By Robert Mc Farlane, Naval Architect
Not a subject that frequently surfaces, but one which fascinates and can easily overwhelm the enthusiastic.
The France II is unusual in a number of way, but of particular interest to the Naval Architect because of the fact that it was
The owners Prentout-Leblond were at the turn of the century operating a fleet of sailing tankers for the oil trade from USA to France. In 1911, Prentout decided to order from Les Chantiers de la Gironde in Bordeaux a five mast barque. This vessel was in fact the second one named France, the first having been built in England, in the 1890, for the A.D. Bordes Company who was operating one of the largest fleet of tall ships, numbering approx. 18 vessels. Prentouts ship was named France II as a difference with Bordess vessel. The France II was ordered by an experienced shipping company to surpass all previous vessels better than anything that had come before it, and hind sight has shown better that anything that have succeeded her. At this time the competition of steam vessels condemned all but the most efficient sailing vessels to extinction. This competition had already made most short & medium length voyages commercially uneconomic for sailing ships. The longest routes however could still be fought for. The France II was therefore intended for the toughest task ; the transport of nickel ore in bulk, from New Caledonia to France ; a circumnavigation of the globe, half in ballast and half loaded with 8,000 tons of rock.
The object of the Association France II Renaissance is to reconstruct this vessel, not an identical copy, but a visual copy and a copy of the spirit of the original vessel. We too will use the same philosophy as the original vessel, using todays technology to the fullest but not to the detriment of the outside appearance of the vessel and its essence as a tall ship in the fullest terms.
The largest impact on the new vessel is needed to facilitate its new task.
The second factor to incorporate is that of time, the original concept was made in the first decade of the century we are now in the last decade, this has produced new constraints and new possibilities.
The constraints are imposed by todays labyrinth of Rules.
Outweighing these constraints are new possibilities have developed during the passage of nearly 90 years since the conception of the first France II.
This plus the huge advantage of having a mountain of data on the building and operation of the original vessel, puts us in a very favorable position.
THE COMPARATIVE NAVAL ARCHITECTURE
The underwater position of the Hull
The most direct impact on the underwater hull is of course the new cargo, the original 8,000 tons of rock is replaced by 15 tons of passengers. This has made it necessary to design a new underwater hull shape. Plus for practical reasons the loaded draft has been reduced from 8m to 6m. In creating a new hull form a number of other factors have been in incorporated resulting in
The above water hull & superstructure
This is aesthetically the same of the original vessel, with identical sheer, bow and stern. The height of the topsides is similar to the vessels original when in ballast condition and will allow two layers of portholes to be fitted.
Here too the original layout has been maintained. The use of power winches of more compact modern design, plus the fact that the volume of standing and running rigging has been reduced by the use of higher strength modern cordage, both have facilitated the liberation of open deck space, much sort aft by our cruise passengers. The original cargo hatches will be visible, but serving new functions as skylights, benches or deck storage lockers. The modern equipment needed for communication, navigation, safety and ventilation will be there, but for the most part will be hidden or disguised as a an object from the original époque. A noticeable addition to the deck will also be an open swimming pool.
The Masts and Rigging
The most visually imposing aspect will keep all its charm and aura, but the huge technological advances in materials will have their greatest impact here. The rig will still have the same number of sails and sail area, will still be manually controlled, but the original weight of over 450 tons, will be reduced to just over half of that. This is made possible by the use of advanced materials such as: -
In addition to being stronger and lighter, these materials are also safer, more user friendly and require far less maintenance than there predecessors. The equipment is however not computer controlled and will still required a substantial crew to maintain and operate it. Something we felt essential to maintain the spirit of a real tall ship, to occupy the trainees and to preserve a part of our maritime heritage.
The impact of these factors will be an equally powerful rig, but much lighter, more easy to maneuver. Due to some minor changes in the geometry and modern sails the ship will be able to sail closer to the wind and provide greater lift. This combined with increased stability will give the vessel a higher performance under sail than the original vessel.
In 1911 there were still no strict rules on stability or protection from down flooding. The ship's geometry and stability were decided on a more practical level, empirical guidelines having been built up over the years. Guidelines intended for the protection of the vessel and to increase the likelihood of delivering the cargo in good condition. There was little or no concern for the crew and their safety.
Todays environment is different, now we have a vast collection of rules and requirements primarily concerned with the protection of passengers and crew. However despite this armoury of rules, now a mix of empirical and calculated data, there are few specific rules for sailing ships. We as Naval Architects are required to apply the rules intended for motor ships to sailing ships, but must propose to the authorities our own additional safety criteria for each individual sailing ship. The designer must therefore take into account the operational knowledge built up over the years, 87 years more than available for the original vessel design. This is available to us, but due to the small number of sailing ships now operating, this data is not incorporated in the contemporary international rules.
