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Index
Part 1 Introduction
Part 2 Features of this system
Part 3 Basis of the drawing
Part 4 Way to refer the drawings
Part 5 Way to utilize the data
Part 6 Points to keep in mind
Part 7 Conclusion
 


Part 4. Way to refer the drawings

During the process of making ships' drawings I thought that the frame drawing only was sufficient but soon realized that it would be more effective to make accompanying drawings as well.
It is not so time consuming to add such drawings to the frame drawing.
The main reason for making the drawings is that most of the existing references are not as accurate as these you can view here.
Providing drawings which are well aligned to each other, the adjustment work at the time of building is remarkably reduced.
In the process of improving my own skills, naturally the way of drawing also changed without affecting the contents of them.
In this part I will explain these kinds of drawings and the meaning of the information given there.


1)
Frame layout
  a.

The first drawing to be made is a side view of the hull which is corresponding to  the sheer plan of the ship.
Major dimensions such as the overall length and height have been precisely tuned to a reduced scale, and the drawing shows the physical relationship of the main structures such as the external form, the keel, deck and so on.
Later on, this drawing is used as a template to draw the hull's curved surface and also as the actual drawing of the keel by removing unnecessary parts from it.

However, the main purpose of this drawing is to decide the layout of the frames as given in figure 2.

  b.

Usually, references such as the ’Anatomy series of the Ships’ explain the actual ship; therefore the frame arrangement is also the same as in the actual ship. The frame arrangement there is very dense, and when the ships are reduced to their model scale, the gap of the frame is only around 0.5 to 1mm compared to about 5mm frame width. When you aim to build a precise admiralty model you must keep this relation. One of the difficulties when doing this is that although it is a structure model the details inside become almost invisible. In general frame models, represented by the Harold Hahn method, the arrangement of the frames and gap width is almost the same – the so called room and space rule.

But here the frame layout may also vary; like single frame only, double frame only, single-double-double-single and so on.

  c.

 In the method given here, the frame layout can be decided freely according to the builder’s liking without influencing the scale. Even if it is the same ship, the image changes considerably with the frame layout. If you are not sure, you can compare several ideas of layouts by making a drawing of each possibility.

Figure 2 shows examples that I prepared for this purpose.
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  d.
When the frame layout is decided, this drawing will be the one expressing the overall structure layout of the hull like shown in figure 3; and various information like below will be included.
Basic dimension such as FP, AP, pitch of cant frames etc.
Accurate height of the upper limb of the hull (it is equal to the top end of the frames)
Station line for model use based on the new frame layout
Actual placement of the frame including cant frame and their numbering
Sheer lines of each deck at amidships (it is expressed as the upper limb position of the beam)
Original position of the hull openings such as the gunport
Main structure of the keel and the status of frame fitting
The structure of the bow and the stern
Shape transformation of the rabbet
Butt line of the futtock
Full scale rulers etc.

030
  e.
By drawing the above information accurately, most of the height information can be transferred to the individual frame drawing, thus the consistency can be kept sufficiently.

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2)
Frame
  a.
The individual frame drawing which is the major part of this method is being drawn with the accurate 5mm grid in conformity with the origin position. The curved profile of the frame is drawn as a view from the front.

The top and the side views are also shown in the same drawing.
The front view can be used for cutting the futtock and for assembling the frame. The top and side views are useful when checking both - the edge and the butt line transformation.

Figure 4 shows an example of the frame drawing.

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  b.

According to the setting of the origin coordinate described earlier, the rule when drawing the front view is that the first half portion frames are drawn as a view from amidships to the bow and the latter half frames are drawn as a view from amidships to the stern.
In the side view the first half is as seen from the starboard side and the latter half is the view from the portside. For your assurance the Starboard and Portside   are clearly indicated in the drawing. Of course, the indications are opposite in the latter half drawings.

Because the frame profile is basically symmetric it will not be harmful if you make a mistake but make sure the direction of bevel and the slant of the top edge do not go wrong. In general the narrower side of the frame has a higher top edge than the broader one.


c.

The frame diagram is comprised of four curved lines namely front outside edge line, front inside edge line, (both black solid) rear outside edge line (red broken) and rear inside edge line (red solid).
In case the frame is showing double frames, the rear side frame is drawn in a green broken line to show the rear outside edge line, and in a green solid line to show the rear inside edge line. In this case (double frame) however, a drawing separating the double frames into single ones is also provided so either drawing can be used as deemed necessary.



  d.
At the frame center portion which joins to the keel, the precise cross section of the parts such as the keel, the hog (rising wood) and the dead wood is also drawn so that the fitting to the frame can be obtained correctly. These fitting relations are also consistent with the keel drawing which is described later on.

  e.

