© Richard Barker

February 2002

In 1952, G.B.Rubin de Cervin wrote¹ about a design for ships proposed for use by the Spanish against Venice, able to sail up to the quays in Venice itself; whence a rather fanciful description as 'Q' ships in the article. The context is that in 1619 someone - by inference a Venetian with shipbuilding knowledge - provided these plans to the Duke of Osuna, Viceroy of Naples, as part of the naval war between Spain and Venice, in which Osuna had also been attempting to acquire ships in England and Holland. These plans, or copies, were obtained by Spinelli, the Venetian Resident in Naples. Rubin de Cervin also reproduced three plates of drawings of this ship, which were in the Archivo di Stato, Venice².

These are typical of shipbuilding drawings of the time - clearly quasi-technical, more or less to scale, but incomplete. Nonetheless, it is worth a glance at the section drawing, as it is replete with construction marks, and annotation in Venetian dialect. Unfortunately there is no mention of tonnage, and no more than a handful of explicit dimensions. The key parameter was that it was not to draw more than 10 or 11 feet (Venetian ?), and had to carry a heavy armament and soldiers to be landed in Venice. It was broadly in the form of a galleass, presumably to ensure its approach without delay.

Details of the drawing

The elevation drawing has a scale in paces, subdivided into feet (passos of five pies). The plan has a scale of paces, part divided into feet, and part into half-paces. The section drawing has the first pace divided into feet, and then is marked in half-paces. The description following is necessarily based on the published commentary and plates.

The section has characteristics individually recognisable from other sources. The breadth of floor is marked, apparently 11 feet (though it scales nearer 13.7 feet, which would be close to half-bocha) - measured as the fondi, roughly on the outer face of the frame but at the height of the top of the floor, which is the point marked here and conventionally; not as the literal flat between the bilge arcs, which is about 9 piedi. The heights are divided above a dual base line - one for the bottom of the keel, and another close to a foot above it from which the measures are clearly made. There are four equal divisions, marked 3pie, 6pie, bocha and regia (which last is translated as main beam, and certainly corresponds to the notional level of a second deck, scratched in as a thickened straight line, but also to the geometric maximum breadth of the hull). Each has a breadth marked, which appear to be piedi 21, 25, 27 and 29. Thus the moulded breadth at the bocha is 27, and the maximum moulded beam at the regia is declared to be 29, though it actually scales close to 30. The divisions are closely 2.5 pie, and the 11 foot draft (on an even keel) is thus at the regia: not a normal place for the waterline, which for stability reasons ought to be below the actual maximum breadth.

The decks are marked (as horizontal lines, without camber, and unrealistically slender) as follows. Prima coperta, tra coperta ('tweendecks) and coperta 7 pie. The dimension in the last of these is clear and scales correctly. The other two are equal and scale at close to 5 pie. 5 could well be the indistinct cipher in their labels. Allowing for any ballast and the curvature of the floors, the space below the first deck is actually very constrained.

The frames are shaped with a flat floor, only turned down sharply at the garboard to meet the keel at about half-height. There is an arc for the wronghead, which may well be centred at the height of the regia, with a radius of 10 pie. The breadth has a short radius arc, apparently centred on the height of the regia. (There are a number of marks which might be compass holes visible in the photograph³). That arc may be close to 5 pie. The net result is not far different from a quadrant raised on a flat floor; but geometrically is certainly different, as there is that tangent arc of short radius below the regia. There must be a third reconciling arc, and this can be seen to have a radius close to 15 pie. Wales (or ribbands) are drawn on the section, passing through the intersections of the frame with the floor, 3pie, 6pie, bocha and regia, but these are certainly not at the surmarks between the component arcs. The maximum breadth scales at closer to 30.7 piedi than the 29 declared: a notional 30 piedi breadth would correspond to the 5, 10 and 15 piedi radii of the frame arcs being rational fractions of the notional rounded number of the breadth. (If the wronghead were say 5.5 piedi, quite possible from the image available, it would be just half of the declared width of floor: without the original manuscript such issues will not be resolved, except to say that most primary measures will be suitably round multiples of the local foot).

