What if the V-2 was used like this?

I had such an strong response from my 1st thread on a similar topic(with the V-1), I am emboldened to another 'out there' topic.

I believe this might be a more plausible then the V-1 usage, which was a long shot gamble at best.
I place the time around July 1944, when the bombing campaign was really taking apart the German oil industry.
And this would be the use of the V-2 as an impromptu AA weapon.
Obviously, not a Hitler approved plan. But then, we know how his choices went.

The V-2 was not operational, they were having the problem of the missile exploding prematurely on re-entry.
But it was launching(mostly). I believe this was a possible use of the V-2 at that time.
V-2's are pre-positioned(like FLAK) in areas deemed likely bomber corridors.
To keep it simple, let us say a Variable Timed fuse has been developed. Simple technology for the German's at that time.
But there were German proximity fuses available, and they were used in some German SAM's.
The idea is simple, launch into a bomber stream and detonate. That's a 1 ton warhead, a lot of fuel, and flying metal.
Now the V-2 could not be aimed quickly, but it was accurate. Very accurate, it would travel through a tight aim point.

The trick is to prepare a missile for launch, and have a bomber stream conveniently overhead.
So you setup as many launch points as possible, and only launch those that happen to be well located.
Fueling time for the V-2 wasn't that long if you look at the critical items.
In practice, few missiles would have had launch opportunities.
But those few could have had spectacular results.

 

Oh, the Nazis thought of that. And it wasn't exploding on re-entry. The problem was they couldn't get the dang A-4 (V-2) off the ground without exploding. The launching was the problem, not the re-entry. They were the most dangerous units to be around on the ground, and it took hours to get them ready to fire. This too is a non-starter.

The V-2 program was the single most expensive development project of the Third Reich:[citation needed] 6,048 were built, at a cost of approximately 100,000 Reichsmarks (2,370,000 GBP(2011)) each; 3,225 were launched. They were also the only "weapon" in history to have killed more people in their construction than they delivered in use.(bold mine)

The rocket used an alcohol-based fuel, and it is estimated that over 30 tonnes of potatoes were required to enable fuel for one V2 to be distilled. In a Germany suffering the privations of war this was a serious consideration. It is also of interest that focus on the V2 as a magic bullet diverted attention from more conventional systems, reducing the numbers of bombers available to the Luftwaffe.

...When Peenemunde became impractical as a manufacturing site, production was shifted to the Kohnstein tunnel system, where 20,000 slave labourers died in horrific conditions. (the only time production of a weapon exceeded the deaths produced by the weapon on the enemy).

The first V2 launched against Britain landed in Chiswick, destroying a large part of Staveley Road, killing three and wounding 17. This rocket had been launched from The Hague, along with another that landed without causing casualties in Epping . On the same day rockets were launched against recently liberated Paris. (emphasis mine)

Goto:

The 8th of September 1944 AD, First German V2 rocket lands on London, famous dates in History

The Nazis had a much better idea "in the works", i.e. the Wasserfall SAM. A relatively simple design based on the A-4 (V-2) but used as a bomber stream interdicting idea. It also was a failure in application, not concept.

The original design had called for a 100 kg warhead, but because of accuracy concerns it was replaced with a much larger one (306 kg) based on a liquid explosive. The idea was to create a large blast area effect amidst the enemy bomber stream, which would conceivably bring down several airplanes for each missile deployed. For daytime use the operator would detonate the warhead by remote control.

Conceptual work began in 1941, and final specifications were defined on November 2, 1942. The first models were being tested in March 1943, but a major setback[citation needed] occurred in August 1943 when Dr. Walter Thiel was killed during the bombing Operation Hydra. After the first successful firing (the third prototype) on March 8, 1944,[2]:107 three Wasserfall trial launches were completed by the end of June 1944. A launch on 8 January 1944 was a failure, with the engine "fizzling" and launching the missile to only 7 km of altitude at subsonic speeds. The following February saw a successful launch which reached a speed of 770 m/s (2,800 km/h) in vertical flight.[1]:69 Thirty-five Wasserfall trial firings had been completed by the time Peenemünde was evacuated on February 17, 1945.[2]:107

(I know it is Wiki…, but still it is cross referenced)

Wasserfall - Wikipedia, the free encyclopedia

But really, only thirty five trial firings in the last months of the war? After years of "conceptual work". Another idea too few, too late to be of any use in reality.

