[citation needed] But in 2010, the Rhaetian Railway announced that it had identified the construction of a second tunnel alongside the first as its preferred option, with one of several reasons being a relatively minor difference in cost.

In comparison to the original Albula Tunnel, the new bore is considerably larger due to newer operational and safety standards.

The Albula Tunnel is a major feature of the Rhaetian Railway (RhB), an extensive metre-gauge network in the southeast of Switzerland that was launched during 1889.

The cold, 6 °C (42.8 °F), water outflows transformed the already fractured rock into a pulpy mass, regularly clogging up the shell of the northern tunnel lead (or adit).

[7] According to industry publication Rail Engineer, the danger posed by rock falls became ever-present towards the latter half of the twentieth century.

[4] A total of 12 cross passages are to be excavated between the two tunnels, which shall enable personnel to travel between either bore, useful during emergency situations and routine maintenance activities alike.

[4] During 2010, the RHB announced that the building of a new tunnel had been identified as the optimal solution; detailed planning work commenced that same year.

[citation needed] Close cooperation between RhB and authorities is necessary, particularly due to the location being an UNESCO-recognised World Heritage Site.

[4] The larger dimensions of the tunnel enables it to accommodate walkways throughout its length, as well as facilitating ideal clearances for the OLE fixtures.

During its construction, the bore was sufficiently large and flat enough for road vehicles to directly reach the rock face, enabling conventional machinery to be brought in.

[4] Fresh air was piped up to the rock face, creating a slightly higher pressure within the tunnel to help blow out both dust and diesel fumes being emitted by the excavation activities.

Channels were also driven to handle water ingress, while both the roof and walls of the bore were stabilised via the application of wet-mix concrete.

[4] Whilst the geology surrounding the tunnel is principally granite, a 110 m (360 ft) section close to the Preda end consists of three different types of rock, known as cellular dolomite, while a 20 m (66 ft) section is largely dominated by a soft and porous type of dolomite akin to fine sand.

[4] As a result of the heavy snowfall typically present in the Swiss Alps during the winter months, which caused unavoidable accessibility disruptions to the tunnel site, all construction work was suspended between mid-December and the end of February.