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

[paulsutcliffe]

Actually I nipped out into the cold and took a photo of the page, hope this helps, see no5

Regards

Paul

[Chuck]

Like this?

 

[Katoom]

Howdy!

  Although obviously not a primary source, here is a drawing from the AOTS Royal Caroline - 1749 by Sergio Bellabarba & Giorgio Osculati with drawings attributed to Osculati.

GunTackle.pdf

  The area around the cascabel is a bit ambiguous but seems to maybe some kind of woven eye that is seized?

  

Edited February 21, 2019 by Katoom
Add jpeg image

[SJSoane]

Thanks, everyone, for continuing ideas about what I had assumed until now was a very straightforward detail.

 

Gaetan, I like your idea of giving the ship to French, and renaming it Le Bellona, because Boudriot's drawings are a delight to view. But I think the British on this website would object to me giving over a British ship to the French without a battle....😊  Beautiful photos of your old project, by the way.

 

druxey, I have been thinking again that a cut splice would also be consistent with the drawings we see in my favorite source, Falconer. Falconer does list this splice (he spells it the pre-Bowlderized form below). He does not explicitly refer to the breech rope for this splice; although this is not in itself a reason to reject the idea.

And Kevin, your very interesting drawing could be a cut splice as well, but with some seizing at the joins.

 

Paul, thanks for going out into the cold to get a picture! It looks to me like this cannon is of the later date, when a cast iron ring was formed into the cannon itself. As we have all struggled here with how this worked earlier, it is very easy to see now what an important invention this was, to cast the ring right into the cannon. Elegant solution to a difficult detail.

 

Chuck, your detail is consistent with earlier comments druxey made, referencing a "turn around" the cascable. This one makes the most sense, along with the cut splice, as a clean and functional answer to this detail. I just wish the Falconer drawings showed something closer to this, and I would be happier with taking it up. It is an outside possibility that Falconer simplified his drawings at such a small scale, I will admit.

 

At this point, the ideas most appealing to me are the simple drape over the button with a seizing, as Siggi recently showed (most consistent with the two contemporary sources, the Royal George section and the Falconer drawings), or a cut splice, which is more functional, and could be inferred in the Falconer drawing but not the Royal George section. I may decide this once I start trying to rig the cannon, and see what suggests itself as more appropriate.

 

Best wishes,

 

Mark

 

 

 

 

 

 

Edited February 22, 2019 by SJSoane

[mtaylor]

I'll go along with the others on this except for one point.   I doubt the breeching rope would have went through an eyebolt when using the gun.  That's a weak point subject to breakage.  If you pull back the gun, the angles involved would tend to lift the forward end.  Maybe not much though.  Then again, the eyebolt might also help keep the breeching on the button when firing.  

 

Falconer does have an interesting set of drawings.  It looks like breeching rope was used also as the tackle to put the gun back into battery.  Somehow, I just think that's really doable due to the diameter of the rope. Top part of your Flaconer scan with the gun pulled back.  The line reeves through the eyebolt and pulleys as well as running over the button.  There's something about this that just doesn't seem like a good thing.

[vossiewulf]

Looking at it with an admittedly inexperienced eye, I assumed when looking at that Falconer drawing that he was showing an alternative arrangement for the gun tackles, and the breeching rope was hidden for clarity. It seems pretty straightforward, there is no way that light line is going to stop that big gun on recoil, so we have to be seeing an incomplete rig. 

[mtaylor]

I looked closer at the Falconer drawing (the upper one).... there is no breeching rope or it's "hidden" as Vossiewulf says.  What we see going over the button is the outhaul tackle line that's laying across the button and then falls off to the rear on the deck.   <smacks forehead>   

[oldpaperone]

And there is this ( from 1841 )

https://commons.m.wikimedia.org/wiki/File:Saturday_night_at_sea.jpg

[druxey]

I thought that we were referring to figure 19 in Falconer, not 18, Mark! In any case, it appears that the breech rope has been shortened in figure 19 in order to secure the gun against the bulwark - it's not in 'action' position and cannot be run in. Presumably one end of the breeching at the bulwark is loosened from the ringbolt, pulled taut and re-secured.

