German logistics, purchase programs and war booty, reality and alternatives 1935-43 (2 Viewers)

[marathag]

One-engined Ju 52 was carrying 1000 kg over 1000 km, while being powered by unsupercharged engines. Stick an 850-900 HP supercharged radial on that A/C and there it is - a no-nonsense transport that can be cheaply purchased, that sips the fuel and that will require far less of maintenance than the 3-engined siblings. Invest some thought in replacing the light alloy parts - where possible - with steel/wood/canvas while you're at it.

But all that light alloy, and the effort to skin that craft.
Naked view of the single engine Aircruiser undergoing restoration, showing the various material used.

General characteristics

• Crew: one, pilot
• Capacity: 16 passengers
• Length: 43 ft 4 in (13.21 m)
• Wingspan: 65 ft 0 in (19.82 m)
• Height: 11 ft 6 in (3.51 m)
• Empty weight: 6,072 lb (2,754 kg)
• Gross weight: 10,000 lb (4,536 kg)
• Powerplant: 1 × Wright R-1820 Cyclone 9 9-cylinder supercharged air-cooled radial engine, 710 hp (530 kW)

Performance

• Maximum speed: 144 kn (165 mph, 266 km/h)
• Range: 608 nmi (700 mi, 1,130 km)
• Service ceiling: 22,000 ft (6,700 m)

4000 pounds of payload.
That's not bad at all

 

[tomo pauk]

4000 pounds of payload.

4000 lbs was the difference between the empty and gross weight. Actual, useful cargo that should be carried to a place 600, 800 or 1000 km away will be perhaps half of that.
The difference between the empty and gross weight of the Ju 52/1m was 4000 kg, or 8800 lbs. It was rated for 1900 (early examples) to 2200 (later examples) kg of actual cargo.

 

[Juha3]

What's your idea for logistics here? Maybe a glider tug like the Bf 109 below carrying a DFS 230?

View attachment 813117

Mistel testing

 

[marathag]

4000 lbs was the difference between the empty and gross weight. Actual, useful cargo that should be carried to a place 600, 800 or 1000 km away will be perhaps half of that.
The difference between the empty and gross weight of the Ju 52/1m was 4000 kg, or 8800 lbs. It was rated for 1900 (early examples) to 2200 (later examples) kg of actual cargo.

But this is about what you get for the desire for a single engine(710hp) transport using wood, steel tube and smaller amounts of duraluminum alloy than the Junkers Trimotor

Moving 16, vs 17 passengers of the Ju-52 over 1000km at similar speeds with much less materials needed to do so. Increasing the HP of the craft is an easy to increase the payload to a degree, if needed- as well as going to a three blade constant speed prop

 

[tomo pauk]

But this is about what you get for the desire for a single engine(710hp) transport using wood, steel tube and smaller amounts of duraluminum alloy than the Junkers Trimotor

If I have to make two aircraft to do the job of one aircraft, it is the opposite of save. It will also need more fuel and more pilots - 'things' that Germany have had more problems to procure than the light alloys. Note that my idea is that the Trimotor is phased out of production ASAP, replaced with 1-engined sibling in the production lines.
Have the companies make the next-gen transport aircraft prototypes, choose the most suitable design (that should be no worse than the Italian trimotors) for mass production. Making the equivalent of the SM.84 would've probably been a boon for the LW.

Moving 16, vs 17 passengers of the Ju-52 over 1000km at similar speeds with much less materials needed to do so. Increasing the HP of the craft is an easy to increase the payload to a degree, if needed- as well as going to a three blade constant speed prop

The 1-motor Ju 52 should also get a 850-900 HP BMW or Bramo 9-cyl engine and a better prop, not the very basic unit the 3-motors used.
Bellanca transports were good in moving people around, however the Ju 52 was much better in moving the cargo.

 

[tomo pauk]

Again blowing in my trumpet: use the captured 25mm ATG barrels to expedite the production of AA guns. A combination of:
- making the French 25mm AA guns,
- barter them with the Romanians (they are short of everything),
- make the MK 108/25 (a bit more of the propellant than the original 108 ( 33-35g?), firing the 'normal' HE shell at perhaps 650 m/s, and the M shell of ~200g at 700 m/s
...might be better than to fiddle with these ATGs in France post 1941.

Just FYI, the monthly production of the 37mm light flak was in double digits until some time of 1942. Germans reckoned that, at 100% of the usage of the production line, just 75 of the 37mm Flak 36 weapons was to be produced monthly. So having something that was not expensive, and was offering the greater range and punch than what the 20mm was doing, ought to have an appeal.

