Mar 252010
 

Numerous sources have mentioned “Prüfstand XII” (“Test Stand 12,” a code-name) and shown the same relatively unenlightening illustrations of it over the years. The idea behind it was this: at the same time production of the V-2 rocket was ramping up in wartime Germany, the western allies were overrunning V-2 launch bases. So the Germans had a missile, but nowhere to launch it from. The idea was raised about putting V-2’s in cannisters and towing them behind U-Boats; this resulted in the first serious design effort for a sea launched ballistic missile. The submarines available to the Germans at the time were far too small to permit carrying V-2s internally, and given the alcohol fuel and cryogenic liquid oxygen oxidizer, it would have been insanely unsafe to do so. So towed cannisters would allow the subs to transport V-2s in relative safety across the ocean.

The submarines would be stripped of armament; towing the cannisters they’d be essentially sitting ducks anyway. This would permit the installation of more powerful engines. A total of five cannisters could be towed at a time. They’d be towed in the horizontal attitude; once they arrived at the launching site, 500 or so miles from the supply base (indicating that the targets for the V-2 remain in Britain), crews would be transferred aboard and then… the subs would abandon them and return home. The cannisters raised to vertical. Before launch the noses of the cannisters would project above the water; bow doors would open. The V-2s would be launched from them much like any other silo-launched missile, with ducts along the sides to the silo to carry the exhaust away from the fragile missile. The cannister would button up again and resubmerge. Four or five days later the sub would return with another five cannisters and would pick up the first five for return and refurb.

A great deal of the plan seems to have been incredibly optimistic, of course.

I recently stumbled across a post-war writeup of the concept by several of the Germans who worked on it. Included were a number of remarkable drawings and diagrams, finally showing the thing in good detail. The same basic concept was pitched to the US Navy in 1955 for use with Jupiter IRBMs, with no success.

I’ve numerous more diagrams of this. I think it’d make a good APR article… and it’d make a spiffy cutaway display model. If anyone would be interested in contracting me to build them such a model… just let me know.

prufstand-xii.jpg

 Posted by at 1:03 pm
  • Michel Van

    Thx for Picture

    oh I love to see this as APRe article

    in some german literature “Prüfstand XII” aka “Die Schwimmweste”
    was also part of America Bomber Project, also like V-1 launch from Sub.

    but chance a Sub with a cannisters get to US coastline are almost Zero

  • admin

    > chance a Sub with a cannisters get to US coastline are almost Zero

    Agreed. By 1945, the US Navy and Coast Guard had the East Coast pretty well under control. I suspect that had a sub shown up with five of these cannisters, there’d be Privateers and blimps on ’em like ugly on an ape.

    • allen

      I read an interview with a german sub commander who said that the navy and coast guard weren’t as much of a problem because they had a schedule that was well known

      “but those little yellow planes…we didn’t know when they would be around”

      apparently the Civil Air Patrol, because they had no schedule, were more feared.

  • tps

    I’ve also heard of this being used with a V2 varient that used storable fuels instead. The French had their own German scientists look into building them after the war.

  • Observer

    Completely crazy. Those tanks between the fins mean that the slightest roll, pitch or yaw during the wobbly first seconds would mean a lot of loud scraping sounds or worse. Unless it was designed to be raised out of the enclosure before launch, and that’s not indicated.

  • Observer

    (But freaking great find!)

  • admin

    Actually, it was to ride rails. Other diagrams provide details of that.

  • Observer

    That explains that.

    They should have cold-launched it with a big shot of their beloved hydrogen peroxide and potassium permanganate.

  • Michael Holt

    The tactical plan for deployment sounds like it would have worked in 1918. One wonders how many old admirals were making decisions about fringe hardware like this.

  • Michel Van

    > a V2 varient that used storable fuels

    that A-8 Design but its study only
    the French used it for there “Super-V2” project
    the Sovjet used it for the R-11 aka Scud A

    how far the A-8 was part of “Prüfstand XII” is today unclear.

  • Pat Flannery

    Interesting drawings; in a book illustration I have of it, the LOX tank at the bottom is shown as spherical… in this one it looks like it can swivel to compensate for rolling on the sea surface before launch.
    They were supposed to have had a couple of these containers under construction at the end of the war that the Russians got their hands on, and they were supposed to have copied it in a system named “Golem”, though I’ve never seen photos of either the German pods or the Soviet Golem.

  • Jay K. Jeffries

    I have been following this German innovation for years and have considered a model previously. The lack of additional information precluded this effort. Would be interested in viewing what additional documentation that you hold.
    R/Jay

  • Pat Flannery

    The drawing of it on this web page is interesting in regards to what is towing it: http://www.prinzeugen.com/V2.htm
    – you would expect it to be towed by a Type IX or XXI U-boat to give it the range to get off of the US coast with all the drag of the launching pontoons, but it looks like it’s being towed by a Type VIIC medium range sub or XIVA “milch kuh” supply submarine.

  • admin

    > you would expect it to be towed by a Type IX or XXI U-boat to give it the range to get off of the US coast

    Hard to imagine why it would sail all the way to the US just to shoot a V-2 into Britain. There were very few German sub bases within 500 miles of the US.

  • admin

    Note also that the website you linked to says this:
    “… such as this Luftwaffe map of Lower Manhattan showing blast damage anticipated by a rocket borne nuclear / atomic weapon…”

    This sort of rubbish automatically means that the whole writeup is questionable, even though they got drawings from Klee & Merk. Reproducing patent absurdity is the sort of thing to be expecte from the likes of Dan Rather or Bob Arndt, and disqualifies one from the “most reliable reporter of the year” contest.

    See here:
    http://up-ship.com/blog/blog/?p=2527

  • Pat Flannery

    That’s the only place I could find mention of the Golem online.
    I’ve been digging around for more info on it, and am coming to the conclusion that it never existed, any more than the Soviet T4A winged ICBM existed (unless that was some confusion with the Burya cruise missile project).
    If Golem had existed, info about it would certainly have come out between the fall of the Soviet Union and now.
    I could see towing one launch canister around behind a U-boat, but by the time you get 3-5 behind it (descriptions vary in the number to be towed) the sub is going to be crawling along at around ten knots even if snorkeling on its diesels.
    BTW, the map of the Sanger Antipodal Bomber attacks on New York doesn’t show his theory that because of their high horizontal velocity on impact the blast area of each bomb would be egg shaped, with the small end at the impact point. I always wondered if that would really be the case if such a weapon were deployed.

  • Mike Coleman

    I have been interested in this and the proposed railroad launching system for the V-2 for years. For both there seems to be a dearth of information. I am a modeller and would love to do one of these in a diorama. There is not a 1/72 scale type XXI sub out there yet (which was the proposed tow vehicle) but there is a nice 1/72 scale type VII with schnorkel as well as a 1/72 V-2 available. That would be large enough to give decent detail to a cut away model. There are smaller scale Type XXI models and it might be interesting to do a “wolfpack” of several subs with their launchers at different stages of deployment. I mean, if you are going to do a fantasy piece why not go all the way with it? I would love to see more drawings of this thing.
    Mike

  • Andrew

    Hello,

    this drawing of Prüfstand XII looks very good. How can obtain a copy? Have you got more of this subject (Prüfstand XII)? I’m also interested in written evaluation made by Germans if such exists.
    PS I live quite close to the place where those Prüfstand XII were made 🙂

    Kind regards
    Andrew

  • MorganG

    I too am a modeler who has been interested for years in doing a cutaway model of this subject. Can you point me to further information?