HBMS Amphion 1798 by Matrim - 32 Gun 18pdr Frigate

[Matrim]

Much more likely to have been me mis-understanding though

[Matrim]

Initial tracing of the profile, half-breadth and body has been completed. It is fairly routine except perhaps to comment that I prefer to always make the lines to long and shorten as opposed to being to short and having to lengthen then shorten. I also trace the half-breadth and body and keep the traces (in a separate layer) so that I can compare the results of my plan fairing to the originals.

 

 

 

What I want to cover today is setting up the other two trace plans. Before starting you will have (obviously…) worked out which plan was the most 'accurate' to use as the 'written in stone' plan. In my case I did this years ago with the profile and frame plan being very similar whereas the inboard works is all over the place warping wise. Therefore my next trace was to be the inboard works because I like a challenge.

 

Now some will not even bother to trace this but I like having it on the master trace because it gives extra build details and it is useful to get this normalized with your master plan early. Anyway the process I used is as follows.

 

I added the bitmap file to a new turbocad document and straightened as before. Once this was done I resized to 'full' size using the two perpendiculars and the supplied length (in the Amphion's case 144 feet). This does not guarantee it will match so I then copied the majority of my primary profile plan (leaving out decoration and external stuff) so I could size this plan according to the master without any worries about upsetting the master. Now the width should be very close to the existing trace but the height can be more problematic. In this case I picked a common point on both plans (the top of the stern post) and added horizontal and vertical lines to the trace the inboard works picture. This allowed me to see the difference in height and then to resize just the vertical dimension on the picture so it was the same. I then dragged the entire trace master over the picture using the front keel boxing joint as my starter and looked for problems.

 

I did find some. Height was good and the front of the ship matched slightly better than the rear. Nothing that was not workable. If lines were 'off' vertically slightly I would trace the original and then move the trace to match the correct deck line. The end result will be inboard works brought into line with the preferred master. When finished I copied just the layer with my new trace over into a new master where it matched exactly (as intended). It was then locked and hidden in case I need it. As an aside I also added the extra mast and rudder data to the original master as it seems more relevant to group it together than to split.

 

 

 

For those who had an un-natural interest in my file system here is a less than exciting shot of my one-note tracker document listing what I have so far.

 

[wrkempson]

A masterful job.  How rewarding to produce such a beautiful set of lines.  I think you should be in pretty good shape for the work that follows.

 

Now, may I inject a few remarks on the subject of tracing the plan.  On Naiad (I believe it was) Ed did not trace the lines so much as measure from the plan and then place the lines into his CAD drawing.  If I do not recall this correctly someone let me know.  Anyway, this got me to thinking about the idea of tracing the plan.  I could be the one who has brought in the term since in the little treatise that I wrote I must have used a line such as "trace everything" or some such.  This is what I did on Euryalus and Foudroyant and the results were quite usable.

 

However, since thinking some more about it, mere tracing is not quite the right way to go.  For example, on the inboard profile the decks and inner bulkheads are a specific width (eg, a 3" deck planking).  So, rather than tracing both lines, one line is placed on top of the plan line and then the second line is set parallel at the specified width from the first line.  And thus throughout the inboard profile plan.  In this way we are creating an accurate drawing that has "corrected" the vagaries of the original.

 

Even more significant is the way I would generate the rabbet lines of the stem.  Rather than trace them with a Bezier (which I did on Euryalus) today I would generate an arc that is tangent to the top of the keel and passes through two points on the inner rabbet line of the stem.  The top of the stem is a straight line which can be drawn in.  Then a second arc is generated as tangent to the first arc and tangent to the straight line and passing through one point on the plan.  The result is a rather elegant line.

 

In the picture below, the red arc is tangent to the top of the keel, the yellow line is straight, and the blue arc reconciles the arc to the line.  When cleaned up the result is the inner rabbet line.  

 

 

When trimmed, this inner rabbet line can be copied offset the prescribed distance (for example, 3" depending on the call out of the hull planking).  

 

 

A similar procedure can be followed to generate the cutwater by a series of reconciled arcs rather than by using a Bezier.  In the picture below there are seven arcs that define the cutwater.  If you trim off the loose ends the results is indeed serpentine.

