HMS Bellona 1760 by SJSoane - Scale 1:64 - English 74-gun - as designed

[Mark P]

Hi Mark;

 

Thanks for the explanation.  I must make one of these.

 

All the best,

 

Mark P

[michael mott]

A very well executed solution Mark, The design of the former block with the clamp holes looks very good.

 

Michael

[SJSoane]

Thanks, Michael. I always appreciate your keen eye and ideas for tooling.

 

Now I have successfully bent a piece, I need to think how I am going to shape it. I am thinking about attaching it to a backing piece that would allow me to clamp it in a vise, as shown in the drawing. Unless someone has a simpler idea.

 

Just for fun, I steamed the original pre-cut pieces that I previously boiled and could not get to the right curvature. They appear to have bent to the former after steaming, as seen in the last photo, and we will see how much spring-back I get tomorrow morning.

 

This is an impromptu experiment in the advantages and disadvantages of cutting and then bending, or vise versa...

 

Mark

[Mark P]

Hi Mark;

 

I would be more inclined to make an inner surface template and band saw it to almost the right shape,  with a fine-tooth blade,  finishing by sanding.  This would seem to be quicker.

 

All the best,

 

Mark P

[michael mott]

And I would be inclined to cut it out with a jewelers saw then file it.

 

Michael

[SJSoane]

I pulled the pre-cut pieces off the formers this morning, and they bent very nicely to the hull. After pondering the not insignificant program of shaping a curved blank, I think I will have more success with the original plan of bending pre-cut pieces. This allows me to shape tight fitting joinery while pieces are still flat, then bend.

 

There was a little more spring-back on the these pieces that I had previously boiled, compared to the blank I bent the other day that had not been steamed or boiled before. So the boiling did seem to affect the wood before the steaming. Only steaming from now on..

 

Mark

[aviaamator]

Cool!!!!

[SJSoane]

Thank you, aviaamator, the opinions of all of you really help keep me focused.

 

Following the good advice of Gary on his Alfred build, I am installing a temporary batten at the top of the wale, against which I can fit the upper strakes for a smooth curve.

 

Not quite sure yet if the pre-cut and then bent strake is going to fit tightly here. It needs some "encouragement" to lie flat against the compound curving surface, and I can't see yet if this will cause unreasonable stress. I am learning much at this critical place in the build; critical because it is so obvious if the wale lies correctly or not, and at the head where the viewer's attention will naturally be drawn when the ship is completed.

 

 

[druxey]

Beware of the line rising too far at the bow. Check the height from the baseboard to the wale edge at the bow rabbet. Usually the curve of the wale flattens or even appears to reverse at the bow. If the wale ends up too high on the bow, it will throw off all the headwork. You won't want that!

[SJSoane]

Thanks, druxey, I will triple check it. I can't quite see if the batten, which is above the top line of the wale, is misleading me...

 

Mark

 

[SJSoane]

I forget to ask in the last post; should an imaginary line connecting the two wales across the stem make a smooth curve? Or do they come to a slight acute angle in relationship to each other? Since the sheer drawing has the wale as a smooth curve up right to when it hits the rabbet, I have been assuming that this would translate into a slight angle to the stem when seen from face on.

 

Mark

[SJSoane]

Here is a different angle view...

[druxey]

Your assumption that the smooth upward curve on the sheer drawing (in one plane) is the same projected on the 3D shape of the bow is misleading. That is the trap!

[SJSoane]

Thanks, druxey, you were right, the point at the stem had crept up. Here is the batten with the corrected curve.

Gary's recommendation of a batten against which to set the wales is really proving to be a great idea. I was able to use it to accurately spile the topmost, foremost plank, and this showed me that there was greater curve on the upper surface than I had previously drawn (my CAD drawing had assumed, I realize in hindsight, that the surface was completely vertical, and this is not the case). The last photo shows how much the upper plank curves.

 

It just goes to show that there is no shortcut to reliable techniques. Set a batten, and spile the planks, set a batten and spile the planks, repeat until this lesson is never forgotten! 

 

Mark

[Gaetan Bordeleau]

Mark, is it possible  that I see 2 curves direction?

[druxey]

That looks right to my eye now, Mark. It's a critical point that many modelers miss. Later it comes back to bite as the headwork won't articulate properly with the bow of the model. I'm glad you posted those photos in time to catch it!

