yvesvidal

You may not like what you are doing at that moment, but we sure do enjoy it, from our perspective. 🙂 Yves

Katuna, I think I know which modeler you are referring to. This is gorgeous but if it is the Hachette kit, they only have two compartments to build....not the entire vessel. Besides, once inserted in the hull, you cannot see any of these incredible details. Finally, I do not have the patience for this level of details, nor would I know where to find the information. But thank you for the picture....it is quite incredible. Yves

Beautiful story. Thank you for sharing it with us. Yes, the magic of flying.... Yves

Well, the engine has been installed in its cradle, similar to what these mechanics were doing on these historic pictures. I have tried to shorten the stand of some of the rockers, to give the overall engine a more realistic look. If all the rockers were in the same position (as implied by the Trumpeter kit), then the engine would have a hard time running. It is not perfect, but at least it is better than what the kit is proposing. Also, I have added the six hand valves on top of the engine. Again, these are present in the PE sheet, but the instructions are not mentioning them. I added a small washer between the shaft and the bulkhead, to make it look more convincing: Still trying to focus my poor camera on these gauges: And finally, giving the engine some offset, like the prototype:. The rear of the engines are closer to each other than the front (shaft/output) side. Now, to work on the ceiling and on the other engine. Katuna, I am still debating about that oily look... It is very tempting but also difficult to represent in a realistic way. Yves

A few pictures of the engine. It is almost finished and I have waived the oily look.... I was ready to use real dirty oil (from my car) but decided otherwise: I still have to paint the exhaust and assemble it. Yves

Katuna, you beat me for the posting. Yes, of course, I noticed these wonderful and historical pictures posted by RAYMIC1 on the models.rokket.biz forum. Quite a different perspective: Those diesel engines are colossal: Finally, a picture taken from the library of "Das Boot". Yves

Very true. There are so many short cuts with basically no savings at the end of the day for the Manufacturer. This kit could be "top", with a little bit more care and a few more parts. Yves

That elevator takes the whole model to another level: Museum quality! Superb. Yves

Lovely. Yves

Much better stand that allows you to admire the beautiful curves of that hull. Yves

Don, I am humbled that the famous Mr. Prince is taking a look at my model. I am in awe at the extraordinary amount of work you have done on these German submarines and have learnt so much by reading your book (the PDF version). Also, thank you for introducing Mr. Tore to this community as he is probably one of the very few men having served on a Type VIIc vessel, still in existence today. There will be more of your material being used in this Blog. It is my absolute reference. Yves

My eyes are exploded. That engine is a challenge to build and to paint. It must have at least 100 parts to put together. I am building it pretty much out of the box. The only change I made was to cut the plastic pushers and replace them with metal wires for more realism. Not an easy thing to do: you need to drill 12 holes with the proper alignment. Trumpeter has been placing a lot of hoses and it makes the assembly a challenge: at the scale of 1/48th, these hoses are too big and are crammed, preventing a nice organization of all the parts, especially around the rockers. I have seen some modelers push the insanity at replacing the plastic valve springs with real springs. I just cannot do that. Besides they are almost invisible once the engine is in place. After painting the entire engine, some kind of "Hemp" color, it is time to install the pushers and paint all the details. My eyes are too shot to go any further today. Yves

Very nice mast. Yves

Thank you Katuna for all this very interesting material. I have thought about showing the oil pan on the engine and regrets that Trumpeter did not include that part in their otherwise extremely well detailed engine. I may fabricate it for the starboard engine, as nothing will be visible on the port engine. I wish you could show in a separate thread, the beautiful work that you have done with your engine, all the piping and oil tanks in the frame of the compartment. Maybe you will start your own thread on the U-371, as you are depicting it, in the Mediterranean sea. Yves

Please, post here what you think is relevant to the Diesel engines compartment. I'd love to see what you have. Yves

Katuna, I know you know, since we frequent the same very specialized forums. I simply hope I can get close enough to what You and Bianco are doing. I am humbled when I see the masterpieces and the extent of research and details that you are putting into these models. Katuna, I use your work as the reference for a lot of details and understanding of that submarine. Thank you for sharing your knowledge and skills with us. With gratitude. Yves

Let's look at some of the information I found on the Diesel Engine compartment. As shown by the blueprint, there are three main tanks in that compartment (and there are many secondary and very important tanks to operate such complex machine). There are two Fuel tanks located under the engines and multiple lubrication tanks located right between the engines, under the walkway. These 3D renderings will help: That first drawing shows the fuel cells under each engine and the multiple oil/lubrication tanks, pipes and associated pumps. Quite complex. The drawing above shows the two engines and the walkway installed between them. Notice that the two engines are not parallel to each other. This is not correctly represented in the Trumpeter kit. I will see if I can give the model some offset on the engines. The three following drawings are showing the armature holding up the two massive diesel engines. Fuel tanks are built in between the frames, whereas oil tanks are installed as separate cells between the main longitudinal frames. I have decided to not represent any of these fuel and oil tanks, as I like to be able to show the nice ribs arrangement. Here again, the Trumpeter kit does not provide the two elevated frames marked with a warning signs. The next diagram show the cooling and anti-corrosion system used for the diesel engines and electrical motors: We saw that the diesel engines were introduced by an opening on the pressure hull. That opening was bolted and carefully made waterproof. the two following pictures show that large opening. On the second picture, the opening is shown in greater details, but it is a later model than the U-552 (possibly even a Type IX). You can also see the large pipe bringing fresh air to the engine compartment. On the U-552, that pipe would be almost straight. Finally, some views and blueprints of the engine itself: I have to say that Trumpeter did an excellent work on the engine details. It is rendered in great details as we will see. Yves