The particular improvements of the new vessel over the original are;
In comparison with the original vessel we will be twice as stable with twice the range of dynamic stability. A much safer vessel.
Down flooding, the entry of water into the vessel from a point on or above deck that allows water to flood down into the ship, was one of the most common causes of ship losses. It is still an area of concern for large sailing ships, and has caused losses even in the last decade, hatch openings and doorways being the main concern. Therefore during the conception of a new vessel we try to make the ship inherently safe, by positioning such openings in such a way that even if the are left open by crew error, they do not expose the ship to immediate danger. In the case of the France II we have sealed the hatch openings and located all doors to the superstructure close to the centerline.
There is also the new demand for stability after the vessel has been damaged. To comply with this the vessel is divided into a number of watertight compartments, such that even in the event that any two compartments are flooded the vessel will survive. The original vessel had no ability to survive such damage.
The loss of the Titanic in 1912 brought world attention to marine safety and was the catalyst for the creation of an international body devoted to the Safety of Life at Sea (SOLAS). Modern passenger vessels benefit from the, in-depth study of plans and construction, plus new materials and safety systems whose development was stimulated by this international body. Here the aim is for maximum fire safety, and a particular philosophy has been developed for the conception of a new ship.
Should these measures fail there is as a last resort, provision to evacuate passengers and crew into special survival craft.
The implementation of these safety rules has significant impact on the vessel arrangements, choice of materials, systems, and operation and on crew training. The results however are impressive, the cruise industry now holding the highest safety records of the entire marine industry.
In keeping with the Prentout-Leblond company hatred of motor ships, the original France II was fitted with two 900 HP diesel engines, intended to help maintain consistent voyage times, but in fact suitable only to maneuver in port but not much more. The decision was eventually taken to remove the engines as the resistance of the propellers when not in use was thought to reduce the speed under sail. A decision which ultimately contributed to the vessel drifting aground and being lost, one windless day in 1922.
The new France II will on the contrary be fitted with complete and powerful modern machinery. A totally different philosophy is being used in its selection. The philosophy here is one of our times, that of speed, convenience, comfort and the current mode of conservation. She will be an environmentally friendly ship. Propulsion will be provided by two independent diesel engines, each driving an independent controllable pitch propeller. The diesel engines have been selected to run at constant speed, and burn high-grade fuel, a regime that produces the best efficiencies and least pollution. The power however is 6000 kW five times that of the original vessel, able to push the ship at up to 17 knots in ideal conditions. This power plus the twin system affords the vessel the highest degree of security, through redundancy. However in tribute to the Prentout-Leblond company the propellers are a special feathering design so as not to reduce the speed under sail when they are not in use.
The rest of the machinery bares no resemblance at all to the original vessel; it does in fact have more in common with an isolated town. It is capable of providing all the services we expect in modern life, including the production and distribution of electricity, purification of drinking water, ventilation, air conditioning, refrigeration, sewage and waste treatment. A completely contemporary machinery room, one that would be found on a conventional cruise ship of similar capacity, with the full range of latest equipment. There is also a sophisticated computer based machinery monitoring and alarm system, that will permit the machinery spaces to operate unmanned, although in reality as a training vessel, it will not be operate as such.
A surprising but logical fact of a luxury passenger ship is that the most complicated system, requiring the most maintenance is the sanitary waste system. France II will be no exception, with over 150 toilets and 150 showers and 200 sinks, this is the most complicated system onboard, plus to add an extra technical challenge the whole lot must function even when the ship is heeling under sail.
The interior designer will discuss the decorative aspects of the interior in a separate note. The practical aspects are as follows.
Inversely to the method used for conventionally for designing. Here we start with the envelope provided by the dimensions of the original vessel and then see what will fit inside.
The France II envelope allows for three interior decks, plus one superstructure deck. Removing from this volume the technical spaces and storage spaces leaves us 4700 m2 of accommodation space. This we have divided between the passengers and crew as follows.
In so doing we must
The trickiest part is to ensure proper circulation. We must provide the most direct connections between service spaces and the space they are to serve, for example the galley must be near the dining room, also near the stores, but should not use any valuable space that could otherwise be used profitably for passenger cabins.
On top of these goals the overriding factor is that the resulting arrangement must be right for the vessels use, in this case a luxury passenger cruise ship. Priority must go to the passengers, arranged to give sufficient area, allow ease of movement between the spaces and give our guests the feeling of freedom. This balance between, freedom, openness and of proximity to the sea and Mother Nature, whilst also protecting and comforting them, is what will give character to the ship.
Satisfying all these requirements within the confines of a steel ship, which is already divided into watertight compartments to protect it from flooding and littered with protected escape stairways, it is not an easy task, but is a fascinating passionate one, and the reason why I am a Naval Architect.
Robert McFarlane, Naval Architect - Naval Architecture of a Replica - Sept 1997