 

Hours to prepare? Not at all, 90 minutes after the missile erection. And if you use certain time critical staging, even less.
There were failed launches in July, but many launched fine. The detonation problem had become critical at this time.
The Wasserfall was a fine concept, but too little resource to implement. That went to the V-2.
But the V-2 was the rocket that worked. Not its intended purpose, but it could have been used to launch a lot of explosive power at a point in the sky.

 

Ok, I'll give you the 90 minutes for a launch window at the end of the mobile V-2 program, but that has to be the mobile program, not a stationary one. If they are stationary, they are targets and that is the only time the weapon is vulnerable. If they have to be mobile to be "non-targets", they won't be able to be positioned for bomber stream interdiction. It is one of those "if not this, then that" problems.

The weapon has to be positioned to be effective on a bomber stream which may (or may not) pass over that area. If they are pre-positioned, they are vulnerable to attack. If they are mobile, they simply cannot get to the position needed in order to be an effective anti-bomber weapon. I am sorry, I don't see how any V-2s could be used in any more effective way than they were. And they were a total waste of resources and treasure in the final tally. Of course when your nation is drawing its last gasps, and you have expended your nation's treasure on failed systems, they have to be at least "tried".

Hitler and the Nazis nearly spent more money (RMs adjusted for inflation) on the the V-2 than America spent on the Manhattan Project, and who got more "bang for the buck" there?

 

No question this was not money well spent. But that is in retrospective. It came too late.
On the spotting of V-2's. That was something that was hard to do. As far as I understand, it never happened. No rocket was destroyed by fighter bombers during the launch prep(ever).
There were 2 time critical tasks that were the choke points on launch.
For example, you get have left a fueled and erected V-2 for some time, camouflage permitting.
The liquid oxygen and the peroxide/permanganate had a limited time span. But those could be done relatively fast.

 

Oddly enough there is one reported hit on a V-2 while it was lifting off, and .50 caliber machine gun bullets not only made the launch a failure, but destroyed the missile itself while it was still in the "lift" phase.

And one must recall that the V-2 used an alcohol and liquid oxygen fuel, not the chemical system as per the "Komet" which was the highly unstable combination of which was a mixture of 80 per cent hydrogen peroxide with oxyquinoline or phosphate (T-Stoff) and an aqueous solution of calcium permanganate (Z-Stoff). An imbalance of these fuels in the combustion chamber could cause an explosion and occasionally did. (bold mine)

Those chemicals weren't included in the A-4 (V-2) propulsion system. The alcohol was the main fuel, the liquid oxygen was the problem.

 

I am having a discussion on another board about Wasserfall and other German SAMs of late WW 2. The discussion here comes to similar conclusions:

1. You need some sort of guidance system to put the missile roughly on target. From launch to detonation on a bomber formation at 25,000 feet you are looking at the bombers moving nearly 10 miles from where they were when you launched. That doesn't account for slant range. With a slant range of say, twenty miles from the launch point you are looking at closer to 15 to 20 miles of movement. So, the V-2 will need some sort of guidance system that allows control beyond visual tracking range.

2. The Pk even with 2000 lbs of explosive remains low unless you have pretty good accuracy. You are back to needing a good guidance system.

3. The next problem is fueling and readying the missile for launch. The LOX componenet is not storable. It takes considerable time to fuel up the missile and ready it for launch. Unless you have good target information early you won't be ready to launch in time to counter the bombers.

4. The likelihood is you can only control one missile from a firing battery at a time so the number launched would be low and the Pk over all insignificant.

It is the guidance problem that holds up all SAM development even post war. Until you have a good system in place it doesn't matter what missile you are using.

 

I had read about that, in the 'too strange' category. If I recall, it was a B-24 bomber that was passing by.
I wonder if this happened as they thought. A B-24 is at 20,000 feet normally(or higher). A V-2 at that height is hauling ass. Not sure how fast, but it has to be pretty quick.
I'd tend to think it was a failed rocket that just happened to blow up, and the B-24 gunner(s) said 'yes, I hit that rocket'.

 

I missed your post, like the items you brought up.

Here's the reasoning, and a few responses to your points.

The bombers are flying in tight box formations, much needed as German fighters are still dangerous.
Breaking up the boxes with rockets was already a successful German tactic.
Planes were mounted with nebelwerfer rocket launcher to do this.
But heavy losses had reduced this tactic. Rocket tubes were large, made plane a risky mission.

