Trans RINA, Vol 153, Part A1, Intl J Maritime Eng, 2011 Jan-Mar


attracted large local audiences. For example Robert Thompson’s Presidential Address to the North East Coast Institution of Engineers and Shipbuilders in 1892 was full of technical data, while Harry Bocler’s paper on ballasting of ships to the same institution in 1942 was likewise practical – he was the naval architect at Swan Hunter & Wigham


Richardson. At the Marine


Technology Special Collection at Newcastle University we have all of Bocler’s detailed notebooks in which he recorded his data and experience – the traditional naval architect’s ‘little black book’ writ large in a dozen red notebooks. In the similar Institution of Engineers and Shipbuilders in Scotland, David Watson’s classic paper on estimating ship dimensions in 1961 (updated by him and Gilfillan to RINA in 1977) was a godsend to naval architects young and old – Watson was then the naval architect at Alexander Stephen.


Throughout the period, the naval architect has remained the general practitioner of the marine technology business,


like his medical counterpart needing to


consider the whole body and knowing when to call in the specialist. Today specialists are routinely involved in the design process, e.g. propeller designers or noise and vibration experts. But


it was not always so – I recall


being surprised to be told by a retired marine engine builder that they routinely designed and manufactured propellers for shipbuilders with virtually no reference to the associated hull. At least that practice kept purveyors of patent propeller designs in business, who would often be called in by shipowners dissatisfied with the seagoing performance of their new ship. The solution was not in fancy blade geometry but in better matching of propeller characteristics to the actual hull and engine.


Indeed predictability of performance at the design stage has been one of the ongoing design improvements – today it is rare for a ship not


requirements. This has been partly due to improving the ‘how’


of ship design. Much


to meet its contract less lengthy manual


calculation, much more sophisticated design aids. How the naval architects of the 1880s welcomed the Amsler integrator to greatly speed up calculation of cross curves of stability, while in modern memory, the replacement of tedious hand


computer programs allowed the designer to readily explore much more complex patterns of damage cases and different subdivision.


Fortunately the introduction of the digital computer in the late 1950s coincided with the rapid expansion of ship types and sizes. It soon drove out the mechanical calculator for calculations like hydrostatics, while every naval architect bought a personal calculator in the 1970s. In only 20 years tankers grew from 30,000 to 300,000 tons deadweight, while new types such as container ships, bulk carriers, roll-on/roll-off ships, cruise ships and liquefied gas carriers were introduced. Designers were enabled to assess the complexities of these new ships – finite element analysis for large tanker and


Not surprisingly design and order-to-delivery times have greatly increased over the years, partly due to ever increasing complexity but also to ever more demanding regulations to be satisfied. A hundred plus years ago, ships would be routinely ordered, designed and delivered in less than 12 months. Maybe not a fair comparison, but contrast that with the UK’s two new aircraft carriers, whose design started about 1992 and are unlikely to be completed before 2017 – 25 years, which is a normal ship’s lifetime. Design costs have increased as a percentage of construction cost, but still remain modest compared with some artefacts.


other complex engineering calculations of damage stability with


In addition to the author’s design issues 5 S’s – Speed, Stability, Strength, Seakeeping and Style – I added seven more in my lectures to first year student naval architects, some more applicable to merchant ships than naval, e.g. Size – there is an optimal size of ship for each trade. Shape addresses hull form more explicitly than Style. Stowage is crucial at least for piecewise cargo like containers or wheeled cargo. Systems recognises that a ship is part of wider system, e.g. a transport network, as well as having sub-systems like cargo handling. Seamen gives the crew a formal place in the design process, both in operating the ship and it being their home. Safety - one could argue that this is implicit in things like Stability, but in today’s increasingly regulated world, it needs to be addressed explicitly. The twelfth for commercial vessels is Solvency - I could not think of another S word that implied achieving a satisfactory financial return. Perhaps for military vessels Stealth or Signatures could be added.


A small but welcome change in design papers presented to RINA is recognition of all the contributing authors by


container ship structures, damage stability for ro-ros, ship motions for cruise ships. But these were only methods of analysis – the designer still had to synthesise, that is propose the


features


metaphorical ‘clean sheet of paper’, and here experience and corporate memory


of the new design from the still had a part


proposing a plausible design for the software to analyse.


The design authority has changed over the years for different ship types between shipowner, consultant and shipbuilder, with no definitive answer to what is best. Especially with fairly infrequent newbuilding, there is a problem


with an owner maintaining an ‘informed


customer’ status, with frequent staff turnover in modern organisations and the rise of the project manager who may have little first-hand subject or intuitive knowledge. Many major merchant shipowners who used to have a naval


superintendents, which has allowed the shipbuilder to become the


in recent years,


architect’s department now rely on technical design authority, especially in seller’s


markets. Interestingly one of the few owner types to have maintained such expertise are those with the greatest technical and commercial successes namely cruise ships.


to play in


A-56


©2011: The Royal Institution of Naval Architects


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