Safe escape and safe access thanks to Smoke and Heat evacuation

Tunnel safety is something that every road user has to deal with, even if we look
- fortunately - under normal circumstances nothing of it. Good Smoke and Heat Removal
is vital in tunnels so that road users can seek safe refuge
and emergency services can gain safe access.

Colt International BV is one such quiet hero, providing this safety through its expertise in smoke control systems. The company has more than earned its spurs in the field of smoke control in infrastructure, supplying systems for traffic, rail and metro tunnels. We speak with Erik Peeters, Commercial Manager Service & Maintenance/Fire Safety at Colt.

A strong focus on fire safety

"Within the Colt Group, internationally, 80% of our focus is on fire safety. It will therefore not surprise you that in the Netherlands we have equipped some 85% of all metro stations with a smoke control system," Peeters explains.

"To be specific, it's about the total combination of smoke control systems. We move air through overpressure, exhaust (extraction) and thrust (displacement). You see the latter used in tunnels and parking garages."

The Netherlands differs from abroad in terms of tunneling

"Whereas abroad we encounter tunnels with two-way traffic in one tunnel tube, here the principle with two tunnel tubes is common. Each tunnel tube has one-way traffic. This is much safer for traffic. Such a tunnel tube, at a certain length, needs ventilation and we develop the right systems for that," continues Peeters.

"Such an installation is basically calculated using a PROTUVEM calculation. For a first indication that's good, but we look further. Among other things, we look.  to how the tunnel geometry sits and how much traffic goes through it. We feed all the data into a Computational
Fluid Dynamics (CFD) model and calculate everything based on the physical properties of a tunnel. It then simulates a worst-case scenario fire. The model then calculates what thrust is needed to get the smoke and heat out of the tunnel. Before the fire, everything must be smoke-free; the smoke must be blown behind the fire. To get the middle tunnel channel and the escape passage smoke-free, Colt makes an overpressure system there. That way you stop the smoke already at the escape doors," said Peeters.

Portal fans in traffic tunnel

Everything from a single source

Designs created with PROTUVEM are validated by Colt with CFD.  "From the design, we immediately create a practical interpretation of the installation based on years of experience. We can -again in-house- further elaborate these in drawings and diagrams, directly taking into account system availability, accessibility, maintainability, safety and operation, among other things. Then our people install the installation, after which a pre-test follows in CFD, using a grid with measuring points. This grid is set out in the tunnel in practice, after which the speeds are measured. That immediately provides validation."

After the fans are selected for the project, they first undergo a Factory Acceptance Test (FAT) at the factory, testing for operation, capacity and noise. After installation, a Site Acceptance Test (SAT + SIT) follows. "After this test, we can deliver the tunnel. With our way of working, the fire safety in the tunnel meets the requirements in the latest update of the Building Code in 2012," Peeters says. "We deliver the tunnel certifiable, but the inspection is done by authorized inspection agencies. Maintenance and Management we also do in-house, 4 + 8 months Management, after 12 months Maintenance. This is followed by renewal of the certificate. So Colt controls the entire process, from design to maintenance phase."