The Best Bomber of WWII: #4

[DerAdlerIstGelandet]

Originally Posted by Neilster

Also, your statement about jet engine fuel consumption is somewhat broad. Early gas turbines were thirsty by modern standards but they were more compact than piston engines and their associated supercharger installations, leaving extra room for fuel. All gas turbines are much more efficient in the cold, dry air at high altitude, which is where a recon aircraft spends most of its time.

Yet still burn way more fuel than piston engine aircraft. Your assumption that they were more compact is also false. Have you ever seen a Jumo 004 placed next to a DB-601? The 004 is much much bigger.

Here is some comparisons to show you that the Piston engines were not larger than the Jet engines of those day. In fact there is no way. Jet Engines are much more complex being made up of Compressors, Igniters, Combustion stages, etc...

DB-601
Bore: 150 mm (5.91 in)
Stroke: 160 mm (6.30 in)
Displacement: 33.9 L (2,070 in³)
Length: 1,722 mm (68 in)
Dry weight: 590 kg (1,320 lb)

Jumo 004
Length: 3,860 mm (152 in)
Diameter: 810 mm (32 in)
Dry weight: 719 kg (1,585 lb)

Therefore the whole compact thingie is not true. Jet engines burn more fuel as well. More fuel than any piston aircraft. As a matter of fact Jet aircraft of that time were very unefficient.

[the lancaster kicks ass]

as a bomber no one single or even a small handful of Blitzs could've done much if any damage, high level = little accuracy and low level = little range the Blitz was by no stretch of the imagination a strategic bomberand couldn't flatten cities, as for it's use as recon yes it was more succesful but little used, and yes a fair few Luftwaffe were, sticking with a plan, allowed to overfly parts of Britain to deceive the enemy with inflatable tanks and wooden aircraft and such, but of course a sprinkling of flack kept them high enough not to realise they were fake......

[plan_D]

No one ever stated the Ar-234 was a strategic bomber. The title of the thread is not "Best Strategic Bomber...". The Ar-234 was a tactical bomber that flew low and fast to attack it's target, just like the Mosquito.

Allied reports never mention anything about a jet recon plane, or anything that resembles the Ar-234 until one was shot down on it's landing pattern. It was operating over Britain until the end of the war, and was never intercepted in flight on these missions. Allied reports never mention the Ar-234 over the Ardennes either where it took part in many picture taking operations.

[evangilder]

But if all it did was perform photo-reconaissance, then how can it really be called a bomber? Yes, I know it was designed as one, but I can't recall any record of it actually dropping a bomb.

[Neilster]

Originally Posted by DerAdlerIstGelandet

Yet still burn way more fuel than piston engine aircraft.

I didn't say they didn't. I was comparing the efficiency of gas turbines at high altitude to that of gas turbines at low altitude. I didn't mention piston engines in this part of my post.

Your assumption that they were more compact is also false. Have you ever seen a Jumo 004 placed next to a DB-601? The 004 is much much bigger.

Here is some comparisons to show you that the Piston engines were not larger than the Jet engines of those day. In fact there is no way. Jet Engines are much more complex being made up of Compressors, Igniters, Combustion stages, etc...

DB-601
Bore: 150 mm (5.91 in)
Stroke: 160 mm (6.30 in)
Displacement: 33.9 L (2,070 in³)
Length: 1,722 mm (68 in)
Dry weight: 590 kg (1,320 lb)

Jumo 004
Length: 3,860 mm (152 in)
Diameter: 810 mm (32 in)
Dry weight: 719 kg (1,585 lb)

A fair comparison would be the DB 605 which is about 2300 mm long. Also, the jet is internally cooled. You haven't considered all the radiators, pipes and pumps associated with water and oil cooling in the piston engine. They significantly add to the volume to be considered. Additionally, the jet's smaller frontal area is the really important figure. As far as compactness goes, this is the most important consideration in high speed flight. Add to that that the jet produces considerably more power in it's normal flight regime, improving it's specific power output in relation to weight and volume.

Hence an Me 262 can have 2 engines in a fighter sized aircraft by placing them under the wings, freeing up the fuselage for extra fuel. Same goes for the Gloster Meteor. This is what I was on about. "Compact" was my shorthand for all of the above.

As for complexity, the gas turbine is conceptually a very simple engine. The early, single-spool turbojets were especially basic. The 004 (to use an example) was actually pretty complicated for it's day as it's an axial flow design that required fancy cooling due to it's lack of high temperature materials. Most jets of the period were centrifugal designs which look like child's play compared to the piston engine behemoths they replaced.

The difficulty in developing jet engines was to get the materials to handle the temperatures required, perfect combustor design and get the efficiencies high enough, not the inherent complexity of the designs.

For comparison, the DB 605 has zillions of moving parts, two cooling systems, a methanol-water injection system and a supercharger that is basically a centrifugal jet engine's compressor anyway. It's massively complicated.

I know a few things about this topic as I'm a piston and gas turbine engine technician.

...Jet engines burn more fuel as well. More fuel than any piston aircraft.

I never claimed they didn't and you have to be careful anyway because the Froude efficiency of a turbojet increases with velocity (until the hypersonic regime) whereas propeller efficiencies decrease exponentially as they approach their maximum theoretical velocity. At low speeds, yes, a piston engine will always be more efficient. I mentioned the high fuel consumption of the early turbojets in my post and the AR 234 carried a large amount of fuel in its fuselage to counter this.

As a matter of fact Jet aircraft of that time were very unefficient.

