KnowraGotthard Base TunnelLinked fromLinked fromThe 4 pages that link to Gotthard Base Tunnel, each with the reason it gives.All 4Broader topic 2Compared with 2AlpsBroader topic: It carries major north–south rail traffic beneath the central Alps.Channel TunnelCompared with: It is a major rail tunnel whose challenge is mountain depth rather than a sea crossing.Seikan TunnelCompared with: It is longer overall than the Seikan Tunnel, though it runs beneath mountains rather than a strait.Tunnel boring machineBroader topic: Its construction used large TBMs alongside conventional excavation methods.