The frame profile is divided into several futtocks based on the diagonal line obtained from a redrawn butt line of the frame layout drawing.
In case you cut the futtock from a trapezoid plate in accordance with the Harold Hahn method, the frame drawing should be used to determine the plate dimension and futtock positioning because as a basic, the futtock end must meet the diagonal line. To identify the similar shape futtocks after they are broken from the plate, each individual futtock in every frame is given a unique number described later and is considered to certainly appear on the center part of futtock when you cut them out from the plate.

Because the stern is generally higher than the bow, the starting point and the angle of the diagonal line differs at the fore halves and the latter halves of the hull. However in a diagonal pair line, the crossing point at the outside of the frame will be equal in height.

  f.
Usually the diagonal line consists of four lines in each side of the frame as a set but only two lines out of four are applied to one frame. The other two lines are applied to the adjacent frame.
The diagonal lines used in the double frame drawing are colored black solid for the front side and red solid for the rear side frames. Meanwhile, in the single frame drawing, the solid line is the applicable line and the broken line is given for the non-applicable lines.

  g.

When you build the model in its upright position, and simply glue each futtock, the frame profile may deviate significantly due to the accuracy of cutting surface or the displacement of gluing.
To avoid such irregular assembly, the frame drawing can be used as a template. In this case a red cross mark in the drawing is used to align the futtock accurately as per the drawing.

This is because the futtock profile cannot be tuned to the draw line until the futtock is shaped exactly as per the drawing.

  h.

There are several ways to secure the strength of the futtocks when joining them in a real ship. One is to connect futtocks with a combination piece called the chock. Another method is to trim the joint portion to a Z shape scarf to increase the contact area.

In case of models, it is better to cut futtocks to a right -angle- to- surface to maintain symmetry between each other. In the drawings for typical models, these options are being drawn together so that the builder can choose the most convenient way. The cutting line by right –angle- to- surface is shown by green cross marks in the drawings.

050
   
To emphasize the artistic view of the model when seen from the side of the hull, it is desirable that the continued butt line of the futtock joint forms a smooth sheer line. However, I noticed that the angle of the individual butt line varies by the way of cutting. The details will be described later but you must be careful that the way of cutting might have its limit according to the size of model or the curvature of the hull.

  i.

One of the assembly methods represented by the Harold Hahn method is well used for structure model building. In this method, the vertical extension is added at the top end of the frame so that the top end of each frame becomes horizontal. Then the hull is assembled on the horizontal board by placing all the frames upside down. To correspond to this method, each frame drawing has a vertical extension up to just above the highest frame end.

By cutting out the top timber together with the extension, the hull can be kept in a horizontal position when it is assembled. The vertical extension is not necessary when the hull is assembled in orthodox upright position.

  j.
In the frame used near amidships, you may notice that there is a dash-dot line just below the top end of the frame. There are several faulting at the upper edge of the hull depending on its structure. Originally I was reproducing such faulting in the drawing faithfully. However in Harold Hahn’s method, this way causes also a faulting to the vertical extension and it may raise the influence to the fairing of the hull. Therefore recent designs are adopting frames without such faulting but   cutting that portion at a later stage. The dash-dot line in the frame drawing is showing the position to be cut at a later stage.

  k.
The cant frame is being placed diagonally against the Z-axis of the ship. To cut the cant frame to its exact shape, it is necessary to obtain the shape viewed facing the right angle to the cant frame. (so-called developed view).

By using this method the developed view can be obtained quite easily thus its shape is precisely given in the drawing.

The difference between the cant frame and the square frame is that the cant frame is joined to the keel with its cant angle. Therefor it is a half frame segmented at the dead wood of the keel.

Another difference is that the futtock joint is not right angled against the sided surface of the frame. Instead it will be slanted when the cant angle is increased.
Until the ‘Pandora’ design this rule could not be decoded but it is being exactly reflected to the developed view as a logically solved status.
When you cut the futtock to a right angle, it looks like the joint line hangs down a bit, but its amount may not be significant. So you can choose either way.
If you apply the slanted cut to the Harold Hahn method, it may be necessary to provide the material individually for each futtock.
The details will be described later but figure 14 is an example drawing of the cant frame based on the above theory.


  l.
In the front view of the drawing, the light blue line across the frame indicates the upper surface of the deck beam. (If the thickness of the beam was obtained the lower surface is also indicated)
Because the curve of the beam is based on the camber it can be used for beam fabrication and for obtaining the deck clamp height. The height of the deck clamp should be adjusted if there is a notch to rest the beam end. The beam line is drawn by penetrating the frame; therefor its position will not be disappeared even after the fairing of the frame. In actual shipbuilding it is better to obtain a smoother deck clamp line by passing the batten to this position. In the drawing, the height of the beam line is being defined as height at the position of the front surface of the frame.

  m.

