The Ship Model Forum

As a huge fan of the �age of uncertaincy� I for long wanted to build a model of the �Popovka� Novgorod, the first circular ship built by vice-admiral Popov in 1872-1874 for the Imperial Russian Navy. The plan of the ship is from Dirk Nottelmann (https://www.shopssl.de/epages/es119126. ... ucts/WI-30) and shows the ship as well in her first appearance as in her last days.

A modelling-comrade of mine, Lothar Wischmeyer, did the Novgorod a few years before and lend me his great silicone forms. The master was turned from beech-wood, the form was of quite thick silicone-rubber on a clay bed to avoid warping of the form.



The form was first coated with a release agent, than a layer of gelcoat was plastered on the form. After the gelcoat did set for about two houres I slathered a paste of 50 percent resin and 50 percent glass fibre pieces on the sharp-edged or generally difficult parts. Than three layers of 160 g fibreglass-mats were laminated with a good amount of resin in each of the forms. After complete drying the hull and the deck were taken out of the form.







I was very pleased with how it came out. Post-treatment of bubbles was quite limited.

As all my models the Novgorod should be radio-controlled. I decided to motorize only the two outer of the six propellers. For these I bought (http://www.mz-modellbaushop.de/]/url]) ... %20028.avi

I like this. The resin castings look like they came out really nice as you mentioned.

I'm waiting for the video link to load out of curiosity.

TommyL.

That is REALLY impressive- workmanship is of highest quality- and it really enthuses me for the Popoffkas ...all over again!!

EXCELLENT methodology--Thanks for showing it here!


JIM B

Hehehe - it's so cute running on the water. Looks like a big tadpole, with the funnels for the eyes and the wake for the tail

This is top notch workmanship , very impressive indeed and a subject with such a rich history .
Dave Wooley

Indeed, that's a fine build!

Really cool made!

Ingenious techniques. Very well done!

Completed

Impressive

i love it - fantastic

And last but not least a video of the ship on the water:

http://www.smc-wuppertal.de/Schiffe/Nov ... %20028.avi[/quote]

This is fantastic!

Being round ,how could anyone tell which way it was going or was that the idea ? Great job on something realy different .

Richard J OMalley wrote:Being round ,how could anyone tell which way it was going or was that the idea ? Great job on something realy different .

http://en.wikipedia.org/wiki/Russian_ba ... p_Novgorod

Thanks for the education

I''ve always been intrigued by this ship. Thanks for pulling it out into three dimensions! A fine, fine build

This is also the first time I've heard of resin soaking paper for hard-to-reproduce items. Could you describe how you did that - what kind of resin, paper, etc? I'm itching to try that!

It looks pretty good indeed!!

One of your props seems to be cavitating big deal.
That could destroy it in not all too much time.
Cavitation can be seen because of the bubbles behind the prop.
Cavitation is water starting to boil because of low pressure at the suction side of the prop.
As soon as the pressure rises again at the other side of the prop the bubbles caused by the boiling water implode releasing quite a lot of pressure, which can damage the prop and anything else in the area.
I don't know how you can solve this problem, having it turn slower does help.
If you want to be able to maintain topspeed you'll need to try adjusting the blades carefully and test when the bubbles are gone.

Greetings Josse

tweety777 wrote: One of your props seems to be cavitating big deal.
...
Cavitation can be seen because of the bubbles behind the prop.

Not really. It's just because the props are only a few milimeters
underneath the water surface. As you can see in the pictures the ship is
propelled with two bell-shaped rotor motors. These are usually
slow-runners. With those it is absolutly impossible to get an
cavation-effect (unless of course the prop get's partially out of the
water - which may happen depending on waves - but that would result in
hyper-cavitation). Cavitation can appear at the propellers of RC racing-boats, where it lowers the speed of the boat. On the other hand hyper-cavitation is sometimes an appreciated effect (created by hydro-props that are only half-immersed) because it reduces the friction of the propeller.

That could destroy it in not all too much time.

Lord, no! That's a model-making-legend. Cavitation may cause destructive problems
with real-size propellers but not with the propellers of our little
ships. The bubbles and as a result the implosion-jet are just too small
to have any effect on the propeller's surface. It may cause a decrease
of effectiveness of propulsion but as far as propulsion ist concerned
cavatation is the most minor problem concerning a round ship without an
effective rudder.

Great build, I've always been fascinated with the round ships. Wish I had those molds!

Hello!
Me the information on the ship Vice-Admiral Popov interests.
Who can help?