yvesvidal

Really impressive. Yves

So, before showing you the finished rear torpedo compartment (I still have a few details to take care of), let's share some information about the intricacies and technical details of that section of the boat. My goal, again, is not only to show you the implementation of that great kit, but also to learn about these incredible vessels and their technical solutions. The picture above shows the two electrical motors/generators used to propel the submersible, when under water. It also shows the two large electrical panels allowing the control of the motors/generators. Switching is done by maneuvering the large wheels. From the "Manual": 1) E motors. The E motors working as electric motors drive the propellers and working as a generators charge the batteries. They are fan cooled, encapsulated, direct current, double armature, with compound windings and commutating poles. The motor is built from two parts, casing with installed windings, which are bolted together. There are also two armatures installed on the same shaft inside. In the upper parts of casings are cold air inlets and warm air outlets. Bottom parts up to the bottom edge of the shaft are water resistant and at the lowest points draining cocks are provided. Each double armature motor has 2 x 8 main poles and the same amount of commutating poles. All poles are bolted to the inner side of the rotating yoke. The shaft has installed two armatures and runs in two slide oil ring lubricated bearings. The bearing on the diesel engine side is built as a thrust bearing for absorption undesirable thrust. The bearings of the E motors are cooled by sea water. During surfaced drive the cooling system is fed by the diesel engine cooling pump and while submerged, by the cooling pump. A fan blower is attached to the casing. It draws fresh air from the E motor room and blows from above into the both parts of the motor. The warm air escapes through outlets in the upper parts of bearing casings and is directed to air coolers, which are installed between the E motors. 3) Main switchboards. b) Main switchboards with Rotary Switches Type VIIC U-boats are equipped with main switchboards with rotary switches provided by A.E.G. Company, Berlin. The stb. main switchboard is connected through the aft battery automatic circuit breaker to the aft battery, the port main battery switchboard is connected through the forward battery automatic circuit breaker to the forward battery. Each battery automatic circuit breaker has following settings: overload current of 6000 A in 10 seconds short circuit current of 12000 A The main switchboards are built from iron framework, which supports switches, control and measurement equipment necessary for driving and charging. The order of the switches on each switchboard from left to right for both E motors is as follows: 1 Main battery switch with charging connection below 1 Starting relay with with indicator lamp 1 Field switch 2 1 Drive direction switch 1 Field switch 1 with indicator lamp 1 Motor - series-parallel - switch 1 Battery - parallel-serial - switch Above the switches are installed the fan blower motor switch, board illumination switch, silent running drive switch, and measurement devices. The speed controller is installed on the right side of each switchboard. Timed relay and auxiliary relay are installed below the measurement devices and above the drive direction switch. Main battery switch is two-pole. When switched on, the battery automatic circuit breaker is connected with main switchboard. The switch is operated by an isolated handwheel. By rotating the handwheel to the right, the switch turns on, rotating to the left turns the switch off. In the bottom part are charging terminals, accessible through flap on the casing. Drive direction switch is five-pole and is used to toggle the current direction in the armatures to change motors direction of rotation. By turning the handwheel to the right, the motor runs forward, by turning to the left, the motor runs backward. The switch is turned off when the handwheel is the middle position. The drive direction switch is interlocked with the motor field switch so that the E motor cannot be turned on, when the field switch is turned off. Motor - series-parallel - switch is a four-pole toggle switch. Turning the handwheel to the right, causes the armatures to be connected in series and the equalizer line is disconnected. When the handwheel is turned to the left, the armatures are connected in parallel and the equalizer line is connected. By means of auxiliary contacts the circuits of the timed relay and silent running drive switch are closed. Battery - parallel-serial - switch is a double three-pole toggle switch. Turning the handwheel to the right, causes parallel connection of the batteries. When the handwheel is turned to the left, the batteries are connected in series. By means of auxiliary contacts the circuits of the timed relay and silent running drive switch are closed. Starting relay is a two-pole circuit breaker. It normally works fully automatically, but in case of damage, it also can be manually operated. This contactor limits too high starting current. Immediately after turning on all switches or after expiration of the adjustable (to 1 second) timeout the contactor opens and in its off-state connects the starting resistor into the E motor armatures circuit. When the contactor contacts close (the current has gone down, the voltage is low), the starting resistor is short-circuited. When the main current circuit opens, i.e. by turning off any of maneuver switches, the starting relay is opened and the starting resistor is connected. When the relay is damaged, the starting resistor can be short-circuited manually. In that case before setting the maneuver switches, the starting relay must be turned off. When starting relay is activated, the indicator lamp lights up. Using the motor - series-parallel - switch and battery - parallel-serial - switch three drive speed ranges corresponding three voltage ranges can be set (see E-Sketchbook). 1. Batteries in parallel, armatures in series 2. Batteries in parallel, armatures in parallel 3. Batteries in series, armatures in parallel Within these three ranges, further adjustments can be done by changing the current in shunt windings using the double motor field rheostat – the speed controller. It also can be used to control the output voltage of the E motor while charging the battery. Each single rheostat is connected in series with single shunt winding of the double-armature machine, then they are connected in parallel with each other. This rather complicated description gives us a feel for what it took to operate these complex machines. Needless to say, the importance of capable mechanics was paramount on these vessels, as everything was done by hand and following a very precise procedure. This drawing shows the cooling system used to keep the electric motors/generators at operating temperatures. As indicated in the Manual, the primary cooling pump is located in the Diesel/engine room (bottom right on the drawing) and distributes cold salted water to the Starboard compressor and the two electric propulsion motors and fans. Definitely a plumber's dream.... or nightmare. The rear compartment similar to the front torpedo compartment, is equipped with a torpedo storage between the pressure hull and the outer casing: These two pressure proof containers are marked in red on the drawing. Internally, the rear bulkhead near the torpedo tube is equipped with an electric compressor on the port side and a diesel compressor made by Junkers, on the starboard side. These compressors are resting on top of the torpedo compensation tanks: The picture above shows the U-995 (only surviving Type-VIIc) which has been heavily modified and is not really representative of what an early Type VIIc was, during the war. Most likely, dual electric compressors were the norm before the Germans realized that due to extreme electrical consumption, they had to swap one of them with a diesel powered Junkers unit. The Trumpeter kit (with its short-cuts) just ignores that part of the compartment and does not offer any starboard compensation tank and no Junkers compressor. Yves

