Your mission, should you choose to accept it, is to design a Tiger II analog that is lighter, more producable, and more economical for the Wehrmacht.
Maneuverability does not need to be improved as a primary design goal, but bonus points for including it as secondary benefits. Alternatively you may downrate the engine to improve fuel economy and range.
20/20 hind sight is allowed for all avenues you choose to take.
The constraints are:
Must maintain the spirit of the Tiger II's design philosophy, specifically, assuming top quality on all materials, it must be immune to standard APCBC rounds from all enemy cannons on the glacis, turret, and mantlet, so minimum of 180mm effective thickness. Bonus points for increasing effective protection over OTL. Composite armors allows, if the Germans had reasonable designs in the works.
Must use the 88mm L/71. Bonus points if you can keep the turret ring big enough to mount a 105mm L/68, or L/52 and a reliable APDS round along side it.
Must carry 55 rounds of ammunition for the main gun, and 1200 spare rounds for the machine guns (on top of the 50 round belts loaded in each machine gun you give it)
No lifting foreign designs directly. No direct copies of IS-2's or Centurions.
Project for your heavy tank may start no earlier than 1939.
Bonus points if you include a drawing, sketch, or rendering.
OTL but with with the reliability upgrades it received by 1945 and a new engine. Seriously, the KT weighs 14 tons more, who thought it was a good idea to keep the same engine?
With that freedom I could just go full ASB and use my hypothetical ideal early 20th century (i.e. pre-1960) tank design. That would involve (but not be limited to):
cast turret design close to that of the Chieftain, for lower production cost, lower materials usage, and excellent sloping armor design
instead of shape on front of commander's/gunner's side of turret, the shape would be a mirror of that on loader's side of turret- that side has better armor and more volume as well
gunner's sight on top of turret for aiming in turret-down position, to allow a field of view down to full gun depression with the modified front turret shape, the front of the turret would have to have a sloped-down section on that side identical to that in the Stillbrew armor package (this is still better than sloping the entire side of the turret down as in the OTL Chieftain)
250 mm frontal armor LOS on turret and upper hull
mantletless gun mount for greater protection and gun depression
initially 88 mm L/71, provision for L11 as OTL or another gun, designed for use with muzzle reference system and fume extractor
ranging gun
stereoscopic or coincidence rangefinder built into turret as in M47/M48/M60, as well as ideally into the commander's hatch as in Conqueror
both of these to be mounted at the same level as the gunner's sight or higher so that both can be used in turret-down position
despite the above, no cupola- just a hatch flush with turret roof for low profile and only rangefinder, periscope vision ring, and machine gun rising above that level
vision ring glass periscope blocks that can be easily replaced when damaged from within the tank
commander's machine gun that can be operated with the hatch either open or closed (like the Chieftain's or T-80UD's gun linked to the vision ring, equivalent to a remote weapon station when hatch is closed)
cast frontal hull as in Chieftain (lower glacis will need to be thickened to match Tiger II's protection), for lower production cost and lower material usage, ideally fully cast hull if possible
supine driver's position for lower hull height
driver's hatch on hull roof (or behind main glacis) with all vision periscopes built into hatch, no vision slots or hatches cut into front glacis, for ease of production (cutting into thicker armor is harder) and armor integrity
rear hull similar to a T-44/54/62/72 with slight wedge-shaped bulges in the upper hull for a larger turret ring but no full sponsons in front of or behind that (unlike the Chieftain)
transverse engine mounting as in T-44/54/62/72 to reduce length and armored volume
liquid-cooled engine for smaller size
diesel engine for greater fuel economy, operational range, and easier production of synthetic fuel
radiators built into top of engine deck as in T-44/54/62/72 to reduce the space required for large radiator air cooling ducts
fuel tanks accordingly outside the hull (not in sponsons or on sides of engine) over the tracks in cells like the T-54/62/72 separated into cells to prevent one hit from draining all of them
ammunition ready rack in turret bustle with blowout panels, and no ammunition racks in floor, to allow lower height and a turret basket
turret basket to prevent loader from having to move with turret and prevent him tripping on open ammunition boxes
suspension bolted entirely to outside of hull for less armored hull volume and lower height, specifically no torsion bars (which also saves on strategic materials used in them)