The gunwale is drawn at approximately twice the height of the regia above the flat floor, but there are clearly two attempts at this detail, with the first (including the frame) drawn lower, and with no effective rail in the waist. An upper deck is also drawn in, but the final bulwarks are still only about 2 feet high. The transom has a breadth about equal to half the maximum breadth at the regia (scaling 15.7); and a height at the top-timbers twice that at the transom. The tuck lies roughly at the height of the bocha, but has the cipher 9, its scaled height above the bottom of the keel. The height of the sternpost scales at close to 20 over the bottom of the keel. The sternframes are formed from an arc of 10 piedi radius, extended upwards by an arc of 15 piedi radius, and a hollowing arc of a still larger radius⁴.

The only detail of structure occurs in the sternframe, where a series of transoms and verticals are drawn, including the framing for a pair of gunports on the second and upper decks. These are only around half a metre square, and while those on the upper deck are impossibly close to the deck, those on the lower deck are drawn with sills at about a metre above the deck, which is equally improbable.

General issues arising from the drawing

There are several points of more general interest. Firstly, the use of the phrase bocha, implying breadth of the hull, in conjunction with the 3pie and 6pie. This is a much older Venetian arrangement in frame design. The very names suggest an original typical usage in a small vessel, where a real height of 9 pie reflects the actual vessel. The system reflects hulls framed with flare at the gunwale, not tumblehome, with real maximum breadth at the head of the futtocks. At ten feet it is not far different here, but the system was employed on larger vessels, and on galleys too. Little is known about the circumstances, and how the geometric moulding was associated with the three points defined. That it was is hardly in doubt: the longitudinal variation of frame shape of all vessels in this environment was determined by sophisticated geometry. It could be that the dimensions were used to determine surmarks between arcs, or, at least, moulds: but there are too many for smaller vessels using at most two arcs; and there is no possibility that measurements, generally to no greater precision than a quarter-foot (here all are in round feet) could closely represent a moulded curve. In this particular case, the sequence 25, 27, 29 at equal vertical intervals represents a straight line, not the manifest arcs, so they must be rounded figures; or require another explanation. It could be that they offer no more than a contractual guide to the approximate shape required⁵.

Secondly, based on a visual assessment of the mould construction in the photograph (without benefit of all the silver-point marks and compass holes that are certain to be present in the original), the third arc for the breadth, necessary only in a larger vessel of more than one deck, essentially, is ostensibly tacked onto a hull designed in the old way, with two arcs to the bocha (though the surmark does not coincide exactly here in attempting to reconstruct from a rough drawing). The bocha ceases to be the true breadth. There is a suggestion of a grid constructed here based approximately on the bocha, but certainly no inked vertical line framing the true maximum breadth. Similar problems of interpretation occur in some of the earlier drawings of Mathew Baker, where an initial grid is drawn for the frame geometry that does not represent the actual maximum breadth. The details are not expressed in text or terminology in Baker's extant work, and are not yet understood. It has a particular impact on what dimensions are being used to define the capacity, or tonnage of the ship. Upperworks may make a ship more seaworthy or defensible, but they do not increase its capacity (rather the opposite, in terms of hull weight and low-angle stability, on the same bottom). When they came to be used widely, and fashioned to be more seaworthy, with tumblehome⁶, there must have been a step change in the method of specifying hull dimensions in a contract, and a corresponding impact on the tonnage rule - though primarily in the correcting factor used with the same product of a length, breadth and depth.

The term pontal(e) occurs in Portuguese, Genoese and Ragusan methods, and may reflect the same point: a relic of a period when ships were not generally built up and multi-decked. It is expressed by Pimentel Barata as "first-deck height"⁷. In tonnage methods and shipbuilding data mostly for the sixteenth century, this pontale is much smaller than the depth measure of comparable English or Spanish ships, for example, where depth reported (and used in tonnage calculations) is more likely to be that at or close to the maximum breadth of the hull, well above the waterline; but not necessarily at a deck level to reflect enclosed volume, either. It is unfortunate that the documents in this case do not preserve a tonnage measure, though few extant contracts at and before this period do⁸. Even where tonnage is recorded together with linear measures, interpretation towards understanding the early tonnage measurement rules in use is usually difficult, and every example is valuable.

