Das Reboot: Type VIIC U-boat. Now With 100% More Submersibility!

[pTrevTrevs]

 

 STOP RIGHT THERE. CLICK THIS BEFORE GOING ON!

Many of you will remember my original U-boat, released exactly one year ago today. Although it featured a complete interior, it was unable to dive due to several factors. This new U-boat, although lacking an interior, is still a vast improvement over the last one. Not only does it look almost exactly like a German U-boat (hell yeah, it even has the holes on the outer hull), this one can dive. That's right, the use of a small mod created by @Fengist has allowed me to finally make a submarine that can dive and surface at will.

The boat sits on the surface just like a real one would have (although it can take a little fiddling with the ballast tanks), and can reach a top speed of 10.3 m/s (8.0 m/s when submerged).

The conning tower provides room for Kerbals to stand, and features an AA gun and  two periscopes. I've tried a new method for building the rear railing; instead of struts, I've used loads of antennas instead. Although it costs more parts, it looks much more accurate and can actually prevent Kerbals from falling over the side.

Overall, this is a much more practical craft (if... you know... a submarine in a game about spaceflight can be considered practical), and in my opinion, the removal of an interior in exchange for a much better looking, faster, drastically more functional craft is definitely a good trade off. The boat has around 540 parts, which is over 300 less than the old U-boat, and when combined with the benefits of 1.1's increased RAM limit, far more people will be able to try this boat for themselves.

Now, let me outline a few technical details and procedures for the most efficient ways to handle the boat.

LAUNCH PROCEDURE

• Make sure you have a mod that will allow you to move the vessel to the water. I recommend Vessel Mover (the link leads to the Vessel Mover Continued thread).
• Open the right click menus for the fore and aft ballast tanks and pin them to your screen. It may be helpful to move them to opposite sides of the screen so you can remember which is which( see above image).
• Move the Boat over the spot you want to drop it on and place the vessel. 
• If the bow is too high, pump some ballast into the rear tank, if the stern is too high, pump ballast to the fore tank. Only minute adjustments are needed for this, so don't go too crazy with it or you risk making the tilting even worse.

DIVE PROCEDURE

• Play this youtube (U-Tube?) video
• Press 1 to activate the water compressors. These will pump water into the fore and aft tanks and the boat will begin to sink.
• Pitch the bow down with the dive planes. This will point the engines downward, allowing you to use their thrust to help push the boat under.
• Speak rapidly in German and play the Das Boot soundtrack as loud as possible.
• Once the boat approaches the desired depth, halt the influx of ballast water (press 1 again) and use the dive planes to level the boat. If you're still sinking, blow a little bit of ballast (press 2). Watch the prograde vector to see which direction the boat is moving.

SURFACE PROCEDURE

• Press 2 to blow ballast. Remember that a little ballast should remain in both tanks (10 in rear, 20 in fore is good for this), so don't completely empty them.
• Pitch the boat up with the dive planes, careful not to let the prograde vector slip too far upwards.
• When the boat is about the reach the surface (40 meters to go) press 2 again to halt the ballast pump. Try and bring the prograde vector to less than 20 degrees above the horizon. If it's too high, the boat will pop right out of the water and bounce a few times. I haven't had it to me yet, but I suspect that if this happened hard enough you could break something.

DOWNLOADS

The boat requires the WIP Make it Sink mod to work correctly, it can be found here

 

The boat itself can be downloaded here

 

Make sure to alert me to any problems and I will do my best to amend them. Feel free to post any pictures you take of the craft here, and please leave some feedback!

 

Edited September 30, 2016 by pTrevTrevs

[TwinKerbal]

....

And I was still using ore tanks. How silly of me....

[Mad Rocket Scientist]

That looks amazing!  Nice replica.

[Castille7]

I'll second that, looks amazing! Looks like a lot of tedious work for sure!

[pTrevTrevs]

1 hour ago, Castille7 said:

I'll second that, looks amazing! Looks like a lot of tedious work for sure!

You wouldn't believe how tedious it got sometimes...

I would like to make a late war variant with a larger conning tower and no deck gun, but I think I'll take a break from the craft, I've seen too much of it by now.

[Castille7]

1 hour ago, pTrevTrevs said:

You wouldn't believe how tedious it got sometimes...

I would like to make a late war variant with a larger conning tower and no deck gun, but I think I'll take a break from the craft, I've seen too much of it by now.

I do know about those breaks, working on the same project for weeks gets tiresome for sure!

[Capt. Hunt]

Just a thought, real submarines use separate trim tanks to adjust their level, a set of separate ballast tanks might help with the trimming issues

[pTrevTrevs]

9 hours ago, Capt. Hunt said:

Just a thought, real submarines use separate trim tanks to adjust their level, a set of separate ballast tanks might help with the trimming issues

The two ballast tanks in the front and back are the trim tanks. There's another set of tanks in the middle of the sub that are nearly full. They're balanced so that they nearly pull the boat under but still need help from the trim tanks. They provide most of the negative buoyancy during a dive, while the trim tanks help balance the boat as well as adding more negative buoyancy to help it go down.