DH Mosquito, daylight bombing offensive?

[Deleted member 1487]

I got my hands on the "Germany and the Second World War" volume on strategic bombing during WW2 and it raises an interesting What If about the DH Mosquito being fast and accurate enough to survive and hit precision industrial targets in Germany by day. Was this even possible in terms of accuracy? In terms of surviveability by day apparently the Mosquito, due to it's wooden structure and resulting low radar signature (also a function of the Germans using longer wavelength radar that couldn't pick them up well) as well as speed made it very surviveable even against the single engine fighter defenses of German at altitude. For longer range missions where the target was somewhat obvious they did suffer during daylight, but against say the Ruhr small groups of Mosquitos appear to have suffered low losses historically even by day. The Fighter-Bomber variant was even able to tangle with and win over even Fw190s:
https://en.wikipedia.org/wiki/De_Havilland_Mosquito#Fighter-bombers

The FB Mk VI proved capable of holding its own with single-engine fighter aircraft in addition to bombing. For example, on 15 January 1945 Mosquito FB Mk VIs of 143 Squadron were engaged by 30 Focke-Wulf Fw 190s from Jagdgeschwader 5: nonetheless, the Mosquitos sank an armed trawler and two merchant ships, losing five Mosquitos (two to flak)[152] but shooting down five Fw 190s.[153]

As to the bomber model:
https://en.wikipedia.org/wiki/De_Havilland_Mosquito#Bombers
https://en.wikipedia.org/wiki/De_Havilland_Mosquito#Operational_history

Post war, the RAF found that when finally applied to bombing, in terms of useful damage done, the Mosquito had proved 4.95 times cheaper than the Lancaster.[101] In April 1943, in response to "political humiliation" caused by the Mosquito, Hermann Göring ordered the formation of special Luftwaffe units (Jagdgeschwader 25, commanded by Oberstleutnant Herbert Ihlefeld and Jagdgeschwader 50, under Major Hermann Graf) to combat the Mosquito attacks, though these units, which were "little more than glorified squadrons", were not very successful against the elusive RAF aircraft.[102]

In one example of the daylight precision raids carried out by the Mosquito, on 30 January 1943, the 10th anniversary of the Nazis' seizure of power, a Mosquito attack knocked out the main Berlin broadcasting station while Commander in Chief Reichsmarschall Hermann Göring was speaking, putting his speech off the air.[103]

https://en.wikipedia.org/wiki/De_Havilland_Mosquito_operational_history#RAF_bomber_operations

The first bomber squadrons to receive the Mosquito B IV used it for several low-level daylight raids throughout the summer of 1942. On 29 August 1942, Mk IVS of 105 Squadron RAF undertook a bombing mission against Pont-à-Vendin. They were attacked by Focke-Wulf Fw 190s. The Fw 190s attacked head-on before turning to attack from the stern. The Mosquitos used their speed to outpace the 190s. On 19 September, Mosquitos attacked Berlin for the first time in daylight. Once again, when a Mosquito piloted by D.A.G George Parry was attacked by Messerschmitt Bf 109s, he was able to outrun them. One Mosquito failed to return.[7]

Could it have made a precision daylight bomber from 1943 on and done more cheaply and effectively what the USAAF was trying to do and achieve the RAF Bomber Commands mission at a fraction of the cost all around?

 

[MrP]

It's an interesting question. Could the Mossie's greater speed and lower cost make up for its smaller payload?

 

[PMN1]

Can you make enough to be effective with the manufacturing capacity there is for this type of construction?

 

[Thoresby]

It's an interesting question. Could the Mossie's greater speed and lower cost make up for its smaller payload?

Payload isn't everything. A single bomb dropped from low altitude onto the target is considerably more useful than hundreds of tons of bombs scattered over the landscape at night.

 

[Deleted member 1487]

Can you make enough to be effective with the manufacturing capacity there is for this type of construction?

If they cut back on heavy 4 engine bomber construction, absolutely. It was cheaper and easier to make, but the labor and production resources were tapped making Lancasters, Halifaxes, and Sterlings.