Le Chasse Maree is an excellent magazine which has been published for many years and covers various subjects related to the sea and boats, in depth. I have a few issues at home and really like it. You picked up an excellent and traditional subject for your build. Yves

I am now moving away from the Trumpeter instructions.... not that I have followed them very much, since the beginning. What should have been glued last, is actually done first. This is done to allow me to fine tune the alignment of the engine(s) and transmission shaft(s). If you do that task at the end, as suggested by the assembly instructions, you run the risk of having the shaft not match the opening in the bulkhead (which is exactly what is happening, already). So, some intervention will be necessary at this location. I have two diesel engines, but they are identical and not symmetrical as are the real ones. So, we need to perform some important surgery on the starboard engine. In addition, keeping the two engines fully assembled will hide the "prototypical" and correct looking engine and presents to the observers, something that is not right. So, I have decided to cut down to the crankshaft case the second engine and prepare it for a little surprise..... If I can do it. More will come later, in a few days.... This is where we stand at this moment. hopefully, most details of the port engine will be visible over the "cut" starboard engine. This is going to be a very busy compartment. Thank you for all the "Likes", encouragement and support. Yves

This wonderful 360 spherical view of the Engine compartment is very useful: https://www.360cities.net/image/submarine-u-995-machine-room I already spotted another error done by Trumpeter, who installed the indicator lights over the rear bulkhead (wall between Diesel and electric engines) when in fact they are suspended to the ceiling, near the wall between Diesel engine and kitchen. When looking at this presentation, please keep in mind that the pictured U-995 is somewhat different from the early U-552 that we are depicting. In addition, U-995 has been modified heavily and retro-fitted with more technology than the early U-Boots. Therefore it may explains some of the differences between the pictures and the model. Yves

So impressive. It is gorgeous. Yves

Some updates, on the Diesel engine compartment: Basically, to give the roof and wall a more interesting appearance, I am doubling the molded wires with real conduits: twisted pairs from CAT5E cables. The fasteners are made of a small piece of tape sliced, to create the illusion of some metallic holders. Also, notice that I made a second hole for the exhaust of the starboard engine (missing in the kit, of course). Once painted, the result is not too bad. All the conduits blend nicely.... Highlight of some details and a touch of wash on the conduits. Still very clean overall, no grease and oil being spilled. Painting the chassis took forever, even with an airbrush: there are so many surfaces.... I cannot even imagine what it would be to paint this with a brush: Et voila, for the moment. Yves

Very true. Nice catch Keith. Yves

Great work Jack. You are very patient..... Yves

Before we dive into the model, let's present the Diesel Engines compartment. First, from the official blueprints: The U-Boot Manual offers a technical Comparison between the two types of engines used on the Type VIIc: the M.A.N. and the G.W. The main difference is in the forced induction: On the MAN, the induction is done through a turbine driven by the exhaust (Turbo-charger), whereas on the Krupp engine, the compressor is driven by a belt. The G.W. engines were much better and more reliable and MAN engines were retrofitted little by little, before the submarines were sunk...... M.A.N. Krupp (G.W.) Number of cylinders 6 6 Piston displacement 57.8. liters 57.8 liters Piston speed 7.2 meters/second 7.2 meters/second Efficiency 82.5 81.0 Speed 470 RPM 470 RPM Supercharger speed 10,900 RPM 10,900 RPM Performance 1400 SHP 1400 SHP Stroke 460 mm 460 mm Cylinder diameter 400 mm 400 mm Length (whole engine) 5630 mm 5600 mm Width (whole engine) 1400 mm 1400 mm Height 2810 mm 2895 mm Engine weight 38.476 tons 43.440 tons Weight to power ratio 13.75 kg/SHP 15.5 kg/SHP Fuel oil consumption (+) 0.165 kg/SHP 0.182 kg/SHP Supercharger Buchi Exhaust gas turbine B.B.C. Roots type charger G.W. Fuel oil regulation Over flow adjustment Chamber volume by means of beveled edge adjustment From a size and shape perspectives, both engines are very similar: The fantastic characteristic of these Diesel engines is that they could run in both directions (reversible) thanks to a very ingenious mechanism to change the distribution. You only had to stop the engine, swing a lever to change the distribution at both end of the engine, and restart it. It would then run in the reverse direction. The operation did not take very long (less than a minute) and could be performed with one or two mechanics. One of the most incredible task during the construction, was the insertion of the massive Diesel engines into the Pressure Hull. This was done through a large opening on top of the pressure hull, which was then welded once the electric motors and diesel engines had been inserted: A smaller and similar opening was also made in the pressure hull, for the insertion of the front electrical batteries. Once installed, the Diesel engine compartment was very full and always maintained in a very nice condition (which is not the case with the Swedish crew, as you can see on the picture): The picture above shows the Swedish crew that took possession of the U-995 at the end of the War. That boat is the only Type VIIc in existence and on display, in Europe. The air intake was provided by the two openings at the top of the sail. These two intakes were funneled through a large duct, running above the Control Room, the rear compartment, the kitchen and entering on the roof of the Diesel room. Thus, fresh air was injected in the Diesel room for the engines (and the crew....) to breathe. I have included the schematic below, for those who wish to understand some of the intricacies of the propulsion system: I will be adding more technical data as we move along with the construction. The above should whet your appetite.... Yves