This is spectacular and with this kit, you are finally allowing non-experts modelers to build Period Ships in the proper way. What are the woods being used in the kit? You also mentioned a price of about $350 for the kit in another thread. Will the frame used to build the ship, be included in the kit? Yves

Trying to finish the rear compartment. It is by far the most difficult to realize and set in location. One of the reasons is that I am trying to make it more complicated than it was designed for. The second reason is that I am trying to power the shafts and allow the propellers to rotate. Finally, the capability to take apart and insert the starboard half-hull makes all the assembly very tight and delicate. A lot fo sanding has to take place to allow the insertion of the half-hull in the main hull. I think that once I put together the entire rear compartment, I am going to glue it (with just a couple of points) to the main hull and get the shafts coupled permanently. It is necessary to file the main bulwark to allow the insertion of the cover-hull: Lots of complexity for not much additional results. We will see how this goes. Yves

Part E of that long deck: We are soon running out of PE parts....which is a good feeling. One more section to go.... But it will wait, as there are far too many delicate parts to glue on it. Yves

Little progress, reconstructing: Yves

Beautiful, simply beautiful. Yves

Alright, a little bit of de-construction. Dubz used to do that a lot on his "better-than-perfect" Syren model. I just unglued the three frames I had built, filed the main keel and will be gluing back the Trumpeter parts. Below are some of the "spare" parts I will be using for that rear torpedo compartment: Yves

Do you believe in Miracles and co-creation? As some of you who are following this saga may know, I have been in search for some spare parts and sprues for this rare model. I want to be able to duplicate certain components of that huge model to make it more attractive and interesting. My attempts at contacting Trumpeter (through Joanna, their sales rep in China and even the local distributor in the USA) were crowned by a complete lack of response and interest for my requests. Obviously, once you buy the kit, you are on your own and Trumpeter will not help you. I have dealt with other plastic models companies in the past (Italeri and Heller) and they have always been responsive. Trumpeter is way too big to take care of a remote and obscure customer in the far land of America. And then the miracle happened, when I had given up and started building painstakingly some parts myself: Being subscribed to the Nautilus Drydocks newsletter, I received one day a presentation of the Trumpeter U-552 model recently completed for a customer. The model was exquisitely finished but did not show any interior details. It was basically built as a regular model, with the hull and conning tower. I decided to contact the owner of the Nautilus Drydocks and inquired if he would be willing to sell me some spare parts for the rear compartment and engine compartment. He counter-offered by telling me that I could get all the parts left over from the build for an unbeatable price. Today, I just received the complete set of parts allowing me to literally build a second interior with all the compartments. Truly a miracle and the proof that we can co-create what we want if it goes along with the desires of the Universe. This will allow me to build the second electric motor and many other things making this model, hopefully better and more complete than what Trumpeter intended. A very grateful THANKS to Bob from the Nautilus Drydocks for allowing me this unique opportunity. https://www.rc-submarine.com/ This link will take you to Bob Martin's web site. Here you can enjoy some of the magnificent models, Bob has been realizing: https://www.rc-submarine.com/copy-of-gallery Yves