 

 

The hang of the decks I have to put in with a Bezier.  I suspect the shape of the line might be a catenary, but even if so I don't think my CAD has a catenary tool anyway.  But once the deck line is drawn in, the attending lines indicating round up should be placed in through measurement as was done in the old days.  This again results is a more accurate drawing that has reworked the old drawing and thereby corrects what was lost due to age and distortion.

 

I think these observations may apply to the frame/station lines as well, but I have not substituted arcs and lines for the Beziers I used on Euryalus.  I am doing just that on my current project.

 

Well, this is a rather long winded way to applaud your work and cast my vote for more of the same.  The observations above are just an articulation of my current thinking.

 

Wayne

 

 

[Mark P]

Hi Matrim;

 

Excellent draughting!

 

One thought that might be of interest:  when I have been copying/drawing a draught,  I make each station line a different colour.  Then,  when the lines are drawn on the body plan,  at the outer edges,  where they overlap a lot,  it is easier to distinguish which is which.  I also make any datum marks on the body plan the same colour as the station line to which they belong.

 

All the best,

 

Mark P 

[Matrim]

Thanks both for the comments. Wayne, you appear to be moving to 'full shipwright' status. Have you considered a book on plans. Might be a possibility when you are happy with your approach....

 

Mark I tend to colour the water lines and have not had particular problems with the stations mainly because I switch the colour of the one I am working on to bright yellow and the ones done to a different colour so I don't tend to get confused. Then again I have probably entirely misunderstood the point..

[Mark P]

Hi Matrim;

 

thank you for the reply.  Everybody develops their own way of working,  and if it works well,  that's all we need.  I thought that you would probably have your own system to avoid confusing frames,  as it seems to be necessary.  I had not really thought of using a temporary colour change.  I'll keep it in mind as it might well be useful for other things.

 

All the best,

 

Mark P

[jud]

A follow up on lying out  those circular curves is to locate where the tangents points are or where you want them to be first, then extend those tangents ahead and back to an intersection with the neighboring tangent. Laying the tangents out first will enable you to locate the radius points so all connecting curves are tangent to each other and also the curves will be tangent to any straight lines coming in or out of the curve or set of curves. Works with curve segments running in the same direction or for reversed curves, much easier to work with than spirals. Working with tangent circular curves is much easier than working with non tangent circular curves although there is a place for them, minimizing their number is good planning.

jud

[Matrim]

There are always people around with more skill...especially on this site so I bow to your knowledge.

 

Quick update. I have repeated the procedure with the frames and as can be seen below they match the primary plan quite well (most notable on the gunports)

 

 

 

Now I will start re-doing the key lines as per instructions.

 

 

[Matrim]

The 'Joys of fairing' (repeatedly). Joking side I do like fairing though the ancient rule of 'if it feels wrong then it is wrong' usually applies and I have already re-done several. I am also taking some liberties with the process which are probably not correct but in the big scheme of things I don't think it will hurt that much.

 

To run through the process I adjust the line colours from the layer colour as I move. On the body and profile lines that are completed are light green (as is the central station line). The current 'active' waterline is yellow. On the half breadth O also tend to use Light Grey to colour out my uncertain lines and to remind me to 'miss' them - not forgetting that left hand side 'bad' station lines should be repeated on the right otherwise you could select that line where the polyline crosses and get a slightly out of sync line.

 

Anyway as that probably made no sense except to four people in the universe here are some 'action' shots.

 

 

So below you can see 'done' light green lines and the current active yellow

 

 

Here are some 'bad' station lines that I have coloured yellow just to make them more obvious. Note the bottom one covers both the left and right halves.

 

 

 

I take the start point from the rabbett on the bow.

 

 

And the same on the stern

 

 

Once the construction lines are dropped I am starting (and this may be heretical) from an adjusted keel line. Since the keel tapers at bow and stern I have aplied the taper - as I will apply it on the model (so not gradually over the entire keel) and am starting from there. On the original plan the waterlines start much deeper so I suspect they are copying the rabbett depth so this may be a bad idea (if any of the 4 has an opinion on this please say)

 

 

Once the two marker lines are done the left is mirrored onto the right section and a bezier joins them together

 

 

 

- not forgetting to 'miss' the dodgy grey lines and all done. I then always change my current work lines to green (for completed) but do not set up the next line as I have forgotten (in the past) whether that was a line I had completed but forgot to change colour or a line ready  to be done. I found it easier to leave it in a stable state which prevented mental stress when re-starting.