[Gaetan Bordeleau]

Recently I did trace this line on my french 74. and for the front part I used masking  tape because the wood batten did not have enough flexibility.

As a comparison, the french ship line is higher.

[SJSoane]

Hi Gaetan,

 

Yes, the wale does make a double curve. i confirmed this more horizontal arrangement with careful re-measuring against the sheer, and also checking against the photo I took of the original Bellona model, where you can see the top of the wale on the port side is just about horizontal when it joins the stem.

 

It is particularly interesting that the French wale you show definitely angles upward in comparison. This is all the more interesting because I understand that the influential Bellona design was derived from a captured French ship. I wonder if  the original French ship had a sloping wale, and if the British adapted the French design to their own traditions in some places.

 

Best wishes,

 

Mark

 

 

 

[Gaetan Bordeleau]

Hi Mark,

I see why you went this way.

My only concern how the planking will end at the blue arrow?

[Siggi52]

Good morning Mark,

 

it's good to see you back at the work bench. In the question of the double curve of the wales I think that there is no double curve. Also, if you want to see, at the Bellona model. Look also at the upper wales. Here some pictures I made last year in Greenwich and Chatham.

 

First the Centurion of 1732, Model made 1745

 

 

then a 60 gunner of 1745

 

 

and Balchen's Victory

 

 

and two pictures from the NMM website, the Victory and Thunderer

 

 

[Gaetan Bordeleau]

Mark I think your reference could be a bad reference because it is a partial planking. A fully planked model is a better reference.

 

Here is what I think the modeler did with this model. He took the highway of the facility. He did represent 3 rows of a wale only. The 3 rows are made  full width planks. If he would have continued his work without tapering extremities of the planks he would face some planks tapering to 0 and this we do not want for the simple reason that we cannot put a nail at the end of a plank finishing at 0 inch.

 

Tapering the end of a plank means thatthe end of the next plank will come higher taking a part of the space of the upper plank.

 

It is very difficult to start to the first plank at the good angle with the good curvature. It is also difficult to photograph  the direction of the plank. Following your work, I returned to mine, observing that I did even worst.

 

I think a good way to verify the regularity of the curve is to take 3 pictures : 1 front, 1 at 90  degrees of the middle of the strake and 1 side. I did repeat the process 3 times and corrected the end each time. The lower line was before, the upper is now which seems to look better. Still needs some adjustments but I think that if the results  is smooth on the 3 photos, then the result can be good. Also I think that taking pictures after doing the work has the same result as usual, The camera has no pity of our work.

 

[druxey]

The reverse curve is an optical illusion. As seen from the side, the curve continues up to the bow. However, if you plot this curve in three dimensions (the bow is curving away fro  the viewer in plan view), the curve flattens out. The rounder the bow, the more apparent is this effect.

[Mark P]

Hi everyone;

 

Siggi,  thanks for the pictures of Centurion,  she's  a lovely model,  and the others.

 

Everyone here is saying essentially the same,  that the wale curves upwards towards the stem,  as Siggi's excellent bows-on shots show.  But when seen from some angles,  it can appear to flatten out a bit.  Siggi's shot of Balchen's Victory shows this just starting to happen.

 

The point then is that,  if the modeller notices the flattening,  he must check his drawings and dimensions,  but most importantly,  he should not try to increase the upward curve of the wale to counteract what is an optical illusion.  Not unless the measurements are wrong;  hence Druxey's comments.  The risk is that the upward curve will be increased beyond what it should be,  when the eye tells us that the wale looks wrong,  but it is actually correct.

 

Mark,  I wish I had the time to spend on my model that you do! I'm envious,  in a good way!  One note of caution regarding the 'Bellona' model,  though.  I think that the top strake of the wale is stopped short of the bow.  There are only 3 strakes,  and there should be 4.  So I would be more inclined to follow the bottom curve than the top curve.

