World’s longest immersed road and rail tunnel

Denmark is set to build one of Europe’s largest infrastructure projects, the 18km-long Fehmarn Belt Fixed Link undersea tunnel to Germany. Immersed tube construction involves making tunnel segments on land and floating them out to sea, sinking and connecting them together

HOW TUNNEL WILL BE CONSTRUCTED

Fabrication: Reinforced concretesegments cast and joined in factorynear Rodbyhavn, Denmark

Launching: Tunnel element fitted with watertight bulkheads and moved to dry dock. Dock flooded with seawater

Transport: Tugs moveelement towards pre-dug trench on seabed

Immersion Pontoons attached .Water pumped into ballast tanks inside element. Element gradually lowered to seabed using pontoon suspension wires

Finishing Elements joined with watertight seals.Trench filled in. Bulkheads removed, joints between elements completed

PROJECT DETAILS

Construction: Plannedto begin in 2018. Tunneldue to open in 2026

Travel time: Seven minutes by train, about 10 minutes by road. Current ferry transit takes 45 minutes (plus waiting time to board ferry)

Cost estimate: €7 billion

CROSS SECTION THROUGH TUNNEL
General fill (sand)
Locking fill (crushed rockor gravel)
Gravel bed
Finished tunnel
Re-established seabed
Protection layer (rock)
Existing seabed
Trench
Two rail tubes
Service / escape tube
Two road tubes, each with two-lane motorway plus emergency lane 

SWEDEN
DENMARK
GERMANY
Copenhagen
Hamburg
Baltic Sea
100km
60 miles


Fehmarn Belt Fixed Link
Rodbyhavn
Lolland (Denmark)
Fehmarn Belt
Fehmarn (Germany)
15km
10 miles

Nine segments make up one tunnel element. Tunnel consists of 89 elements,each weighing over 70,000tonnes
217m
42m
Tunnel depth 40m

Source: Femern A/S