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5. HULLS AND THEIR CONSTRUCTION

Reviews some Practical Methods of Building the Huli, of any Old-timeShip Model—Explains in Detail the Building of a Cardboard Hull and How to Make one on the Laminated System.

The hull is a very important item of any ship model as virtually it is the foundation upon which the whole of the ornamental or spectacular part is built.

Primary considerations for the hull of any old-time ship model are correctness of form, durability, and practicability of constructional method.

Constructional methods vary enormously in model work, but on the prototype the almost universal method was to erect a framework or skeleton composed of a principal longi­tudinal member at the bottom called the keel, to which vertical timbers are attached at each end known generally as the stem and stern posts, theformer being at the bows or in front, the latter at the stern or after part. Other shaped timbers known as floor timbers are fitted transversely to the keel, and spaced fairly closely together, their outer ends being jointed to other timbers which curve upwards and are generally known as ribs. These arc supported crossways by horizontal members called beams, and longitudinally by stringers and wales, and generally all the joints are strength­ened by angle pieces of wood known as knees. These and sundry other timbers constitute the frame of the hull, and its contours are similar to that of the finished hull.

The exterior of the frames are covered by planks, disposed more or less horizontally and known as the skin or planking. An example of a model built in this regulation way is illus­trated by fig. 36, which represents an English fourth rate of the period 1715. This model is exhibited in the Science Museum, London, and is a fine piece of work. Its value to some extent lies in the treatment of the underwater part of the hull, which is not planked, but shows all the ribs, floor timbers, the keel, stem and other parts of the framing.

Another interesting model, in the Science Museum, reproduced in fig. 37, is an 80-gun ship of H.M. Navy dating about 1719, practically four years later than the previous example. Here again the underbody of the hull is shown in frame and a close inspection of it reveals much of interest Compare these two models and it will be seen how little difference there is in their general aspect—at least in so far as the hull is concerned. Yet to the student and historian there are features about them which tell in no uncertain way the period to which each belongs.
Often it is possible to go further and particularise as to the exact ship that is portrayed, specially when the model is of a ship later than about 1710. This aspect of old-time ship modelling should never be forgotten or disregarded, but it wants a lifetime of study. The purpose of this book is to explain how to make worth-while representative models, leaving the minutiae of detail to the serious student.

The constructional work on a plank-built model follows that of the prototype, each individual timber being separately represented, but this kind of work calls for remarkable skill and dexterity, consequently the amateur is counselled to avoid it and choose something less onerous and difficult. After all is said and done, when a model hull is completely planked it looks just the same whether it be built in exactly the same way as the real ship, or made in some simpler manner. One simplified method is to carve the hull from a solid block of wood and cover the exterior with strips of thin veneer glued in place on the exterior of the hull.

Each piece of veneer must be cut to a suitably curved form, be proportioned in accordance with the scale of the model and correspond in character to that of the original. When carefully done the hidl is remarkably effective, especially if the veneer has been pinned to the block with the pin-heads just visible and arranged in vertical rows, as if actually driven into the ribs.

When it is desired to show portions of the interior of the hull, it is necessary to either build it up with separate timbers and planking, or to adopt a compromise and build on the composite system. By the latter method the lower part of the hull is made from a solid block, and the upper part either planked on short ribs fitted to the block, or the middle of the upper block can be sawn and carved away as requisite. The exterior of such a hull can be planked with veneer, ivory, ebonite, nacrolac, thin card, or with other desired materials, or it can be painted and only the wales, skids and other protruding timbers separately attached. It is all a matter of personal inclination or ability, although to some extent conditioned by the purpose of the model.

A very practical method of building a hull is that known as the laminated or bread and butter system; the usual custom is to prepare a number of planks of wood about \ inch thick or as may be convenient. They are sawn to the shape of the corresponding waterplanes, the pieces glued together and the square edges carved away, a method which produces an accurately shaped hull with a minimum of labour and cost.