regular 2-piece large road wheels (no interleaved or overlapping suspension) using reversible wheel halves for ease of production and maintenance, wheels to use rubber-saving measures as in later Tiger I and Tiger II wheels with only inner rubber tires sandwiched between the rims and core, no large rubber-tired wheels if there is a shortage of rubber
Christie suspension mounted externally (i.e. angled springs attached to bell cranks) as in the Merkava, possibly with more angle for greater spring length as in the Cromwell or Comet, using Belleville washers as in Panzer 61/68 rather than coil springs for ease of production and lower strategic material usage
if possible hydropneumatic units would be developed, they would be used from the start or later on as drop-in replacements for the existing suspension as both would simply be bolted or welded to the outside of the hull in their entirety
tracks would be reasonably wide but not excessively wide as in the T-34 or other tanks, if necessary grousers like Winterketten or wider tracks like Ostketten could be developed and used normally
small snorkel and separate exhausts and intakes for fording (why not), but only if it does not interfere with engine cooling or production cost, if it does interfere then this element should be dropped
I would have just gone straight to perforated or Chobham armor but it's more costly to manufacture and the threat in production is more important than its advantage over cast armor in this case. Any of these can be explained in greater detail if anyone wants (I might make some efforts at images but I'm not very good).
That being said, at best Berlin survives long enough to get nuked and this is Nazi Germany after all, so the best thing to give them would be either the designs for the Maus or the A38 Valiant and make them put all their effort into building it (I'm not sure which design is "better" to use).
It's just a direct lift of a foreign design, but also it has less armor than the Tiger II and therefore doesn't meet the minimum armor requirement, it has less operational range than a Tiger II, and it has worse ergonomics. It's not a very efficient or practical design by post-WWII standards.
With that freedom I could just go full ASB and use my hypothetical ideal early 20th century (i.e. pre-1960) tank design. That would involve (but not be limited to):
cast turret design close to that of the Chieftain, for lower production cost, lower materials usage, and excellent sloping armor design
instead of shape on front of commander's/gunner's side of turret, the shape would be a mirror of that on loader's side of turret- that side has better armor and more volume as well
gunner's sight on top of turret for aiming in turret-down position, to allow a field of view down to full gun depression with the modified front turret shape, the front of the turret would have to have a sloped-down section on that side identical to that in the Stillbrew armor package (this is still better than sloping the entire side of the turret down as in the OTL Chieftain)
250 mm frontal armor LOS on turret and upper hull
mantletless gun mount for greater protection and gun depression
initially 88 mm L/71, provision for L11 as OTL or another gun, designed for use with muzzle reference system and fume extractor
ranging gun
stereoscopic or coincidence rangefinder built into turret as in M47/M48/M60, as well as ideally into the commander's hatch as in Conqueror
both of these to be mounted at the same level as the gunner's sight or higher so that both can be used in turret-down position
despite the above, no cupola- just a hatch flush with turret roof for low profile and only rangefinder, periscope vision ring, and machine gun rising above that level
vision ring glass periscope blocks that can be easily replaced when damaged from within the tank
commander's machine gun that can be operated with the hatch either open or closed (like the Chieftain's or T-80UD's gun linked to the vision ring, equivalent to a remote weapon station when hatch is closed)
cast frontal hull as in Chieftain (lower glacis will need to be thickened to match Tiger II's protection), for lower production cost and lower material usage, ideally fully cast hull if possible
supine driver's position for lower hull height
driver's hatch on hull roof (or behind main glacis) with all vision periscopes built into hatch, no vision slots or hatches cut into front glacis, for ease of production (cutting into thicker armor is harder) and armor integrity
rear hull similar to a T-44/54/62/72 with slight wedge-shaped bulges in the upper hull for a larger turret ring but no full sponsons in front of or behind that (unlike the Chieftain)
transverse engine mounting as in T-44/54/62/72 to reduce length and armored volume
liquid-cooled engine for smaller size