I like the contrast of color. I would keep it unpainted. Yves

Superb PE assembly. You are a Master at that game. Yves

Moving along with Deck D, right behind the conning tower: I am not letting the brass pieces, time to oxidize: Two more sections of deck and we will be done: The primer used is a can for automotive painting. Works very well on clean brass parts. You will agree with me that this deck is a nice and radical departure from the Trumpeter plastic molded deck. I am not regretting a single second, the efforts (and money) invested in that RCSUBs deck. Yves

It is going to be interesting when you start sanding this beast..... There will be a lot of saw dust produced. Tree nailing will probably put all local groceries shops out of tooth picks, for a long time. Yves

Thank you Jonathan. I believe your project deserves a Build Log in itself. Very interesting early concept for a torpedo launcher. Moving to the part "C" of the deck and mot likely the most difficult due to the anti-skidding plates around the gun: Once again, kudos to RCSUBs for their impeccable photo-etched brass kit with excellent explanations and a few spare parts: Not perfect and I cannot wait to see how it will look like with a coat of primer on top. Yes, much better. At least I can see where some small imperfections are located and sand them carefully. That hull is starting to look like a TYPE VIIc. A few more details: Yes, the area around the gun looks pretty neat once coated. And the numerous hinges are correctly aligned for the most part. I hope you are enjoying....as much as I do :-) Yves

While I am blocked on the rear compartment, I have decided to go back to the deck and glue some PEs. I just finished the second part of the deck with these countless hinges to glue carefully. They are about the size of a pin head (or slightly bigger) and are a challenge to place correctly aligned: This is my first attempt at using PEs and I am so glad a nice coat of primer and paint will cover the rather sloppy job I did. It will harmonize everything and hide a lot of imperfections. Yves

Moving along: One can clearly see the torpedo compensation tank. Unfortunately, Trumpeter only gave one in the kit, leaving plenty of open space on the side. Such a pity! Yves

Superb work Jack, as always. Yves

Still working on the rear compartment. Installation of the LEDs: four of them connected in series. That should give us close to 10.8 Volts: The electrical compressor is pretty much done: Yves

The Electric Compressor, pimped up a little bit. It should be a four stages compressor, but Trumpeter forgot the second cylinder.... The Rear torpedo tube on its platform and the canister containing the mines: Finally, the electric panel to control the propulsion motors: Lots of detail remain to be placed and painted. Yves

Our next efforts are focused on the Rear torpedo tube, electric compressors and torpedoes compensation tanks. A summary of the stern tanks seems on order to explain the rear compartment: The Trumpeter kit provides one of the compensation tanks (2.35 tons of salt water), one electric compressor and the torpedo tube. Once again, it is very spartan and it is regrettable that no additional parts are provided in the kit, as these two components would not detract the viewer from the intricacies of the compartment. Below is a picture of what we are talking about, from the U-995 submarine. The large compressor sits on top of the torpedo compensation tank. The torpedo tube is visible on the left of the picture. To the extreme left is the other diesel compressor installed on the U-995, sitting on the other compensation tank. Not visible, to the right of the torpedo tube is a large canister containing mines and other "goodies" that can be launched using the ejection tube. Underneath the metal floor, is the torpedo stowage area for one eel, sitting right between the two electric motors. On the early Type VIIc units, there was two electric compressors. The German engineers replaced the starboard electric compressor later on by a diesel unit, as the electric consumption was way too important with both electric compressors. It is not clear if U-552 has two electric or a combo electric/Diesel compressors. From the manual: a) Electric air compressor. The compressed air required for blowing ballast tanks, starting diesel engines, for torpedo launching installation, anchor installation and so on, is produced by two electric, 4-stage air compressors, located in the aft torpedo room. Their performance is 6.1 liters/minute at 205 kg/cm². Compressed air from each stage is cooled down in a cooler. The air cooler and lubricating oil cooler are located in one case outside the compressor. The compressor is cooled by sea water. The two-stage cooling water pump is located on the coupling side of compressor and is driven by means of helical gears from the crankshaft. The gear type lubricating oil pump is located on the front side of compressor at its base plate and is driven from the crankshaft by means of gear wheels. The compressor is driven by a direct current, shunt electric motor, with starting compound winding on commutating poles. The motor is splash-proof and self-cooled with air. b) Diesel air compressor. Type VIIC U-boats since Boat No. ____ are provided with one electric air compressor and one diesel air compressor. The diesel air compressor is a horizontal, double piston, two-stroke diesel engine with free pistons which are directly coupled with a four-stage compressor. Its performance is 8.5 liters/minute at 205 kg/cm². After compression the air from each stage passes through a condenser for cooling. The cooler for all four stages is located beneath the compressor in individual cases. The air is cooled by means of sea water. The cooling water pump, rotary vane type, driven by a gear shaft, forces the water in the following order: cooler IV, combustion chamber cooling jacket, compressor stage I, compressor stage IV, cooler III, compressor stage III, compressor stage II, cooler I, cooler II. The lubricating oil pump, driven by means of an eccentric from the gear shaft, lubricates all sliding parts. The compressor is driven by two-stroke diesel engine made by Junkers, with two opposed pistons, which are coupled together by means of two sets of traverses, two gear racks with a geared wheel located between them. Engine pistons control intake of air, which is compressed and exhausted. The stage I compressor piston is connected with left engine piston, the stage II compressor piston is connected with right engine piston. The stage IV compressor piston is coupled with the left piston rack and the stage III compressor piston is coupled with the right piston rack. The compressor is started by means of compressed air admitted to particular compressor stage chambers. The compressor casing is splash-proof. c) High pressure compressed air flasks. Compressed air is stored in 12 high pressure air flasks with total capacity of 3.900 m3. Each flask has capacity of 325 liters and is tested at pressure of 280 at. The flasks are grouped in 6 banks (2 flasks each), which are located as follows. Bank 1 Upper deck aft, on both sides of the aft external torpedo container Bank 2 Upper deck, above the diesel engine assembly patch Bank 3 Petty officer's room port and stb. Bank 4 Forward torpedo room to port Bank 5 Forward torpedo room to stb. Bank 6 One flask in the bow buoyancy tank, one flask on the stb. side forward of the external torpedo container. The flasks are smooth shaped and are lined with lead. On both ends they narrow into the neck, capped by means of flange and cover. To drain the flask a drainage pipe is provided in the deepest point of flask. Furthermore, the flasks are inclined 4 degrees from the horizontal. Yves

