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

[EdT]

Research continues.

 

I still cannot speak to the issues of the upper deck and continue to believe that its radius of curvature is constant over the length of the deck. The Bellone draft may well have errors. There were several in the Naiad drafts. But my opinion remains just that - an opinion.

 

However, I have continued to explore Steel with regard to the quarterdeck round up at the stern that does match the roundup of the top of the lights in the drawing attached to my last post. I believe I have found the answer in the voluminous treatise on mold loft processes (70+ pages). In this description the quarterdeck transom is lofted to the curvature of the upper counter rail - the curve of the lights. This complicated description is then followed by the sentence, in parentheses, "(The after beams of the quarterdeck must be gradually sprung to answer thereto.)". From this, I conclude that the qdeck beams were made to the specified round up. As the stern was approached they were then "gradually sprung" probably using the pillars, to match the round up of the slightly more curved qdeck transom. I know in later periods, springing beams this way to level out the deck was fairly common practice. This explanation makes enough sense to me to conclude what has become an obsessive search.

 

Hope this helps, Mark.

 

Ed

[druxey]

'Spring' Ed, in the 18th century referred to the round-up of the stern transverse curves. Your quote, "The after beams of the quarterdeck must be gradually sprung to answer thereto." implies - to me, at least - that the beam round up increases, rather than is forced up by pillars. Thanks for coming across that one. I don't recall having read it. This should set Mark's mind at rest, as well as those of us that have participated in this thread!

[SJSoane]

Hi everyone,

 

I deeply appreciate your help on this increasingly interesting question.

 

As you have all seen, I am trying to deduce the roundup at the stern transoms from the sheer diagram which shows the beam heights at the side and midships; I can also measure the heights of the knuckles of the upper and lower counters from the sheer diagram since it shows the stern timbers at the sides and midships.

 

Now it would be nice to validate this against a drawing of the stern; but very unfortunately, there is no drawing of the Bellona's stern that I have ever been able to find in the Maritime Museum collection. I only have photos of the 1760 model.

 

So I have been reconstructing the stern construction from what I believe I know from the sheer drawing, and what I can infer from the photos of the model.

 

I have attached my working drawing of the stern (ignore the 5 plan drawings of the various transoms and knuckles at the bottom of the drawing). I am showing my reconstruction of four lines: lowest is the roundup of the wing transom; then above it the line of the knuckle at the top of the lower counter; then above it the line of the knuckle at the upper counter which is also the line of the sills of the lights; and then finally the line at the top of the quarterdeck transom which is also the head of the lights.

 

And the best I can tell, as Ed mentioned, the roundup of the knuckle of the lower counter is not the same as the transom of the upper deck behind it. Nor is it the same as the line of the knuckle of the upper counter or the transom of the quarterdeck. But I believe from looking at the model that the quarterdeck decking sits directly on the quarterdeck transom, and so the quarterdeck transom has the same roundup as the quarterdeck beams behind it.

 

I am showing here the roundup of the quarterdeck transom as I measure it in the sheer drawing; 5" at the outer face of the transom at midships. The balcony obviously carries out beyond that. So this is where druxey's warning is important. If I dropped the roundup of the quarterdeck transom to 3" here, I think the stern lights would look squished at the top. 

 

I was surprised to see that there are five beams in the quarterdeck abaft the last gunport. So if adjustments have to be made to kick it up at the stern to match the transom, it will be 5 beams to fix.

 

Last thing, Steel says, the "lower gallery lights in the length on the rake should be 3'-6"." That suggests that the upper knuckle and the top of the quarterdeck transom would be parallel. Even at 5" roundup mine looks flatter at the quarterdeck transom. A little worrying.

 

And regarding the quarterdeck transom, Steel says, "round up agreeably to the lights below, and moulded as broad as can be gotten." That seems to affirm Ed's idea that the transom was adjusted to make the stern lights look right. And yet the model shows the deck the same as the transom.

 

My head hurts....

 

Best wishes,

 

Mark

 

 

 

 

[SJSoane]

 

Sorry, forgot to add in response to Ed's last post. I now think this is probably right, that the last five beams are slightly adjusted to pick up the 2 inch difference by the time the deck hits the transom. This is now my story and i am sticking with it...;-)

 

Mark

[Sailor1234567890]

It's interesting to me how we as a species can lose a technology that we had once mastered. Trying to replicate something like a ship that was built 200 + years ago should be easy. We did it before. How hard could it be to build one now? We have power tools, we have computer softward to do the design work, yet even with all this extra "help" to get the job done, we would be hard pressed to build a large vessel like this. Pyramids.... forget it. Yet, relatively small groups of enthusiasts like us will labour for years to figure out something and keep pushing to "get it right". I love that.