 

[marathag]

DH Mosquito still has two large Merlin shaped lumps, plus the spinning prop disks for radar return. Radar stealthiness of twin engined prop planes is still pretty low.

And in daytime, you get contrails.

 

[Deleted member 1487]

DH Mosquito still has two large Merlin shaped lumps, plus the spinning prop disks for radar return. Radar stealthiness of twin engined prop planes is still pretty low.

And in daytime, you get contrails.

I didn't stay it was stealth, just that the 50cm wavelength German radar coupled with their mostly wooden construction made it harder to pick them up quickly enough to intercept. I mean small groups of them bombed Berlin by day in 1943 without defenses being alerted and they did low level accurate strikes on the exact radio broadcaster transmitting a speech. I think the props on the Mosquitos were wooden BTW.

 

[Just Leo]

I think the props on the Mosquitos were wooden BTW.

I think you're mistaken, judging by the fact that wooden propellers don't bend in crash-landing photos.

 

[marathag]

I didn't stay it was stealth, just that the 50cm wavelength German radar coupled with their mostly wooden construction made it harder to pick them up quickly enough to intercept. I mean small groups of them bombed Berlin by day in 1943 without defenses being alerted and they did low level accurate strikes on the exact radio broadcaster transmitting a speech. I think the props on the Mosquitos were wooden BTW.

The USN XAF 1.5m wavelength radar was able to detect 14" shells in flight. Far faster, less radar area to reflect. I am unconvinced.

 

[Deleted member 1487]

I think you're mistaken, judging by the fact that wooden propellers don't bend in crash-landing photos.

Fair point.
Seems that the RAF did use some wooden props, but not DH:
http://www.britmodeller.com/forums/index.php?/topic/234982990-propeller-blades/

The USN XAF 1.5m wavelength radar was able to detect 14" shells in flight. Far faster, less radar area to reflect. I am unconvinced.

You got a source on that?
Besides I'm not saying that the Mosquito was invisible, just harder to detect than the average aircraft because it had a lower radar signature compared to other metal frame aircraft.
https://en.wikipedia.org/wiki/De_Havilland_Mosquito

One benefit of the wooden construction was that it presented a relatively weak signature on contemporary radar.[81]
Sweetman, Bill (1989). Stealth Bomber. Shrewsbury SY1 1JE United Kingdom: Airlife Publishing Ltd. p. 17. ISBN 9781853100970.

http://militaryhistorynow.com/2014/...-the-top-secret-history-of-stealth-warplanes/

With the advent of radar at the outset of World War Two, the race was on to design a warplane that was undetectable by the revolutionary new range-finding technology. British aircraft designers got out to an early lead with the De Havilland DH. 98 Mosquito. Introduced in 1941, the twin-engine, fighter/bomber’s airframe was constructed of radar absorbing plywood. While not specifically designed to be stealthy from the outset, the plane’s low signature as well as its top speed of nearly 600 km/h (375 mph) made it a tough target to track for Axis radar operators.

http://www.gyges.dk/Anti Mosquito.htm
I guess the combo of the small size, wood, altitude, and speed all combined to make them hard to track. Also operating in small groups helped too. The one thing that made they detectable at night was the H2S system, which gave out a rather noisy signature that made them easy to track via Naxburg passive detection.

 

[Astrodragon]

The USN XAF 1.5m wavelength radar was able to detect 14" shells in flight. Far faster, less radar area to reflect. I am unconvinced.

Not convinced about that.
The RN's 50cm gunnery radar could detect the splash of an 8" shell, but not a 6" one. The shell splash is a lot bigger than a 14" shell...

 

[King Augeas]

Some possible problems...

German reaction. Confronted with fast unarmed bombers, the Luftwaffe can form dedicate fast interceptor squadrons stripped of armour etc. Low-level raids are very vulnerable to light flak AIUI, while high-level raids meet the usual problems of inaccuracy and weather.

