The Pionierlandungsboot was the first design before the German Wehrmacht (not the Kriegsmarine!) changes later to the Pionierlandungsboot 40.
For me the Pionierlandungsboot 40 was the easier design, more straight lines / walls and less curves. But with the time I improved my skills, learned new functions with sketchup, so I started with the design of the Pionierlandungsboot 39. The original was a design from the Wehrmacht and had nothing to do with the Kriegsmarine. The Kriegsmarine concentrated on destroyers cruisers and other big ships. But the Wehrmacht thought about the need to transfer stuff from A to B, anyway on the open sea or via a river.
Back to my drawing. I am close the finish the 3D file. I found a way to open the doors and to use it very similar to the original design. The ramp and the doors are moveable.
There are still some small errors inside the drawing and I have to check some of the dimensions, but I would say in 2 or 3 days it should be done.
So enjoy the first impressions for the German Pionierlandungsboot.