Small hulls, that is those up to, say, 12 ins. in length, can be successfully made with plaster-of-Paris, either plain, or in conjunction with fine fibrous material such as the hair used by plasterers. Numerous compositions can also be employed in a similar way. The method is to prepare a rough block of plaster and while moist to shape it, as nearly as practicable, to. the contours of the hull. The whole is then allowed to dry quite hard and is then carved or scraped to the true shape with   ordinary carvers'   tools   aided   by such   home-made implements as broken pieces of glass or sharp pieces of flat steel and the like.

Hulls from about 6 ins. in length up to 24 ins. or so can be made very successfully with cardboard, the result when the work is done neatly being durable, realistic and very attractive, no evidence of the nature of the material being apparent after it has been suitably painted. Examples of what can be done in this way are the Revenge, illustrated on page 13, and the Ark Royal on page 43.

The technique of cardboard modelling of this kind has to allow for those little mistakes and errors in cutting which in themselves may not be more than the thickness of a pencil line but in the aggregate amount to considerable dimensions. Several systems have been tried out by the author, but that which has proved most satisfactory is the cellular system; models made on this method have successfully withstood severe handling and considerable changes of temperature and humidity.

The first requisite is a drawing called the "lines", showing the true external shape of the hull, the lines being drawn in such a way that it is possible to construct from them a hull corresponding to that shape and to any desired size. From such drawings—for example, those on plate No. 3, which give the lines of the Royal Albert—another set of full-size drawings have to be made showing each separate piece of card. The preparation of such drawings calls for considerable technical skill and an understanding of the limitations of cardboard as a material of construction. To aid the reader a set of suitable drawings are given on plate No. 2.

Having obtained or prepared the drawings on cardboard, proceed to cut all the pieces exactly to shape, then take the long centre card and clip it by the lower edge to a strip of smooth straight wood, to keep the card flat. A few drawing pins will hold the card in this way quite nicely.

Next place the ribs or crossway cards into their respective slots after a little adhesive has been applied to each joint.

The work at this stage then appears as in fig. 38 where the last or transom card is shown being fitted into place.

Fig. 38. Early Stages in Building a Cellular Cardboard Hull.

Follow this part of the work by spreading some adhesive on the top edges of all the lower rib cards and then press the main deck card into place as shown in fig. 39, taking care to allow it to assume a nice easy fore and aft curvature called the sheer.

Fig. 39. Fixing the Main Deck Card.

The next proceeding, after the adhesive is dry, is to plank the hull, which is done with seven strips of card on each side cut to certain curves.    The best way to cut the planks is, as shown in fig. 40, to use ordinary strong scissors and cutthe curves as smoothly and accurately as possible.

Fig. 40. Cutting a Curved  Plank.

Unlike other methods of planking, thefirst plank to be fitted is that known as thegunwale.

Fig. 41. Fixing the Gunwale.

This comes immediately under the main deck card, and is notchednear thestern to fit  over the  projecting bracket  pieces  which  support   the stern gallery. The card is fixed as shown in fig. 41 by coating the inner face withadhesive, and pressing it gently into place and holding it there untilthe adhesive sets.

A few pins can be driven in here and there to keep the card in place, while the corresponding card on the other side of the hull is fitted in a similar way. The next plank to be fitted is that known as the garboard strake, and this fits against the centre card at the bottom; it should be twisted inwards at each end so that the card takes a natural curvature and needs only a minimum of pressure to get it into place. The planks are made rather longer than necessary so that any slight errors can be allowed for, and the overhanging ends can be cut as requisite so that they will lit nicely at the bow and stern.

Fig. 42. Shaping and Fixing the Planks.

When these two planks are fixed in place on each side of the hull try one or two of the others in their places, and if necessary smooth off the edges of the rib cards as a slight error in their cutting or placing may cause a bump which should be removed by sandpapering the edge of the offending card.

Proceed to fix in the same way the remaining planks, as shown in fig. 42, drawing them closely into position and fixing them temporarily with pins as requisite. The last two cards are rather wider than the others and come at the "turn of the hull," or that part which is most curved, and to ensure a good fit the plank has to be drawn along between the finger and thumb as shown in fig. 43 to make it more or less half rounded in cross section. After this treatment the hollow side is coated with adhesive as before, and the card fixed in place.