Target selection. Bomber Harris's disdain for "panacea targets" was well founded in the sense that many people had said "Hit this set of targets and the war will be over in six months!". Oil was the exception, but it was not known that it would be the exception beforehand. It may appear a reasonable exception with hindsight, but I daresay the same could have been said about ball-bearing factories, aircraft plants, tank factories, coal mines, reservoirs, Berlin etc. at the time.

So I don't think the Mosquito could have been used to have achieved the aims of the CBO. It's too one-dimensional and easily countered, and the problems of target selection remain. What it can do is be a more effective supplement to the heavies - a more varied mix of attacker types would have complicated Germany's defensive plans.

 

[PMN1]

If they cut back on heavy 4 engine bomber construction, absolutely. It was cheaper and easier to make, but the labor and production resources were tapped making Lancasters, Halifaxes, and Sterlings.

Do the factories making the big metal aircraft have the woodworking skills to make wooden ones?

Now if you can get the fast unarmed bomber made of metal......

 

[Deleted member 1487]

Do the factories making the big metal aircraft have the woodworking skills to make wooden ones?

Now if you can get the fast unarmed bomber made of metal......

They can be trained.

Some possible problems...

German reaction. Confronted with fast unarmed bombers, the Luftwaffe can form dedicate fast interceptor squadrons stripped of armour etc. Low-level raids are very vulnerable to light flak AIUI, while high-level raids meet the usual problems of inaccuracy and weather.

Target selection. Bomber Harris's disdain for "panacea targets" was well founded in the sense that many people had said "Hit this set of targets and the war will be over in six months!". Oil was the exception, but it was not known that it would be the exception beforehand. It may appear a reasonable exception with hindsight, but I daresay the same could have been said about ball-bearing factories, aircraft plants, tank factories, coal mines, reservoirs, Berlin etc. at the time.

So I don't think the Mosquito could have been used to have achieved the aims of the CBO. It's too one-dimensional and easily countered, and the problems of target selection remain. What it can do is be a more effective supplement to the heavies - a more varied mix of attacker types would have complicated Germany's defensive plans.

Sure Harris will be a problem, but things like Ball Bearings was a very serious blow to the German war economy, what wasn't expected was that Speer would find a ton of unreported ball bearing stockpiles within businesses that were hoarding them and kept the war effort moving until production could be brought back online. Oil was known to be such a target, which is why the US had to drag the Brits to actually act on it. The Mosquito attacks on mines in Norway caused massive damage with minor losses and effort (10 Mosquitos put a major Molybdenum mine out of production for 1 year in 1943 and caused major shortages within the German economy). Harris ironically hated other panacea targets...but had his own: entire cities. He refused to give up on that throughout the war because it was always 'just another few targets and the Germans will quit'. He just chose the wrong panacea and wouldn't admit he was wrong. Beyond that the Allies totally missed the German electrical production industry, which the USSBS report claimed was their single biggest missed chance of the war to end it years earlier.

The problem for the Germans is that the Mosquito WASN'T easily countered, they never really found a counter for it IOTL. Jets would have been the answer, but those didn't come about until after the war was lost anyway and were unreliable. Perhaps have a POD that Obsessednuker proposed in another thread: have Harris die late in 1942 and someone else take charge and shift away from cities to industry, especially as things like OBOE and H2S made that possible by night and by day the Mosquito demonstrated it had the ability to survive on it's own and knock out targets.

 

[PMN1]

They can be trained.

How long is that going to take?

Lest face it, they didn't retrain those in the three Vickers factories that were making Wellingtons and they continued making Wellingtons because they couldn't make anything else.

 

[tomo pauk]

The ability of ship-borne radars to detect their own, big shells was discovered during the Salerno invasion.
As noted above, the low-flying deep penetrating daylight raids play to the German strength, since now the thousands of light Flak barrels can contribute. Pushing Merlins to make plentty of power (needed to outpace fighters) kills range. A plus for Mosquitoes, if the production is much increased in timely manner, is that they can handily outnumber LW fighters by many-to-one. Another plus is that heavy Flak is pretty much out of game.

