Editing Auguste de Montferrand (section)

===St. Isaac's Cathedral (1816–1858)===
{{Main|Saint Isaac's Cathedral}}
[[Image:Saint Isaac's Cathedral in SPB.jpeg|thumb|200px|right|St.Isaac's]]
[[File:Model-of-St.-Isaac's-Cathedral-St.-Petersburg.jpg|thumb|200px|Design model of the Saint Isaac's Cathedral, 1818–1821, designed by Montferrand, wood, plaster, metal, oil paint, gilding, collection of St. Petersburg Academy of Arts]]
[[Image:Montferrand dome design.jpg|thumb|200px|left|Dome structure, 1838]]
[[Image:FR Petersburg, sobor Isaakiewski, in, architekt August de Montferrandt, 2013.08.02, fot. I. Nowicka (2) CORR.jpg|thumb|200px|The bust of de Montferrand inside St. Isaac's Cathedral, 2013]]
The previous St. Isaac's, laid down by [[Antonio Rinaldi (architect)|Antonio Rinaldi]] in 1768, was partially completed in 1802 by [[Vincenzo Brenna]]. In 1816, Alexander I assigned Betancourt to find the architect who could rebuild the cathedral; Betancourt pointed at Montferrand. Four original concepts, using as much of the old structure as possible, failed; the fifth was approved in February 1818.<ref>Shuĭskiĭ, ''Огюст Монферран'', p. 86.</ref> Rivalry between court architects temporarily halted the project between 1821 and 1825.<ref>Shuĭskiĭ, ''Огюст Монферран'', p. 95.</ref>

Montferrand's first decision was to use a [[shallow foundation|slab foundation]], rather than a [[deep foundation|perimeter of piles]]. The foundation work took five years. It took more than a decade to obtain the 48 granite columns for the main [[portico]]. Columns were roughly cut in [[Hamina|Fredrikshamn]], delivered by barge, and finished on site one by one, using a gigantic [[lathe]] of Montferrand's own design.<ref>Shuĭskiĭ, ''Огюст Монферран'', p. 102.</ref> The columns were raised in 1828–1830; polishing took four more years. In the same time, bricklayers completed the main walls and vaulted ceilings.

Montferrand was nearly killed in November 1837, when the crews were lifting 64-ton dome columns to their full {{convert|168|ft|m|adj=on|sp=us}} height.<ref group=nb>24 [[sazhen]] = 168 ft.</ref> Montferrand fell from the scaffolds, but nearby workers managed to catch him.<ref>Shuĭskiĭ, ''Огюст Монферран'', p. 122.</ref>

The design of St. Isaac's domes was novel. Prior to St. Isaac's, steel-frame exterior domes were coupled to masonry internal domes. Montferrand proposed an all-metal triple-dome system, where the middle conical dome carried the lightweight interior and exterior frames. This reduced dome weight from an estimated {{convert|7440|t|st|sp=us}} to {{convert|2680|t|st|sp=us}};<ref group=nb>1838 design.</ref> a further {{convert|600|t|st|sp=us}} was saved in the construction process. The dome, completed in 1841, cost two million roubles less than originally estimated.<ref>Shuĭskiĭ, ''Огюст Монферран'', p. 127.</ref>

Decorating the cathedral's interior took another 16 years. Montferrand managed artists such as [[Karl Briullov]] and his brothers, [[Peter Clodt von Jürgensburg|Peter Clodt]], and [[Ivan Vitali]], all under close inspection by the State and Academy bureaucracies. The cathedral opened on May 30, 1858—the 186th anniversary of [[Peter the Great]]'s birth.