Closed and backfilled coal shaft of the Anina mine, sunk from 1862, reaching 650 metres depth; now sealed after final closure in 2006–2007.
Puțul 2 Anina, officially known as Puțul II „Gustav", was a vertical coal extraction shaft forming part of the Mina Anina complex in Steierdorf-Anina, Caraș-Severin County, Romania. Sinking of the shaft began in October 1862 at an elevation of +567.415 m, and it was named after Baron Gustav von Berg, administrator of the mines at Steierdorf-Anina from 1856 to 1860. The shaft reached a final depth of 650 metres to horizon 5 and served as a principal hoisting shaft for the mine, connected underground to Puțul I. It was equipped with a series of winding machines, culminating in a distinctive flat-rope winding machine — the only one of its kind in Romania — installed in 1912.
The shaft also hosted, from 1977, a telegrisometric methane monitoring centre. Following the decision to close the Anina mines, Puțul II Gustav was shut on 29 December 2006 and its shaft was backfilled, completing on 11 May 2007. The shaft compound is not listed as a heritage monument; the heritage focus for the Anina mine complex rests on the Puțul I site.
The shaft known as Puțul II „Gustav" was sunk at a surface elevation of +567.415 metres. Sinking work began in October 1862. The shaft was named, in keeping with the custom of the time, after Baron Gustav von Berg, who served as administrator of the mines at Steierdorf-Anina between 1856 and 1860. The site is located in the Steierdorf district of the modern town of Anina, approximately 1.5 kilometres south of the main Anina urban centre where Puțul I is situated.
The first winding machine used during sinking was a 16-horsepower locomotive-type steam engine (locomobil). A second winding machine was manufactured in 1871 by the firm Breitfeld & Evans of Prague; it was a steam-powered machine with two cylinders producing 60 hp. This was later replaced by a Ganz-type electric winding machine manufactured in 1907, rated at 200 kW, with a maximum hoisting speed of 10 m/s. The Ganz machine was commissioned on 29 July 1912, used flat extraction cables (105 × 15 mm), had a maximum hoisting depth of 650 metres, and was equipped with two cages each with one deck capable of carrying two one-cubic-metre wagons per deck. This flat-rope winding machine was unique in Romania: it was the only winding machine in the country operating with flat extraction cables.
The shaft reached its final depth of 650 metres, extending to underground horizon 5, and was connected underground to Puțul I, forming part of an integrated extraction and haulage system for the mine. On 29 September 1977, a telegrisometric centre GTT 60.40.U was commissioned within the Puțul II Gustav compound. This installation provided automated remote measurement of methane concentration across 40 sensor points, serving as an important safety system for the entire mine.
Following the decision to close the Anina mines after the fatal explosion of January 2006 and the subsequent permanent cessation of mining on 30 December 2006, Puțul II Gustav was formally closed. On 29 December 2006, at 18:00, the dam at underground horizon V (at the elevation of -68.50 m) was closed, and at 22:00, work began on closing the dam at horizon VI — the last underground connection with Puțul I. Backfilling (rambleere) of the shaft was completed on 11 May 2007.
Unlike the Puțul I complex, which was listed as a national heritage monument of Class A and is undergoing restoration for museum use, the Puțul II Gustav compound has not been identified in sources as a listed heritage monument or as part of the planned mining museum development.