
Introduction to Pipelines and Tunnels ◾ 99
Gas
In open
atmosphere
Inside the tunnel
High throw jet from high momentum
liquid discharge
Low momentum
liquid discharge
Gas plume from low momentum emission
Turbulent momentum jet from
high momentum gas emission
Liquid
UFT
UFT
UFT
UFT
UFT
UFT
UFT
UFT
UFT
UFT
Hazmat
Hazmat
Hazmat
Hazmat
UFT
Sensor
Electro-
mechanical
systems
(a)
(b)
(c) (e)
Ground level
Above ground
level
(f)
Emission events
Underground freight transport
Drawn by: Anna Doro-on Scale: Not to scale
ES
December
UFT=underground freight transport
Below ground
level
e
(d)
Figure 3.3 Emission events of freight transportation system.