Stretch uboat

[tigercat]

Now their is a conversion set for Revell' s Mark VII uboat that stretches the hull,so you can model the D variant . Has anyone made it and if so  Do you have to stop at 1. Could you use more than 1 conversion set together.

[Joe C-P]

Well, you'd probably need more room to fit the tubes for the sea-launched V-2.

[Hobbes]

I think you'd have to stack three Type VII on top of each other to fit a vertical launching tube for a V-2 

[zenrat]

V1 launched from a ski jump built into the top of the hull might be more practical.  Store them with the wings detached in tubes either side of the conning tower.

I've got a nagging feeling I didn't just think that up.

Ah, seems I didn't.


Also
http://en.wikipedia.org/wiki/Rocket_U-boat

[Mossie]

I remember reading somewhere that the tow for the V-2 launcher would have been the Type VIIF, although I can't find it now.  IIRC, the Special Hobby VIID conversion can be used to create the VIIF, with a bit of scratching.  The main thing would be the launcher of course.  Condor do a 1/72 V-2.

[Dizzyfugu]

I's have serious doubts about a single hull V2 u-boat launch platform...  Even a normal ship would IMHO be a shaky thing.
As much as I like the basic idea, I think the outcome would be rather ridiculous. A V1 launch platform (as tested by the USA) sounds much more practical?

[PR19_Kit]

It might have been possible to carry the V-2 horizontally in the U-boat's hull and elevate it to the launch position using a marine version of the Meilerwagen (sp?) maybe?

But it would have needed some SERIOUSLY big doors in the hull top to do it, with the accompanying potential leakage problems, and they'd still have had to find some method of storing the fuel before launch. Not to mention the problem of figuring out exactly where they were before launch of course, intertial navigation not having been invented then....

[martinbayer]

There's some information on the actual submarine V-2 launch concept here: http://www.prinzeugen.com/V2.htm

Martin

[rickshaw]

Launching either the V-1 or the V-2 from a platform which is tossing around on anything other than a millpond would be fraught with difficulties.  The already inaccurate weapons would have very little chance of hitting anything they were aimed at as their primitive guidance systems were designed to only do one thing, fly them in a straight line until their fuel ran out.  So, if it was pointing in the wrong direction at the moment of launch because of an errant swell or wave that would be the direction it would go.

Rather than trying to put the V-2 into the submarine it would be better, as was proposed to have a container towed behind the submarine, which at the moment of launch flooded chambers in the stern so that it then floated upright and have a hatch in the now top (once bow) open and the rocket fire out of it.  Keeping the rocket fuelled during the crossing would be nigh impossible and of course, playing with the fuels again in a tossing sea would be fraught with danger.

The a-9 ICBM was a much better bet but even then, its accuracy was low.  You'd be lucky to hit a city, let alone any specific target in it at the ranges they were talking about.

[Captain Canada]

I haven't seen the conversion set, so can only speak from imagination, but I don't see why not. The length might get a little crazy tho unless you intend to make it deeper as well.

[zenrat]

Launching either the V-1 or the V-2 from a platform which is tossing around on anything other than a millpond would be fraught with difficulties.  The already inaccurate weapons would have very little chance of hitting anything they were aimed at as their primitive guidance systems were designed to only do one thing, fly them in a straight line until their fuel ran out.  So, if it was pointing in the wrong direction at the moment of launch because of an errant swell or wave that would be the direction it would go...

Which I guess is one reason to launch from submerged.  The wiki article says they test fired a nebelwerfer from 12m down so they were thinking in that direction.

I've just realised I have no idea if "real" sub launched ballistic missiles fire from flooded tubes or if they keep a lid on it so to speak.

[rickshaw]

Launching either the V-1 or the V-2 from a platform which is tossing around on anything other than a millpond would be fraught with difficulties.  The already inaccurate weapons would have very little chance of hitting anything they were aimed at as their primitive guidance systems were designed to only do one thing, fly them in a straight line until their fuel ran out.  So, if it was pointing in the wrong direction at the moment of launch because of an errant swell or wave that would be the direction it would go...

Which I guess is one reason to launch from submerged.  The wiki article says they test fired a nebelwerfer from 12m down so they were thinking in that direction.

I've just realised I have no idea if "real" sub launched ballistic missiles fire from flooded tubes or if they keep a lid on it so to speak.

They "keep a lid on it, so to speak".  Basically the missile is ejected using a bubble of air.  In the case of ballistic ones, they then fire their rocket still submerged and after exiting the surface, line up their inertial navigation systems with their programmed target and off they go.  Their major problem has always been knowing where they are, when they are launched.   A difference between their actual launch position and their believed launch position can potentially equate to a miss.   

So, ever since their development, there has been an effort to improve naval navigation systems to make sure the submarine's own inertial navigation systems are kept as up to date as possible, so they know their position accurately when they launch.  A succession of various electronic systems have been developed to do that, starting with bare bones inertial (updated by periodic astro-navigation sights), LORAN, Omega (and the Soviet equivalent RSDN-20), GPS.

You may be too young to remember the massive controversy and debate in Australia in the early 1970s about the Woodside Omega station in Victoria which was crucial to that system working in the SW Pacific and the Indian Oceans.

Without these external navigation aids, the submarines internal inertial navigation system is subject to increasing "drift" the longer they are submerged and don't update it, so that there will be increasing uncertainty as to their actual position on the Earth's surface.  The V-2 and V-1 launching submarines didn't have such electronic aids to help them in their navigation.  It was all dead-reckoning while submerged (and therefore inaccurate as the submarine might be subject to currents without it knowing) and when surfaced, how good an astro-nav shot the captain/navigator can make.

[PR19_Kit]

They "keep a lid on it, so to speak".  Basically the missile is ejected using a bubble of air.  In the case of ballistic ones, they then fire their rocket still submerged and after exiting the surface, line up their inertial navigation systems with their programmed target and off they go. 

Neither Polaris or Trident missiles light up their main engines until they are well clear of the water surface IIRC. They're ejected from the launch tubes effectively by a shot of steam, but enclosed in the bubble to keep the water away from them. Their emergence into the air gives them the signal to fire their engines.

At least that's what I was told when I was doing some work on the periphery ofthe things back in the 80s-90s. and it certainly looks like that when you see vids of a launch. They shoot out of the water with steam all around them, hang there in mid-air for a short while, the engines fire and off they go.

[rickshaw]

Thats interesting and quite possible.  All the film I've seen though seems to show the Polaris and/or Poseidon SLBM emerging from the water with their boosters firing.   I've seen it usually referred to as a "gas generator" rather than steam.

[zenrat]

Thanks guys.  What depth do they launch from?
I can't find a simple answer.
I did however find this website https://www.fas.org/nuke/guide/usa/slbm/d-5.htm which says "Trident II is fired by the pressure of expanding gas in the launch tube. When the missile attains sufficient distance from the submarine, the first stage motor ignites...and the boost stage begins. Within about two minutes, after the third stage motor kicks in, the missile is traveling in excess of 20,000 feet (6,096 meters) per second."

Some footage here but it doesn't add any more than you gentlemen have told me.
http://www.youtube.com/watch?v=uljVI4m5e3c