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

[druxey]

There were hollows cut into the floors under the pumps so that they could suck all the bilge water up. (See TFFM.) Falconer is schematic only. Also see Lavery, Arming and Fitting, etc, page 75, the right hand diagram

Edited December 28, 2022 by druxey

[SJSoane]

Thanks, druxey,

That earliest version of the Cole-Bentinck pump illustrated in Falconer would certainly have left a lot of water in the bilge, since the height at which water is captured is about level with the top of the keelson. I can see why the subsequent modifications included dropping the pump base as far down as possible.

It is quite intriguing to see the evolution of a technology, and also to see an early version of a user's manual that you refer to in Lavery's book. My brother once worked as a technical writer for a software company, and the writers complained that the engineers kept tweaking the software right up to the point of release, leaving the written manuals sometimes incomplete and inconsistent. I wonder if Cole and Bentinck kept tweaking their design after their user manual was produced?🙂

[mtaylor]

13 hours ago, SJSoane said:

It is quite intriguing to see the evolution of a technology, and also to see an early version of a user's manual that you refer to in Lavery's book. My brother once worked as a technical writer for a software company, and the writers complained that the engineers kept tweaking the software right up to the point of release, leaving the written manuals sometimes incomplete and inconsistent. I wonder if Cole and Bentinck kept tweaking their design after their user manual was produced?🙂

As a former tech writer, I can see that this may very well have been the case.  Tech (even ship tech) progresses by leaps and bounds and like other forms of engineering the paper work is always playing catch-up.

[druxey]

I'm sure that lowering the intake was a very early mod!

[SJSoane]

Press release March 1, 1760; "The Admiralty just learned that the proposed Cole-Bentinck chain pump will not be available for another 10 years. The HMS Bellona currently being fitted out in Chatham Dockyard will have to install a standard pump". 

 

I bothered me that I was recently showing a pump designed a decade after the Bellona's launch, even though I am trying to show her as she was designed. I looked again at sources, and found information I had overlooked in Lavery's Arming and Fitting, page 71; a redrawn section through the Resolution of 1708. It is the only drawing I have found of a pump before the Cole-Bentinck, and so I will go with the idea that this pump was probably closer to the one installed in the Bellona in 1760.

 

Lavery points us to some drawings in Blanckley's Naval Expositor of 1750. Taken from the Gutenburg permission free ebook online, here is the key idea at the upper wheel. These sprockets are driven into a solid elm wheel, over which the chain rides.

 

With this, and then interpreting as best I can the drawing of the Resolution, here is my best shot at the design of a pre-Cole-Bentinck pump, ca. 1750. Distinctive elements: 1) the return tube does not go all the way to the lower end of the pump; 2) the bottom of the pump rests right on the outboard planking, set into a deep slot beside the keelson; 3) it has a bottom roller, like the later Cole-Bentinck design. I can see how the chain and burrs would bump over that, tightening and loosening the chain and causing the problems mentioned in various sources regarding this traditional pump. And the chains have no mechanical hook to the sprockets, allowing the slippage mentioned earlier.

 

But at least this is closer to authentic for 1760 than I have managed so far. Unless anyone has come across a contemporary drawing of a circa 1750 pump, this is my best bet...

 

Mark

 

 

 

[Hubac's Historian]

Fantastic and assiduous research - love it!

[druxey]

Your drawing looks very good to my eye.  The solid upper wheel with sprockets is correct for the period. The hole through the center of the wheel should be square, not round, as is the axletree that runs through it at that point. Blanckley mentions wedges driven on all four sides to keep the wheel secured. The rowle at the lower end is shaped with a concavity; it has a smaller diameter at the center than at the ends.

[SJSoane]

Thanks so much, Marc and druxey.

 

While our digital resources today open up research to more of us not close to the major libraries, it is still sometimes frustrating not to be able to dig into an archive and find just the right item. So we do the best we can with the help of people on this site!

 

druxey, I am glad you have looked this over and think I am headed in the right direction. I will fix the square hole in the  wheel. I still don't quite understand what the solid piece is that guides the burrs once they come around the rowle at the bottom; could it be a solid piece of metal the width of the tubes, bolted between the metal side panels supporting the rowle? And I wonder what holds in place the lower end of the return tube, just floating in the air in Lavery redrawing of the 1708 Resolution?

 

When I drew the chain and burrs at different points coming around the rowle, I could see just how much that chain would have clanked, tightening and loosening. Amazing it didn't come off more regularly!

 

Best wishes to both of you for the new year!

 

Mark

[Alex-Ks1]

On 2/16/2013 at 9:40 PM, SJSoane said:

And then inboard...

and a jig.

