German type XVIIb

[MFR1964]

https://youtu.be/EHsm53WilZE?si=UwkXIX_tbgSSNlYt

Got me some playtime with the torpedo launchsystem build inside the type XVIIb.

Manfred.

[MFR1964]

Beside building my multi purpose toolbox i did some work on the XVIIb, still have the issue with too much torque running the Decaperm motor, so i decided to give it a go with a different motor i have in stock.



Took out the Decaperm, the lower is the monoperm, the upper the Decaperm.



Made a makeshift construction to get the monoperm inside the Decaperm cradle.

Now the question did it work?, made several test drives with the monoperm, less torque as intended, longer endurance on the battery, but also less speed, as a matter too less to my taste, so i went back to the Decaperm, restrickited the throw on the throttle forward, made a testdrive today,, better result on the speed, torque stays a issue, but when you go easy on the throttle i can live with that.
Next stage this winter will be, replace all the batteries inside, those are about 5 years old and the capacity is fading, this will give me also the oppertunity to place the lead from inside the ballasttank near the keel, giving me the advantage of more volume inside the ballasttank, so hopefully she will be getting a higher freeboard, busy days ahead.





Found some replacement switches on the web, top is the old one, the same i use inside the boat for controlling steering of the torpedo tubes, as you can see there are two variations, one relais or two relais, the bigger one's you can program for holding the relais when needed, the single relais has only the function on or off.



I'm going to use a single relais for steering my torpedo doors, the channel i use has only a on/off function, i'll report back with the result.

Manfred.

[Albacore 569]

I know what its like., I have a half-completed Type XVIIB I like ot finish. I been building other boats and hope my experience will go into the Type XVIIB.

Do you get the Sub Committee Report.? If you do, hold on to your nickers. The next issues (winter) and part 2 (spring) is all about HMS Meteorite. I hope its good and I am worthy..

From Edited proof. Teaser

[MFR1964]

Same story with me, the type XVII has a edge, still not enough stick time to say i can fully control her, from the experience i have sofar she's fast and likes to run fast, to get better results in the future i still have to tinker on some components, she has become more or less my experimental project what is possible into the exstreme, i've got me enough slow runners, the spirou as a exception.
The fun bit on this boat is, refining her each time i run her, today i've made a high speed run as well above and underwater, estimated speed about 14 km/u underwater, i know this from my V80 which has a topspeed of about 12 km/u, unfortunally the levelkeeper had some issue's so i had to abort the testing, for now she's on the bench to see what the problem is, what i did found out was that under some occasions she would steer up and stayed that way, i could simulate this also on the bench and i'm on the hunt why this is happening and how to solve this.

And yes you are worthy, i will look forward on that article.

Manfred.

[MFR1964]

Still tinkering on the XVIIb, first solved the levelkeeper issue, it stayed at the steered up positon in some chases, also during my testdrives i noticed that the small valve for trimming the boat didn't work that well, adressed that issue, and made a new rudder last few days, slightly bigger as the old one, hope to get the turningradius smaller by this, for now it's a wopping 10 meters, good enough for open water, but tricky inside a swimming pool.



Gave this servo horn a slightly differend position.



This copper sleeve guides the rod which steers my divingplanes, a bit of lubication was needed, for now everything is working as intended, did some testing on the bench, by tilting the boat into the extreme tested if things keep working, for now the result is positive.


Made this contraption to keep the water out of my small valve, there are two valves inside the XVIIb, a big one for filling the ballasttank at the first stage, the second one is used for trimming if needed, there tended to get water inside the small valve, by making the contaption it will be much harder for the water to get in my valve.



The new rudder freshly painted.



Removed the old rudder by removing both carbon pins on top and bottom, the new one has a pin all through, much easier to get the rudder off.



The new pin will slide all the way in, made a little stopper on top to keep the pin from falling out. gravity will hold it in.



The difference between both rudders, the new one is enlarged by 10 mm, not scale but practical, hoping to get a smaller turningradius, i'll report back with the results of all modications.

Manfred.

[trout]

Manfred, it is a joy to see you build. As far as 10% larger rudder, ihave never had anyone look under my boat or at my rudder/planes and say, it is not accurate. Performance is what really catches people’s eyes. I think it looks good and will not stick out like a sore thumb. As my health is getting stronger, I am getting more time to fix/build subs. You and David really inspire me to push forward. Thank you!

[MFR1964]

Good to hear your health is getting better Tom, as for modifing your sub to preform well, as long as it looks good it's fine with me, most people don't even know what the specific things are on a RC submarine, they are allways amazed what's inside to make this happen and the result, a wake from your scope is for them more as enough.


Manfred.

[MFR1964]

The XXVIIb is on the bench for changing the batteries, unlike a wet hull it's some more work with a dry hull type, because all batteries are down at the keel, so taking all the stuff above away is the first step.







This is all the stuff i first have to remove, it will take some time, i do have a list for connecting all the cables, all connectors are marked accourding to the list.



At the frontpart the compressor lives, she has to be disconnected first and taken out.



The compressor is the first layer, it stands on a plate which covers the front batteries, this is the empty hole with the front batteries removed.



All the stuff that came out, the firingsolution electronics for the tubes, compressor and the receiver



Now the frontpart is empty i can dig in on the rearpart, to be continued.

Manfred.

[Albacore 569]

The Subcommittee HMS Meteorite article I wrote, part 1 will appear December 1, 2026, Part 2 following spring issue

My type XVIIB model still awaits finishing. When I get more experience then will try again. I bought it when I knew a lot less and my eyes were wider. As Merriman wrote, it's probably the toughest project anyone could attempt. Hats off salute to your skills.

[MFR1964]

Can't wait on those articals, extra knowlegde is always wellcome, yeah she's special, only the rudder arrament gave me some grey hairs, a bit different as usual.
For now i have to gut out the rear compartment, order new batteries and start building battery packs, will alter the lead issue by adding as much inside the boat instead of inside the ballasttank, hopefully it will give me some more freeboard.

Manfred

[Albacore 569]

Since I wrote that article earlier this year, I had learned U793 a type XVIIA boat did tests with 4 admirals including Doenitz no less along with Walter on board too on one particular yard trial. It was a reflection on just how much the German Navy had hopes for Hydrogen Peroxide propulsion then for the future.

The article shows in documents how much they knew about the Type XXI and Type XXIII electro boats, but the Type XVIIB were not learned of till late fall of 1944 or early spring 1945 and caught Allied Intelligence by surprise. These subs became the most exotic and suddenly the most sought-after U - boats at the end of the war. The article goes into that. I hope the article can dispel the hindsight how much a dead-end T stoff propulsion was and try and put the reader in the viewpoint how most felt about the technology at that time.