diesel engine for greater fuel economy, operational range, and easier production of synthetic fuel
radiators built into top of engine deck as in T-44/54/62/72 to reduce the space required for large radiator air cooling ducts
fuel tanks accordingly outside the hull (not in sponsons or on sides of engine) over the tracks in cells like the T-54/62/72 separated into cells to prevent one hit from draining all of them
ammunition ready rack in turret bustle with blowout panels, and no ammunition racks in floor, to allow lower height and a turret basket
turret basket to prevent loader from having to move with turret and prevent him tripping on open ammunition boxes
suspension bolted entirely to outside of hull for less armored hull volume and lower height, specifically no torsion bars (which also saves on strategic materials used in them)
regular 2-piece large road wheels (no interleaved or overlapping suspension) using reversible wheel halves for ease of production and maintenance, wheels to use rubber-saving measures as in later Tiger I and Tiger II wheels with only inner rubber tires sandwiched between the rims and core, no large rubber-tired wheels if there is a shortage of rubber
Christie suspension mounted externally (i.e. angled springs attached to bell cranks) as in the Merkava, possibly with more angle for greater spring length as in the Cromwell or Comet, using Belleville washers as in Panzer 61/68 rather than coil springs for ease of production and lower strategic material usage
if possible hydropneumatic units would be developed, they would be used from the start or later on as drop-in replacements for the existing suspension as both would simply be bolted or welded to the outside of the hull in their entirety
tracks would be reasonably wide but not excessively wide as in the T-34 or other tanks, if necessary grousers like Winterketten or wider tracks like Ostketten could be developed and used normally
small snorkel and separate exhausts and intakes for fording (why not), but only if it does not interfere with engine cooling or production cost, if it does interfere then this element should be dropped
I would have just gone straight to perforated or Chobham armor but it's more costly to manufacture and the threat in production is more important than its advantage over cast armor in this case. Any of these can be explained in greater detail if anyone wants (I might make some efforts at images but I'm not very good).
That being said, at best Berlin survives long enough to get nuked and this is Nazi Germany after all, so the best thing to give them would be either the designs for the Maus or the A38 Valiant and make them put all their effort into building it (I'm not sure which design is "better" to use).
It's just a direct lift of a foreign design, but also it has less armor than the Tiger II and therefore doesn't meet the minimum armor requirement, it has less operational range than a Tiger II, and it has worse ergonomics. It's not a very efficient or practical design by post-WWII standards.
Can you get major casting production of armor plate in place in Germany by 1944?
How much is all that add-on going to cost? Can Germany afford it? Can she produce it in quantity and reliably?
The L7 (I assume you mean the L7 and not the 120mm L/11) isn't what I specified. Germany actually did use 105mm L/52 guns, and was planning a 105mm L/68 upgrade for the Tiger II. Use these.
The engine, drive shaft, and torsion bar suspension are dictating the hull height, not the driver's seat. How are you going to redesign it?
Hl 230 was liquid cooled already.
What diesel design are you going with? Designing it from scratch? How long is the tooling going to take, what's diesel production in Germany like? Can you keep your tanks gassed up? Who's building it and what aren't they building instead?
Whats your power figures? How much does this beast weigh?
The 71 cal gun of 8.8cm means a lot of barrel is protruding from the turret, about 6.5 meters with the muzzle brake? A compact vehicle (= possibility for lighter weight) will also mean greater chance for the barrel to dig in the ground on an uneven terrain. So I'd go for Merkava-style tank - engine in one side of the front, driver next to the engine, gearbox in the extreme front, turret at the aft half. So we should get a compact tank, well armed & armored, lighter than the OTL Tiger III. Engine is the standard HL 230. Lighter weight should also allow for 'normal' torsion bar suspension, much like at the KV and IS tanks.
It's just a direct lift of a foreign design, but also it has less armor than the Tiger II and therefore doesn't meet the minimum armor requirement, it has less operational range than a Tiger II, and it has worse ergonomics. It's not a very efficient or practical design by post-WWII standards.
The Report on Armour Quality and Vulnerability of the Royal Tiger Ministry of Supply (1944) claims that the front plate was 30% thicker than it needed to be.