 

Mark

not much more to say but excellent , outstanding work 

[Alex-Ks1]

On 12/14/2022 at 3:43 AM, SJSoane said:

Mike, interesting! My slots are 1/32".  I haven't seen an end mill that small. That really would simplify this, and I see I have more of these in the stantions in the bulkhead beakhead. Do you recall where you got the end mill that small?

there is a company MSC .COM   that supplies all machine shops, they may have end mills that small.  I know they supply my shop, they have a large on line catalogue 

[druxey]

The bumping would be even worse at the bottom end around that small diameter rowle! The 'in the air' tube would probably have been be supported within the well that surrounds all the pump mechanisms.

[SJSoane]

The cheeks saga continues. I finally got both cheeks, both sides, close to finish size and pinning in place:

 

I made the cheeks up in two parts, hopefully to get the grain to run roughly parallel to the scratch moulding still needed to be done on each outboard surface:

I also used, for the first time, my handy vise attachments that hold irregular pieces. I don't know how else I would ever have held these multi-curved surfaces for shaping:

Then came the awful discovery that I had cut the top of my knee at the head to the wrong profile. Fifteen years ago I made my best guess at this shape (photo from 2008):

And then as the cheeks neared completion, I started wondering how the moulding continuing on from the top cheek--the hair bracket-- would be supported for its full length to the scroll at the top. I looked again at the original Bellona model, and saw there had to be a much higher core up from the knee of the head, between the hair brackets and abaft the figurehead:

I tried making one piece, with a slot to slip over the knee, but soon gave up on that as pretty impossible to cut a slot tapering in two directions while keeping it aligned athwartships and fore and aft:

I finally realized that the top of the knee should have looked more like this upper left piece in the drawing below:

So tomorrow, I will see how I can fit my retro piece onto the top of the knee, between the upper cheeks:

Wish I had understood that 15 years ago, and good thing I am not in a hurry....

 

 

 

 

 

 

 

 

 

 

 

 

[druxey]

Ah, the joys of discoveries and figuring out revisions. I had exactly the same issue with my first scratch model, a 64. I cut a small notch into the back of the knee to locate the central extension of the knee. then glued in a slightly over-sized piece. Once the hair brackets were carved and added, I filed the assembly down flush athwartships. Hope this might help you.

[SJSoane]

Hi druxey, yes, that does help. I see one of the biggest issues here is getting the fore and aft edges of the core and the two hair brackets to be flush with each other. Maybe I make the hair brackets first, glue them to the core, file them flush to each other, glue the whole thing down onto the top of the knee and then attach the cheeks. otherwise, I would be trying to file the core and the hair brackets flush to each other while on the ship--not a pretty idea to contemplate!

[Hubac's Historian]

I love the fore-thought of making the cheeks up from two pieces!

[druxey]

I suppose it depends on the state of your nerve!

[SJSoane]

The work on the cheeks and hair brackets continues.

 

Getting a grip on these irregular shaped objects is a challenge. My GRS vise has saved the day, using small strips of leather to pad against the pin jaws.

 

The biggest challenge by far--and still continuing-- has been fairing the upper cheek into the hair bracket. The photo below shows a paper template taped to the knee, which gave me a rough idea of the cheek's upper curve, but it was only approximate.

 

 

I found greater success once I made the hair bracket and the core behind it, and temporarily pinned and tacked these to the knee. then I could sight the curve of the cheek and adjust accordingly. Getting closer:

But it still needs a final fairing between the cheek and the hair bracket, which I think needs to be done off the hull. My thought is to tack the two together at their joint, then temporarily glue them down onto a flat surface so I can smooth the two pieces together.

 

Can I get some technical advice? I have read about modelers gluing delicate pieces to a base with paper between, to be worked on. is this carpenter's glue, full strength or diluted?

 

And then how do you then get the delicate piece off the base, and get the glued paper off the back of the piece? I don't want to soak these in water. Is isopropanol used?

 

Having invested so many hours into these pieces, I don't want to mess up at this last stage!

 

Mark

 

 

 

[dvm27]

What works for me in these situations is to tack the two delicate pieces together or tack the assembly to a ply base using pinpoint drops of yellow glue. It only takes a couple of minute drops to tack the pieces together (like tack welding) and they are easily separated with isopropyl alcohol when finished.

[SJSoane]

Thanks so much, Greg, just what I needed to know!

[Wintergreen]

Just silently following along here. Well, not silent now though...

Mark, your attention to detail is remarkable. Fascinating, in fact. Also knowing how long you've been on this project. 

I don't know how many of you that keep tabs of spent hours? I don't, and that is because it is irrelevant to me. Even if my current project is light years away from what we see here, it is the journey that counts for me. Not how many hours or the cost of accessories. 