Thirdly, it is difficult to understand how a ship such as this was to function with so many decks. The space below the upper deck is generous, at 7 feet beam centre to centre, or close to 6 feet clear between deck and beam - but then it had to accommodate the oarsmen. It is the two spaces for stowage that are the mystery. The 'tweendeck space of 5 feet centre to centre is not in fact atypical for contract measurements of the sixteenth century for merchant vessels in the Mediterranean. A clear height of about 4 feet (especially Venetian feet, about 1391mm, or 4.5 English feet⁹) is just sufficient to handle almost any barrel; but at the same time rather wasteful for the butt in use in the Adriatic, of perhaps 0.6 tons, and approximately 3 Venetian feet in diameter. If these decks were planked, then much of the space was necessarily wasted. The space below the first deck is even more constrained, as wherever the 5 feet is measured to in this sytem (top of beam at the side of the ship to the top of the keel seems most likely, but cannot be proved here) it has to include the floor timbers and any ceiling planks; and any ballast. On that basis, even a Venetian butt might be too large to be accommodated in this space. It is possible that the beams at the "first deck" were not in fact planked, but represent merely a structural feature for the frame¹⁰. In other contracts the phrases intra coperta and infra duas copertas, or altezza insenta occur. Orlo and banda occur for the height of bulwarks, too. In the contracts seen for two-deck Ragusan vessels the usual phrase for the first space above the floor is pontale, sometimes at the bocha, sometimes related to the first deck. It is as though they are expressing a system such as we have in the present Venetian drawing: pontale is the old height at the bocha, and the copertas and intra coperta are the physical divisions of the decked spaces, which do not correspond with the bocha.

The earliest tonnage rule¹¹ for single deck ships is based on a multiplication of bocha and pontale (and then keel length): it is not so clear what happens when there are two breadths and at least two depths to choose from. The old tonnage rule appears, then, to have been developed for single-deck (or un-decked) vessels, and confusion reigned when it was applied to more developed hulls.

Wider implications of the composite features of the drawing

Finally, the great interest of this single draught, ostensibly from Venice, lies in its relationship to English shipbuilding design, and in particular the unresolved enigma of the "Venetian" frame designs given by Mathew Baker in the so-called Fragments of Ancient English Shipwrightry¹², around 1570. The present drawing is closely dated at 1619. The geometric arc system is in precisely the form developed by Mathew Baker. Baker also records a series of complex multi-arc frames which he explicitly describes as those used by the Venetians, implying furthermore that up to around 1550 they used four arcs¹³.

However, this is unlike all other known Venetian records for Venetian shipbuilding. All the manuscript sources such as those studied by Lane and Anderson, or the earliest version of the so-called Fabrica di galere, by Michael of Rhodes, ca 1434¹⁴, record a system where horizontal measures across the frames are recorded at a series of levels, in some cases just the trepie, siepie, bocha, etc; and in others at rather more levels at intervals of for example one pie. Such measures are usually only given to the nearest quarter-pie. The two systems are not compatible. It is probable that the system of offsets is providing a compact, portable record of a more complex system, which is adequate for a contractual record of the size and shape of ship¹⁵. While this system cannot re-create the original arcs, it could re-create the effective shape by adjusting a spline to be a close match to the majority of points set out on a moulding floor, from which new templates could be created. In the characteristic Mediterranean system of rotating the template for the side of the hull about the bilge, in all frames fore and aft of the master frame, this is quite adequate.

Bellabarba effectively states and demonstrates the point in an article tracing the development of design processes¹⁶. He states that the design was based on arcs, and only communicated to the shipyard as the series of offsets. Galleys could suffice with a single arc, while large ships might use four - he cites Teodoro's manuscript of 1550 as a case in point for that. However, he re-creates the drawing for a galley in his article, and demonstrates the problem in most descriptions perfectly. A single arc is to reconcile a straight side sloping at about 73 degrees (though the explicit dimensions given are for 75.96 degrees), and the flat floor. Yet it is to have two touches with those lines and also pass through two arbitrary points defined as offsets at specific levels (and at many more levels in other cases). This cannot work, and indeed the drawing as published is fudged: the single arc centre shown is not correct - there are two centres, and the two arcs do not meet properly. Neither does the straight line actually pass accurately through the top of the side at the declared point. The reality is that the offsets at specified levels, given to a limited accuracy in such records, are only an approximation of the geometric values. It is not difficult to see how moulds thus created and copied and modified over a long period might drift from an original arc, or compound of arcs and lines, to appear more like parabolae.

