In twin transportation tunnels, cross passages allow people to move from one tunnel to the other in the event of an emergency and are a critical safety feature when tunnels are operational.

Cross passages are spaced along the tunnel route to comply with regulatory requirements for emergency evacuation and fire-fighting. Typically cross passages are spaced every 100 to 500m.

There are a range of excavation methods used to construct cross passages. The reduced diameter, compared to the main tunnel and short length mean they are commonly constructed without the use of a TBM and are excavated by hand mining or mechanised excavation using small backactors or roadheaders.

Management of dust during cross passage construction is critical. The use of dust collectors (dedusters) is widely recognised as the most effective method of dust control within these confined environments.

Small mobile units can be easily positioned at the end of the cross passage or in the adjacent tunnel with ducting erected to the dust source. This stops dust travelling along the length to the tunnel reducing the impact and pressure on the main tunnel ventilation system and other tunnel workers.

Grydale designed the JMS-10-MEC-XP (10m3/s, Mobile, Electric, Castor) deduster to manage dust during cross passage construction at Melbourne Metro. These units are now being used on Westgate Tunnel in Australia and will shortly be operational on the HS2 project, in the UK, along with JMS-6-MES (6m3/s, Mobile, Electric, Skid) dedusters for cross passage and portal construction.

The small footprint of these units and mobility make them perfect for dust control during cross passage construction. The use of a Variable Speed Drive also makes the units energy efficient with units only using power required to meet the required air volume while still achieving a filtration efficiency of 99.99% at 0.067 micron meeting the most stringent dust control regulations worldwide.

These units are also suited to other dust control applications such as on abrasive blasting project and mining operations.

We have units available for short – long term rent as well as stock for immediate purchase in Australia, UK and North America.

For more information please contact us for more information –

JMS-6-MES-XP Mobile Electric Skid Deduster
JMS-10-MES-XP Mobile Electric Skid Deduster