Nesttun–Os Line

Proposals to build a railway from Nesttun to Os were first made during the planning of the Voss Line from Bergen Municipality to Voss Municipality. Initial plans called for slightly longer route via Osøyro, Samnanger, Norheimsund, and Granvin. At the time it was required that local municipalities finance 20% of railways, and in 1874, Os Municipality was encouraged to purchase shares for NOK 8,000. This was rejected by the municipal council, and eventually the Voss Line was instead built via Dale. In 1884, a committee was established in Fana to consider the possibility of building a branch line from Nesttun to Fana. But neither the municipality nor the county were willing to give grants to the line, and, the plans were shelved in 1885. At the same time, the physician Daniel Schumann Krüger started to popularize the possibility of building a connection from Nesttun to Osøren (now Osøyro). At the time it was popular to build tracks along existing roads and use slow locomotives, and Krüger at first proposed such a solution, but later determined to support a conventional railway.

In 1884, a line from Os to Nesttun was estimated to cost NOK 885,000 plus land acquisition costs. Public meetings were held and in 1885 a committee was established. The following year, an application was sent to the state for NOK 3,000 in grants for preliminary work. It was presumed that the railway would be private, but the committee wanted to receive partial state funding. While the government favored the railway, the grant was a lower priority among the many proposed railway lines at the time. In 1888, an engineer from the state investigated the route, and recommended that the line be built via Rådal to increase the population which it would serve. In addition, Fanahammeren and Stend were regarded as transport hubs at the time. Following this, shares were issued for NOK 50,000 in the company, but this was not sufficient to finance the railway.

Instead of raising more capital, Krüger tried to reduce the cost. He proposed reducing the minimum curve radius from 100 to 50 metres (330 to 160 ft) and reduce the gauge from the 1,067 mm (3 ft 6 in) gauge used on the Voss Line to 600 mm (1 ft 11+5⁄8 in). This would allow the railway to have sharper curves and allow it to pass around any obstacles and hills, removing the need for cuttings and tunnels. Engineer Nicolay Nicolaysen Sontum started planning the cheaper railway in 1889, and he estimated the cost to NOK 500,000. After the project was marketed in the Bergen press, shipowners Fredrik Georg Gade and Johan A. Mowinckel supported it, as did major Wollert Konow (SB). An application for a concession was sent on 15 March 1890, in which Gade and Mowinckel guaranteed the necessary capital. This made Nesttun-Os the first railway in Norway to be built without state grants. The construction contract was signed with Sontum on 29 March.

The concession was granted on 2 February 1891 and had a duration of 40 years from the date the line started operation. The delay was in part because there was a debate about the gauge in the Parliament of Norway. The company opened for sales of shares on 3 March 1891. The largest owners were Gade (20%), Mowinckel (10%), Os Municipality (5%) and Krüger (2%). The municipality used a whole year's budget on the share purchases, and borrowed money to be repaid in 40 years. In addition to the share sales, the railway received free real estate from many farmers.

The railway was constructed in 750 mm (2 ft 5+1⁄2 in) narrow gauge, the smallest gauge ever built in Norway. The smallest curve radius was 50 metres (160 ft). This combination made it possible to avoid any tunnels whatsoever and the longest bridge was 8 metres (26 ft). But it also meant that all goods had to be off-loaded at Nesttun and that the railway had a maximum speed of 25 km/h (16 mph). The railway was of vast importance for the Os community, as it allowed for day trips to Bergen. The rail trip took only two hours, and was considerably faster and cheaper than travel by steam ship.

Despite a boom caused by World War I, the railway lost business to road transport, which provided faster service. On 2 September 1935, it became the first Norwegian railway to close, and most of the track was demolished the following year.