The present source document also suggests then that the original Venetian system may indeed have been based on arcs, though most other traces of it have disappeared. There is no proof, however, that the clear (and characteristic) multi-arc system of the 1619 drawing relates to methods used a century earlier in Venice. That also raises the question of whether by 1619 the English system may have migrated back to Venice; or whether for example the unknown shipwright who prepared the drawings and was "someone close to Osuna and well-informed about matter in Venice" could have been of a different nationality, accustomed to working with arcs, but also familiar with the moulding system using offsets preferred by the Venetians, and perhaps many another shipyard in the Adriatic or Naples.

We might note that at this period Robert Dudley had been working in Italy for some years, claiming to have built successful warships¹⁷, and from around 1610 had been writing on naval architecture¹⁸ (he had been a pupil of Mathew Baker indeed, at one point) and using that very term at an early stage. He was based in Pisa and Leghorn. He constructed a large galleon in 1608, the St. Giovanni Battista, 64, a ship which had success against Turkish warships. How far the influence of that success spread to other shipbuilders is a matter of speculation.

There are a series of midship sections and longitudinal plans in Dell'Arcano del Mare¹⁹, for ships and oared vessels. The galleon has a profile much like the northern European warships of the early seventeenth century that feature in English and Danish draughts, for example, and narrowing and rising lines all extending the full length over the posts. The midship sections use scales of English feet, and a system which follows Baker, but with an exaggerated shape - very shallow, with a long flat reconciling arc. Dudley is said to have taken a great many mathematical instruments with him from London, in 1605/6, but not to have updated his knowledge of these. The details of these midship drawings have some resemblance to one of Baker's drawings, in terms of carpentry - knees and inclined pillars to the decks in particular, but in terms of a background grid, shape, and other details he is very different (which may be partly due to the engraver, of course).

Interestingly, it appears that the second, futtock arc ends at the corner of a grid of breadth and depth 24 feet wide and 5 or 6 feet deep above the keel. The breadth arc then forms the true breadth at around 8.5 to 10 feet above the keel, and significantly wider than 24 feet. The futtock arc is thus a reconciling arc in name only here - it is actually formed second in order, not third. It thus matches an intermediate set of moulds in Baker's work, where the corner of a grid might well be the archetypal bocha. However, the corner of the grid in Dudley's examples is in no way the bocha of the lower hull as described above: it is far too low in the hull.

The futtock arc is determined to touch a quadrant drawn inwards from the lower corner of the grid, as in many Portuguese examples, with a radius of about 4 feet. Its actual use appears to be by trial and error, however, with no system apparent.

A Portuguese example

There is one example known from the Portuguese archives, of a similar date, that shows a similar combination of features. There are sufficient differences for it to be a coincidence, in all probability, but it will be mentioned here for completeness. Manuel Fernandes compiled a set of ship draughts and texts, dated 1616²⁰, which includes one anomalous section for a very large ship (some 14.8 metres beam) at sheet 83. This vessel, described as a four-deck nao, does not correspond to any of the texts in the volume, and is indeed in a different drawing style. The majority of his draughts are based on a single circular arc for the ship's side, faired to the floor with a short-radius arc, more or less in keeping with most of the Portuguese manuscript sources extant from the period 1570. This one draught has a prominent arc forming the bilge, which is more than mere fairing - it is an integral part of the construction, with a radius equal to one third of the breadth of the ship. A long arc then sweeps up to a point between the second and third decks. Above that there is a third arc of the same radius as the bilge arc, which forms the breadth of the ship, above the third deck, followed by a short reverse sweep in the tumblehome, forming the bulwark. Also uniquely in this collection, there are a series of offsets marked for the main arc below the breadth. These define the distance between the maximum breadth of the ship and the actual breadth at each level. (In contrast, the sternframe on sheet 82 has actual breadths marked for each transom in its drawing; and of course the Italian system has breadths rather than narrowings, too). They are at intervals corresponding to deck heights, of 7-1/2 palmos de goa, from the base line upwards, but they do not occur at deck positions. All the measures fall within the main arc. There is however no obvious zero point at the upper end, for any numeric progression; and the centre of an arc is clearly defined. The supposition must then be that they have been measured from the drawing, to the nearest half-palmo. We might speculate that these would be of most use on a moulding floor, where a radius of nearly 16 metres is likely to be inconvenient to handle directly, or failing that, as a means to check the accuracy of assembly of the numerous frame components in a ship of this size - one futtock per deck at least. We thus have another three-arc system broadly in line with the contemporary English system, though the rationale for its geometry is unclear; coupled with an unusual set of offsets. The midship section alone says nothing about how the frame was to be modified fore and aft, and equally if the offsets are to check accuracy of assembly, they relate only to the midship frame.