 

 

If anyone disagrees vociferously with me using those two rabbett lines as the start point then also please say. I vaguely recollect being told to use those years ago but as that was on MSW1 and around six years ago have utterly forgotten.

 

 

 

 

[wrkempson]

I think that as a rule I would think of a water line as the inside of the hull planking.  Thus, the water, like the inside of the planking, will end at a point that is the distance of the planking thickness from the outer rabbet line; this point will create a line with the rabbet line that is perpendicular to the water line.  Think of it as the planking being drawn in, but only the inner side and end line of the planking.  This is something I have started doing in the last few years.

 

So, I would construct a circle with the radius of the thickness of the planking (3" in  my example) and the center at the intersection of your construction line and the side of the  keel.  This circle gives the depth of the planking that is let into the keel.  Then terminate your water line (or polyline marker) on the circle so that the line is tangent to the circle.  Draw a line from this  point to the circle center and you will have the 90 degree line representing the end of the planking.

 

Is this why the old drawings have the water lines set into the keel?  I think so but can't say I have read this  anywhere, it just makes sense to me.

 

 

The inner rabbet line as drawn on the plans (parallel to the outer rabbet line) is a kind of fictional convention  since it does not exist on  the ship when built.

 

Wayne

[Matrim]

Thanks for that Wayne - it makes sense and adds a tiny improvement to the plans as well so I will re-do using that approach. 

[Matrim]

k, waterlines on the half breadth are now done, I also validated the 'curves' against the original traced waterlines as so (original in yellow)

 

 

Remembering that my waterline locations don't match the originals (so they would not be 'on top' of each other) this allows the angles to be approximately validated to see if anything is drastically off.

 

After this the Buttock Lines went in, this is a nice easy job.

 

After the Buttock Lines the station lines were re-done. For the distance I measured the traced gaps as so (remembering one of the station line gaps is larger than the rest presumably to not include a station line that matches the central ones closely and to allow 'better' locations for some of the aft lines)

 

 

Here the red dimension is the larger one. From this I settled at 62 inches for standard gaps and 75 for the larger.

 

 

Here they are drawn in. I keep the central station line a different colour (green). You also get a good view of the Buttock Lines as well (Pink)

 

Finally I compared locations to the originals. This has no relevance beyond showing how closely the body plan station lines will be close to the originals. As can be seen they are relatively close though some of the furthest aft lines are separating slightly so I can expect some line shadowing there.

 

 

Next up re-drawing the station lines on the body plan.

 

 

 

 

[wrkempson]

I think now is the time to decide on the scantlings for your floor and first futtock timbers.  The 62" figure will have two Room & Space measurements for a R&S scantling of 31" or 2' 7".  Steel gives the R&S of a 32 gun frigate as 2' 3 3/4 ", but his 32 is shorter than Amphion so a 2' 7" figure might fit for the longer LBP that you have.  Into that 31" must fit a floor, a first futtock and a space.  Steel gives 13" for the siding of the floor and futtock of a 32, but again I think we might up that to 14".  Twice 14" is 28" leaving a space of 3".  This is a bit spacey, but I think it might serve.  Now, into the 62" will go a two floors, two futtocks and two spaces, but because the spaces are distributed over three gaps (the bends are not sistered) we have 6/3" gaps of 2" air gaps between the timbers.  Again, this seems to me to be a bit spacey but not impossible.

 

Now for the 75" figure.  This longer distance is due to the presence of a frame that has only a floor timber without a companion first futtock.  This is what will cause the floor to "shift" from being on the forward side of the frame pair to the after side.  This arrangement was handled in a plethora of ways, but you will have to play around with spacing and disposition to make things work.

 

If any of this makes sense then take it for what it cost you.  These are just some speculations I went through when I saw the 62" and 75" figures.

 

Good work all around as far as I can see.

