Chapter 1 ALUMINIUM, THE MARINE METAL 1. Historical review . 10 1.1 Early beginnings, 1890 to 1900 . 10 1.2 Weight reduction, safety and decoration of ships 1920 - 1950 . 13 2. The development of aluminium-magnesium alloys of the 5000 family . 14 3. Marine applications of aluminium . 15 3.1 High speed ships . 15 3.2 Boating and yachting . 16 3.3 Work boats . 16 3.4 Ship superstructures . 16 3.5 Offshore . 17 3.6 Coastal installations . 17 4. Innovation . 17 Alcan Marine 9 1. ALUMINIUM, T IS AN OLD STORY that goes back I over a century, and one which incidentally accompanied the birth of the aluminium industry. The industrialisation of aluminium production by dry electrolysis began in 1886 with the utilisation of the patent of Paul Louis Héroult in France and Charles Martin Hall in the United States. Less than a decade later, from 1891 to 1897, a number of The Aluminum World, December 1895 [2]. Figure 1 attempts were made both in Europe and the United States to build ships from aluminium. 1. 1.1 Although short-lived, these experi- HISTORICAL REVIEW Early beginnings, ments proved highly illuminating 1890 to 1900 and informative, and the perform- Although much more expensive The very first boat known to be ance of these vessels revealed the than steel, some 30 times more in made of aluminium, a “steam [1] full potential of aluminium for 1895 (1), aluminium quickly launch” 5.50 metres in length, marine applications. aroused the interest of maritime with a beam of 1.28 metres and a circles (figure 1). Its light weight draft of 0.61 metres, was built in In the Nineteen Thirties, alu- was initially the principal reason 1891 by the Swiss shipyard Escher minium’s adventure in ship con- for the use of aluminium in ship- Wyss in Zurich [3]. Its hull alone struction was re-launched on new building. weighed 440 kg. This boat was concepts based on the use of spe- powered by a steam engine that cial alloys and methods of assem- (1) By the year 2000 aluminium was ran on oil (figure 2). around 4 to 5 times more expensive than bly that have continued to advance steel, or between 2 and 2.5 times allow- to the present day. ing for a 50% reduction in weight. THE AMPORELLE Alcan Marine 10 THE MARINE METAL Alfred Nobel, the inventor of “Le Vendenesse” was 17.40 dynamite and creator of the metres long overall, with 180 m2 famous prize, placed an order with of canvas and a displacement of the same shipyard for a boat, “Le 15 tonnes. The 2 mm thick Mignon”. This vessel was 13 aluminium skin, riveted to steel metres long, had a 1.80 metre frames, saved 40% on the weight beam and a draft of 0.61 metres, of the hull. and was kept moored in front of Nobel’s villa at San Remo in Italy. It Inspired by experience with the too was powered by an oil-fired Vendenesse, the holders of the Aluminium launch (1891). Figure 2 steam engine. During trials on America Cup had the skin of their Lake Zurich, “Le Mignon” attained boat “Defender” made from 2.80 metres and a draft of 1.45 a speed of 13 km/h (8 knots). aluminium. With its weight thus metres with a displacement of 14 reduced, it won the America Cup tonnes. The bare hull weighed just In France, a wealthy aristocrat and unopposed in September 1895 2500 kg. The skin and frames keen regatta yachtsman, Comte (figure 3). were made from aluminium sheet Jacques de Chabannes de la 1 to 5 mm thick [4]. Palice, appointed a naval architect Navies too took an interest in to design the first aluminium aluminium. Thus it was that in In 1895 the same yard also sailing boat in history, “Le 1894 the French navy placed an constructed a 58 metre (190 feet) Vendenesse”. This vessel was built order for a torpedo-boat, “Le long torpedo-boat, the “Sokol”, for the at Saint Denis near Paris, and was Foudre”, with the British shipyard Russian navy. Powered by a 4000 HP launched on the 6 December Yarrow & Co. This vessel had a engine, it attained the speed record 1893. length of 19 metres, a beam of for the time of 32 knots [5]. THE HSV ALISO Alcan Marine 11 The Aluminium World, October 1895 [7]. Figure 3 The superstructures of a number a situation aggravated by an igno- much longer on the other hand. of ships of the US Navy were rance of the metallurgy of age In 1893, five aluminium launches made of aluminium but were hardening alloys at that time (2), with a length of 12 metres and a rapidly replaced by … steel [6]. I heterogeneous methods of beam of 3 metres were con- assembly. Parts made of alu- structed in France at the initiative The use of aluminium in naval minium were riveted to frames of the Ministry for the