[druxey]

Things to bear in mind:

 

1) The roundup or spring of each transom and gallery increases as you go upward. This counteracts the illusion of sagging.

 

2) The apparent spring in photos can look exaggerated as the lower the viewpoint, the greater it appears to be. This illusion is because of the round aft of the various knuckles and rows of lights.

 

3) Any row of lights have the same height throughout, as you've noted, Mark. 

 

I thinks that exhausts the subject - for now, anyway!

[Gaetan Bordeleau]

Same picture, 2 different place, but with a side angle 

Anatomy of the ship Bellona p 25

Ship of the line vol 2 p 117

 

There must be a better picture somewhere?

[SJSoane]

Hi everyone,

 

So I think I see how this works, now that I have looked at the quarterdeck plan more closely, I believe there is enough space between the aftermost beam and the transom to allow the decking to smoothly rise from the normal beam roundup to the higher roundup on the transom. All beams keep the same roundup, the transom matches the roundup of the lights, the deck connects the two. You can see how this would work in the photo of the model. The quarterdeck planks at midship can be seen through the doorways in the side, sitting on top of the transom.

 

So you were all right about the standard beam roundup, and I was right about a higher roundup on the transom. Re-reading the obscure parts of Steel sometimes reveal unexpected insights!

 

Ahhh.....

 

Mark

 

[druxey]

If you're happy, Mark, we can all rest easy tonight!

[Alex M]

Hi Mark,

 

first I must say: first clas work you have done on your Bellona! After some weeks absence in the forum I have now a lot of updates to read! You building repot is one I follow and waiting for new images. You have also started a very good discussion about stern construction. It is trickly part I have puzzled by my Anson too. I have researched some drawings of 64 and 74 gun ships, because there are very often only size difference, the construction is the same. I have seen some stern plans, that shows the difference (from one to one and half inch) in the round up of quarter deck transom and the lights. One of these is the Hunt's Ardent (1782 rebuild) here:

 

 

The plan of Anson show the same difference. Also from Ardent: the lines represented the decks at the side are drawn at different distances in different plans (sheer, inboard works and framing plan). Those plans of same ship are drawn at different times, and are only as accurate as draftsman can do them, or as shipbuilder can inspect them (if been neccessary).

 

If you look at sheer draught, there is the lower line of quarter deck planks, touching the lower point of balcony rail at middle line. At the outer ends of balcony rail it should raise just one or one and half inch. The rabbet of balcony rail was cut with different depth to match the difference in round up.

 

As been stated abowe by Druxey and Ed, the round up of deck beams ist constant in the whole deck length. It is also only one number for them given in contracts and establishments.

 

Hope this help a little, and because my bad english you can understand what I wrote.

Alex

[gjdale]

Gee Mark, this is reading better than a "whodunnit"!!!

 

Glad to hear you've solved the mystery though. Great work.

[druxey]

In the illustration of Ardent's stern, Alex, remember that the centre of the projected stern gallery is further aft than the outer ends, so is also higher because of the angle created due to its sheer.

[SJSoane]

 

Thanks, everyone, I am working on wood now thanks to all of your help.

 

And Alex, thank you very much for the Ardent drawing. That is the only drawing except Steel's 80 gun ship that I have seen of the old fashioned stern with the balcony like the Bellona. It helped me enormously to check the various curves against my own reconstruction.

 

Best wishes,

 

Mark

[Alex M]

Hi,

 

sorry Mark for boring your Post, by it's very interesting question. Druxey, I know what you mean: round aft. I post another image where I redraw the curves I mean.

 

 

Also note that the transom is drawn as where it at the after end of balcony. I don't think it is drawing error, because the drawing is very accurate due to paper distortion. The lines show just the difference in the round up between windows and deck. The disposition on the Anson drawing is similar to Ardent.

 

 

Alex

[druxey]

That's the general idea, Alex.

[Gaetan Bordeleau]

By comparison with a french 74, the curve of the gallery is exactly the same as the deck.

[SJSoane]

 

HI everyone,

 

This is indeed a fascinating issue; the more you look at it, the more interesting it becomes. Thank you Gaetan, for showing us the French method. I know very little about the French traditions--except that my Bellona was apparently copied from a captured successful French ship--and it is very interesting to see the constructional differences.

 

As I begin building the stern, I am astounded at the constructional complexity and subtle visual effects they worked so hard to achieve. Beauty still counted for a lot back then!