 

Wayne

Edited July 28, 2016 by wrkempson

[Matrim]

Thank you Wayne, as an 'assist' the Prosepines Build book (sister ship and the only one I can access) stated
 

 

Room and space of the timbers to be 2ft 7in

 

 

The floor timbers are

 

 

Floor timbers 9-G  sided 13 inch

9aft and G forward 12 inches

Length midships - 20ft 6 inch

 

 

 

and lower futtocks

 

Lower Futtocks between 9 and G sided 13 inch

9-13 + G- >= sided 12 inches

Forward and aft 11.5 inches

 

 

 

 

So it looks like they increased the 'space' of the room and space for this class...As an added precaution I measured the frame sizes and space on the traced frame plan and the frames are usually slightly over 13 (since it is a trace that is well within copy error boundaries) and the space is usually 4.7ish dropping to 3.5 ish towards the front of the ship.

[Matrim]

Work is progressing nicely. I started to re-do the body plan station lines but rapidly something felt wrong. In this case when comparing the newly drawn lines with the originals I noticed that the station line was not bulging as deeply as the original. As at this point the station lines are in identical places bar the odd cm this should not be occurring.

 

 

The purple lines are new and the green original. As you can see the anchor points on the pink Buttock lines and the waterlines. Initially it looked like the hull needed a few extra buttock lines to help assist in drawing the curve so I added one and redrew one of the station lines (browny orange on top of the existing)

 

 

This seemed to correct the issue as the line now at least appears to be matching the expected curve more closely.

 

On starting to re-do some of the earlier lines I was still not happy and decided some of the buttock lines were 'out' anyway. 

This could be due to many reasons but the most logical was a waterline misstep or including an 'uncertain' line when it should have been avoided. To test the theory I removed the buttock lines and added some new.

 

I then re-started and the problems seemed to go away. The key is that if the buttock lines are built of the original station lines that also built the waterlines then they should match. If either seems to be pulling away from the other then something is wrong. 

 

So my (current) full approach is as follows.

 

I color the current working station lines on vertical half breadth and profile yellow with all 'done' lines red.

 

 

 

Then the buttock lines on the profile have their horizontal constructions added for the working 'yellow' line

 

 

I then draw these in with a pink Polyline (so I can tell this apart from the waterlines which will overlap somewhat)

 

 

The vertical construction lines for the lower waterlines are then drawn in with a random different color (I think this looks Khaki like)

 

 

You'll notice how you can see how the buttock line polyline is  in sync with the lower waterlines line.

 

The upper waterlines and cap rail vertical constructions are then added. Also note (if you have good eyesight) the rapidly finishing cap rail (line on the left at this point). This is one reason I tried to make the new station lines match the original as presumably they were placed to avoid nasty locations. Though that could also be utter rubbish..

 

 

A better picture to show this is the cap rail height picture that I am taking from the underside of the cap rail (this could be wrong). Here you can also see the waist cap rail ending just past the station line.

 

 

And the upper polyline added

 

 

When drawing the bezier close attention was paid to whether the buttock lines and waterlines were working well together

 

 

And finally a close up of some of the redone lines (purple) with the original traced body (green) matching a lot better.

 

 

As I move further away from the center I expect these lines to separate slightly as my stations move slightly at either end of the ship compared to the originals but they should still follow a visibly similar shape..

 

 

 

 

[Matrim]

Now the lines are redrawn I have started firming up some of the other lines. The keel, rabbett and false keel were adjusted in size and the beakhead shape adjusted slightly to cope (I ended up using some of Waynes circles listed up above to get the angle looking better). Then these lines were transposed over to the body plan.

 

Here are the full size adjustments over the old.

 

 

 

and the adjusted

 

 

After this I drew in the new 'cutting down line',in my last research log this was covered in huge detail (or to put it another way some valiant souls spent three pages of log correcting my mistakes in understanding). Anyway this time I drew a vertical parallel line 9.5 inches either side of the centerline and copied it over the profile from that.

 

Here is the stern side, the cutting down line is green

 

 

My next 'major' task is to get the frames drawn in so before that I tidied up some of the joints and then corrected the gunports. As with the cutting down line I have covered this already and the basic purpose is to ensure the lines lose any angles caused by bad tracing. End result

 

 

The key being to remember the horizontal lines are not always horizontal to the keel.