I guess you mean inefficient. I've already covered this above but the bottom line is if you want to go faster than about 530mph, you need a jet. In 1944/45 jets were especially good in high altitude combat and were very fast at low level. For an interceptor these are vital qualities. Even the Meteor 1, who's figures don't look too flash on paper, was reported to be far superior to contemporary Spitfires in mock, high altitude dogfights. A P-51 might have had longer range but it would have been dead against a P-80 Shooting Star. It all depends what you mean by efficient.

Cheers, Neilster

[Neilster]

Originally Posted by evangilder

But if all it did was perform photo-reconaissance, then how can it really be called a bomber? Yes, I know it was designed as one, but I can't recall any record of it actually dropping a bomb.

This is from The Arado Ar-234

Bomber sorties did not take place until Christmas Eve, when nine Ar-234Bs, each carrying a single 500 kilogram (1,100 pound) bomb, took off from a German airbase single file to attack Liege in Belgium, in support of the Wehrmacht's ground offensive then underway in the Ardennes. Such attacks continued until the weather became too nasty in early January to allow operations to be safely continued.

An inventory of Ar-234s at that time indicated 17 of them in service, with 12 configured as bombers and 5 as photo-reconnaissance machines. This quantity was surprisingly small, since 148 had been delivered to the Luftwaffe by the end of 1944. The small number of the aircraft in service was almost certainly due to the disruptions caused by Allied air attacks on German industrial and military infrastructure.

The continuous, harrassing presence of Allied airpower made operations increasingly risky. When 18 Ar-234s were relocated to a new airfield in early January 1945 and came in to land, they were bounced by Spitfires who shot down three of them and damaged two others, killing two German pilots. Nonetheless, as the weather improved again, Ar-234s performed as many sorties as they were able, attacking targets in the Low Countries and mounting a large number of attacks in the defense of Aachen, Germany, on 21 February 1945.

Cheers, Neilster

[plan_D]

"But if all it did was perform photo-reconaissance, then how can it really be called a bomber? Yes, I know it was designed as one, but I can't recall any record of it actually dropping a bomb."

The sole operater of the Ar 234B-2 bomber was KG 76. On 18 December, 1944, the 9. Staffel was transferred to Munster-Handorf. It performed the worlds first jet bomber raid on 24 December when nine Ar-234B-2s attacked the rail yards at Liége. Each armed with a single SC 500 (1,100 lb) bomb the Arado bombers all attacked, and reported success without loss. Only minor damage occured to one Ar 234 when it's undercarriage failed on landing.

9./KG 76 continued raiding Allied positions in Belgium throughout early 1945. Six Ar 234s attacked Gilze-Rijen during the famous attacks on 1 January, 1945, by the Luftwaffe against the Allied airfields. Other attacks were mounted on Antwerp, Liége and Bastogne.
In February III Gruppe was declared operational after full conversion to the Ar 234B-2 bomber. They performed no more operations until March, when the US captured the bridge at Remagen. III./KG 76 were sent to destroy it, attacking five times in one week, losing five planes in the process. The bridge was eventually collapsed from the repeated attacks.

[syscom3]

Originally Posted by plan_D

[i]......Each armed with a single SC 500 (1,100 lb) bomb the Arado bombers all attacked, .....

Nine jet bombers carrying nine bombs total.

Not much of a payload to be considered usefull, is it.

[red admiral]

THE GREAT PLANES Community - Lancasters, Halifaxes and Lancastrians

You might be interested in this discussion of jet engines on Lancasters/Lancastrians. It addresses the fuel issue of the early jets.

[Henk]

Any answer on my Question about the Junkers 390 bomber?

Here is a pic of a Arado 234 dropping its load. Great plane the Arado 234.



Pretty impressive.

[plan_D]

Very useful, syscom, as they destroyed the rail yards. The Ar 234 was a tactical bomber, and unless you're calling tactical bombers useless, the load of nine planes carrying one 1,100 lbs bomb each to hit a target with precision is very useful. Or are you losing the braincells that grasp there's more than one type of bomber that isn't a strategic bomber?

[syscom3]

Originally Posted by plan_D

.....Or are you losing the braincells....

Just keep thinking that way, bucko......

I'd take a mosquito or a Lanc over a -234 any day.

[plan_D]

The Lancaster is not a tactical bomber, syscom. It is not in the same catergory as the Ar 234. The Ar 234 performed tactical missions where nine planes each carrying 1,100 lbs of bombs is very useful.

I notice you have quickly steered away from your claim. And have not admitted your mistake.

[syscom3]

SBD Dauntless's sank a "ton" of ships.

That made it superior to the -234.

B25's and B26's, Beaufighters and Mosquito's carried a far heavier payload and accomplished far more.

That made it superior to the -234.

A20's were the single best light attack bomber of the war and it accomplished far more than the -234 did.

That made it superior to the -234.


And youre claiming that nine -234's each carrying a single 1000 lbs bomb, attacking an undefended railyard is proof positive its the greatest tactical bomber of all?

[FLYBOYJ]

Originally Posted by syscom3

SBD Dauntless's sank a "ton" of ships.

That made it superior to the -234.

B25's and B26's, Beaufighters and Mosquito's carried a far heavier payload and accomplished far more.

That made it superior to the -234.

A20's were the single best light attack bomber of the war and it accomplished far more than the -234 did.

That made it superior to the -234.


And youre claiming that nine -234's each carrying a single 1000 lbs bomb, attacking an undefended railyard is proof positive its the greatest tactical bomber of all?

If you want to speak in terms of operational records and accomplishments, you are correct, all the aircraft mentioned are miles a head....

If you want to speak in terms of advancement, innovations and production achievements, the -234 is superior to all of them.

And one of those "what ifs." If Germany possessed 4000 of these in late 1943 things might of been a little different!!!

What if?!?