The idea is not to so much shoot down bombers with V-2's, though I think that will happen.
The idea is to break up the combat boxes. And if you launch a multiple V-2 salvo, that's some heavy metal.
The Wiki states '20 seconds after launch, a V2 was out of reach'.
That should be in the 20/30,000 foot range, or it might even be a bit faster.
At a bomber speed of 250 MPH, that's about 1.4 miles travel after launch, maybe a little less.

The V-2 setup process may not be as onerous if you optimize some things.
Prep time seems to be 90 minutes after V-2 erection. Much could be done in an early prep.
The 2 time critical items seem to be the LOX and the peroxide/permanganate fill for the turbopump.
How long is that? I don't see LOX fill times, but I do see that fuel time is given as 10 minutes.
And the launch procedure allows for a 1 hour time window after the LOX fill up.
I think 1 hour is an adequate window, at least in the context of the time/need.

I'm not 100% sure what the prep time could be shaved down to.
10 minute fuel time would imply LOX fill would be at least 10 minutes.
But how much longer? Haven't seen that info yet.

 

None of that negates the need for getting the missile to actually intercept the box. Without guidance that is almost never going to happen. A simple ballistic missile won't possess the accuracy to intercept the box. Also, you need a reliable means to detonate it at the right moment. This means almost certainly a command detonation and that in turn requires accurate tracking of the missile and target.

Let's assume the V-2's average speed is 2000 mph for this example (from launch to reaching the target point) and that the bombers are moving 300 mph. This means that at 33 miles down range the V-2 has flown 1 minute. In that same time the bombers have moved 5 miles. It would be quite useless to assume that the V-2 would simply be fired vertically at a bomber formation as this would make the effective area of targetting essentially ZERO. That is, you would have to have the bombers fly directly over the launch site; hardly a realistic proposition. You also still need to be able to track the V-2 and target to get the detonation at the right point.

It might be possible but only if you are using the missile with a good slant range and not firing it simply vertically. The requirement that the bombers fly directly over the launch site is unrealistic.

 

There is a trick here that I did omit.

I think you're right this would not have been practical as a general air defense. The odds are too poor for a convenient direct over flight of bombers.

I'm thinking of 1 or maybe 2 site setups. Probably 1. And there was 1 site that had regular bomber arrivals. That would be the Leuna synthetic fuel/chemical complex.
And was an extremely critical site to the Germans. Probably the most valuable in Germany.

The closer you can pull the rockets into the proximity of the site, the greater your chances of bombers being where a predetermined rocket path would be. More rockets increase your chances. Not all rockets will be well positioned. You only fire those that are well positioned.

The V-2's were working well at this point in the sense they could push up to 20000/30000 feet. They were having their re-entry problems, so weren't usable for their intended purpose at that time.

And the fusing was the only missing part at the time. But there were proximity fuses in use on the other developmental SAM's. A radio triggered fuse might have been the best option.

 

If for mathmatical simplicity we chose a slightly slower speed for the V-2 of 1,800 mph this translates to .5 miles/sec. This implies even if you get in the box you aren't going to be staying their very long and the box is moving at just a bit under 1/10 of a mile / second. That's quite a targeting problem. For one thing you need a pretty accurate time of flight to various altitudes to even come close. Radar might give you those in test launches but I suspect there would be a fair amount of variation from one V-2 launch to the next both due to the missiles them selves and the ambiant conditions.

 

Thanks for feedback, this is interesting.
You won't be in the box long, fusing is critical. Even being in the box may be a tough shot.
But the 1,800 mph is more of the top speed. The V-2 is quoted as being supersonic around 20-25 seconds. So we're probably talking about half that speed, should be a bit less actually.
The other 'player' here is you have burned up about 1/3 of your fuel. So you should have about 4,500 pounds of the ethanol fuel mixture. And a proportionate amount of LOX.
The specific energy of TNT is 4.6 mega joules per kilogram. Ethanol seems to be around 30 mega joules per kilogram. Of course the mix is 25% water, so down rate that to 20 to be conservative. You have about double the weight of unburned fuel as warhead. Your secondary explosion is going to be very large.
Add to this about 10,000 pounds of metal for shrapnel of the V-2 body. I'm wondering how accurate you need to be.

edit - the specific energy quotes for ethanol varied, but 26.8 seems to be the 'most' correct, which 0.75 x 26.8 gives 20.1, these are rough numbers

 

