Lufthansa 1938 Trans-Atlantic competition

[Skybolt]

Lufhansa held two successive competiton for the supply of trans-atlantic airliner. First was in June 1937, a month or so after the Hindemburgh "accident" (really thje competitons terms were in preparation since at least the beginning of 1936 and the perspective probably suppliers knew this, Dornier almost surely; Goering was opposed to the airships and simply waited until aeronautical engeneering could produce aircraft capabel to rival the Zeppelins). On this competiton another topic.

In 1938 Lufthansa held another competiton, for Trans-atlantic airliners. Solid information is scant, but it seems that there were two specifications: one for a North-Atlantic airliner, with a take-off weight in the order of 140 metric tons, and one for the South-Atlantic route, with a take-off weight in the 70-ton class. Or it could be there were two classes, both able to fly the different routes. Anyway, all the companies involved answered with Flugbooten, with the exception of Focke-Wulf, which offered its Trans-Ozean. Since I've already covered the TO in another topic, I'll examine here the Flugbooten proposals. Companies that answered one or both the specifications were (AFAIK):
Dornier - 140 and 79 ton
Hamburger Flugzebau (later Blohm U. Voss) 70 ton
Heinkel 70 ton
Weseflug 140 and 70 ton

I haven't be able to find any Junkers proposal. The 1938 land based (a sort of scaled-up Ju-52 with double-deck) EFo 21 could have been a candidate, but since is known that only he FW was land-based, I'd exclude it. Efo-21 would have been in the 70-ton class. The 1939 EF-53 was a four-engines trans'atlantic airliner, a forerunner of the later EF-100, but this too wasn't officially tendered to Lufthansa. There were spare RLM Junkers assigned numbers from Ju-91 to Ju-94, not used except possibly the J-92, an experimental four-engine bomber and troop transport (probably an evolution of Ju-90?).

 

[Skybolt]

Let's strat from the 140-ton class proposals and from the lesser known.

Weserflug WFG 2238

Sources differ of the engines of this project. Some says it had 4 coupled Jumo 9-223 2500 HP each, but another source says 8 separate engine paired to single shaft driving 4 doueble contrarotating propeller, with a total installed power of 17600 HP (this means 2200 hp each, so Jumo 213 ?).
Anyway, sources agree on dimensions and take-off weight: span 70 m; lenght 41,8 m; take-off weight normal load: 125 tons (it was the featherweifìght in its class). Maximum speed 450 Km/h. At least 40 passengers in luxury accomodations, more in conventional one.
In 1939 Weserflug prepared a military version project for lond distance recon and anti-shipping warfare. For this version maximum range was indicated at 10900 km.

Weserflug offered a proposal in the 70-ton class, the WFG 2236, more on this later.

 

[Skybolt]

Dornier Do 214.

This project is well known, having been covered in popular books like Bull Gunston's Giants of the Sky.

Dornier offered its P-93 in the 140 ton class, leaving the smaller Do-216, which will be treated later, in the 70-ton class.
Engines could be of four diffrenet types, always 8 in number in a push-pull configuration: DB 606 (2600 HP), Jumo 218 (3000 hp), DB 613A (3500 HP) and DB-613-C (it was a 4000 hp coupled lin-line engine). Span was 60 m, lenght 51,60, take-off weight 145 tons. Maximum speed 490 KM/h. Passengers were 40, with a crew of 12, comprising a cook.
Dornier proposed officially its machine to Lufthansa in 1940. In the same year the RLM ordered the study of a military version, which was Dornier P-192. Work on both civil and military version continued until 1943, when RLM ordered to cancel the projects.

 

[Skybolt]

Seems that B&V didn't tendered a project in the 140-ton class, but this is controversianl. Alot have to be done in studying the unbuild projects of the Hamburg firm. Attention has been monopolized by asymmetrics and jets, but Vogt and its assistants (Amtmann in primis) were real geniuses and this shows in everything they did.
Which project B&V tendered to Lufthansa in 1939/40 is doubtul. Two possibilities exists: one is the P-80, wich Nowarra describes as a trans-atlantic plane with two floats (similar to the CANT Z 511 ?) with a span of 60 m and a take off weight of 79 tons. engine were 4 coupled Jumo 208. This seems part a line, including the P-78, a long range seaplane with two floats, 6 Jumo 208 and a take-off weight of 52 tons, and the P-79, long range seaplane with two floats, 70 m span, 75 ton at take-off a 4 doulde Jumo 206. P-80 is the civilian version of this last project.
Another possibility are the sequnce of projects from P-81 to P-86, for long range and trans'atlantic airliner with 4 Jumo 218 engines and span from 46 to 55 m. Of the P-83 is known that it could carry 32 passenger across the Atlantic.
A third possibility, on which more is known, is a machine in the P-45 - P-150 line. These were flying boats that used a rocked powered detachable float to assist the take-off The P-45 was developed in 1937, but the later P-150 seems ok for the tiume-frame (1939) It was lighter than the 70 ton presumed by Lufthansa for this class, but the method of take off probably permitted a considerable saving in weight. Besides, the P-150 was pressurized and had a cruise altitude of 8350 m. If someone has more info, please post it here.

Data for the P-150 were: span 43 m, lenght 31,5 m, wing area 185 sq/m, max speed 525 km/h, cruise speed 420 KM/h, ceiling 10000 m, range 6600-7750 km, engines 4 Jumo 223 of 1650 HP each (remember the rockets at take off...) 20 passengers plus crew. Takeoff weight 47 tons.

 

[hesham]

Let's strat from the 140-ton class proposals and from the lesser known.

Weserflug WFG 2238

Sources differ of the engines of this project. Some says it had 4 coupled Jumo 9-223 2500 HP each, but another source says 8 separate engine paired to single shaft driving 4 doueble contrarotating propeller, with a total installed power of 17600 HP (this means 2200 hp each, so Jumo 213 ?).
Anyway, sources agree on dimensions and take-off weight: span 70 m; lenght 41,8 m; take-off weight normal load: 125 tons (it was the featherweifìght in its class). Maximum speed 450 Km/h. At least 40 passengers in luxury accomodations, more in conventional one.
In 1939 Weserflug prepared a military version project for lond distance recon and anti-shipping warfare. For this version maximum range was indicated at 10900 km.

Weserflug offered a proposal in the 70-ton class, the WFG 2236, more on this later.

My dear Skybolt,


here is anther drawing to Weserflug P.2138.


http://www.flying-things.ch/air46.htm

 

[VictorXL188]

Further to the Weserflug 2138, here's a couple of illustrations of its warlike variant, the 2136. I noticed that the one on the water only seems to have four engines, which is probably the coupled set up like the 2138 GA above, albeit that these look like radials. However the right illustration shows the appearance of six engines, as does the flying example over the waterbound one. Go figure!. Both illustrations taken from http://www.flying-things.ch/air46.htm

 

[hesham]

Project

I discovered it from long time.

 

[Grey Havoc]

However the right illustration shows the appearance of six engines, as does the flying example over the waterbound one.

Long range reconnaissance vs. cargo variant?