It is known that before this period there had been at least one English shipbuilder named Lambert at work in Lisbon²¹, though on vessels of some 400 tons, not of the size drawn by Fernandes. Whether there is any connection to explain this one draught is a matter of speculation.

A Greek mould

There is one midship section, in the Fragments of Ancient English Shipwrightry (f12) for a Greek ship. We might suppose that it was collected by Baker in 1552, when he visited Chios in the Bark Aucher; the alternative source being Levello or other shipwright from the Adriatic working in England, probably in the 1570's. This is identified as a screatse, and is of around 100 tons burthen. This is indeed a known type of vessel in Adriatic and Aegean waters, the skyrasa²². It is of interest here not because it has any offsets - it does not - but because it is another example of a mould from the area of Venetian influence that simply does not show the characteristics recorded in extant Venetian sources. This has, uniquely in the Fragments, a curved floor, followed by the usual series of three tangent arcs²³. It shows a series of construction lines for the geometric rationale, which is similar in principle to Baker's early methods, most similar to what he calls Venetian. This is not quite a case where the initial grid of breadth and depth defines the surmark between the top of the futtock and the additional arc at the breadth, that creates the tumblehome. The difference is so small, however, that we might wonder whether the detail had been copied correctly, and the original did perhaps have a surmark at the bocha.

Conclusion

This note is primarily intended to draw attention to this little known Venetian drawing, and a Portuguese counterpart, each containing an unusual combination of data for the design of a midship frame. Specifically, each has one element that is ostensibly alien to the local shipbuilding tradition as revealed in the majority of extant texts. The Venetian drawing in particular has a wider potential significance, in that its whole rationale differs from the norm of Venetian sources. Perhaps in time this pair of unusual drawings may throw light on what was happening in real shipyards, but for the present they are an enigma.
 
 
 
 

This paper is accompanied by one figure, taken from Mariner's Mirror.
 
 

Footnotes

1 "Galleons and 'Q' ships in the Spanish conspiracy against Venice in 1618", in Mariner's Mirror, Vol.38, 1952, pp163-183 + plates. Two sceptical notes appeared in the next volume (39, 1953, pp60-1).

2 The section drawing of interest here bears the stamp N16-lxxxv. The drawing is also reproduced by G.Penzo, Venetian ships, London 2000, fig.18 (also as Navi Veneziane, Trieste 2000), in which it is stated that the whereabouts of the drawing is not currently known. Longitudinal views of the vessel are in Figs.17, 19.

3 The photograph available is too small for accuracy, and the drawing itself slightly sketchy and assymetrical, but the method of seeking the geometric construction is as used in recent work on the Mary Rose. A summary is given in R.A.Barker & B.Loewen, "Raiding lost arcs" in Proceedings of International symposium on archaeology of medieval and modern ships of Ibero-Atlantic tradition, ed. F.Alves, Trabalhos de Arqueologia 18, Instituto Português de Arqueologia, Lisbon 2001, p429.

4 This re-use of the arcs of the main frame in the sternframe is also apparent in the Mary Rose.

5 Rubin de Cervin appears to state that the curve of the side was formed by a meza luna (p179), but that is erroneous; current theories appear to revolve around the use of parabolae in Venetian shipping of earlier periods but are not convincing in this writer's view.

6 For a wider discussion of tumblehome as such, see R.A.Barker, "Why tumblehome ?", in Mariner's Mirror, Vol.84, 1998, pp95-7.

7 Eg J.da Gama Pimentel Barata, "The Portuguese galleon, 1519-1625", in D.Howse, ed, Five hundred years of nautical science 1400-1900, Greenwich 1981, pp181-191 translates pontal as the height of the first deck, which is not the main deck in the ships he is describing, but in the hold. The unit of measure, the palmo/pedalj, seems to be the same in the same three areas.

