Richard Barker
DRAFT for South Asian Studies – 3 October 99 - Editor regrets publication not possible
The paper in SAS 14, 1998, The vattai fishing boat...Tamil Nadu, indicates that the authors had discussions with the present writer during the preparation of the paper. In fact one of the authors (McGrail) sought this writer’s views on the moulding of the vattai, and was told of some fundamental points of disagreement with his interpretation. There are other aspects of the published paper that call for comment.
The paper by Blue et al (pages 51, 67-70) uses the term Mediterranean moulding, referring to Sarsfield, 1988. However, readers should be aware that Sarsfield used this "for lack of a better expression", and he was referring only to the use of geometric graduations of successive frames by techniques that are first recorded in a Mediterranean context – and do not occur in the vattai, at least as reported by Blue et al. The term is unsatisfactory in that the methods occur in various Atlantic traditions, which increasingly look much older and more varied than we have believed from textual sources alone. The term also suggests more commonality than actually exists. Rieth 1996, also cited, for example, is concerned with just one group of methods that certainly occurs in the Mediterranean, but elsewhere too: especially Portugal and Atlantic Spain. The other major strand of geometrical moulding is becoming known as an Atlantic method, but in some manuscripts is clearly linked to a Mediterranean counterpart. Clearly, neither term will suffice. Wrecks being excavated in Portugal do not follow the style of the Portuguese manuscript sources. There are clear differences between Mediterranean and Atlantic France, too. There is a presumptive common origin, possibly in the Mediterranean in antiquity, but we cannot resolve the issue further at present. It should be remembered that Sarsfield was describing for the first time an unexpected survival of these techniques in Bahia, in some aspects degraded from the highest textual European descriptions, yet in others more sophisticated than most extant accounts. Discovering, subsequently recognising, and returning to record these survivals was his major contribution before his untimely death.
Terminology for the frames
The paper introduces (page 53) the terms equal and unequal frames for the vattai. McGrail indicated that this was a literal translation on site. We already have a recognised term for the equal frames - they are master frames in the European texts describing the methods from which the vattai is supposed to derive. The only difference, in this boat of unusual form, is their relatively large number.
The term unequal is unsatisfactory, though there is no recognised single-word term. Other than the master frames, all frames are unequal: we need something to distinguish the frames that occur between the masters and the almogamas (couples de balancement, quarter frames, hammerheads, etc), and those beyond. In general the frames in the extremities, here termed passive, may not all be passive. In at least one European tradition they may include pre-determined timbers located by and fastened to temporary ribbands, to which the planking is then attached, which arguably makes them active frames.
The key point is that though each of the frames between the masters and the almogamas differs in result, and are to that extent unequal, they are created from identical moulds, in a strictly controlled and wholly pre-determined fashion. An acceptable term must reflect those two aspects. They are "part of the design process", and allow for pre-assembly of frame components. The literal translation of many texts would be timbers (frames) of account. Graduated frames would be better. The present writer has no intention of accepting the term unequal.
Origins of the vattai and thoni
Portuguese, Dutch and British presence in the area are noted in the paper. French influence in the vattai is suggested solely on the existence of a diagonal on the scrieve board, and in French 17th century texts. (A French plan of 1692 is reproduced by Anderson in Mariner’s Mirror, Vol.28, 1942, pp246-7 + plate).
Hornell is reported to have suggested vattai=batel, that is a Portuguese origin. The complex frame joints suggest Portuguese methods, from the likely European sources.
The terminology of other features of the design and construction must also be relevant, and one significant term appears in the paper: mestri for the chief craftsman is a fair indication of the former involvement of a Portuguese mestre, and not English, French or Dutch - unless it is also a more general local term. The other term reported, asil, for the mould, is not obviously European. As far as the thoni is concerned, it may be pertinent that the majority of the shipowners are Catholic, according to C.W.Hawkins, "The Tuticorin Thoni", in Mariner’s Mirror, Vol.51, 1965, pp147-154.
The actual units of measurement in the boatyard are also significant, and do not appear to be recorded, though the text refers to Imperial inches.
Hawkins has a different version of the development of the thoni, from local sources, which contradicts Hornell’s to some extent. The type developed as a lighter of 50-70 tons about 1914, was further enlarged to about 130 tons around 1920-5, and to around 300 tons in the late 1950’s. The frames are reported to be called karavai. This does suggest a local adaptation, possibly of the vattai’s design, and/or construction, but equally likely influenced by the European ship-owners who required the large lighters to be built.
