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
Art
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.