In his post-war memoirs, Speer explains further the character of especially the dome.
This structure, the greatest assembly hall in the world ever conceived up to that time, consisted of one vast hall that could hold between one hundred fifty and one hundred eighty thousand persons standing. In spite of Hitler’s negative attitude toward Himmler’s and Rosenberg’s mystical notions, the hall was essentially a place of worship. The idea was that over the course of centuries, by tradition and venerability, it would acquire an importance similar to that St Peter’s in Rome has for Catholic Christendom. Without some such essentially pseudoreligious background the expenditure for Hitler’s central building would have been pointless and incomprehensible.
The round interior was to have the almost inconceivable diameter of eight hundred and twenty-five feet. The huge dome was to begin its slightly parabolic curve at a height of three hundred and twenty-three feet and rise to a height of seven hundred twenty-six feet.
In a sense the Pantheon in Rome had served as our model. The Berlin dome was also to contain a round opening for light, but this opening alone would be one hundred and fifty-two feet in diameter, larger than the entire dome of the Pantheon (142 feet) and of St Peter’s (145 feet). The interior would contain sixteen times the volume of St Peter’s.
The interior appointments were to be as simple as possible. Circling an area four hundred and sixty-two feet in diameter, a three-tier gallery rose to a height of one hundred feet. A circle of one hundred rectangular marble pillars – still almost on a human scale, for they were only eighty feet high – was broken by a recess opposite the entrance. This recess was one hundred and sixty-five feet high and ninety-two feet wide, and was to be clad at the rear in gold mosaic. In front of it, on a marble pedestal forty-six feet in height, perched the hall’s single sculptural feature: a gilded German eagle with a swastika in its claws. This symbol of sovereignty might be said to be the very fountainhead of Hitler’s grand boulevard. Beneath this symbol would be the podium for the Leader of the nation; from this spot he would deliver his messages to the peoples of his future empire. I tried to give this spot suitable emphasis, but here the fatal flaw of architecture that has lost all sense of proportion was revealed. Under that vast dome Hitler dwindled to an optical zero.
From the outside the dome would have loomed against the sky like some green copper mountain, for it was to be roofed with patinated plates of copper. At its peak we planned a skylight turret one hundred and thirty-two feet high, of the lightest possible metal construction. The turret would be crowned by an eagle with a swastika.
Optically, the mass of the dome was to have been set off by a series of pillars sixty-six feet high. I thought this effect would bring things back to scale – undoubtedly a vain hope. The mountainous dome rested upon a granite edifice two hundred and forty-four feet high with sides ten hundred and forty feet long. A delicate frieze, four clustered, fluted pillars on each of the four corners, and a colonnade along the front facing the square were to dramatize the size of the enormous cube. Hitler had already decided on the subjects of these sculptures when we were preparing our first sketches of the building. One would represent Atlas bearing the vault of the heavens, the other Tellus supporting the globe of the world. The spheres representing sky and earth were to be enamel coated with constellations and continents traced in gold.
The volume of this structure amounted to almost 27.5 million cubic yards; the Capitol in Washington would have been contained many times in such a mass. These were dimensions of an inflationary sort.
Yet the hall was by no means an insane project which could in fact never be executed. . . . As early as 1939 many old buildings in the vicinity of the Reichstag were razed to make room for our Great Hall and the other buildings that were to surround the future Adolf Hitler Platz. The character of the underlying soil was studied. Detail drawings were prepared and models built. Millions of marks were spent on granite for the exterior. Nor were the purchases confined to Germany. Despite the shortage of foreign exchange, Hitler had orders placed with quarries in southern Sweden and Finland. Like all the other edifices on Hitler’s long grand boulevard, the great hall was also scheduled to be completed in eleven years, by 1950. Since the hall would take longer to build than all the rest, the ceremonial cornerstone laying was set for 1940.
Technically, there was no special problem in constructing a dome over eight hundred feet in diameter.
Source: Albert Speer, Inside the Third Reich, 1971, pp. 222–4
The project underlines an adolescent feature of Hitler’s approach to architecture: whatever he designed had to be gigantic. His boulevard had to be wider than its counterpart in Paris. In Linz he wanted to extend a stone frieze to make it the longest in Europe. The same city’s redesigned bridge had to rise 270 ft above the Danube – making it unrivalled in the world (Fest, 1973, p. 526). The Reich Chancellery was to have a corridor running from the main entrance to his study over a quarter of a mile long. Hitler wanted a visitor to feel he was ‘visiting the master of the world’ (Trevor-Roper, 1961, pp. 103–4). Even in his mountain retreat, the Berghof, he had to incorporate the largest lowerable window in existence. According to one commentator, this emphasis on scale covered up amateurish and unsatisfactory characteristics in the conception which stood behind many of the undertakings (Fest, 1973, p. 531). But what would it have been like to arrive in a capital city planned according to this way of thinking?