Colonies. construction was not pursued made of steel (using steel rivets They were made in sections that beyond 1900 owing to the fact that and even rivets in cuprous alloy!!!) could be taken apart and carried the service life of these vessels These were ideal conditions for on men’s backs, and were was generally very short. The producing galvanic corrosion intended for use in the explo- aluminium showed signs of severe whose effect on the aluminium ration of two major African rivers, corrosion in contact with seawater was both rapid (within just a few the Congo and the Niger; they just a few weeks or at most weeks) and severe on a material had a service life of several several months after they were already sensitised by the presence years, beyond 1900 [11]. launched [8]. of copper or nickel, I contemporary surface finishes There were a number of reasons were unsuitable for aluminium, for this failure: not to say catastrophic for corro- I the metal itself. In order to sion resistance due to the use of harden aluminium to obtain red lead oxide, as was the case on acceptable mechanical properties, a number of ships such as the tor- up to 6% copper was added to it in pedo-boat “Le Foudre”. Europe [9] and up to 4% of nickel in the USA [10]. It is well known that The service life of aluminium ves- (2) The age hardening of aluminium alloys containing copper - “the duralu- Alcan Marine these elements are not at all sels operating in fresh water mins” - was discovered by Wilm in 12 favourable to corrosion resistance, environments at the time was 1908. 1. ALUMINIUM, THE MARINE METAL from an alloy with 13% silicon, GRILLES AROUND THE LIFT SHAFT 1.2 known at the time as “alpax”, used OF THE LINER MAURETANIA Weight reduction, in the equipment of warships, safety and decoration such as the casings of engines, of ships 1920 - 1950 pumps and fans, electrical enclo- The experience of the final decade sures, doors [12], etc. of the 19th century had demon- strated that aluminium could be Out of considerations of safety used to significantly lighten a boat (superior strength in the event of and hence to increase its speed. fire) and weight, officers’ cabins The triumph of “Defender” in the were increasingly equipped with America Cup of 1895 was proof of furniture made from aluminium, this. usually painted duralumin [13, 14]. In the first half of the 20th century, Aluminium also found increasing from 1920 onwards, aluminium use in the interior equipment of regained an increasingly important merchant vessels and liners: place in both civil and military ship- I both for safety reasons, super- ping. There were three main rea- seding timber furniture that would sons for this: burn and give off smoke and I the availability of aluminium- fumes in a fire, magnesium wrought alloys of the I and to enhance decoration (3) 5000 series. These are ideally on prestigious liners. The furniture suited for marine applications in in the cabins of the Normandie for general and for shipbuilding in par- example were made from “dura- ticular (cf. Chapters 2 and 3), lumin” [15], while the public areas I the need to reduce the weight on many liners (salons, dining of warships to meet the require- rooms etc.) were adorned with Figure 4 ments of the Washington motifs in aluminium that were Conference of 1922, often commissioned from famous I the safety (and comfort) of pas- designers [16]. sengers travelling on liners. Through its association with lux- ury, prestige, comfort and safety, In the Nineteen Twenties, the first aluminium found widespread use and probably most widespread on the last transatlantic liners to (3) Including the many outstanding artis- applications were parts moulded be launched. 1600 tonnes of alu- tic creations in the Art Deco style. RIVETED CONSTRUCTION OF THE DIANA II Alcan Marine 13 Figure 5 minium alloys were used on the immersion test (6) [29, 30]. The pur- France, launched in 1962, in 2. pose of this test was to study the superstructures, funnels, lifeboats THE DEVELOPMENT behaviour of aluminium in ship- etc. [17]. OF ALUMINIUM- building on a representative MAGNESIUM mockup. The first boats to be made entirely ALLOYS OF of aluminium were launched at the THE 5000 FAMILY Marine applications, especially on beginning of the Nineteen Thirties. board mercantile vessels and war- These were the first marine Detailed studies of aluminium- ships, were convincing enough for applications of an alloy with 3% of magnesium alloys of the 5000 it to be accepted from 1930 on magnesium (4) whose industrial family (or series) began in 1900 [19].