 

[marathag]

Ju-52
General characteristics

• Crew: Two
• Capacity: 17 passengers
• Length: 19 m (62 ft)
• Wingspan: 29 m (96 ft)
• Height: 5.5 m (18.2 ft)
• Wing area: 110.50 m2 (1,189.4 sq ft)
• Empty weight: 5,720 kg (12,610 lb)
• Gross weight: 9,500 kg (20,944 lb)
• Powerplant: 3 × BMW 132A-3 9-cylinder air-cooled radial piston engines, 510 kW (680 hp) each for take-off

.

Aircruiser

• Crew: one, pilot
• Capacity: 16 passengers
• Length: 43 ft 4 in (13.21 m)
• Wingspan: 65 ft 0 in (19.82 m)
• Height: 11 ft 6 in (3.51 m)
• Empty weight: 6,072 lb (2,754 kg)
• Gross weight: 10,000 lb (4,536 kg)
• Powerplant: 1 × Wright R-1820 Cyclone 9 9-cylinder supercharged air-cooled radial engine, 710 hp

if I have to make two aircraft to do the job of one aircraft, it is the opposite of save

Big picture, the two A/C can do a better job than a single Ju-52 based aircraft, you are saving.

Are still ahead of the game, as it's roughly 6000 pounds of easily and economically built aircraft with one pilot and one engine to move 16 passengers(or similar weight of cargo) 1100km while using 1/3rd the fuel Vs 12,600 pounds of aircraft with 3 little or one big engine with pilot and co-pilot moving 17 passengers 1000km, with more fuel burn, and more complex to build and repair.

same totals of aircrew to fly, very similar total airframe weight. but is moving twice the passengers with less fuel use.

But if heart is set on a twin engine transport the size if the Ju-52 and have 1000+hp motors to equip,
the Gold Standard is the Douglas DC-3, who were selling licenses to build around the globe in the 1930s to anybody,, with the Soviets, Italians and Japanese among the buyers.

General characteristics

• Crew: two
• Capacity: 21–32 passengers
• Length: 64 ft 5 in (19.7 m)
• Wingspan: 95 ft 0 in (29.0 m)
• Height: 16 ft 9 in (5.16 m) (level attitude) 23 ft 6 in
• Wing area: 987 sq ft (91.7 m2​)
• Empty weight: 16,865 lb (7,650 kg)
• Gross weight: 25,200 lb (11,431 kg) payload w/full fuel, 3,446 lb
• Powerplant: 2 × Pratt & Whitney R-1830 Twin Wasp 14-cyl. two row radial piston engine, 1,200 hp (890 kW) each

Performance

• Maximum speed: 223 kn (257 mph, 413 km/h) at 8,500 ft (2,590 m)
• Cruise speed: 183 kn (211 mph, 339 km/h)
• Stall speed: 68.0 kn (78.2 mph, 125.9 km/h)
• Range: 1,370 nmi (1,580 mi, 2,540 km) (maximum fuel, 3500 lb payload), cruise speed/range at 10,000 ft ASL, cruise fuel consumption of 94 gph at 50% power, 157kt IAS, 1,740 nm

If cannot afford to make DC-3, then twice as many Aircruisers isn't a bad tradeoff.

Only negative of the DC-3 is it's all alloy construction, being more expensive to build and repair than something like the older Aircruiser.

But yeah, stop building Junkers Ju-52, no matter what, ASAP

 

[tomo pauk]

Big picture, the two A/C can do a better job than a single Ju-52 based aircraft, you are saving.
Are still ahead of the game, as it's roughly 6000 pounds of easily and economically built aircraft with one pilot and one engine to move 16 passengers(or similar weight of cargo) 1100km while using 1/3rd the fuel Vs 12,600 pounds of aircraft with 3 little or one big engine with pilot and co-pilot moving 17 passengers 1000km, with more fuel burn, and more complex to build and repair.
same totals of aircrew to fly, very similar total airframe weight. but is moving twice the passengers with less fuel use.

Aircruiser's gross weight was 10000 lbs. Empty weight was 6070 lbs. Means that fuel + oil + cargo must not cross 3920 lbs.
1+16 people + their (very light) baggage = 17 x 200 lbs = 3400 lbs. There is some 520 lbs of weight allowance left for fuel and oil - it is going to be one short trip.
In the same time, the Ju 52/1m was carrying 700 kg of fuel (~1540 lbs) + 105 kg (~230 lbs) of oil, with difference in gross weight and empty weight of 3000 kg (7000 minus 4000), or 6600 lbs, leaving almost 4800 lbs for crew+cargo.

Making a cheaper aircraft is all good. Making it far less capable than needed is not good. I see no reason why the Aircruiser will do well with just one pilot, while the Ju 52/1m will not.

