Whole Moulding

One method of boat design used by wooden boat builders in Newfoundland can be traced to a method of design employed by English shipwrights in the sixteenth, seventeenth and eighteenth centuries.[1] Known as “whole-moulding,” this method was brought by those who settled in Newfoundland during the same period.

David King and Lance Lee describe this whole-moulding as “an elaborate designing system based on the arcs of circles.” In Half-Modelling (1976) King and Lee say that, “for small hulls, [American] colonial boat builders used a technique called ‘whole moulding’. This employed three battens, two curved and one straight, called the ‘body mould’, the ‘hollow mould’ and the ‘rising square’. These were shifted around to specify the shape of the hull at each section. This was usually done right on the site: the frames were made from the moulds and placed directly on the keel.”[2]

Erin McKee also describes this method in Working Boats of Britain: Their Shape and Purpose (1983):“In its simple form a whole moulded boat needs only three aids. The first is the rising square, which is no more than a batton with the heights of the floors marked in for every station. These marks are called ‘rising sirmarks’ as they are taken from the rising line. The second aid is the breadth mould and this has the convex shape of the midship section, except that it is usual to extend the lengths of the floor and topside beyond the centre and sheer lines to provide space for further sets of sirmarks. There are three of these: the marks on the first set when aligned with the corresponding rising sirmarks give from one or other of the remaining sets, the height and half breadth of the sheerline, and the position of the head of the floor timber, for every frame. The third aid, the hallow mould, the sirmarks of which are set on the rabbet line, is then laid tangential to the breadth mould for the reverse curve.”[3]

King and Lee explain that the design process is based on four longitudinal lines known as, “narrowing” and “rising” lines. They say that these lines, “determined the points of maximum breadth and the contour of the bottom, and thus whether the boat would be wide or narrow, fast or slow, heavy or light.”[4] According to McKee, “a set of three whole moulding aids can be used to produce a wide range of boats, either by changing the sirmarks or even re-adjusting them by eye.”[5] 

[1]  David King and Lance Lee, Half-Modelling (Bath, Maine: Bath Marine Museum, 1976), p 4-5 in David A. Taylor, Boat Building in Winterton, Trinity Bay, Newfoundland (Gatineau: Canadian Museum of Civiliation Corporation, 2006 [1982]), 52-53.

[2] Ibid.

[3] Erin McKee, Working Boats of Britain: Their Shape and Purpose (London: Conway Maritime Press, 1983).

[4] David King and Lance Lee, Half-Modelling (Bath, Maine: Bath Marine Museum, 1976), p 4-5 in David A. Taylor, Boat Building in Winterton, Trinity Bay, Newfoundland (Gatineau: Canadian Museum of Civiliation Corporation, 2006 [1982]), 52-53.

[5] Erin McKee, Working Boats of Britain: Their Shape and Purpose (London: Conway Maritime Press, 1983).