[SJSoane]

Hi everyone,

 

Yes, the upper drawing in Falconer (18) clearly shows the rig without a breech rope. Why the tackle is shown tied to the button I have no idea.

 

As we all look at (19) more carefully, it is admittedly a little confusing. That rope shown in the breech position is clearly too thin. And yet, it reeves through the ring and eyebolt on the side of the carriage, which is where the breech rope goes. And Falconer's text referring to this drawing says that it shows the breeching rope "where it is employed to lash the cannon when it is housed during the course of a voyage." I have no idea why he shows such a thin line for what he is calling the breech rope. I can't imagine replacing the thick breech rope for a thinner line when the cannon is stored.

 

When we look at the gundeck plan, his text referring to this says "the use of the breeching, as it checks the recoil of the cannon, is shewn in plate III. DECK."  So this shows the gun run inboard for loading, not for storage.

 

druxey, I think you are right that the breech rope must have been tightened up at one end when the cannon was stored. Falconer's deck drawing shows the rope as too long in its action length to tighten up for its storage length. I also find it interesting that the position when pulled fully inboard does not leave a lot of room for swabbing out the cannon and inserting a new ball. The ramming rod must have been projected out the gunport when in use. I wonder how many fell overboard in the heat of the moment?

 

So one lesson from this closer inspection is that the drawings themselves might have some inconsistencies in them (like the thickness of the breech rope); and so might we fear that the arrangement of the breech rope at the button is also simplified?

 

And likewise with the photo of section of the Royal George; might we fear that the breech ropes were replaced much later in a renovation of the model, by someone who did not know any better? How far can we trust our primary sources?

 

Need that time machine again. Druxey, I hope your steampunk design is well underway!

 

Mark

[SJSoane]

Putting aside the breeching rope for some thinking time, I have moved on to casting the cannon. I am setting the masters in the clay moulds, ready for the rubber mould pour.

 

Can someone remind me what to use for a release agent between the clay and the rubber mould material? I can't find this anywhere in my notes or sources. Do I just use the release material for rubber to rubber?

 

Mark

 

Edited February 24, 2019 by SJSoane

[AON]

Was talcom powder mentioned?

[druxey]

Talc is for the actual metal pour to improve flow! I don't think release is required for the clay walls: they are disposable anyway.

[Gaetan Bordeleau]

I have  a lot of talc powder at home; it comes from what we call soap stone, a very soft stone, easy to cut  with a hand saw. We use this stone for carving and talc powder is sprinkled on dancing floor, and it is very slippery.

[SJSoane]

Hi everyone,

 

The sprues are now installed in the moulds, as well as the locating dimples. I took extra care this time to clean up the clay at the edge of the master. Last time, I left the clay either a tiny bit high or low, and this creates a thin edge on one side of the mould or the other, which deteriorated over time. So I spent a lot of time with a sharpened toothpick to get these as clean as I can.

 

Probably pouring rubber tomorrow. I did read on the instructions on the rubber mould material that I should use the rubber to rubber release even on the box sides and the clay. When in doubt, read the instructions...😀

 

Mark

[Hubac's Historian]

Looks great, Mark!  Best of luck with the moulds.

Edited February 27, 2019 by Hubac's Historian

[mtaylor]

Fingers crossed that all goes well, Mark.

[michael mott]

Nicely done Mark, I'm sure that you wont have any trouble with these.

 

Michael

[SJSoane]

Thanks, Marc, Mark and Michael, for the good thoughts. My challenges with technology in photo etching have spooked me a little when I get outside the realm of wood.

 

So here is the first pour of rubber. Won't know if I got a good pour without bubbles for another 4 hours or more.

Also, let me know if that is a good buy for potato chips in the background...😀

 

Mark

Edited February 27, 2019 by SJSoane

[michael mott]

55 minutes ago, SJSoane said:

Also, let me know if that is a good buy for potato chips in the background...😀

I am more interested in the Coffee ad to the immediate top left. LOL

[druxey]

A nice slow pour from one corner of the mold usually ensures no entrapment of air bubbles. Hope it works out!

[shipmodel]

Hi Mark - 

 

From what I can see you should get a good set of molds for your castings.  One trick that I picked up from some forgotten article is to vibrate the mold as the rubber is setting, which will help any small bubbles rise to the surface and disappear.  If you do not have access to a vibrating table (the article was in a scientific journal which assumed that your laboratory had one)  then tape a powered toothbrush to the side of the mold and let it run while the rubber is setting.