 

All the best,

 

Mark P

 

 

Edited January 13, 2018 by Mark P

[EdT]

Hi Mark,

 

I think that the important thing to keep in mind here is that the upper plank of the wale (as well as other topside planking and rails) follows the sheer line that is drawn on the sheer plan and that measuring heights up from the base at each frame line on that line will yield the correct line as drawn and probably as built as well, since shipwrights would likely mark the height of this line on the frames.  These heights  would be given in the tabulated data sent to the yard.  This method would yield the reverse curve effect that Druxey describes.  However, I would argue that this is not so much an illusion as it is the true line of the plank, since the heights of the sheer line on the sheer plan are not true lengths along the side of the hull.  The distances between frame lines along the hull, especially at the bow, are greater than those shown on the plan - tending to flatten the curve in those areas.  So, if you are building the ship "as designed"  I would merely measure up from the base the heights on the plan at each frame and trust that to be correct.  We could probably debate whether this method was always followed in the yard, or for that matter in the construction of models at the time.  There might have been more of a desire to have a pleasing line in the latter case - and maybe even in the former.

 

By the way, if you depart from the sheer line at the wale in the interest of aesthetics, you will need to adjust the planking above - or end up with a mismatch at the top.  My recommendation would be: strict adherence to the drawing.

 

Ed

Edited January 13, 2018 by EdT

[SJSoane]

Thanks, Gaetan, Siggi and druxey, for your thoughtful help with this question. I worried in the middle of the night, because all of your examples, and my own of the Bellona, show the two wales coming to the stem at an acute angle, not as a horizontal line as my previous photo showed.

 

So after more careful measuring, which continued to confirm my location, I realized that it had to do with the angle of the photo. As I show below, dropping the camera down reveals that my wales also come to the stem at an acute angle.

 

And then I realized that the only way the wales could form a horizontal line from one side of the stem to the other would be if the bows were a perfect hemisphere at the stem. But since the hull is slightly pointed at the stem, the wales will have to form an acute angle.

 

Mark

[SJSoane]

Mark and Ed, I missed your comments before I just posted above.

 

Ed, I take your advice to heart; attending rigorously to the drawing is going to avoid any visual ad hoc adjusting that will later get me into trouble. I am also reassured that the wale appears to be parallel to the top of the hull right at the bows, since that was also carefully plotted from the sheer.

 

Interestingly, as I tried to figure out why my plotting on the hull was originally erroneous right at the stem, I double checked my means of measuring. I had been using a gantry like yours to measure from a set height above the hull. But I unfortunately discovered that in my recent move, the gantry came out of true. The top of the gantry is not completely parallel to the base, and sheer drawing relationship to the top edge of the board has changed slightly. I don't know if this is the increased humidity, or things got knocked, but recalibration is definitely necessary!

 

Mark, I see what you mean about the original Bellona model. Yes, they did leave off the topmost, foremost strake, I believe to avoid running into the temporary batten in this demonstration model. So I am definitely working to the top line of the wale taken from the sheer drawing, and I will be planking with four strakes in the wale. And it is a joy to be able to work on this more fully in retirement, although I still don't get as much done as Ed does in a day. He sets a standard to which I continue to aspire!

 

[druxey]

As long as the vertical height(s) at the stem rabbet is/are correct, you should be fine!

[SJSoane]

After recalibrating my gantry for measuring off the sheer drawing, I decided it would be prudent to re-plot the wales, just in case things went astray during the move.

While I was at it, I re-thought how to attach the batten above the wale, for more accuracy. I had previously plotted points the thickness of the batten above the wale, so I could see the points from above while attaching the batten (too hard to look for points under the batten, in the shadow). But this proved to be inaccurate; the batten itself was not completely the same width along its length, and I had now plotted more points against other points, allowing errors to creep in.

 

So, instead, I drilled holes at the plotted points at the top of the wales, which I could see clearly without the battens in the way. And I then put small nails into the holes, using these as stops against which I could very accurately hold the batten while drilling and fastening it.

 

This was a reminder to me that--at least for me--registering one piece against another is going to be more reliable than free-handing.

 

Mark

[SJSoane]

I forgot to mention, thanks Siggi, for the spectacular photos of bows. These are the kinds of images that keep me going, because I am reminded just how beautiful these ships and models are when they are completed.

 

And it looks like more models are now on display at Chatham and Greenwich? The last time I was there a number of years ago, there were very few compared to the massive numbers in the old display at Greenwich before the museum was renovated. I had pretty much given up on Greenwich.

 

Mark

[SJSoane]

The first planks of the wales are on, so far, so good. They are a little oversize in thickness to allow for leveling later, but the hooked joints are tight. These were the most challenging pieces I have installed so far on this project, with compound curves and tight tolerances on the hooked joints.

Mark