Except you may not get a secondary explosion you may just get a ball of flame. Indeed that is the most likely result. The fact that it is quoted as being supersonic at 20-25 seconds may indicate how problematic this is. If we use the speed of sound at sea level = 340 m/s that is equivalant to an accelleration difference between 13.6 m/sec**2 and 17 m/sec**2 or a distance traveled of between 3,400m and 4.250m at the time it reached the speed of sound or a distance of 3,400m vs 2,720m at 20 seconds. That's if I haven't messed up the math (a = v/t and d = a*t*t/2). Note also that 3,000 m is less than 10,000 ft and it's moving at about .2 miles/sec at that point. Which suggest about .3miles/sec at 20,000 ft at which point I wouldn't expect it to be flying completely verticle either. Note also that a 15mph wind could impart as much as 440ft of horizontal movement after 20 seconds.

 

I'm going with "ball of flame" on this one. In a failed V-2 launch seen her at 44 seconds: YouTube - ‪Nazi Film Shows V-2 Rocket Test 1946/5/2‬‏ you have a large flash of flames, but there does not seem to be any evidence of a powerful explosion. After all, the launch tower aside of the crashed V-2 is still standing.

curious2,
If the V-2 is only expected to travel some 20,000 - 40,000 feet and explode, what makes you think the rocket would be fully fueled? I would think the rocket would only be partially fueled, so as to not waste precious fuel and also to cut down on the prep time.

 

What you get for your secondary blast is not obvious to me. Could be fire, could be explosion. I tend to think the vaporized oxygen would stimulate the explosive part.

Now there is one last aiming refinement here, you actually know where the bombers will be, over the target point(or very close). This is for some target areas that were hit quite repeatedly. If the bombers bomb it, they have to go over the top.

In which case you have a much reduced problem, your aim point is focused over the target. A V-2 can be aimed to this point(as I understand it). Position rockets within a 1 mile radius for simplicity.

The downside is the risk to the target from V-2's going amok. Depends on the target area to some extent. And how much the Germans willing to risk to try to turn the bomber offensive.

 

That is perfectly possible, and might have been the best way. I've left it fueled so as to have numbers from the actual rocket for a conservative case. It is also possible that the handling characteristics could change if less fuel. But I would think the low fuel scenario would eventually happen if this method was used at all.

I know what you mean about the fire ball. But in those cases you don't have a 2200 pound warhead stimulating things. I'd think the fuel would be massively vaporized. Which makes me wonder if that wouldn't be an explosion.

 

I'm still a skeptic, the cost of each one of these advanced weapons was too great to be used as a SAM. Partial fuel load or no, the best cost per unit ranged between 50,000 and 100,000 RM, and I don't think that includes the cost of the ametol, just the rocket system itself. Now, scratching off the guidance part would make it cheaper, but would including the proximity detector fusing (undeveloped) be much cheaper than the guidance they already had installed?

And to create a real "explosion" the stuff has to be contained in some way unless it is an explosive by design. Fuel igniting in open air is horrendous, and "pretty" but less concussive shock-wave producing than one would expect, especially in the altitude being discussed here.

 

It makes no sense economically. Just using what you have in a catastrophic situation.
Large scale use may not have been needed. Successful deployment in a few locations could have created quite a shock. Possible change in bombing tactics might be the best outcome.

The V-2 had an allowance for a proximity fuse for an air burst over a target. The Germans didn't manage that fusing during the war. But there was the attachment points(I believe) for a fuse. Putting a new one in there might have been not so bad. The Germans had a number of proximity fuses in use on their other SAM's. Not clear how well they worked.

The explosion from fuel is a tough one. I don't know of a case where this has happened. I.e. firing off a war head with a lot of fuel. May have happened sometime, but not sure of the results.

 

I don't see vaporization at all. I see hot pieces of shrapnel puncturing the fuel tanks immediately following detonation of the warhead, ie. before much vaporization can take place. The only vaporized fuel will be confined to the fuel tanks.

You need to vaporize the fuel first and then detonate the warhead as seen with an FAE here: YouTube - ‪BLU-96 Fuel-Air Explosive (FAE)‬‏
Of course, you have the V-2 traveling at supersonic speeds, so there is the distinct possibility that the warhead will be too far away from the cloud when it detonates.

However, if you have your heart set on fire, you could probably design an incendiary warhead similar to the Japanese "San Shiki" shells. But, even that I don't think will help this much as an effective AA weapon.