Now - escorted Mosquito raids, in conjunction wit USAF bombing raida...

 

[riggerrob]

Another incentive was reducing casualties compared with heavy bomber crews. Losing a Mosquito meant losing only two crew: pilot and navigator. OTOH losing a 4-engine bomber meant losing: pilot, navigator, bombardier, nose gunner, flight engineer, radio operator, mid-upper gunner, tail-gunner, etc. Casualty rates approached 25 percent of RAF heavy bomber crews .... similar to trench-fighters during WW1.

To improve accuracy, Mosquitos would need to bomb from low altitudes because everyone's bomb-sights were wildly inaccurate from high altitudes.

Finally, a Mosquito could drop 4,000 pounds of bombs compared with 14,000 pounds from a stock Lancaster or 8,000 pounds from a B-17G.

 

[Deleted member 1487]

How long is that going to take?

Lest face it, they didn't retrain those in the three Vickers factories that were making Wellingtons and they continued making Wellingtons because they couldn't make anything else.

No more than 6 months. Most people working in the aircraft industry weren't skilled labor going into it.
The Wellington stayed in production because it was still useful enough, was super cheap and easy to be made, production was already established, and there was a demand.

The ability of ship-borne radars to detect their own, big shells was discovered during the Salerno invasion.
As noted above, the low-flying deep penetrating daylight raids play to the German strength, since now the thousands of light Flak barrels can contribute. Pushing Merlins to make plentty of power (needed to outpace fighters) kills range. A plus for Mosquitoes, if the production is much increased in timely manner, is that they can handily outnumber LW fighters by many-to-one. Another plus is that heavy Flak is pretty much out of game.
.

Really? Tell me how well did that stop the US fighter sweeps/strafing runs in 1944-45 despite their being a massive increase of light FLAK in Germany compared to 1943? Mosquitos could come in high and attack that way too or descend to lower altitudes to attack. Range wasn't an issue to hit most targets of value in Germany. Economical cruise gave Mossies something like 1800-2000 miles of range without 'cookie' bombs, so having to go faster to penetrate 400 miles deep isn't a problem.

Now - escorted Mosquito raids, in conjunction wit USAF bombing raida...

Fully doable by late 1943.

Another incentive was reducing casualties compared with heavy bomber crews. Losing a Mosquito meant losing only two crew: pilot and navigator. OTOH losing a 4-engine bomber meant losing: pilot, navigator, bombardier, nose gunner, flight engineer, radio operator, mid-upper gunner, tail-gunner, etc. Casualty rates approached 25 percent of RAF heavy bomber crews .... similar to trench-fighters during WW1.

To improve accuracy, Mosquitos would need to bomb from low altitudes because everyone's bomb-sights were wildly inaccurate from high altitudes.

Finally, a Mosquito could drop 4,000 pounds of bombs compared with 14,000 pounds from a stock Lancaster or 8,000 pounds from a B-17G.

Even higher altitude raids by Mossies was able to be surprisingly accurate even at night against larger factories and oil facilities. I'm talking even at 25-30k feet. Leuna was the size of a German city center, so we know that Pathfinder Mossies could easily hit that.

 

[marathag]

Not convinced about that.
The RN's 50cm gunnery radar could detect the splash of an 8" shell, but not a 6" one. The shell splash is a lot bigger than a 14" shell...

https://www.nrl.navy.mil/media/news-releases/2013/the-fleets-first-radar-turns-75

In December 1938, the XAF radar was installed aboard USS New York (BB 34) in preparation for Fleet exercises in the Caribbean in early 1939. During the at-sea exercises, the 200 MHz XAF system successfully spotted aircraft at distances up to 48 miles and ships at 10 miles, and could even follow 14-inch shells in flight. It also detected and pinpointed destroyers making nighttime simulated torpedo attacks.

 

[Theoretical_TJ]

Re the bombsights, 617 squardron got down to 10 meter accuracy from 20,000 feet using a gyroscopic bombsight similar to the Norden.