 

With some of the rest of the ship..

 

 

Port cills were quick and easy. I decided on the gap I wanted them to stick out and the followed the following procedure.

 

Add angles construction lines along the top and bottom edges

 

 

Add vertical construction lines the distance I wanted them to stick out

 

 

Add a parallel construction line at the top 5 inches away and two of the same type 3inches away from the lower edge of the port

 

 

Draw the cills in

 

 

Remove the construction lines.

 

 

Finally I moved them all to a separate layer as I had originally drawn them as part of the gunports but decided they belonged more closely with the frames as they would not be visible as the gunport would.

 

Next up the large job of the frames.

 

 

 

[Matrim]

Carrying on my 'repeat everything I did last time' process I have now finished the square frames, added the rising wood and completed the Centerline presentation plan.

 

I was extra careful ( more careful? I dont want to over egg the pudding) with the rising wood as it was uncertainty concerning the Bearding Line that stopped my build and pushed me back the drawing board (drawing pc? we need new words..)

 

Anyway once I had drawn it in and notched the wrong side (doh!) I then re-checked the base line against my original traced frame plan which I had cunningly not removed and left invisible in case of need - just to apply a sanity check on the line.

 

Here is it... I have temporarilly made the bearding line red (it is usually light green which is the same colour as the original plan frame trace)

 

 

As can be seen the line is very close to the original so I am pleased things match up.

 

The centerline plan ( as before) is loosely (closely) based on EdTs wonderful draftmanship though not as advanced..

 

Here is the front

 

 

And here is the rear

 

 

You'll notice (well perhaps not) the orange 'turret like' line on top of the frames. That is the rising wood. Last time I left this and drew it in after drawing the frames. It makes much more sense to get this on the master plan now so it can be used to get the correct keel base when lofting the frames. I am keeping to the decision I made with the previous build to use less angles (and milling the contents) and using rather more horizontal joins that perhaps is historically accurate. I did wonder whether I should perhaps re-draw some of the angled frame joins with the same simplifying aim in mind.

 

Anyway next up are the cant frames and the build board plan. I may well start generating some scale build plans at that point and only loft the frames when I need them. I will have to see how confident I am when I get closer to that point.

[Matrim]

Time for another terribly unexciting update. I have now started on the forward cant frames and after some abortive attempts finally managed a process which I was happy with. 

 

Initially I used the traced frames as a starter (the central dashed lines of the double frames). I took a vertical construction line from the lowest visible waterline to the keel and repeated for (usually) the cap rail. Joined the two together and then extended to get my four center points.

 

 

I could then place a vertical where it split the keel and added two parallel lines 10.5 apart.

 

 

I then added little temporary lines where these broke the keel line.

 

Next I moved to the cap rail and added a line perpendicular central line where it broke the cap rail.I could then add two more perpendicular lines also at 10.5

 

 

Now I could join the little temp lines on the keel to the equivalent end points on the construction line (not the cap rail as that would move the lines out of sync)

 

 

Now I extended to new lines so they stretched far beyond all waterlines

 

 

The next job is to add the filler frames. For this I measured the gap between the relevant double frames

 

 

Deducted 21 for the frames themselves, divided what was left by 3 and then added construction lines of that length, then 10.5 either side and then added my helper lines so I could remove the constructions

 

 

The process at the cap rail was similar except here I started by drawing a construction line between the two double frames and used that to right angle my working construction lines

 

before adding the lines as before, extending and eventually trimming

 

 

Eventually I completed the lot. The singles at the end followed the same approach but with less gaps as the far edge was the edge of the last single frame and for the singles closet to the square frames I used my last 'new'  frame as the start point but followed essentially the same process

 

 

Now I could move onto drawing the frames themselves. This followed the 'usual' approach. Vertical constructions through each point (starting from the keel as that makes a nicer line even though that section will eventually get chopped off)

 

 

Repeat for upper waterlines and then join in

 

 

This will keep me busy for a bit and the same process will be followed for the stern cant frames.

 

 

 

[maaaslo]

Hi

Magnificient and trully masterfully crafted plans are being drawn here.

