element is the reason why personal relations are so important – ship owners must feel they can trust the shipyard, the designer and the equipment maker.  There is too much at stake – this is critical the more expensive the assets. 

Given a possibility in the future, how would Rolls Royce Marine respond to providing solutions for a cruise industry linking India, knowing its untapped potential and exciting challenges?

We have had projects in India for several decades so it is a very interesting market.  With my experience with the maritime sector in India, however, cruise vessels do not seem to be a wise place to start.  We are developing designs that are medium spec’ed and easier to build while maintaining many of the quality hallmarks.  We are happy to assist Indian shipyards building UT- and NVC designs. 

While Rolls Royce Marine has been doing reasonably well like we said earlier, there is still a lot of potential remaining to be tapped. Will it be able to match the prowess of the aerospace division in the coming years?


The two markets are fundamentally different.  Aerospace is an industry with very high entry costs so that once you are established you are among very few.  This makes the industry easier to be big in, then in the marine industry where entry costs are much lower and margins are under heavy pressure these days due to the low oil price.  However, we have a lot of untapped potential but matching aerospace will probably be hard.  

Ship design is still transitioning from a rule based design methodology to risk based design methods. How far has your organization been able to adopt the factors of risk assessment into the process of ship design?

We use it to some extent, but the adoption rate varies considerably except where it is mandated by class for which we fully comply, of course. Class notations are vital in our business. 

On a different note, please tell us about your time with students of Management Science. Especially about the skills you deem are vital among management personnel in the field of ship design.

Irrespective of industry, I think an important trait of a good manager is the willingness to always learn something new, constantly reading and updating himself so that he does not become outdated and falls behind. Another important trait is the ability to use facts to solve problems instead if going with the guts all the time. Sure, gut feeling will be an element in many cases, but it has to be aided by facts.  However, what must never be underestimated is the ability to handle people.  Brilliance in subject-matter, but lack of people skills, will imply that this person is suitable for technical work and not management.  Therefore, I look for students that are fact-based and willing to question things and learn new things.  Good humour at own expense and humility are also important traits. Leadership potential is severely restricted in people that constantly have to prove how smart they are because I know from experience that such people will fail as leaders. 

Last question to you, the questions for this interview have been framed by eager students and budding engineers in the field of Naval Architecture, who have looked forward to interacting with you through this interview. What message do you have for them?

I hope you all find something useful in my answers, but more importantly; keep on learning the rest of your lives about management, philosophy and other topics NOT related to engineering or naval architecture– then you can contribute more widely as well and build your career.  

To know more about Dr. Emblemsvåg and his work, you can visit his website:  www.emblemsvag.com

The picture used above does not belong to LSD, and full credit for the same goes to the respective owners.