Description of the moulding process
The most serious problem with the paper is the description of the moulding process of the vattai. This is doubly significant in that the paper claims (page 71) to have recorded the processes of design and construction to the point where an accurate model could be made. It also purports to encourage Indian scholars to record such methods (page 41). It is appreciated that the team did not observe the whole process during a visit of three weeks, but the problems with the description are fundamental.
These problems start with the photograph of the scrieve board, Fig.12, and related text. Even allowing for the perspective of the photograph, and that the chalk lines are only rough highlights for the photography, the photograph simply does not show what the text describes. The diagonals do not meet at top-centre - we might accept a little inaccuracy with the chalk. But on one side there is a vertical line at quarter beam, on the other there are two different vertical lines, neither at quarter beam, and wholly unexplained. Fig.13 shows only divisions at the quarter points. The purpose of these unreported lines remains unknown.
We should know whether the curve for the bilge is an arc, or created with a spline - without this definition, including dimensions, we cannot create an exact model. Arcs are the norm, even for Norse vessels, judging by published drawings, but they do not always occur. In repetitive building from templates they may be modified over time, or even be replaced by splines through control points, as in the Bahian vessels.
The text suggests (page 55) that the mould is used like a French curve for each frame between two points, at the top of the board, and on the diagonal. This is a bad analogy: a French curve is an arbitrary curve, whose location is adjusted by eye, and all the moulding methods referred to by the paper require this degree of freedom to be removed - for symmetry, for fairness, and for replication. That is a key reason for the development of moulding systems. There must then be a mark on the mould to control its position against the points described, for each frame. This is not recorded. Assessing the photograph, it appears probable that there is a mark at the top of the mould where it crosses the top of the scrieve board for the master frame position - based on moving a traced copy of the unique mould to match each frame shape.
The next step for each frame is stated to be to rotate the mould about the point where it crosses the diagonal, until a point on the horizontal part crosses the vertical three-quarter beam line. However, this seems improbable, from the evidence presented, in two respects. Firstly, there is no such rotation of the mould apparent in the chalk lines. Rather, the part of each graduated frame between the diagonal and the floor is a good match for the master, after little more than translation. Secondly, the narrowing of the frames is so large that it is difficult to see how any viable rotation of the mould will bring a single mark on its horizontal arm back to lie on the same vertical line for each frame - it is very ill-conditioned. There is only a small angular rotation in the three frames drawn. It seems far more likely that the floor is simply a tangent from the line of the translated mould, drawn with the mould itself, and directed at the bottom-centre (there being no side of a keel to terminate at in this case).
The knuckle implicit in the text and in Fig.13 e-g is not apparent in Fig.12. If it does exist, it might be more characteristic of late sixteenth century Portuguese methods than of any English method.
The movement of the two control points for successive frames follows a formula that was not fully determined, but in which the top of the frame is said to narrow three-quarters of an inch for every inch that the point on the diagonal moves, in each case from the position of the previous frame. Again, the photograph does not support this, and neither does geometry. Estimating from the photograph, the ratio is not three-quarters, but closer to a half. The progressive amount by which the point on the diagonal is to move remains unknown, so again no model is possible. Indeed it is stated that the rule of proportion between depth and breadth is not known.
One point not explained on page 55 is what the position of the mould on the scrieve board has to do with marking the slabs of timber for the frame - unless the slab is placed directly on the scrieve board, and so obscures the frame outline. Since there is a complex joint to be marked on both parts, there has to be a method of ensuring that the joint is cut correctly. This is an area where the European texts and other records are silent - we do not know how the various mortice joints were marked on moulds or timbers. Hawkins, writing of the thoni, says only that the frames were drawn full-size on the floor, and that boards placed over the lines were chiselled to make the templates.
While this writer’s analysis relies on a perspective photograph, it may be in error; but by inspection, so is that proposed in the paper.
The paper states (pages 69, 70) that it is not known what form of frame connection existed in the Bahian vessels reported by Sarsfield. There was a plain overlap held by dowels made from steel reinforcing bar (pers.comm. 1984, concerning Cajaíba, 1983 – "iron drifts" – reinforcement ("construction rod") was also used in the master-frame-and-ribbands yards to take off the frame shapes).
Richard Barker