O Liuro da Fábrica das Naus
This treatise was written by Father Fernando Oliveira and dates to 1580. It is a remarkable corpus of information concerning shipbuilding in the 16th century and extremely valuable to scholars of Iberian shipbuilding. This nautical book was first published in 1898 by commander Henrique Lopes de Medonça in his publication “Padre Fernando Oliveira and his Nautical works”. The book is comprised of a prologue and nine chapters. Although it was never completed, it contains information on a variety of nautical themes; including wood suitable for shipbuilding, materials required for the construction of a vessel, various types of watercraft, construction and measurement of ships, and other valuable information. This manuscript appears to be a continuation of an earlier work by the same author, entitled Ars Náutica (ca. 1570).
Fernando Oliveira was an ambitious man of the 16th century, and had many interests which he pursued during his lifetime. He also had an immense amount of nautical experience, which gives credibility to his work on such matters. Oliveira was probably born in 1507 in Aveiro, Portugal. He began his studies with Dominican priests at age nine or ten, with whom he continued his education until age 25. The next known appearance of Oliveira is in England in 1546, in the court of Henry VIII. Oliveira had been the pilot of a French galley that was enmeshed in a struggle with an English naval unit in May of the same year. The French galley was subsequently captured and the crew imprisoned by the English. Oliveira apparently impressed the English royalty and became a guest of Henry VIII. It is possible that Oliveira was employed as an ambassador in the negotiations over the French galley and its crew at this time. Ancient records from the period reveal that Oliveira was, for some reason or another, paid £100 during the reign of Henry VIII. It is also known that he returned to Portugal with a letter from Dom João III, likely declaring the accession of Edward VI.
Upon Oliveira’s return to Portugal in 1547, he was interrogated by the Portuguese Inquisition for his beliefs. During this inquisition, Oliveira refused to denounce Henry’s religious views. He reportedly claimed that he “had been Henry’s servant, and eaten his bread”. Subsequently, Father Oliveira was imprisoned until 1550 in the monastery at Belém.
In the autobiographical section of O Liuro da Fábrica das Naos, Father Fernando Oliveira mentions that he had traveled the world, working and studying in shipyards in Spain, Italy, France, and England. It is likely that Oliveira studied the Thames shipyard during his time in England, and very possibly met his contemporary in shipbuilding practices, Matthew Baker. Many of Oliveira’s drawings are similar to the ones represented in Matthew Baker’s Fragments of English Shipwrightry, a coeval manuscript that gives information about English shipbuilding during the 16th and early 17th centuries. An example of this similarity includes the analogy of a ship’s hull and the body of a fish. This hull morphology, according to the authors, is what is attributed to the smooth sailing capabilities of the vessels.
Father Fernando Oliveira was knowledgeable on a diversity of intellectual fronts, and composed a variety of instructional works during his life. His free-thinking mind is revealed in some of his compositions. He wrote Arte da Guerra do mar, a manuscript detailing methods of naval warfare, in which he severely criticized the introduction of slavery by the Portuguese. He also comments on the advent of firearms as “an invention certainly more infernal than human”. Oliveira’s first published work is a textbook on the Portuguese language, entitled Gramática da linguagem portuguesa… It is a justified assumption that Father Oliveira was a man who did not merely write instructional works on interesting subjects solely from his armchair. His practical experience and cosmopolitan view suggest a sophisticated intellect and considerate authorship. His diverse career path offers further substance to this conclusion: Dominican priest, grammarian and historian, cartographer and pilot, adventurer and occasional diplomat, and theoretician of war and shipbuilding.
O Liuro da Fábrica das Naus is divided into a prologue and nine chapters. The prologue essentially explains the significance of the navigation and ships for Portugal, which is part of a peninsula that has forever been affected by the sea. He mentions that information on shipbuilding has not been previously properly taught, but was instead hidden. For these and other reasons that the author mentions, he decided to produce this instructional manuscript. The following is a table of contents to this book:
Chapter 1: On the Antiquity of Ships
Chapter 2: On the Types of Wood that are Suitable for the Building of Ships
Chapter 3: On the Time when Woods Should be Cut: and the Manner in which they
Should be Cut
Chapter 4: On the Materials Used in Shipbuilding
Chapter 5: On the Kinds and Ways of Ships in the Art of Navigation: and Their Names
Chapter 6: On the Need for Art in the Construction of Ships, and on the Nature of that
Chapter 7: On the Way the Art of Shipbuilding Imitates or Alters the Nature of Some
Fishes and Animals
Chapter 8: On the Construction and Measurement of Carrier Ships
Chapter 9: The Gear Required for Cargo Ships
Chapter two describes the types of woods that are suitable for shipbuilding, and Oliveira suggests the two most appropriate kinds of wood for a ship were cork-oak (Quercus suber) and pine (Pinus pinea). The cork-oak was used for frames, and the pine for planking. Chapter four details the materials that are used in shipbuilding. Oliveira mentions iron nails, oakum and pitch for caulking, and grease used in lubricating the vessel. Chapter five briefly describes various kinds of vessels, including naos, galleys, galleons, and caravels. Although all chapters of this book offer important insight to aspects of Iberian shipbuilding practices during the 16th century, the eighth Chapter is the most instructive for the study of the structural characteristics of a caravel.
