According to  GREAT WESTERN RAILWAY .
The Royal Cornwall Gazette Falmouth Packet, Cornish Weekly News, & General Advertiser (Truro, England), Friday, October 22, 1886; pg. 7; Issue 4343. 19th Century British Library Newspapers: Part II :

GREAT WESTERN RAILWAY

OPENING OF ANOTHER VIADUCT IN WEST CORNWALL

As is already publicly known, the Great Western Railway Company are fast replacing the old wooden bridge between Penzance and Plymouth with substantial stone viaducts built on the most approved principles.  Last year they opened the Angarrack viaduct, between Hayle, and Gwinear-road stations, which was erected at a cost of £30,000; and they have since been busy with the Guilford and Redruth viaducts, the last of which is fast approaching completion, and will be opened for traffic at the beginning of next year.  The Guilford viaduct is situate about a mile to the east of the Hayle station, and was commenced in February, 1885, under a contract entered into by Mr. Henry Stevens of Ashburton (who build the imposing structure at Angarrack), for £17,000.

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There were not so many spectators present as on the occasion of the opening of the Angarrack viaduct, but several hundred persons were in attendance, and raised hearty cheers during the proceedings.