Can you get major casting production of armor plate in place in Germany by 1944?
How much is all that add-on going to cost? Can Germany afford it? Can she produce it in quantity and reliably?
The engine, drive shaft, and torsion bar suspension are dictating the hull height, not the driver's seat. How are you going to redesign it?
Hl 230 was liquid cooled already.
What diesel design are you going with? Designing it from scratch? How long is the tooling going to take, what's diesel production in Germany like? Can you keep your tanks gassed up? Who's building it and what aren't they building instead?
Based on that, the timeline is as follows:
1937: Durchbruchwagen I development started in January, Durchbruchwagen II development started in April
1938: Durchbruchwagen I and II tested in spring-autumn, VK30.01 H and VK 20 series development started along with HL116, HL190, and MB 809 engines in May-June
1939: VK30.01 P development started along with Porsche Typ 100 engine in December
1940: VK30.01 H prototype chassis built and tested in spring-summer, VK36.01 H development started along with HL174 engine in summer
1941: VK30.01 P prototype built and tested autumn, VK45.01 P and VK45.01 H development started along with HL210 and Porsche Typ 101 engines in summer, VK 20 series are redesigned as VK 30 series after Barbarossa, first MB 809 engine tested in March
1942: VK36.01 H, VK45.01 P, VK45.01 H, and VK 30 series prototypes tested, Panther and Tiger I emerge as production designs, HL210 engine and Tiger I enter production in August
1943: Panther enters production in January
So we can see that the production tanks were developed from little more than early testbeds from mid-1938. The engines were developed from scratch from mid-1938 onwards. By allowing a 1939 development start, you have allowed users to redo the entire Tiger I, Panther, and engine development except for the first 6 months, including building specialized production facilities (both the Tiger and Panther needed them), and to do it without the repeated redesigns to new specifications which probably eliminates that 6 month delay. At that time there are no sections dictated by Tiger II dimensions that would be redesigned; the Tiger II doesn't even exist yet and it would be designed from a clean sheet instead of the Tiger I. Combined with the 20/20 hindsight also allowed, it can and will result in users developing from scratch the ideal ASB tank that can be built with technology of the time.
The L7 (I assume you mean the L7 and not the 120mm L/11) isn't what I specified. Germany actually did use 105mm L/52 guns, and was planning a 105mm L/68 upgrade for the Tiger II. Use these.
Whats your power figures? How much does this beast weigh?
Since the turret is based on the Chieftain, it would indeed be capable of mounting an equivalent to the 120 mm L/11 as an upgrade, but the 105 mm L/52 or L/68 would work as an upgrade instead. Ideally they would be compatible with a muzzle reference system and fume extractor though.
Power and weight would be ideally slightly lighter than the Chieftain. The lower glacis and side armor is thicker, but turret armor is slightly more efficiently laid out and thinner, engine compartment and thus hull is shorter, and sponsons are not full length. 53 tons would probably be the target weight. Power would be ideally the same as the OTL Tiger II, about 650 hp.
I know that's kinda flippant, but its the only answer that accomplishes these things significantly. The Tiger II fulfills no role that the Germans need filled. Indeed it does nothing other than eat resources that can go into existing designs, which there already aren't enough of. So the correct solution is to just put those resources into designs that already exist, and aren't pieces of crap.
Working with some of the suggestions posted here and the OP's challenge, E-50 hull but with VK-4502 suspension and rear mounted turret and Maybach HL234 900 hp engine mid-mounted, main armament is 88mm L/71 but some sources state the E-50 turret was designed to take a 105mm gun as well.
The E-50 was estimated to weigh between 50 and 75 tons, when comparing the E-50 to the Tiger-II(68 tons), I get the impression that the E-50 is smaller and would have weighed less, how much less I can't guess, maybe between 55 to 60 tons?
So pros, lighter weight, more powerful engine, no complicated interleaved wheels and better maneuverability. Cons, bad gun depression and slow but not as slow as OTL Tiger-II.
All things considered even with the advantage of hindsight, this is the best I can do.
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