One thing i would like to ask. Since i only visit the forum occasionally, i do not recall seeing any previous versions of your plans, nor i recall actually stumbling upon any of the previous works you have mentioned in your first post. What exactly are you planing to do with the finished plans? Are you going to release the data in any form? If so, how would one be able to obtain the results and where?

[Matrim]

Thanks for the compliment though a lot of others do 'better' plans than I do.

 

I am actually at a point now where I could start building of the plans (I should really do an update though will probably wait until I get the frame master out) as I may avoid doing the individual frames until I need them. It took avery long time to get little individual pieces out of the way last time so I will have time during the build itself.

 

I had not thought about releasing them plus would need to complete the model to be confident the plans were good enough for the same (and that is a looong time away)..

[Matrim]

Time for another presentation plan. This one is for the frames so not particularly exciting plus I a may re-work the hawse pieces as their is something there I am not quite happy with, the full plans go into some interesting fiddly work that I have not decided whether to reproduce or not.

 

After this comes the building board plan or the 'fishbones' as I like to see it, which is possibly the most useful of the large plans. After that I may churn out the individual build plans for the central section of the ships spine - keel, false keel, stem and apron etc.

 

[druxey]

Looks good, but do the aft cant frames really run down all the way to the keel? Usually they sit on a stepped or curved ledge on the deadwood. This also applies, to a lesser extent, on the fore cant frames at the forefoot.

[Matrim]

Good point as they dont!  I usually take the cant frames from the keel so that the curve, when it hits the ledge, has a smoother curve (I found it appeared disjointed slightly when started from the ledge which may just be the way I was drafting it) therefore It looks like I forgot to trim...

 

Revision one incoming quickly..

[Matrim]

Here is the revision. Took a little longer as I had to adjust the master first then re-apply to thje presentation frame plan.

 

[druxey]

Much better, Joss!

[Matrim]

K next up we have my fish plan (or the gangway overhead frames plan if you have no poetry). This is almost the key starting plan as it shall be printed full scale size (well in scale sections), laminated, then glued to the building board.

 

In certain respects I have simplified it somewhat in that I have not completed all the relevant hawse piece details (mainly as I am still considering re-work there) or added much stern structure detail beyond the outline. Both these areas will be worked on against the master as and when I need them so may be added to a version two of this plan which would provide more structural detail than the building board would need. I also decided to not add the station numbers as they don't have much use for this plan.

 

Additions that did not exist in the last are more details on the rising wood and the keel/false keel seperators. I found in my earlier look at building that I found it difficult to ascertain the correct overall size of those pieces as I did not have a single plan with 'all' the keel on. Since this plan is the total size it makes sense for that information to be on here so it should assist with building the keel/false keel/rising wood beyond its usual main purpose of assisting in frame layout and size generally.

 

Finally I might switch the scale of this I was originally going to keep to 1:60 but might drop to 1:50. I don't plan on including the top gallants, the masts will be angled to catch the wind (reducing height and width of the end model) and the extra size will help make some of the bits like the rising wood much less fiddly when I get round to them. Not decided either way yet though.

 

[mtaylor]

Joss,

 

While you're probably right about not adding the station numbers, you might consider adding frame numbers if you haven't already.   

 

Looking good still.

[druxey]

If you are considering upsizing, why not 1:48 (a standard scale) rather than 1:50? As Mark mentioned, I'd also recommend numbering/lettering your frames, as it's so easy to mix them up (or put them in back to front!).

[Matrim]

Seems sensible so I have added them on (0n the frames themselves but below where the keel and supporting wood will go once building starts). It does beg the rather irrelevant question of 'what did they name the two single frames between ( (  B  )and B?

 

So on the plan moving out from the (0) central frame I have

 

(0) double

(Al)

(Ar)

(  B  ) double

?

?

B double

Cl

Cr

D double

 

and on

 

For the moment I am using B-l and B-R but I did wonder  if there was a correct naming convention ( admittedly a question of spectacular unimportance)

[druxey]

I imagine with a parallel body those frames would be designated (B double), (B aft), (B fore), B double, C aft, C fore, D double, etc.

Edited October 30, 2016 by druxey