 

Best wishes,

 

Mark

[SJSoane]

Hi everyone,

 

I have started construction on the stern. The first images show constructing the transom at the quarterdeck into which the vertical timbers will dovetail. When I taped it in place in the third image, I realized that there were too many parts in motion, and I would need a jig to keep it all aligned.

 

So the next images show a jig at the location of the stern lights. The most important thing to keep straight in this construction is the equal spacing of the stern lights.  The jig represents the windows themselves, with the correct round up and round aft, and the locations of the vertical timbers. I then cut slots for the timbers into which I could locate them while shaping them. I did not have to work very hard to create the right bevel; I just filed the aft faces flush to the jig.

 

You will also see that I initially mounted the jig on a right angle fixture over a slab of granite. This allowed me to use a flat, parallel surface from which I could construct the radiating lines for the vertical timbers with a drafting triangle. Once I found the correct angle on one side, I could flip the triangle and draw exactly the same angle on the opposite side. That kept everything perfectly symmetrical from the center. I initially tried to do this while the jig was located on this ship itself, and there were too many things in the way.

 

Still lots to do...

 

Mark

 

[Gaetan Bordeleau]

Mark,

 

you are more clever than I am, your jig assures you the correct spacing which is  a very difficult job to do ... without your jig.

 

Gaetan

[Tarjack]

Hello Mark,

 

now............................. after 2 hours of great entertainment I can only say........ amazing
this is absolute Craft Art

Keep going on

[SJSoane]

 

Hi Gaetan and Robert,

 

Thank you for your kind comments. I debate back and forth about whether to take the time to build a jig, because I am trying to increase my hand tool skills and I have tended to rely too much on jigs rather than on hand-eye coordination. But in this case, there were definitely too many moving parts at the stern to keep everything in place without one.

 

Best wishes,

 

Mark

[druxey]

A very good method you've got going there, Mark. The result will probably be more symmetric than the prototype!

[garyshipwright]

Good to see you back Mark. Wil be keeping a eye on this part and am sure to learn some thing to help on Alfred Stern. Does seem that this is one of the hardest parts other then the rail at the stem. Keep up the good work sir. Gary

[SJSoane]

 

Thanks, druxey and Gary,  This construction is all the more amazing when you see how big these pieces are in relation to my captain.

 

For those looking very closely, you will see that the center timber is temporarily coming down onto the top of the sternpost. It will be cut away for the rudder hole, but I wanted to anchor its lower end while shaping everything.

 

Mark

[mtaylor]

I've become a believer in jigs... especially after seeing this.  I'm looking forward to seeing your complete stern section.

[michael mott]

Beautifully executed Mark! I also really like those toolmakers clamps.(touch of tool envy).

 

Michael

[Gaetan Bordeleau]

MIchael

http://www.leevalley.com/fr/Wood/page.aspx?p=68938&cat=1,43838,68966&ap=1

[SJSoane]

I am working away on the stern construction, and realized that I did not yet understand how the helm port transom and the upper deck transoms fit. Here is a sketch of a possible reconstruction.

 

The helm port drops down to clear the helm, but it also means it runs into the side of the stern post. I had assumed that it would run clear entirely across the stern, but it clearly gets cut in half at the stern post.

 

And the upper deck transom has to accommodate both the hole for the rudder coming through, and also give a landing for the decking. It gets very broad...

 

I'll reflect on this and see if it still makes sense in the cold light of morning.

 

Mark

 

[druxey]

In what you have sketched, it seems likely that the helmport  transom tenons into the sides of the stern post. The curve down would be more of a dogs-leg, using naturally crooked timber. The upper deck transom does seem excessively wide. As a result, it might be of two pieces tabled together. Check the NMM 'Collections' site and look at  ZAZ1411 for another solution, as well as ZAZ1483, ZAZ1482 and ZAZ2098. This shows the curved beam ahead of the rudder/post and (presumably) a separate transom aft of the rudder head.

[SJSoane]

Thanks, druxey, this is very helpful. I looked up the plans you referenced, with a curved beam forward of the rudder head. I also found ZAZ7907 and ZAZ7908 that show the very broad transom. Gary had shown me something similar. The reason I am attracted to this is that the upper surface of the Bellona's upper deck planking hits the fore side of the vertical timbers right at the same level as the inside of the counter knuckle, leaving no landing whatsoever for them unless there is a fairly wide transom to get some thickness for a planking rabbet. The first drawing below shows how tight this is.

 

The second photo shows tantalizingly shadowy details of what is going on inboard of this construction....

 

Mark