As designers of the dual two-lane Medway Immersed
Tube Tunnel - only the second of its kind to be built in the UK -
we introduced innovations in tunnel ventilation
At the forefront of ventilation system design since the 1920s,
our leading edge skills in aerodynamic and thermodynamic analysis
address the issues not only relevant to new systems, but to the
refurbishment and regeneration of existing systems in normal,
congested and emergency operations mode.
Good ventilation and aerodynamics are vital to modern tunnel design
– especially in rail and road tunnels where passenger comfort is of
paramount concern. As trains get faster and tunnels get longer,
aerodynamics and thermal effects in tunnels can be significant and
ventilation can have a profound effect on tunnel design.
Mott MacDonald’s own STEPS people movement program
is a valuable tool for optimising ventilation design and
performance From predicting tunnel flows, alleviating
pressure and monitoring temperatures to maintaining visibility and
the ambient environment of users of transportation tunnels – we
have the experience and tools necessary for developing a wide range
of sustainable design solutions.
Our sophisticated suite of computer software programmes allows us
to develop tailored solutions for each project. Simulations enable
us to produce appropriate, cost-effective ventilation system
solutions while adhering to fire and safety requirements.
Advanced aerodynamic and thermodynamic programs
We designed the ventilation and cooling systems
throughout the Channel tunnel crossing Our in-house
aerodynamics program provides transient pressure, flow velocity and
aerodynamic drag predictions for highly complex situations
involving multiple tunnels, cross passages, ventilation shafts,
underground stations and multiple train movements. Using our
in-house thermodynamic program, we are able to predict tunnel
system temperatures, detailing various heat loads and sinks as well
asheat deposition rates.
These programs, validated over the past 30 years by Mott MacDonald,
were fundamental in confirming the feasibility of the New York
Cross Harbour tunnel. This project would accommodate diesel-powered
locomotives hauling freight trains several kilometres in length,
and with no immediate ventilation shafts possible under the large
expanse of water.
Evidence of our innovative work in tunnel ventilation – our North
American company Hatch Mott MacDonald’s tunnel ventilation experts
have brought benefits for Metro North Railroad commuters using New
York’s Grand Central Terminal. Our state-of-the-art solution
relieves the high temperatures previously endured in the 15-track
lower underground trainshed. Enhanced fire safety is another
advantage of the new jet fan system designed using the latest
computer simulation and visualisation techniques.
Our ventilation expertise reduced temperatures in
the lower underground trainshed at Grand Central Terminal, New
York
