What if the V-2 was used like this?

Not sure exactly on your scenario. The way I look at is the warhead detonates, and that blast wave propagates into the mass of the rocket which is going into the blast wave. So you can look as the blast wave as a giant brake. That wave hits the fuel tank area which may have been punctured by shrapnel. But that would seem to me to be very close in time.
The warhead and the rest of the missile should be one piece, not sure if you think the warhead separates before the blast.

 

Just another thought on how this would have played out if it is was considered. As far as I know, it wasn't.
The Germans would certainly have used the least fuel that they could. This would reduce the difficult analysis of the fuel and its behavior near the warhead blast.
Rocket faster, less lag time to target. The acceleration would be high down low in the atmosphere. The V-2 shouldn't have had a problem with that per se. It was designed for that acceleration towards the end of the fuel burn.
But it would be happening in the lower atmosphere(much thicker air). Not clear to me if the outer skin/shell would remain intact with such high speeds in the thicker air.

edit - They could of course had added a larger(and heavier) explosive warhead.

 

This has been delt with to a fair extent already but I will point that the USN tried for some time to figure out how to get the remaining fuel on it's solid fuel missiles to detonate on impact and was unsuccessful in doing so reliably. Occasionally one would but not enough that it was ever considered worth counting on.

But how many target areas were hit repeatedly and how for off of directly overhead were they? They almost assurdly approached the target from slightly different angles and due to different winds probably don't cross directly overhead. Note that the calculations below show that a 15 knot wind can produce a bomb being off target by a quarter of a mile in 20 seconds. The bombs are going to take a lot longer than that to fall from 20,000 feet. Indeed I get around 170 seconds from 6,000 meters. So with even a 5 knot wind the bombers may be off a direct overhead flight my over 2 miles. Then there's the question of just what altitude they were at. There were often several boxes at different altitudes. How accurate was the German radar in tracking specific boxes?

There's also the problem of what happens if they get stafed by fighters released from escort duty or hit by TACAIR.

 

I concede I cannot give a good answer on the fuel. Ethanol vapor is explosive when mixed with air. But the situation is too complicated. I guess there may be some real world cases where a tank of ethanol was near an explosion. That may be a reasonable comparison.

There weren't too many targets being hit over and over. The big synthetic fuel plants(such as Leuna) were. A few U-boat pens were hit over and over. There weren't that many V-2's, so I'd think that situation balances out somewhat.

Having the bombers come over the target is not a guarantee, but is easier than a large target where the flight paths will be much harder to predict.

I'd look at the V-2 as being similar in role to the flak in this scenario. German radar were of the Wurzburg type(some of them). Some provided very precise information for gun laying.

On the fighter intercepts, that is something I had thought about. It would appear that the V-2 was an easy target. That does not seem to be the case. It wasn't as large as might be thought, 50 feet long and a 5 foot 5 inch cross section, not that large a difference from fighters in operation.

Actual V-2 launches were never hit by fighters, and they did try. There was 1 strange story that a bomber shot down a V-2. I'd be skeptical that happened, more like a V-2 exploded due to natural causes.

V-2's were well camouflaged, I think that stays the same. Also, I would expect decoys. Those should be cheap to make.

Lastly, how long does a fighter have? 20 seconds after launch the V-2 is in the bomber stream. 10 seconds, maybe 12 seconds after rocket start? Too fast after that to be likely.

 

That still means you won't have many at any one site which will lead to few or no hits.

But how do you interface the radar data with the V-2. If there are several boxes you have to make sure the one the radar is reporting is the one you are firing at. V-2's weren't exactly fast launches either so there's going to be some significant delay between the last radar reading and the launch.

But are they well camouglaged if they are ready for launch? and near a prime target area.

 

I think this would be a small program. Probably not going to beat back the bomber offensive, but still could be useful.
Let's say there are 6 V-2's prepped. They have assigned boxes just like the flak. The delay between firing and arriving will be longer. But still good accuracy at the aim point normally.
Perhaps one is fired based on radar data, i.e. you take your best shot. Larger warhead compensates for accuracy to some degree.
The fusing is very critical, and that has been minimally discussed. Good fusing could make a large difference. That's what could be the advantage over the flak whose fusing was of poor accuracy.
As far as camouflage, I think that is the usual netting taken down maybe 5 minutes before probable launch, Not perfect, but helpful.
Bringing down the fighters within range of light AA could be the biggest benefit.

 

The next problem is radar and command guidance. The Germans are going to experiance a huge volume of jamming from the US bombers. By late 44 at least half of the bombers in a raid will have 1 or more jammers aboard and virtually all will be dropping massive quantities of chaff (the radio operator is responsible for doing this). You could reasonably expect every guidance radar to have an 80 to 98% degredation in accuracy due to this barrage of noise, chaff and, deception jamming going on. This will make tracking difficult or impossible.