In a similar way there is a drawing in which the position of the gun port is precisely indicated. As you know, the gun port height is highly related to the deck line. This is not important for the fabrication of the frame itself but is very useful when you assemble the hull.
Same as the acquisition of the deck line, a smoother gun port line is obtained by passing the batten based on the gun port position. In the case you changed the gun port spacing, you must be careful to check whether or not it will interfere with the shroud etc.


  n.
The hull really is symmetric when viewed from the front but in manual drawing this is a very hard task to do without error. With the PC the task of obtaining a symmetrical figure is quite easy, extremely accurate and can be done instantly. These accurate drawings can be effectively used for fabrication and the assembly process of a model. Therefore the work load for the model builder will be significantly reduced.

  o.

In addition, there are many basic dimensions, characters etc. in the drawings so that verifying them with the other drawings is easier.
Because there are hundreds of parts with very similar shapes, it is essential to add the name by using unique identification numbers for the frame and the futtock. The rule and the meaning of the numbers which were finally decided upon are shown in figure 6. With these numbers the context of the frame, physical relation between the frame and the station line; relation between the frame and the constructing futtocks, construction of the futtock and physical relation of the futtocks, etc. can all be identified. In fact I have received good evaluation from those who built a model using these drawings saying that they were very useful. Incidentally the frame number is also representing the file name of the drawing so that the file can be lined up by this sequence.


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3)
Keel
  a.
The keel is a structure which is combined with the frame most closely, and the accuracy to fabricate its joint shape has a big influence on the workmanship of the model. In addition, when the frame alignment is changed from the original, some contradiction may occur to the auxiliary structures such as the deadwood and the hog. In that case the keel drawing is adjusted a bit to have good conformities everywhere. In the keel drawing, the cross section where the frame meets the keel or the frame crosses the keel this is indicated by a different color. The main purpose of the keel drawing is to show its outer shape and the fitting in relation to the frames. It is up to the modeler's choice to arrange the structure while maintaining the fitting relations. For instance the deadwood in the actual ships consists of several layers of the wood block, and the keelson provides a notch for each frame.

  b.

The keel drawing can almost be completed by simply deleting unnecessary parts such as the frame, deck line and so on from the frame layout drawing.
In case of a bigger ship, it might be that the thickness of the keel is different at the middle and the end; and in this case the notch of the frame must follow this change. By showing the thickness change in the top view of the keel, the keel thickness can be accurately reflected to each frame drawing.
Figure 7 shows an example of the keel drawing.

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4)
The top view of the hull
  a.

The main purpose of this drawing is to acquire the mortising shape of a fixture board to support the extensions from the top end of the frame. The fixture board is essential in case of upside down assembly by the Harold Hahn method.


  b.

The way of drawing is to first copy the top view of each frame and arranges it to its position in the hull. Because the coordinate axes are all unified in every drawing, arrangement can be done simply by numerically specifying their position. Top view of the frame may be rotated 90 degrees when it is arranged.
After arranging several frames, the mortising hole can be drawn by connecting the outside line of the extension smoother. Just in case, by arranging all frames in this drawing, it can be checked if the frame shape is correct or not.

  c.
The placement of the cant frame is not corresponding to the station line but their consistency can be confirmed by arranging them based upon the frame pitch and the cant angle.

  d.
There are no frames at the stern and bow but the entire circumference shape of the hull upper end can be drawn by referring the frame layout drawing and the other material such as “The Anatomy of Ships” or other material.

  e.
The envelope which connects the maximum breadth of the frames can also be drawn here. These lines are corresponding to the breadth line of the ship plan. Figure 8 shows an example of the top view of the hull.

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5)
Other drawings
  a.
Because of highly raised precision of the frame drawings, as a substitute of poor material yield of the Harold Hahn method, the possibility of the method which cuts the individual futtock shape directly from the material has also risen. In several designs of ships, drawings with the same assortment of futtocks gathered in one sheet are also provided.

Because they were not newly drawn but were made from frame drawings by deleting the unnecessary parts, the shape precision is exactly same as in the frame drawing. If the material size is obtained in advance, the cutting template drawing in which the futtocks were arranged effectively in that size is also provided on request. Since there are over hundreds of similar shapes in the futtock, each futtock is clearly indicated with its unique identification number and if necessary the red cross mark.



  b.
In addition, the drawings of the transom and the hawse timber are given in some models. Because it shows the roundness convergence of the stern and the close joint relation with the stern post and the aftermost cant frame, the transom drawing has high importance. Therefore I attached as many as possible of those drawings.

  c.
Figure 9 and 10 show an example of the drawings of the futtock brake- down and the transoms respectively.

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