Decals are included with the kit. Yves

The ceiling of the rear torpedoes / electric motors room, is pretty much done: Decals have been added on the dials and indicators. When dry, I place a few drops of clear-coat to simulate the glass lenses. The wheel is used in case of emergency and failure of the main steering system. It looks relatively realistic. I am avoiding the dirty / patina presentation as most of these vessels were well maintained during their short lives, at least in the inside. Yves

Greg, I hope you do not mind me posting these pictures here, but the Italian Artist Perinotto just published the Tome 4 of his drawings with two very interesting drawings: Notice the carriage/cart holding the Me-109, and used as a catapult on the deck of the Graf Zeppelin. Very advanced technology. Yves

Gorgeous and so unique work. Your model is truly a jewel and you are an artist. I love the uniqueness of that approach, even though I am far from being able to do what you did with the Mikasa. The paint is for me a way to hide the imperfections of my models and the lack of details sometimes. I have the Mikasa and may one day try to copy you.... Thank you for showing us this great model. Yves

Working on the roof of the rear compartment: The Trumpeter kit is more or less accurate here and there is room for additional details. The holes will host the four white LEDs, the last hole to the left is the rudder control axle. Some of the pipes are original and prototypical, others have been left to the imagination of the artist. The mechanism on the ceiling of the rear compartment is the manual control of the rudders, in case of the failure of the electric systems. A large wheel will take place, once I have painted the ceiling. From the "Manual": 1) Steering System. a) General. The rudder installation includes the following: Two identical main rudder planes parallel to each other, Forward dive planes, After dive planes, Plane drive, Steering stations, Steering lines. Steering plane construction: To keep the driving force low, all steering planes are built as displacement, balanced rudders. They are made from watertight plating on both sides, with stiffeners provided between the plates. The spaces between plates are filled with tarred wood. Steering plane protection: A skeg is provided to protect the main rudder, especially from hitting the bottom, from which two arms lead to both rudders and are attached to the rudder pins. To prevent entanglement with naval mine wires and antisubmarine nets all linkages are made smooth and all faces are rounded. The outer edges of dive planes are protected against naval mine wires. To avoid corrosion (galvanic current between bronze and steel in sea water) all steering planes are provided with zinc protection plates. b) Main rudder installation. The main rudder is twin type and can be either electrically or manually driven. The main rudder is driven by means of vertical intermediate shaft, which passes through the pressure hull between frames 1 and 2 and which is driven by worm gear. The shaft bearing is installed at the pressure hull and is re-tightened from inside by a stuffing box. The top of the intermediate shaft (in the upper-deck) is attached to a double arm, which is connected by means of two long connecting rods with two, center-facing, main rudder arms. Each main rudder has an area of 2.75 m². The rudder maximum deflection is 33° when electrically driven and 35° when manually driven. Ruderblätter Rudder planes Fester winkel Fixed angle Drehpunkt des Ruderblattes Pivot point of rudder planes Hauptruderhebel Main rudder arm Schubstange Connecting rod Senkrechte Zwischenwelle Vertical intermediate shaft Doppelhebel Double arm The maximum deflection of the main rudder and forward and aft dive planes is limited electrically by means of a limit switch and mechanically by means of mechanical limit stop. Yves