The type of ship that Oliveira generally refers to is a nau, and is a larger, bulkier cargo ship compared to the caravel of discovery. Nevertheless, much can be learned from Oliveira’s instruction that can be applied to all Iberian ships from this period, which consequently can be attributed to the caravel.
Oliveira begins the eighth chapter by asserting that the beamier the ship, the more cargo it can carry and the more buoyant it will be. Likewise, the vessel must be strong, a good sailor, and of good capacity. He cautions, however, that although a somewhat beamy ship is preferred, it should not exceed the limits of its proper dimensions. Size of ships depends on the purposes for which they are built, and the voyages they are meant to undertake. Certain considerations must be taken, such as the length of journey, degree of safety, and anticipated weather patterns. All these variables and others help determine how a vessel should be constructed. Larger ships should be built for longer journeys to accommodate for the victuals and materials that are needed. In this section, Oliveira comments that small ships are not a good choice for the trips to India because the expenditure would exceed the gain, and also because they are not as safe for long journeys as are the larger vessels.
During the second half of the 16th century, when this book was written, caravels were no longer the prime exploratory vessel they were even fifty years earlier. After the routes to the Indies and Americas were discovered and cartographers recorded these routes, there was less need for a vessel that could brave the uncharted waters and unknown rocky coasts. Oliveira mentions other reasons why smaller ships are not practical for long journeys at this time. Larger ships have a better ability to defend themselves against pirates than do smaller vessels. A ship’s size alone is enough to intimidate an enemy, and smaller ships cannot carry enough men to be feared by an enemy. He also states that the journeys to India were always made with ships of over 500 tuns, and these have made the safest journeys, for they handle the sea better. Thus, it is easy to see why late 16th and early 17th century treatises on shipbuilding have less emphasis on the smaller vessels such as the caravels.
Oliveira describes the dimensions of ships in a relative way. He asserts that all ships, regardless of shape or size, can be built by using one part of the vessel as a proportional basis from which to derive other parts of the vessel. He refers to this as rata pars, which means ‘certain part’ in Portuguese. Oliveira likens this concept to the proportion of the human head to the rest of the body. If the head is large, other parts of the body will also be large, in a proportion corresponding with the size of the head. He then assigns the keel as the part of the ship by which all other members of the same vessel are measured. He writes that once the length of the keel is known, shipbuilders can get the width and height of the vessel, the bottom, bow and stern rakes, and other main components of the ship.
Oliveira gives the keel to beam ratio of a ship as 1:3, with a width that is slightly greater than the height of the vessel. The ship that Oliveira refers to in his examples is a theoretical nau of 18 rumos. Thus, a ship with a keel of 18 rumos would have a beam of 7 or 8 rumos. Its depth would be a bit less than that of the beam. Oliveira writes that the exact measurements would be up to the discretion of the experienced carpenters.
Oliveira describes the keel essentially as the backbone of the vessel, and declares that it should consist of a thick piece of strong timber, such as cork oak, since all of the vital structures of the vessel are set upon it. This is a principal that has been utilized since ships started integrating keels into their longitudinal framework; but a strong, thick keel is especially important for an ocean going vessel that must withstand the intense pressures of Atlantic sailing conditions in unknown waters.
Next, Oliveira touches on the bow and stern rakes, which are also proportions of the length of the keel. The rake of the bow is approximately one third the length of the keel. This rake is obtained by erecting a vertical line at the butt of the keel, forming a perpendicular reference which is as high as one third of the length of the keel (this is also the height of the deck). Next, a compass is used to swing an arc from the bottom of this perpendicular (where it meets the keel), until it reaches the height of the predetermined deck line. Oliveira asserts that this method is the best in existence, because the more one utilizes parts of a circle, the more efficient the bow of the vessel will be.
