Diesel engine room

I’ve been working on the diesel engine room; added some textures, sounds, and animations. Haven’t yet baked lights for the prototype.

I also bought an amazing book from Amazon written by the son of the founder of Cummins Disesel. I’m hoping to use info from it to correctly update the 3D model and ensure I have an accurate simulation under the hood for the Krupp Germaniawerft F46A6P diesel most VIICs used.

Would love any feedback and as always, the updates are live in the sim.

Model Updates

I’ve been working on adding details to the model. The external body is built around the pressure hull. I tried to add appropriate holes in the body for water to pass through an am using a temporary texture/bump map. Lots left to do, including conning tower, but I am happy how this is coming along.

2D water

In the 2D view, I want to be able to visualize flooded compartments and even let you see the consequences of forgetting the intake valve open when diving! I’ve been working on a 2D water rendering system that allows me to do just that! Here’s a quick demo of it in action before I hook up the ballast tanks and other rooms to it.

Sample video

Sub construction scene

Part of the fun of a sim is being engrossed in a deep and rich world that feels as close to the real one as possible. Not only does the sim have to behave like the real thing, it has to look like it to; atmosphere matters.

Because I’ve always been fascinated with the construction of the U-Boats, and I need to make a super accurate model for the sim, I am building a scene where the user will get to see the U-Boat they will command being build, piece by piece. Using archived materials, I am building a model I can use for this. Here is the work in progress so far:

The view of the girders and keel I build in blender as 3D model being compared to
U-534 – yes, that was not a VIIC but the girder size will do

Continue reading → Sub construction scene

Diesel starting air tank

The M.A.N. Marine Diesel Type M 6 v40/46 engines were started and reversed using air tanks. Each diesel engine had a 125L air tank that held air at 75 atm. A pressure reducing valve stepped the pressure down from 75 atmospheres to 30 atmospheres to start the engines.

U507 Engine Starting Air plate

For the latest release, I’ve added the simulation aspects to use air to start or reverse the engine. For now, no main air manifold is present so the tanks will not refill. After a single start, they will fail to restart again.

Double click the diesel motor to get more info on the engine and specs. As I dive deeper into the sim, more of the underlying components will be made interactible on the 2d schematic.

Physics model

The Silent Hunter series did a decent job at simulating the U-boat physics. If you play close attention though, you can somewhat tell they were a bit ‘scripted’.

For the U-boat Simulator, I am working with a very generic physics method aimed at somewhat accurately simulating a few key things:

  1. Air resistance (the conning tower has resistance applied to it when moving or in strong winds)
  2. Viscous water resistance
  3. Slamming forces
  4. And hydro-static forces (buoyancy)

To achieve a generic model, the U-boat and other boats in the game have a hidden optimized mesh model which represents the sub. Each frame, the mesh is recalculated into two pieces, one for above water, and one for under. Each triangle in the mesh then has the 4 values mentioned above computed. This means that the U-boats design plays a crucial role in it’s maneuvering profile.

Physics mesh

Continue reading → Physics model

Power-plant / drivetrain

One of the most important aspects of a deep simulator is the ability to override the automation of certain systems and have full control over all settings. In a U-boat, the power-plant is arguably the most important system; it moves the boat, and charges (or discharges) batteries, blows ballast tanks when surfaced etc.. . Without the power-plant, the U-boat is useless.

In order to simulate an accurate and fun system, I have pulled specs from the VIIC manual. The main powerplant layout includes two banks of motors, engines, 2 clutches, and the propeller itself.


Continue reading → Power-plant / drivetrain