8 For example, the large collection of sixteenth century data provided in F.Ciciliot, Nautica Genovese, Savona 1993, has no complete data sets at all, though some might be associated from separate documents by date. Tonnage seems only to be defined after construction ? It is a moot point whether this is because tonnage was still not assessed by arithmetic rule, despite the existence of such rules long before in Italy.

9 Rubin de Cervin gives an equivalence of 1.1 English feet, but this is not accurate enough. In 1554 it seems to have been 347.735mm (1.141 English feet), but other values from 1.137 to 1.167 are recorded.

10 For a roughly contemporary comparison we have the example of the English Defiance of 1591, whose specification includes "…. a beam of 32 feet, and be 15 feet under the beam of the main overloppe [here meaning main gun-deck, not an orlop in the hold] . Eight feet above the keel ten beams were to be placed on which to lay a false overloppe so far as need shall require". Cited by M.Oppenheim, History of the Administration of the Royal Navy, 1509-1660, 1896, p129, from SP Dom. ccxxiii, 45.

11 R.C.Anderson noted its existence in "Jal's Memoire No.5 and the manuscript Fabrica di Galere", in Mariner's Mirror, Vol.31, 1945, pp 160-7. (Jal had not). He gives it in an anglicised form, without any original terminology, as T=(K*B*D/30) for Venetian feet and butts (p.165, citing f50 of the manuscript). In fact the original text, published by E.A.d'Albertis, Le construzione navali…., Rome 1893, pp217-8, is little more informative: portada of any ship, square or lateen, uses….cholumba (in paces, with a divisor of 6), bocha, choverta.

It appears, from the results, not any explicit text, that the same form of rule was being used in Ragusa in 1512, in cases where bocha, pontale and keel length are the only three contractual measures recorded.

In "Italian naval architecture about 1445", in Mariner's Mirror, Vol.11, 1925, pp135-163, Anderson had attempted (p.150) to fit a rule of K*B² to Timbotta's data for ships of the mid-fifteenth century (for lack of depth data, and knowing such a rule was later used in England) but without success. He had no success with the Timbotta data in 1945 either, using the Fabrica di galere rule of K*B*D, but we may note that the data covered a wide range of ships sizes, up to 1000 butts, and its actual date is unknown, as it is inserted in a later copy (1500 +/-) of a manuscript originally written nearer 1410-20.

Gatti also observes the same problem with fragmentary data from Ragusan contracts from 1512-1583, with the additional problem of having to convert Ragusan carri to Venetian butts, an uncertain process. Again, the thirteen contracts cover 5 different types of ship from 30 to 200 carri; and only 5 give both depth and tonnage, so difficulties are not surprising. L.Gatti, "Imbarcazioni Ragusee nel secolo XVI", in Studi di Storia Navale, ed H.Bresc et al, 1975, pp73-96 (kindly provided by Furio Ciciliot).

In fact, it is noticeable that two of the early Ragusan contracts do result in a tolerable match, but they are all small vessels where only three dimensions - bocha, pontale and keel are recorded at all, and it may be supposed that the vessels more nearly match those for which the rule was formed.

12 MS 2820, Pepys Library, Magdalene College, Cambridge.

13 R.A.Barker, "Fragments from the Pepysian Library" in Revista da Universidade de Coimbra, Vol.XXXII, 1986, pp161-178.

14 Sotheby's catalogue, Western MSS, 2 December 2000, pp60-72, a text taken from that by Andreas Mayor in a catalogue of 1966, and with more illustrations.

15 Touched on in R.A.Barker, "English shipbuilding….", in É.Rieth, ed, Concevoir et construire les navires, Technologies, Idéologies, Pratiques, Vol.XIII, 1998, pp109-126, at p119.

16 S.Bellabarba, "The ancient methods of designing hulls", in Mariner's Mirror, Vol.79, 1993, pp274-292.

17 J.Temple Leader, The life of Sir Robert Dudley, Florence 1895, collects the evidence.

18 See also O.Dunn, "Robert Dudley books and manuscripts owned by John Temple Leader", in Mariner's Mirror, Vol.47, 1961, pp 142-4. These points are directly from Leader.

