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[Martin (Admin)]

John has asked me to split the subject.
http://www.modelboatmayhem.co.uk/forum/index.php?topic=6250.msg61603#msg61603


Please post any question here.....

[charvey]

Hi John,
Thankyou for a very informative article.

I do have a question which may well be out of the scope of this thread, but...

I have a set of shipyard drawings for a model I am planning to build, including side and top views, and a shell expansion.  As you say I can trace the outline of the keel, and the positions of all the frames and bulkheads are marked. Unfortunately I cant see the profile of the frames.  Is there a way I can interpolate the profile of each frame, or is there a specific name for this plan / detail that I may be able to ask for? Plan B is to attempt to re-draw these plans in a CAD program so I can get a reasonable estimation of the frame profile.

Many thanks

Chris

[FullLeatherJacket]

Chris

You need the Hull Lines and Frames drawings, along with their associated Tables of Ordinates (usually given on the same sheet). These wiil give the co-ordinates of the points on the frames and hull lines which the designer used to specify the templates for lofting. You should be able to put these straight into a CAD package - as dimensions along the X and Y axes - and, with suitable scaling, plot a full-size plan for your model.

Give me a shout if you need any further help with CAD stuff.

FLJ

BTW.......I know where I can get my hands on the original tracings of that Swordsman plan....... "nudge, nudge,  ,  ; say no more, squire!"

[charvey]

Hi John and FLJ,
Thanks very much for all the information, that is excellent and makes sense to me. 

I have deck plans which should give me two of the WL lines in your sketch, these deck lines appear on the side view plans so that should be easy enough, but is complicated by the fact that the decks slope.  The model is of a paddle steamer which had a main deck and a lower deck within the hull shell, I also know that the hull plating for the bottom slopes at 3 degrees, so for the mid section I can just extrapolate these lines till they join.  I also have a design and "as builts" for a secton through the engineering spaces with lots of annotations of constructional detail giving frame spacing dimensions, and tells me which frames were extended into the deck housing to support the promenade deck. These plans also gives the bilge radius for the mid section. 

I do wonder if the copies of these plans I have are not the whole sheet, since there are no borders etc.

I think that using a CAD package will help me since I should be able to verify any assumptions I make in my interpretation of the plans, and "tweak" things about if they don't look or fit right.

FLJ,
What CAD package do you use?  I use Microstation because I used it during my course at university and find it much more intuitive than AutoCAD.

John,

Can I be cheeky and put in a request for a short topic on Shell Expansion drawings, particularly the interpretation of the symbols that are scattered across it?

Many thanks

Chris

[romainpek]

Thanks for your informations.

I have a question about "extra lines" you sometimes find on plans. They are usually dashed and appear often as diagonals. What are they used for ? If you have the side view + the formers drawings, you should not need anything else, isn't it ?

I post an example below...

[Bluebird v2]

good morning there Romain

I have very limited information on 'sailing ship' lines.

However, the information I do have is that these lines represent frames which you can make up and slot into your model this aids the shaping of the bow and stern section of these old sailing vessels.   

I have included a scan from a book which I have, and, if you look closely, you will see them.     

This represents the model on a building board, ready for the frames to be added and then planked.

It may not be necessary to add these frames, but, depending on how 'tight' the curve is on the bow section and on the stern, will determine whether or not you put these in.   To be honest, I would put them in on your model build.

I do hope this is of some help to you.

Aye
John E
Bluebird

[romainpek]

Thank you John ! 

I even see now at what angle should these "oblique formers" be set on the view above !

A trickier question now (at least for me).

These are the formers for an IOM, you will notice a lot of oblique lines on them, however nothing on the other plan views are named the same...

I wonder if they are needed to build the boat or needed to draw the formers... what do you think ?

[Bluebird v2]

hi there Romain

If you are referring to the lines drawn diagonally from the centre line A, B and C, these lines are drawn in by the draughtsman to check the accuracy and fairness of the frames.   The chances are, you will not have a side profile of this.  As when viewed, they look similar to a 'what is classed as a Buttock line'.  The only reason they are there, as we have said, is to check that your frames or your sections all run fair.

Hope this will help you.

aye
john e
bluebird

[romainpek]

Thank you again. Basically, I don't need these extra lines.

Fine with me !