 

[Shortround6]

To really show how bad the Ju 52 was, the Douglas Sleeper Transport (DST) was issued it's certification (#607) on May 21st 1936 and began service on June 25th 1936 flying non-stop service from Chicago to New York and on Sept 18th they started non-stop from Los Angles to Chicago. Notice that both routes are taking advantage of the west to east winds over the US
However this early version of the DC-3 carried only 16 passengers but in convertible seats-berths and had sperate dressing rooms and lavatories for men and women.
The Gross weight was 24,000lbs while the empty weight was 15,750lbs. Useful load was 8250lbs and with 650 US gallons of fuel the payload was 3475lbs. (16 passengers, 3 crew, 755lbs baggage and mail.)
The plane was powered by Wright Cyclones of 930hp for take-off and max continuous power of 850hp at 5800ft in the early versions but as time went on later Cyclones were offered with greater power.
Performance for the early version was 212mph at 6800ft or 219mph at 11,500ft, Cruise speed using .75% power was 184mph at 10,000ft. Cruising range was 1250 miles using 93.6 gal per hour. Plane was offered as a "day" plane with passenger seating for 28. This many have required a less fuel to keep the gross weight the same. Lower cruise speeds extended endurance
This does explain why the DST/DC-3 rapidly dominated the world air transport market. Nothing else came close to the same capacity, speed and range for the same fuel burn.
There were planes that could hold more people, there were planes that could fly further, there were (soon) passenger planes that could fly faster. But most had some rather severe limits, the high capacity aircraft were slow, the fast ones didn't carry enough people. And measured on a passenger per mile traveled per pound of fuel burned nothing came close.

There was a huge gap between the Ju 52 and the DST/DC-3 and a lot of planes did fall in-between.
The Ju 52 did offer good short field/rough field performance and the fixed landing gear offered less maintenance. But is that enough?

 

[Shortround6]

1+16 people + their (very light) baggage = 17 x 200 lbs = 3400 lbs. There is some 520 lbs of weight allowance left for fuel and oil - it is going to be one short trip.

The 'standards' of the time were 170lbs per crew or passenger.
Yes there was often a lot of juggling that went on between all seats filled and luggage. Different airlines had different policies (polite way of saying pricing ) for baggage. Free carry on luggage may have been rare

 

[SaparotRob]

. Different airlines had different policies (polite way of saying pricing ) for baggage. Free carry on luggage may have been rare

Testify, Brother!

 

[Shortround6]

Again blowing in my trumpet: use the captured 25mm ATG barrels to expedite the production of AA guns. A combination of:
- making the French 25mm AA guns,
- barter them with the Romanians (they are short of everything),
- ..............................................................................................................................................
...might be better than to fiddle with these ATGs in France post 1941.

You are going through a lot of trouble deal with, in the real world, not a lot of actual barrels. Trying to cut them up to make AA gun barrels doesn't really save much. Light AA gun barrels were considered as consumable. They knew they would need many more barrels than actual guns. The slower firing AT guns lasted for more shots.
I don't know it the AA guns you served on carrier spare barrels on the vehicles but I think some of the US twin 40mm vehicles did. Now in WW II Chrome plating the bores for longer life did become common, assuming you had chromium. Post WW II barrels often had better steel.
The Germans shuffled many of the 25mm ATGs of to beach defenses or to training units. The troops need to learn how to hitch-up, tow, un-hitch and dig-in with something.
Crews also learn maintenance, Gun cleaning, etc.
I would note that the French 25mm ATGs did not tow well, they broke even at low speed (horse). But if you don't use the 25mm ATGs for training, what do you use?

 

[ThomasP]

FWIW

In the 1930s BOAC / Imperial Airways / British Airways seem to have used 170 lbs average passenger weight + 45 lbs baggage per passenger.

The RAF seemed to use ~220 lbs per individual ground trooper at embarking weight, and ~240 lbs per individual paratrooper at jump weight, with additional equipment carried as cargo or in parachute supply containers as needed/allowed.

 

[z42]

Germany could have designed a DC-3 clone to replace the Ju-52. There's a couple of problems though. First, the use of steel, wood and canvas construction comes at some weight penalty compared to light alloy construction. Secondly, Germany doesn't have an equivalent cheap and reliable workhorse engine like the R-1820/1830. The BMW 132 is probably the best option, however it is somewhat weaker than the 1820/1830, further compounding the first issue with the weight penalty. The Jumo 210/211 might do, but it's 3x as expensive as the 132, and further it's uncertain whether those engines would be available for a lowly transport aircraft.

Maybe scale down the DC-3 size a bit, so that two BMW 132's are enough, or then scale it up to a four engine aircraft? Given the hostility towards four engine aircraft in Germany, maybe the second isn't workable.

 

[ThomasP]

It does seem like the twin-engine transports were the way to go in WWII, at least until you get into the 'heavy' lift and/or longer range types like the Viking or York.

 

[tomo pauk]

There was a huge gap between the Ju 52 and the DST/DC-3 and a lot of planes did fall in-between.
The Ju 52 did offer good short field/rough field performance and the fixed landing gear offered less maintenance. But is that enough?