 

Measures and counter measures, that's war in a nutshell.
At this time, say mid 1944, the V-2's dumbness, i.e. its inertial guidance is something of advantage. It was like the V-1 in that respect, self contained.
The Germans actually had radars that were little bothered by chaff. I'd have to dig up the particulars on that.
Later, the V-2's had radio controlled guidance which would have been more desirable for accuracy. But counter measures are going to affect that.

 

The whole idea seems absurd to me...its trying to re-invent the wheel...this would be almost impossible to aim, even with guidance its a bad gamble. The price per shot to the damage done would be rediculously restrictive...and at the end of the day, the Germans alredy had way better anti bomber weapons...Fighters....cheaper, with great guidance, enough firepower to bring any bomber down...and the AAA already in place travels very fast, had effective aiming techniques and they still rarely hit anything...its a desperate measure like "ramming"...nice idea, fail.

 

I think you have that backwards. The early models had rudimentary radio control, ie. the Germans shut off the fuel flowing to the engine by remote control. Thus, controlling the range of the V-2. Later models used the inertial guidance, or a combination of the two.

As it was the British had setup a radio surveillance post in Ottenby, Sweden to monitor radio transmissions in the Peenemünde area for the specific reason of intercepting V-2 radio signals. Avlyssningsstationen i Ottenby - The Ottenby Listening Watch

 

Some of what you say is true. Fighters were better, but not when you have pilots with little training.
The AAA was improving, but its primary failing was the fusing. The needed accuracy wasn't there. Not enough anyways, though the best radar guns the German's had were doing well at the very end.
Again, if the fusing for the rocket is good, that is its advantage(maybe).
And not a general solution. Mostly for shock value over a short period of time. Possibly disruptive to bomber aiming. It couldn't have been a much worse use for the V-2 than its actual mission which caused little military damage.

 

That could be, but was that for the instrumented versions as part of the development? I'll check out the time line on that.

 

With the exception of a few experimental prototype millimeter wave radars they developed right before the end of the war from captured British technology everything the Germans had was badly effected by jamming and chaff. Würtzburg, the main fire control had several fixes applied to make it more resistant to chaff. The most common was Würtzlaus. They tried doppler with K-laus but the electronics of the period are sufficently indescriminate that this worked poorly. Wind-laus was another try. This allowed the operator to compensate for wind drift to zero out movement of chaff (theoretically) and remove it from the display. Problem is that wind at altitude is rarely the same as ground level...
Basically, they didn't come up with a working solution.....

 

The degree of effect of chaff is a topic in itself. There was an effect, no argument there.
Take the Leuna target as an example. Allied radar countermeasures did not affect the targeting of the AA to the point of being worthless, far from it.

And a simple calculation may illustrate why this is not as crazy as it might seem.
The V-2 weighs in at around 28,000 pounds.
The number of heavy shells that was required to bring down a bomber was in the 1000's. The numbers quoted seem to vary, but 4,500 seems to be one of the more conservative numbers.
Again being conservative, say those are 88mm which weigh in around 20 pounds a projectile.
That's 4,500 * 20 = 90,000 pounds of metal and explosive. That doesn't count the shell propellant.

 

Another small but interesting bit of information about the history of the V-2's guidance and control system.
Apparently the V-2(actually A-4 at that time) was used as the testbed for the Wasserfall's control system. Which did make sense. If you don't have a working version of the rocket, you'd use the closest thing to it.
If you've testbedded the V-2 with an AA control system, I think that's a safe bet for what would have been used.

 

Problem there is is that Wasserfall proved to be a miserable failure as a weapons system mainly because its guidance and control system was horribly unworkable.

 

That may be an over simplification in some respects. The Wasserfall was in development. That's what happens in development, failures happen.

Mostly, the Wasserfall itself was the trouble. It simply wasn't ready. Resources weren't there as the V-2 sucked those up.

There was an operational test of the V-2/Wasserfall guidance on June 13, 1944. The guidance seemed to have worked well initially. The V-2 went into a cloud and the operator was thrown off. V-2 ended up in Sweden and some of the recovered parts were eventually bartered to the Allies for some spitfires.

Interesting as far as it goes, worth more reading.

 

Wasserfall was much further developed by the Soviets post war as the R 101. They spent nearly a decade trying to get it to work only to realize that it was not going to. They had problems with the guidance system. Then problems with the aerodynamics. Then problems with the control systems and surfaces. It was just a mess. In the end they dumped the program as unworkable.

 

The Wasserfall didn't work out. Now if the Germans had put all their resources into developing a SAM, they would have probably ended up with something. I actually think the Germans canceled the Wasserfall at the very end. Not that it mattered much at that point.
I was quite surprised about the V-2 with the AA guidance test. That test seems to have performed well. The rocket flew and responded properly up to the point the line of sight was lost.
I see no other records of other test shots like this one. They may have declared success, then prepared to move on to the Wasserfall prototypes.