Splendour Under Sail - PAGE 43 
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and one single screen. Half of the workstations are colour and the total package has enough power to make the speed and imagination of the operator the only limiting factors.
To get drawings from the computer we have two plotters. Both can handle drawings a metre wide by up to so metres in length. One is a pen plotter which does the more precise drawings and can handle colour. Its problem is that it works at 30 cms per second. While this looks astonishingly quick to a casual observer, a construction drawing of a large yacht, even at 1:30 scale, may have more than 500 metres of line on it, and 40 minutes is sometimes a long time to wait for a print. For this reason we also have an electrostatic plotter whose output is almost as good, but takes only three minutes to do an A0 drawing, irrespective of the amount of detail shown.
It is easy to get carried away by the esoteric requirements of naval architecture. While it is exciting to automate the exacting task of lines fairing and to get an automatic interface with a velocity prediction program, we found on analysing the time spent in our office that less than ten percent of drawing office time is spent doing lines plans and associated calculations. Nine times as many hours are spent doing things like interiors, sail plans, construction layouts, keels and rudders.
A typical project begins with pencil sketches of elevation, deck and interior. It is only at the next stage that the computer takes over. We do not believe anyone should sit down at a workstation without knowing reasonably precisely what he is trying to achieve.
The lines plan is done almost completely by hand on a drawing board (on a grid which is run off in a few minutes by the computer). Part of the reason for this is that the essential art of the yacht designer is his appreciation of the subtleties of curve which can make the difference between excellence and mediocrity in the finished yacht. If the curves are to be represented on a computer screen which is itself curved, much of the subtlety of shape is lost. Zooming in and out, rotating the image and doing all those dynamic manipulations which look so good at computer demonstrations is of limited help. We have found that at least for the moment, we prefer to establish the essentials of the hull shape on paper first.
We have a very useful reference file facility. Any workstation can display up to 32 reference files (in any combination of 63 levels) in addition to the file it is working on. These reference files cannot be edited, but they can be clipped, scaled or rotated independently of the working file. Thus the same file can be displayed on several workstations or overlaid on a file other users are working on. A designer working on the interior can display the construction layout as a reference file and make sure his interior takes full advantage of the space available between structural elements. Furthermore, if any changes are made to the reference file by another user, they will appear on his screen as they are made.
This ability allows several designers to work on the same project, each being immediately aware of what the others are doing. It gives us the chance to put an intense burst of effort into a design to meet a deadline and makes straightforward the process of integrating different facets of the design into a coherent whole.
The question of scale in a computer does not arise. All designs are full size, and can be defined to an accuracy of a hundreth of a millimetre over a length up to 42 kilometres. While this is far beyond our needs, the precision we can put into the design means that as a matter of course we can ensure that the yacht is buildable; that a spanner will fit over a particular nut, or that there is sufficient clearance between a generator and the insulation around the engineroom. One can zoom in from the overall view of the yacht to the smallest detail, so custom components can be designed in situ, ensuring that the finished unit will fit the space available and its mounting bracket will correspond exactly to an appropriate structural element.
|The builders appreciate the knowledge that the drawings can be plotted at any scale they wish, from a small A4 publicity drawing to a full sized template on Mylar film. Dimensioning is easy, instantaneous and accurate. We have found that the more information we can give to a builder, the more chances he has of making accurate quotations and controlling costs.
The computer has a capacity for storage and recall which makes it possible to store drawings of all components like winches, engines or galley equipment and these can be placed into a design at the touch of a button. We have often had to ask the equipment
Although Ron Holland Yacht Design has the most capable CAD system available initial design concepts are committed to paper by use of traditional design methods. A balance between the experience of interpreting the three-dimensional influences of a particular sheer line or deck edge line and the overall visualisation of a basic design concept are best drawn using plastic splines held in place by lead "whales".
and one single screen. Half of the workstations are colour and the total package has enough power to make the speed and imagination of the operator the only limiting factors.
To get drawings from the computer we have two plotters. Both can handle drawings a metre wide by up to so metres in length. One is a pen plotter which does the more precise drawings and can handle colour. Its problem is that it works at 30 cms per second. While this looks astonishingly quick to a casual observer, a construction drawing of a large yacht, even at 1:30 scale, may have more than 500 metres of line on it, and 40 minutes is sometimes a long time to wait for a print. For this reason we also have an electrostatic plotter whose output is almost as good, but takes only three minutes to do an A0 drawing, irrespective of the amount of detail shown.
It is easy to get carried away by the esoteric requirements of naval architecture. While it is exciting to automate the exacting task of lines fairing and to get an automatic interface with a velocity prediction program, we found on analysing the time spent in our office that less than ten percent of drawing office time is spent doing lines plans and associated calculations. Nine times as many hours are spent doing things like interiors, sail plans, construction layouts, keels and rudders.
A typical project begins with pencil sketches of elevation, deck and interior. It is only at the next stage that the computer takes over. We do not believe anyone should sit down at a workstation without knowing reasonably precisely what he is trying to achieve.
The lines plan is done almost completely by hand on a drawing board (on a grid which is run off in a few minutes by the computer). Part of the reason for this is that the essential art of the yacht designer is his appreciation of the subtleties of curve which can make the difference between excellence and mediocrity in the finished yacht. If the curves are to be represented on a computer screen which is itself curved, much of the subtlety of shape is lost. Zooming in and out, rotating the image and doing all those dynamic manipulations which look so good at computer demonstrations is of limited help. We have found that at least for the moment, we prefer to establish the essentials of the hull shape on paper first.
We have a very useful reference file facility. Any workstation can display up to 32 reference files (in any combination of 63 levels) in addition to the file it is working on. These reference files cannot be edited, but they can be clipped, scaled or rotated independently of the working file. Thus the same file can be displayed on several workstations or overlaid on a file other users are working on. A designer working on the interior can display the construction layout as a reference file and make sure his interior takes full advantage of the space available between structural elements. Furthermore, if any changes are made to the reference file by another user, they will appear on his screen as they are made.
This ability allows several designers to work on the same project, each being immediately aware of what the others are doing. It gives us the chance to put an intense burst of effort into a design to meet a deadline and makes straightforward the process of integrating different facets of the design into a coherent whole.
The question of scale in a computer does not arise. All designs are full size, and can be defined to an accuracy of a hundreth of a millimetre over a length up to 42 kilometres. While this is far beyond our needs, the precision we can put into the design means that as a matter of course we can ensure that the yacht is buildable; that a spanner will fit over a particular nut, or that there is sufficient clearance between a generator and the insulation around the engineroom. One can zoom in from the overall view of the yacht to the smallest detail, so custom components can be designed in situ, ensuring that the finished unit will fit the space available and its mounting bracket will correspond exactly to an appropriate structural element.
|The builders appreciate the knowledge that the drawings can be plotted at any scale they wish, from a small A4 publicity drawing to a full sized template on Mylar film. Dimensioning is easy, instantaneous and accurate. We have found that the more information we can give to a builder, the more chances he has of making accurate quotations and controlling costs.
The computer has a capacity for storage and recall which makes it possible to store drawings of all components like winches, engines or galley equipment and these can be placed into a design at the touch of a button. We have often had to ask the equipment
Although Ron Holland Yacht Design has the most capable CAD system available initial design concepts are committed to paper by use of traditional design methods. A balance between the experience of interpreting the three-dimensional influences of a particular sheer line or deck edge line and the overall visualisation of a basic design concept are best drawn using plastic splines held in place by lead "whales".
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