Here's a site with information and many links to further articles about the Gothic.
Includes the timings of various performances.
http://www.musicweb-international.com/brian/sym1.htm
Sarge
Why is this called a symphony, when it's really like a sinfonietta?
Part one: 2 piccolos (1 also flute), 3 flutes (1 also alto flute), 2 oboes, oboe d’amore, cor anglais, bass oboe, Eb clarinet, 2 Bb clarinets, basset horn, bass clarinet, 3 bassoons, contrabassoon, 6 horns, Eb cornet, 4 trumpets in F, bass trumpet, 3 tenor trombones, 2 tubas, 2 sets (min 3 drums) timpani, 2 harps, organ, celesta, min 8 percussion: glockenspiel, xylophone, 2 bass drums, 3 side drums, tambourine, pair cymbals, gong, triangle; strings [say 16.16.12.10.8]
Part two:Soprano, alto, tenor, bass soloists, large children’s choir, 2 large mixed double choruses [in practice 4 large SATB choirs]
orchestra: 2 piccolos (1 also flute), 6 flutes (1 also alto flute), 6 oboes (1 also oboe d’amore, 1 also bass oboe), 2 cors anglais, 2 Eb clarinets (1 also Bb clarinet), 4 Bb clarinets, 2 basset horns, 2 bass clarinets, contrabass clarinet, 3 bassoons, 2 contrabassoons, 8 horns, 2 Eb cornets, 4 trumpets in F, bass trumpet, 3 tenor trombones, bass trombone, contrabass trombone, 2 euphoniums, 2 tubas, 2 sets (min 3 [in practice 4] drums) timpani, 2 harps, organ, celesta, min 18 percussion: glockenspiel, xylophone, 2 bass drums, 3 side drums, long drum, 2 tambourines, 6 pairs cymbals, gong, thunder machine [not thunder sheet], tubular bells, chimes, chains, 2 triangles, birdscare; strings (20.20.16.14.12)
4 off stage groups: each containing 2 horns, 2 trumpets, 2 tenor trombones, set (min 3 drums) of timpani
(in summary: 32 wind, 24 on stage brass, 24 off stage brass, 6 timpanists, 18 percussion, 4 keyboards and harps, 82 strings - total orchestra c190 players, plus adult choir of min 500 [assumes largely professionals], children’s choir of 100, 4 soloists = c800)