The rake of the stern is not as great as that of the bow. It is formed in a similar way. The perpendicular is formed at the point on the keel where the sternpost begins. An arc is then drawn from this perpendicular down to the keel. This arc is subsequently divided into seven parts, each of which is the same length of the rake aft of the perpendicular.
Oliveira briefly mentions the placement of the gio, or wing transom. Essentially, his main emphasis lies in the leveling of the timber, which is fundamental for the balance of the vessel. He continues with the strengthening of the keel, which is achieved with the placement of keelson and deadwood. He stresses that these timbers must all be thick and strong, as the structural integrity of the vessel relies on these components.
Next, Oliveira demonstrates how to lay the bottom of the ship. This is an extremely important part of the manuscript, for it shows how the shape of the vessel is conceived. Described for the construction of naus, this method was used for caravels and other watercraft as well. The laying of the bottom is a fairly involved process which will be only briefly discussed here. First, the master frame, which is the center of the predetermined section of the hull, must be situated ahead of the middle of the keel. As Oliveira notes, this is mainly to obtain a longer run in the hull, which provides the vessel with better maneuverability. The floors (flat timbers forming the bottom of the frame) of the master frame are essentially flat. However, as the frames are placed fore and aft of the master frame, the floors are raised according to a predetermined scale (discussed below). As these floors are raised, they are simultaneously narrowed in order to give the vessel the necessary curves that allow for good sailing capability. This narrowing is achieved in the same manner as the rising of the floors, which is by a predetermined algorithm that is obtained through the creation of a graminho.
There are various ways to make a graminho, but the end result is a scale obtained by the division of the length of the keel and the number of predetermined frames that will be placed on the keel. The compartida is this length that is divided, and indicates the amount by which a pair or pair and a half (as the case may be) is to rise and narrow. This compartida is distributed proportionally throughout the length of the keel, and is what gives the vessel the shape desired by the shipbuilders. Frames fore and aft of the master frame have a separate scale which determines their respective rising and narrowing.
Oliveira also describes how the loft the frames of the vessel, which are comprised of the aforementioned floors, and the corresponding futtocks which are fastened to these floors by treenails and iron nails driven transversally through the corresponding members. The design of the futtocks and toptimbers that make up the upper part of the master frame is conceptualized through the geometry of a circle. Ancient shipbuilders used circular arcs to form the shape of the frame, which is based on a set of rules that is explained in detail and illustrated by Oliveira. Subsequently, the other predetermined frames are fabricated using the master frame as a point of reference, rising and narrowing accordingly.
Oliveira asserts that the formation of the bow should be full and not narrow, as a fuller bow facilitates better steering than a narrower one. If the bow is too narrow, it will be a poor sailor and more easily fall off course. He adds that a narrow bow will cause more turbulence and will not break through waves as easily as a wider bow. He stresses that the frames and timbers that form the bow and stern of the vessel outside of the predetermined frames must run smoothly so as to not create any irregularities in the ship.
The author then describes the positioning of the beam of the vessel, which is the widest point at the main deck, and says that it is situated at a height equal to one third of the keel length. This beam is narrowed as far as the tail frames equally forward and aft. He claims that this reduction is equal to an eighth of the greatest beam. Outside of the tail frames, the reduction is equal to three eighths of the greatest beam.
In explaining the outer planking of the vessel, Oliveira writes that the timbers must be of a thickness suitable for the purpose of the ship, and must account for the voyages it must make as well as the conditions it must endure. The wales (larger external planking that provides additional support) of the vessel should be at least two fingers thicker than the planking, but not as wide as the planks.
Oliveira continues discussing other details of construction which generally apply more so to vessels larger than the caravel, and will not be mentioned here. It is apparent that the information provided in this manuscript gives the scholar of Iberian seafaring an invaluable look into the theories and practices of ancient shipbuilders during the 16th century. By examining Oliveira’s manuscript in detail, general traits of Iberian ships are revealed, which is an important step in the understanding of the structural characteristics of the caravel. Most of the shipbuilding methods and features described here would be expected to appear on an Iberian caravel from this century, and many would likely be found on earlier caravels of discovery. Oliveira’s manuscript on the construction of naus was the forerunner of nautical treatises, and some of the later treatises, such as Livro primeiro da architectural naval by Lavanha, describe and demonstrate many of the same shipbuilding methods and ideas as Liuro da fábrica das naus. With the knowledge gained by investigating these ancient texts, a fuller picture of 16th and 17th century Iberian ships in general—and the caravel in particular—will be obtained, and thus applied to the study of Iberian seafaring.