This document discusses submerged floating tunnels (SFTs), which are tubular structures that float under water and are balanced by buoyancy, weight, and anchoring cables. SFTs allow for tunnels in extremely deep water and can be very long without compromising stability. The key components of an SFT are the tube, anchoring system, and shore connections. Tubes are made of prefabricated sections that are assembled on dry dock and sunk into place. SFTs have advantages over conventional bridges and tunnels like being invisible above water and providing very low gradients for traffic. A case study describes a proposed transatlantic tunnel between North America and Europe using SFT technology.

1. SUBMERGED FLOATING TUNNEL

2. CONTENTS
 INTRODUCTION
 STRUCTURAL COMPONENTS OF SFT
 PRECASTING OF SFT
 COMPETITIVE FEATURES OF SFT
 CASE STUDY ON A SFT : TRANSATLANTIC TUNNEL
 ADVANTAGES
 CONCLUSION
 REFERENCES

3. INTRODUCTION
 Submerge Floating Tunnel(SFT) is basically a tubular
structure that floats under water, which is balanced by
it’s buoyancy, self weight and constraint forces
resulted from cable system and thus submerged at
certain depth under water.
 The bridges are fixed against excessive movements
and designed to accommodate road and rail traffic.

4. 1.Conventional bridge
2.Floating tunnel
3.Immersed tunnel
4.Underground tunnel

5. WHY A SFT
 They allow construction of a tunnel in extremely deep
water, where it is difficult to build conventional bridges
and tunnels.
 It’s structural performance is independent of length, so
that it can be very long without compromising it’s
stability and resistance.
 They would be able to deal with seismic disturbances
and weather events easily.

6. STRUCTURAL COMPONENTS OF
SFT
Submerged floating tunnel consists
of many structural components.
These components should provide
strength and stiffness against the
various forces acting under the water
surface. The three basic structural
components are:
 Tube
 Anchoring
 Shore connections

7. Tube
 It should accommodate the traffic lanes and the
equipments.
 Tube is composed of elements of length varying from
one hundred meters to half a kilometre.

8. Anchoring
 There are basically fours types of
anchoring:
 SFT with pontoons
 SFT supported on columns
 SFT with tethers to the bottom
 SFT unanchored

10. PRECASTING OF TUBE
 Huge tunnel sections are constructed on dry
dock, then dock is flooded and the panels are
transported to their respective places.

11. COMPETITIVE FEATURES
OF SFT
 Invisible
 Length only from shore to shore
 Very low gradient
 Access to underground service-
parking space at ends

12. CASE STUDY ON A SFT:
TRANSATLANTIC TUNNEL
 A Transatlantic tunnel is a
theoretical submerged floating
tunnel which would span the
Atlantic Ocean between North
America and Europe.

13. COMPONENTS OF
TRANSATLANTIC TUNNEL
Transatlantic tunnel consists of
many components. The main
components of this Tunnel are listed
below.
 Gasket/shell
 Sea anchors
 Utility conduits and service port
 Vacuum pumps
 Maglev train
 Guide ways

14. Shell Sea Anchor

15. Service Port Components of
Transatlantic Tunnel

16.  Allows construction of tunnel in extremely deep
water, where conventional bridges or tunnels are
technically difficult to build.
 Any type of cross-sectional area can be provided
since being prefabricated.
 No obstruction to navigational routes as
compared to conventional bridges since all of
the tunnel is being placed under water.
ADVANTAGES

17. CONCLUSION
 The submerged floating tunnel will set up new trends in
transportation engineering and which shows with the
advances in technology that will reduce the time required for
travelling.
 And make the transportation more effective by hiding the
traffic under water by which the beauty of landscape is
maintained and valuable land is available for other purposes.

18. THANK YOU