Bellona is looking wonderful, by the way. 🙂 

 

Keep it up!

From one leftie to another 😉 

 

[SJSoane]

Hi Håkan,

 

Thank you so much for your kind thoughts. 

 

I started a log on June 5, 1998, when I first started the actual construction (as opposed to the drawing for several years previously), noting issues I was working on, how I solved it, and how long it took. But the log quickly fell by the wayside. I still worked out details in it, but no longer kept track of time. And there are many months-and even a few years--not even accounted for.

 

Like you, I realized it is the journey that counts. The Bellona is like a good friend, someone to spend time with, and who continues to reveal secrets the more I study and work.  

 

I am not sure what I would do with my time if ever I finished. I am too old to start another multi-decade project. So I think I will just drag this out, hoping I finish right before I can no longer see, or I have to deal with shaky hands.

 

And great to hear from another left hander!

 

Best wishes,

 

Mark

 

 

 

[druxey]

As Greg suggested. Sometime I use rubber cement to 'glue' down pieces. The only drawback is that it does not hold well in shear, so if you are planning on heavy cuts...

[Wintergreen]

30 minutes ago, SJSoane said:

I am not sure what I would do with my time if ever I finished

I would suggest that you build all the launches to her. But maybe you already have? 

However, I like your attitude, you are finished when you say you are finished. A little like the wizards... they are never late, nor are they early, they arrive exactly at the time they decided upon.

Time will tell how far we came on our journeys 🙂 

[Wintergreen]

13 minutes ago, druxey said:

so if you are planning on heavy cuts...

Sorry, but that comment had me cracking up 😄 thank you druxey!

"not likely!" I guess Mark will answer

[SJSoane]

Greg's and druxey's gluing ideas worked well. Tiny drops of carpenter's glue between the piece and a sheet of plywood held everything firmly enough to sand fair on three sides. Isopropyl removed it from the ply, and as the British say, "Bob's your uncle!"

 

Good trick for refining small delicate parts.

 

Glued together on the hull, still not fully faired to each other:

then glued down on plywood:

 

 

Faired, and pinned back on the hull:

 

 

This piece reminds me of the great quote on Remco's HMS Kingfisher site: "Treat each part as if it is a model on its own, you will finish more models in a day than others do in a lifetime."

 

Mark

 

 

[SJSoane]

Waiting for the glue to dry on the port upper cheek assembly, I looked more carefully at the area around the figurehead, double checking on the heights for clearance for the bowsprit, and also where the rigging will begin to fasten. Better to catch problems now, as parts are beginning to fall into place. I redrew the Bellona figurehead, with more detail that might begin to lead into the carving--at the very least, a blank to make sure everything fits.

 

And, I did discover a mistake from 25 years ago. I marked and cut the slot for the gammoning in the keel when I first started construction. Now I see that I thought was the fore end was actually the aft end of the slot. So it is exactly its own distance back from where it ought to be!

It will take some fine work to fill the slot and cut a new one. Don't tell anyone!

 

Here is an updated drawings with the new Bellona figurehead, and the beginnings of rigging at the bow:

 

 

 

 

 

[druxey]

Tell your 25 year younger self off! With any luck, the errant gammoning hole will be covered by the trail boards, so no-one will be the wiser. A couple more inches clearance under the bowsprit for the figure might be good as well.

[AON]

Regarding the bowsprit clearance.

Can't that be done by changing the angle ever so slightly to suit.  No one will be taking a protractor to it.

[SJSoane]

Hi druxey and Alan,

 

The last image was a little misleading; the bowsprit shroud coming across the drawing make it look like the bowsprit was lower. The drawing below without the shroud shows the actual clearance I am working to, which is from the original Admiralty drawing.

 

While referring to the previous drawing, you can see my drawing of the bumpkin or boomkin has no stays or other supports.

Lees' Masting and Rigging pages 130-131 says that no rigging was fitted in the first years of the bumpkin, although he doesn't say when it first came into use. The few models I have seen of ships contemporary to the Bellona ca 1760--like the Thunderer-- do not show any rigging other than the shoulder block for the fore tack. Does anyone have any further model examples or further evidence of what may or may not have been used as additional stays for the bumpkin around 1760?

 

 

 

[AON]

I see it now.

 

 

 

Funny how the mind goes where it wants to.

 

 

 

Regardless, when the time comes I think you can set a reasonable gap by adjusting the angle ever so slightly.

 

 

 

But then again... I am no Druxey!

 

 

 

 

 

 

 

25 years eh?

 

 

 

and I thought I was taking long.

 

 

 

Thanks for making me feel better.

 

 

 

 

 

 

Edited February 3, 2023 by AON