It will be noted that the card planks overlap a trifle, or are arranged "clinker" fashions, also the ends of the last two cards having to be worked under the edge of the gunwale card, but this will be apparent when actually doing this work.    When the adhesive has set quite hard, any overhanging ends at the stern are removed by cutting off the surplus and rubbing gently with new fine sandpaper; the whole of the exterior is then rubbed down with finest sandpaper.

Fig. 43. Curving a Plank between Finger and Thumb.

The bulwarks, upper decks and superstructures are then added as described in the previous chapter.

Any type of hull can be made in the same way, or if very great care is taken when planking and each plank is cutaccurately, the hull can be "carvel" planked, that is to say, the edges of the planks fit one against the other and do not overlap.

Plank-built hulls—that is those built up witha wooden framework, as previously mentioned—call for much more care and skill, but in essentials the method is the same as the foregoing, the centre card representing the keel, stem and stern post, the cross cards taking the place of the ribs or frames, but thin cedar, mahogany or pine is used instead of cardboard for the planks.

Here again the planks must be cut to a suitable curvature, not necessarily in one continuous piece, but may be of any convenient length, provided their ends are butted at a rib so that sufficient support is provided for both of them.

The wales can be represented either by thicker timber than that employed for the skin planking, or an additional layer, of veneer or thin wood can be added where necessary to give the desired effect. This plan is applicable in the case of cardboard hulls if the latter when made as before described are covered with small pieces of paper gummed over the planks so that a smooth surface is gradually built up, which, after being sandpapered, should be coated with white shellac varnish. After this has dried the hull should be sandpapered lightly and then the wales and doublings added in the form of long thin strips.

One of the most popular and convenient ways of making a hull, especially for a representative scale model, is known as the laminated system. This consists of a series of superposed boards, each fashioned to a certain shape. The edges have then to be carved away and the job is done. There are, however, a few points to consider if troubles are to be avoided. First of all as regards the drawing; this, if prepared for building on the laminated system, will have a series of horizontal lines, called waterlines, on the sheer plan and the corresponding curves on the half breadth plan; but if this is not the case suitable waterlines should be drawn and the curves set out from them and from the body plan. The next procedure is to prepare a series of boards each exactly as thick as the corresponding space between the horizontal waterlines, but the length and width of each piece should be slightly in excess of the finished sizes. A centre line is then drawn along the middle of each piece, and each clearly marked for identification. The half breadth plan—that is the drawing showing the shape of the waterlines as seen in plan—is then placed on the board, with the centre line on the drawing exactly over that on the board; the drawing is fixed with drawing pins, and the shape of the curve transferred to the board by pricking through the drawing with a stylus or sharp awl. The drawing is turned upside down, replaced on the board with the centre lines in register as before, and the same prick marks pierced again, thus obtaining the other half outline which completes the shape. The prick marks on the underside of the drawing are ticked off, to avoid making mistakes when pricking off subsequently.

Fig. 44. Diagram showing Effect of Curvature on Shape of Planks.

The prick marks on the plank are then connected by a curved line and the surplus wood cut away with a bow-saw or a keyhole saw. The edge of the plank is then planed up until it is quite true, as can be ascertained by laying it on the drawing. This procedure can be followed for all pieces where the shape is such that the hull does not bulge, nor is any part of its breadth greater than that of the line on the drawing. This should be apparent from fig. 44 which shows, in an exaggerated manner, what is meant.

Here planks No.  1-2-3, will be correct, the curve as of the hull reduces in width downwards, and the parts shown black on the right of the drawing have to be cut away. Planks No. 4 and 5 must be marked out on their upper surfaces with their corresponding curves, but if the board was sawn to that shape there would be a deficiency of wood at the lower parts as indicated by the shaded portions and the shape of the hull could not be attained, consequently any such layers must have the outline of the lower plank trans­ferred to its underside, and the wood be sawn away to which­ever line is the widest.

Fig. 45. Shaping Hull with Chisel.

