Dumas Akula Submarine Conversion
The project target is to build a static diving scale true Akula submarine based on the Dumas Akula kit.
The kit is scale 1:130 which is app. 85 cm long (33") and has a beam of 10 cm (4"). (The real sub is app. 110 meters long and has a beam of 13.5 meters).
I am only going to use very little from the kit, as all the fins are just metal plates and the diving system is dynamic. I am therefore only using the top and bottom hull, the sail and the radar dome. The project is divided into several different building areas, and therefore the tracking of the project will be in separate articles. These activities are pretty much independent, and will be done in parallel to speed up the waiting on parts to arrive.
The sub will consist of:
- The Dumas Akula kit
- New rudder and planes
- WTC (Water Tight Cylinder)
- Piston dive system
- Retractable diving planes
- Working periscope
- CPU control system
The Russian name for the submarine is Giepard. See the link section for useful Akula links.
The project will be described in the sub categories as shown in the menu at the left.
How does a radio controlled sub works?
In order to avoid that the motor, battery and electronics get wet it must be in a water tight place in the sub. There are several ways to do this, and the way that I have chosen it is to use a water tight cylinder (WTC) which is a water tight tube which is placed in the sub. It is then only the inside of the WTC that is water safe, while the rest of the sub is "free flooding". This WTC will be placed below the water line to make it easier to dive the sub.
When the sub wants to dive, it must add weight equal to the volume of the sub above the water! This means, that in order to make it easier to dive (require less weight) the volume of the sub above the water must be minimized. This is why the WTC is placed below the water line. When the sub dives, water will flow into the free flooding area above the WTC so it is only the volume of the hull that must be equalized. This is also why that there should not be any air trapped above the water line (e.g. the radar pod should be free flooding).
The sub is diving by adding weight by sucking in water - in my case by using a piston. In this way the air volume below the waterline is getting smaller and by that the buoyancy smaller. This will force the sub under water. When the sub is completely under water the diving dept is controlled by the dive planes and not by the diving tank. When the sub wants to surface again the process is reversed.
How deep can they go?
The radio waves must be in the MHz area to be able to penetrate the water, so 2.4 GHz will not work. In Denmark that leaves us with either 27MHz or 40MHz as 35MHz are reserved for airplanes.
The radio waves can go to a dept of app. 3.5m, so diving below that dept will be without radio control!
The pressure at 10m is 1 bar, so to make a safe sub, the WTC should be able to handle at least 1 bar.
The boat will not work in saltwater as the radio waves can't penetrate that.