19 Sir Robert Dudley, Dell'Arcano del Mare, Florence 1646, in four volumes. The work was published posthumously: the material is thought to date from the 1620's. The galleon profile at least is reproduced in Charnock, History of Marine Architecture; Witsen reproduced some of these sections, as "English" - four of these are given by A.J.Hoving, "Dutch 17th century shipbuilding" in Model Shipwright, No.58, 1986, p35.

20 M.Fernandes, Livro de Traças de Carpintaria, Ajuda Palace Library, Lisbon, MS 52 XIV 21, (Facsimile edition, Academia de Marinha, Lisbon 1989).

21 CSPD 1595-1598, ed M.A.E.Green, HMSO London 1869, cclii.58 9 June 1595, William Lambert of Liverpool, five ships at Lisbon; similarly cclxviii.69, September 1598, John Lambert of Chichester, many ships after the English fashion at Lisbon. Also reported in Naval Tracts of Sir William Monson, Vol.IV: three named ships of 400 tons by Lambert at Lisbon.

22 Known, but references are rare. Hakluyt mentions one at Candia in the sixteenth century. R.C.Anderson, in Mariner's Mirror, Vol.6, 1920, p189 gives several examples. Pantero Pantera (L'Armata Navale, Rome 1614) mentions it as a square rigged type (schirazzo), Antoine de Conflans (Le livre de faiz de la marine…. MS ca 1515) has it as a trading vessel in use at Venice (esquiracces).

23 The labelling and dimensions are corrupt but recoverable: a breadth of 40 feet and depth of 10 should read 20 and 10. Worked numerically the system actually produces a breadth of 19'11", rather than the 20 feet stated, too.

Curiously, the curved floor timber recurs in other English manuscripts of the early seventeenth century: both the Newton MS (R.A.Barker, "A manuscript on shipbuilding, circa 1600, copied by Newton", in Mariner's Mirror, Vol.80, 1994, pp16-29), and the Scott MS (formerly RINA MS.798, now in private hands) show it. However, each is superposed on what is otherwise a standard English three-arc mould, with the centre of the breadth arc defined on the initial grid of breadth and depth.

R.C.Anderson reconstructed the mould of the Mary Gonson, a ship of about 1514, with a curved floor timber, but did not give his reason for doing so: "The Mary Gonson", in Mariner's Mirror, Vol.46, 1960, pp199-204. (See also R.A.Barker, "Blisters - a Venetian bubble ?", in Mariner's Mirror, Vol.71, 1985, pp82-3, though this is in need of revision after such an interval).
 
 

Additional note on the "Venetian drawing of 1619"

© Richard Barker

April 2002

Éric Rieth wondered (in a letter of 25 March) whether we should have a more detailed discussion of the ribbands in this drawing, which I did not comment on to any extent: specifically they look like real timbers; and are they related to the diagonals in later drawings ?

Yes, I agree they look like real timbers, but I am not so sure that they have anything to do with "diagonals". It seems to have been characteristic that ships around 1500 had lots of heavy strakes, extending well below the waterline (- but not that low !; whereas by 1600 in England there was only a main wale, which more or less touched the waterline, and nothing below that). There were not enough of these strakes in illustrations for them to be seam battens, though. They are conspicuous in the Greenwich painting of "Portuguese carracks". Perhaps this 1619 drawing is just a sketch reflecting what the planking might be ? It is conspicuous (at the level of a crude drawing) that the spacing of most of the "ribbands" is reasonably constant along the curve of each section - does that suggest that it would fit a simple planking scheme with the maximum of straight planks ? There is that one "rogue" nearest the keel, drawn differently though......

But in this sketch (and that is all it is, as finished: a geometric grid to start, and some compass work, but not a high quality drawing) there is only the one section and the sternframe. Any "curve" of the ribbands is thus extremely arbitrary, and any diagonal would have to be related to many sections. I think they represent the existence of real wales/ribbands, noting that the first starts at the end of the floor. Intended to provide fairing and shapes for some part of the remaining sections, plus strength during assembly.

I do not see any evidence to sort out how more than that, though. We might suppose meia-luas or similar up to "almogamas", but equally it could reflect a particular builder working on three frames and ribbands ? Perhaps that might be because it was a very atypical shape for a specific purpose, with no standard measures or proportions to apply to meia-luas ? But we are reduced to guessing.