In this case, however, at layer No. 4 the hull curves outwards at about the middle of the thickness of the wood as at A, and if it were cut to either of the lines No. 3 or 4 the resulting piece would be deficient in the middle as shown at B; consequently it is necessary to look at the body plan and make sure that the wood when cut to the shape of a waterplane, or deck plan, will be broad enough. On most old-time ship model hulls the latter conditions will probably be met with at about the L.W.L. or just below it, and at the turn of the hull near the stern.

After the pieces of wood have been prepared in the way described they can be screwed or nailed together temporarily and the angles curved roughly to shape, sufficiently to get an idea of the real form of the hull. The most useful tools to use are fiat chisels, a flat gouge and a very small spokeshave.

Fig. 46. Testing Hull Shape with a Mould.

An early stage in this work is shown in fig. 45, where a f-in. firmer chisel is being used to cut away the angles of the planks at the stern. The chisel is held and guided by the left hand and driven downwards by short, sharp blows delivered by the base of the palm of the hand, the picture showing just how this should be done. If the wood is particularly tough a wooden mallet should be employed and the chisel driven by its aid. As the work of carving the hull progresses, several templates or "moulds" should be made and used as shown in fig. 46 to test the correctness of the hull form.

This picture shows just how the work will appear to the eyes of the worker, and how easily the errors are revealed. Moulds should be made for the midship section, and for two or three of the sections near the bows and near the stern. The outlines can be pricked off the full size body plan on to a piece of cardboard on which should be drawn the L.W.L., a vertical centre line, and marks to indicate the whereabouts of the keel and the upper gun deck. To locate the moulds a cross section line, at each station, should be ruled on the hull and the correct moulds numbered accordingly.

Fig. 47. Carving with Chisel, also showing Use of Wood Blocks.

It will be found that the hull is an awkward thing to hold during the carving processes, and in the absence of a large size woodworker's vice or cramp, the best plan is to nail blocks of wood to the work bench as shown in fig. 47, and to steady the hull with a strut of wood, one end of which is nailed to the hull and the other to the work bench.

Incidentally this illustrationshows how to manipulate the chisel while cutting inthe same direction as the grain of the wood. The chisel is held almost flat on the work, guided between the fingers of the left hand and pushed forwards withthe right hand, a curve being given to the cut by slightly rotating the chisel while pushing it forwards. On this work the handle of the chisel can be grasped by the right hand and may have the forefinger extended towards the blade, as this grip gives an excellent sense of direction.

Fig. 48. Spokeshave in Use.

The small spokeshave previously mentioned is shown in use in fig. 48 as it appears to the worker's eyes; the two handles of the spokeshave are grasped between the fingers with the thumbs at the back, and the wholepropelled forwards with a brisk, light sweeping movement. The cut should as far as possible be made diagonally across the wood and always with a sweeping or curving motion.

The carving of the stern is a more difficult matter especially where it reverses into the overhanging part of the counter. A view of this as seen by the worker is given in fig. 49, the hull resting keel upwards on the bench and the cut being made with a sort of scooping movement of the  chisel  or gouge; which in this case is grasped by thehand with the fingers encircling the handle.

Fig. 49. Shaping the Stern.

After the hull has been shaped in the foregoing manner to the level of the upper gun deck, the bulwark planks are added as described in Chapter VII.,pages 73 to 75, and the deadwood fitted. The outer ending of the stern need not be fashioned from the planks themselves as owing to the presence of end grain they would be liable to split and break away. A better plan is to make a transom or cross member from ⅛-in. fretwood, and glue it to a flat formed on the end of the hull by sawing and planing to the exact rake or inclination desired. This is shown in place in fig. 50, which also illus­trates the employment of plastic wood as a means of rectifying any little errors that may have cropped up.

Fig. 50. Using Plastic Wood at the Stern of a Hull.

The plastic wood is used in very much the same way as putty, and can be pressed into place with the blade of a pocket knife, which should be dipped into water to prevent the plastic wood adhering to it while the work is in progress.

The foregoing constitutes the basic hull on to which the wales, stern gallery and other details are built. The keel and outer keel strip is simply a rectangular strip of wood glued and pinned in place, cleaned up to size and exact shape, after the stem and stern posts are in place. The method of fitting these parts and of carrying on the work on the hull is explained in subsequent chapters, dealing specifically with the Royal Albert.

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