 

Best of success to you.  I look forward to seeing how things work out.

 

Dan

[SJSoane]

I poured the second rubber for the first two boxes, all went well. Then I started pouring for the final two boxes, and just as the stream started into the box I realized that I had not coated them with mould release! Retirement seems to have addled my brain. So I mopped it out, and will have to wait until it dries to make sure there is no rubber left from the aborted pour before starting again.

 

While waiting, I started working on the planking plan for the planks under the guns. I have copied the run of planks from Falconer. Next, working out the plank ends.

 

Michael, I should have paid more attention when you pointed out the coffee add under the moulds. It is even titled, "Wide Awake Coffee"...

 

Mark

[druxey]

Aiee! Good save, though. Hopefully the second pour will be after using the release agent, Mark.

[SJSoane]

Hi druxey,

 

Retirement seemed like a good idea until I discovered that my brain flew out the window. When I was juggling a dozen things, I could still keep track of details. Now I have only one thing to juggle, the details slide away. Or, maybe it is aging!

 

So here are some decking questions, while my moulds dry.

 

I am laying out the decking for mounting the guns, likely building 5 strakes from the waterway to accommodate the length of the guns.

Do I have it right that a 3 or 4 shift planking plan has all of the butts falling on beams, not any ledges?  This means that the lengths of the strakes are quite irregular, given the irregular spacing of the gundeck beams (see above).

 

Is there any particular functional or historic reason to choose 3 or 4 shift planking? Goodwin suggests that weather decks were 4 shift, but I see no other information pertaining to the gundeck.

 

I am assuming that the planks taper at the bow and stern, as Falconer shows. I am also assuming that there is NOT a band of anchor or top and butt planking adjacent to the waterway in this ca. 1760 ship. Goodwin (p. 59) says that this practice came in only at the end of the 18th century.

 

Mark

 

 

 

[druxey]

I know that the strakes of top and butt under the guns was adopted at some point in the 18th century, but exactly when is the question. Plank butts always fall on the beams, not the ledges. (Most ledges are only 3" or 4" wide, so there is insufficient landing to secure the ends on.) Also, avoid butts in the binding strakes opposite hatch openings. 

[SJSoane]

Thanks, druxey, it is amazing how many details seem obvious until you start actually working with them.

 

The rubber pours were successful! No bubbles, good rendition of detail including the king's cypher.

 

I did have a moment of concern when the two halves intially would not pull apart, but once I peeled off the outer paper boxes, the rubber came away nicely.

 

Plaster of Paris sleeves next.

 

Mark

[druxey]

Looking excellent!

[michael mott]

Wow! what is interesting mark is in looking at the last picture, it reminds me of those images that one sees occasionally where the image can be seen in one of two ways either a positive shape or a negative one. and the barrel appears to be raised up from the surrounding surface because of the lighting.

 

A beautiful surface indeed.

 

Michael

[SJSoane]

I picked up a cold on the plane back from our trip, which slowed me down the last week. But now better!

 

I initially tried building a Plaster of Paris sleeve around my moulds, to stabilize them and pull the two halves together securely. But I had trouble pulling them tight with tape before pouring the plaster; for some reason, this time, the tape just would not secure tightly to the rubber. And then I used old plaster, which was so lumpy and needed breaking up that it began to harden before I could pour it into the boxes. I had to throw all of that away.

 

Reading the Micro Mark instructions again (when in doubt, I keep telling myself, read the instructions), it suggested pressing the moulds halves between two pieces of wood. I initially tried that using clamps, but this distorted the mould and I cast an oval section gun.

 

 

So then I tried holding them together with rubber bands (per the instructions), and this worked well.

Here is the first cast:

 

Once I cut off the gun head with a jeweler's saw, I clamped it in the lathe, using a chuck on the protruding end of the muzzle to center it, and then clamping it in a four jaw chuck using a split ring of wood.

 

 

Then I could drill for the bore, and face the end.

 And the result:

 

Needs a little filing to clean up the trunnions, but the process seems to work.

 

Mark