Sunday 23 June 2013

When Is A Dome Not A Dome?

...When it's a Barrel Vault, of course!

Hi, All!

The barrel-vault roof nears completion.

As you may have noticed, I was quite correctly corrected last week by Legatus Hedlius, who pointed out that my engine room's roof is not a dome at all, but a barrel vault...

Components - rivetted and painted.

Anyway, suffice it to say that work on the barrel vault has continued in the last few days, with the painting and fixing of the components I featured in my last post, the addition of must of the roof's structure, a lot of 'glass' and of course, many, many rivets.

The inner structure is glued together.

With the addition of rivets and paint to the various bits I built last week, it was time to glue the whole structure together. This was a very quick and simple matter, and I was soon on to the next part - adding more strips at right angles to the girders.

The finished end and girders form a framework, over which strips are laid to create the roof grid.

The inner structure, prior to adding the acetate 'glass'.

The whole thing grew increasingly sturdy as I worked. Once the long strips had been added, I filled in the gaps between them on the back of the girders, to create an even surface onto which the acetate sheet could be placed (after a swift coat of paint).

Acetate is added to the sloping edges. The external framing is ready to lay over the top.

Here you can see the angle brackets, festooned with rivets. These serve a real funtion, strengthening the roof and holding everything in-line.
The first bits of acetate to go on were the sloping edges, followed by the rest of the roof. In all, the whole structure was done with only four pieces of acetate - the work of a few minutes.

Acetate is laid over the inner structure.
Up to this point, I had been painting all the components as I went, to avoid getting paint on the acetate. However, the only way I can complete the exterior detailing of the roof is to build it up in layers directly on top of the acetate - so I'm going to have a bit of careful (and time-consuming) painting to do.

Strips of plastic are laid over the acetate to create the outer structure. These will have to be carefully painted later.

The outer detailing took shape in the reverse-order of the inner. That is to say, I placed the curved strips first this time, and finished with the long girders. I will have to add a lot of rivets, of course, and I'll be disguising the ends of the roof with a decorative curved gable.

More detailing is added. Rivets will be next...

And so, here's this week's Rivet Count:

So far this week, I have added a further 987 rivets to my previous total of 8,321, meaning that the whole project now stands at:

9,308 !

I'm fast approaching ten-thousand... With several hundred still to add to the roof and yet more detailing to add to the engine room, it won't be long at all...

So that's that for now. More soon!
I think this is starting to look sufficiently Victorian...
All the Best!


  1. I hope there are't too many stone-throwers around, as you know what they say about glass houses ...

    Excellent work! It really is looking Crystal Palace-ish.

    Why didn't you paint the outer strips first before gluing them on?

    1. Thanks, Roly.

      I didn't paint the strips first as the whole roof has to be built up in layers. As the interior isn't exactly perfect (shock, horror!) I couldn't build a 'mesh that could be accurately laid over the model in one piece (the maths behind such an endeavour and the probability of getting it wrong were terifying!)

      Consequently, I needed to build the exterior a piece at a time over the acetate. Painting the strips first would weaken the bonds when glued...

      I had to make an executive decision. I'll just have to take my time with the painting.

  2. This really is developing some perspective now! Most impressive progress.

    Did the acetate stick with the liquid poly or did you use superglue? Either way I am incredibly impressed you seem to have suffered no 'fogging' to the acetate from the glue!

    1. Thank you, Scott.

      I used the super-duper-superglue I showed you at my place. Brilliant stuff - and no fumes!

  3. When I grow up I want to be you.

  4. An outstanding development, I was curious as to how you were going to glaze it.

    1. Thanks, Michael - I hope your curiosity is satisfied.

      I found it a perfect outlet for my glazed expression...

  5. Fantastic work.

  6. Elegant work indeed! Worthy of Joseph Paxton himself.

    1. A J, Old Bean!

      Thank you. Although Paxton's work tended to be a little larger than mine.

  7. My God Man! That is breath-taking, I sit in awe and weep for my tiny talents compared to yours.

    Carry on boldly, you are an inspiration to us all!

    1. Anton, you are too kind!

      Thank you - and I shall.

  8. You are paid too little!

  9. Colonel ... words fail me ... well nearly - I have enough left to type - this is incredible work sir, I am in awe of your talents and achievement

    1. Thank you, sir!

      I am flattered by your lack of verbosity!

  10. Careful painting or a *lot* of masking. Quite the conundrum. The audience waits with bated breath to see how our hero will triumph over this latest obstacle. Of course, this spectacle of light in the engine room causes wild speculation amongst the technical correspondents about the suspended transparency that must be the pilot house.

    1. Hmmm... Haven't quite figured out the best process yet - I'll let you know!

      As for the pilot house/bridge and other constructions, I am a long way off... but I have big ideas!

      Nice to be 'our hero'...

  11. A stupendous example of a barrel vault indeed!

  12. This is truly a fantastic model, and very inspiring!