We are in agreement that the 3-engined Ju 52 was badly behind the curve in aggregate. I've suggested a few timnes earlier (and so did you IIRC) that a more capable transport would've served the Germans better. And it was feasible thing to do, be that with 2 engines, three or 4.

Reverting back to the 1-engined type (but improved a bit) frees thousands of engines for that project, while still supplying the LW with a decent transport aircraft until the force of the better transports can be had, and whose utility is still there in the 1940s.

The 'standards' of the time were 170lbs per crew or passenger.
Yes there was often a lot of juggling that went on between all seats filled and luggage. Different airlines had different policies (polite way of saying pricing ) for baggage. Free carry on luggage may have been rare

All of this points in the same direction - the Aircruiser filled with the advertised number of people will be going nowhere as a military transport.
We can recall that paratroopers also carried the chute (doh), helmets, weapons, food & water for at least a day, heavier clothing and boots. Further, the German (and not just their) paratroopers required that the heavier equipment is dropped in canisters, that puts a premium on the actual weight of the cargo that a transport A/C can carry over a few hundred of kilometers and safely return home, ie. without being left without gasoline.

Germany could have designed a DC-3 clone to replace the Ju-52. There's a couple of problems though. First, the use of steel, wood and canvas construction comes at some weight penalty compared to light alloy construction. Secondly, Germany doesn't have an equivalent cheap and reliable workhorse engine like the R-1820/1830. The BMW 132 is probably the best option, however it is somewhat weaker than the 1820/1830, further compounding the first issue with the weight penalty. The Jumo 210/211 might do, but it's 3x as expensive as the 132, and further it's uncertain whether those engines would be available for a lowly transport aircraft.

Maybe scale down the DC-3 size a bit, so that two BMW 132's are enough, or then scale it up to a four engine aircraft? Given the hostility towards four engine aircraft in Germany, maybe the second isn't workable.

Check out the SM.82.
A widebody aircraft of mixed construction, 3 engines of 950 HP (ie. the ballpark of the late 1930s BMW 132 and Bramo 323), it was capable for carrying 40 soldiers. Difference between empty and gross weight was 7300 kg as the transport; need be, a bomb load of 4000 kg was a possibility. Another thing was that, as a widebody aircraft, it was capable of carrying the oversized cargo that it will not fit on many transports of the day.

 

[tomo pauk]

You are going through a lot of trouble deal with, in the real world, not a lot of actual barrels. Trying to cut them up to make AA gun barrels doesn't really save much. Light AA gun barrels were considered as consumable. They knew they would need many more barrels than actual guns. The slower firing AT guns lasted for more shots.
I don't know it the AA guns you served on carrier spare barrels on the vehicles but I think some of the US twin 40mm vehicles did. Now in WW II Chrome plating the bores for longer life did become common, assuming you had chromium. Post WW II barrels often had better steel.

I'd like to point again that the 25mm ATGs were captured by thousands. Even if half of the barrels are earmarked as spares, there is a lot left over to work with.
The 25mm ATG was rated for a 320g shot fired with 150g of propellant. The 25mm AA ammo used about 105 g of propellant with a 250g shell. So while the AT barrel turned into the AA barrel will be firing more of them when the enemy is engaged, there is 30% less of propellant per shot, and it fires a lighter projectile.
Being a part of the 'MK 108/25', that will fire under 35g of propellant, will put even less stress to the barrel.

 

[tomo pauk]

Crews also learn maintenance, Gun cleaning, etc.
I would note that the French 25mm ATGs did not tow well, they broke even at low speed (horse). But if you don't use the 25mm ATGs for training, what do you use?

There is something like 12-14 thousands of the 37mm ATGs of German production, plus many hundreds of captured 37mm guns in the inventory, with the 5cm pak entering the service by late 1940. Add also the 47mm captured guns there.
Thus - use the 37mm guns for training.

 

[yulzari]

Check out the SM.82.
A widebody aircraft of mixed construction, 3 engines of 950 HP (ie. the ballpark of the late 1930s BMW 132 and Bramo 323), it was capable for carrying 40 soldiers. Difference between empty and gross weight was 7300 kg as the transport; need be, a bomb load of 4000 kg was a possibility. Another thing was that, as a widebody aircraft, it was capable of carrying the oversized cargo that it will not fit on many transports of the day.

The SM82 seems to cover the ground of a better Ju52 in wood and steel. If the SM79 is any guide it could come with three BMW or Bramo engines or something French or in twin engined form with Jumo 211 engines. Bigger than a Bristol Bombay and much bigger than a Ju52. Well liked by the Luftwaffe who used several. The similar, but not identical, SM75 offers all sorts of long range possibilities over undefended air space possibly including maritime reconnaissance.