This web page requires a JavaScript enabled browser.
OKthePK.ca
 
 


 Vol. 17 No. 5
 May, 1987

Stay Safe in 87
 


Vent Shaft Breaks Through to Tunnel


Inspectors check the ventilation shaft.
 
After 22 months of drilling and blasting, work crews broke through the bottom of a 349-metre-deep ventilation shaft in Rogers Pass, B.C., 1 Apr 1987, linking it with the Mount Macdonald tunnel.
 
The 8.5-metre-diameter shaft is the key component to a ventilation system that is designed to purge the 14.6-kilometre railway tunnel of locomotive exhaust. The system is the only one of its kind in the Western Hemisphere.
 
The ventilation system is important to the operation of the tunnel because exhaust fumes from one train must be purged quickly before the next train arrives. If the ventilation system works slowly, fewer trains will be able to use the tunnel, resulting in a capacity problem that the Rogers Pass Project was designed to solve.
 
In effect, the ventilation shaft bisects the tunnel to permit twice the train frequency that would otherwise have existed.
 
The mid-tunnel facility allows the eastern portion of the tunnel to be purged while a train is passing through the western portion.
 
It will operate this way:
 
As the train approaches the tunnel's east portal, a specially-designed portal door will open automatically while a mid-tunneldoor will remain closed. Fresh air will be forced down the eastern section of the 366-metre vent shaft and along the length of the train to cool the locomotives and force exhaust fumes out the east portal.
 
When a train reaches the middle of the tunnel, the mid-tunnel door will open and when the rear of the train has passed the middle of the tunnel, it will close. Air will then be forced along the train and exhausted up the western section of the vent shaft.
 
The power and fan systems for the ventilation system will be housed in a surface building near the top of the shaft.
 
When the project is completed, the railway will be able to run a train through the tunnel every half-hour.
 
 


 
This CP Rail News article is copyright 1987 by the Canadian Pacific Railway and is reprinted here with their permission. All photographs, logos, and trademarks are the property of the Canadian Pacific Railway Company.
 
 
http://www.okthepk.ca     Victoria British Columbia Canada