Thursday, October 22, 2009

DOTT plans affect west side residents (ii): Tunnel entrance

 The new LRT  LeBreton Station is to be located roughly where the current transitway station is at Booth. The entrance to the tunnel portion of the new LRT service under the downtown core will be immediately east of the station. Its location and design is in accordance with the Escarpment Plan that outlines how the adjacent lands are to be developed.

During the tunnel construction period of 2-3 years, tunnel boring machines will eat their way through the limestone bedrock six to ten stories down under the street level of the core. All this chewed up rock has to come out of the 3km tunnel somewhere, and that somewhere is the entrance on LeBreton Flats. Running 24 hours a day, the boring machines themselves will be quiet and unobtrusive. But the tailings -- the chewed up rock removed to make the tunnel -- will be dragged out on mine cars 24 h/day and then lifted up and the rock contents dumped into dump trucks, that will rumble off at all hours of the day and night.

The tailings may be trucked to a site on LeBreton Flats to be piled up and stored, and later ground up to make construction gravel and for other uses in constructing the LRT system (a lot of fill, for example, will be required for a lengthy embankment at Hurdman). The contractor may install gravel crushers on the Flats to grind the rock. A similar setup was installed years ago during the transitway construction and the dust fall on the residents was noticeable and unplesant. The contractor may even install a temporary cement plan on site to make concrete to construct the stations and access shafts.

Residents of the Dalhousie area between Bronson and Bayview have seen the "land take" of much smaller projects. The high pressure water pipeline constructed over the last 3 years saw large areas temporarily fenced off to store equipment, supplies, and dirt. Similarly, the sewer regulator chamber currently being constructed at the intersection of Old Wellington and Booth has required large fenced off areas, road diversions, and conversion of space for temporary bus turning loops. The tunnel construction impacts for will for much longer time period, and involve much larger quantities of materials and crews. Imagine a snow-dump type operation running 365/24/7 !!

Planners for the LRT are aware that noise mitigation features will be required. It will be up to the community to demand sound and dust attenuation. Possibly we can ensure that some of the features are permanet, eg improved landscaping along Albert.


  1. Did they actually say they were going to transfer the "tailings" (I'd call it spoil since tailings are what results after ores are extracted from rock) from, well, mine cars (which have to be on rails) to trucks? I don't suppose it occurred to them to just leave the spoil in rail cars and pull them out by train along the O-Train line at night by first building a spur line roughly along the Transitway? I realize there will be some noise from hauling out cars by train at night, but it would be a single trip - in with empties, out with loadeds. If the train creeps along at just a few miles per hour (at least until it gets to the cutting near Gladstone) there wouldn't be too much noise and the lack of any grade crossings (assuming the Booth Street bridge is built with the first spoil to come out) means there would be no train whistles to wake people up.

  2. To use rail cars to pull stuff out of the tunnel and then along the OTrain makes sense if the destination of the stuff is along the rail line. But I gather they hope to use much of it -- crushed on site or made into cement on site -- right back into the tunnel project. To get to Hurdman to build the embankment for the new track there would probably be trucked as all the rails are removed...

  3. There's still got to be more material to bring out than could be used for the project - pretty much by definition. There are plenty of single track railways in the Ottawa area along which surplus spoil could be dumped to build up a second roadbed for future double tracking. No railway company is going to say 'No' to a donation of free material for possible future widening, even if it never occurs. It could even be piled up near Leitrim for the future extension into Riverside South.

    At Hurdman the VIA tracks still exist not too far away. Some kind of siding is all that would be needed, so spoil can be transferred to truck there. Whether spoil is transferred at LeBreton or elsewhere doesn't matter - except to the extent of how much extra trucking would be saved. In other words, if it's possible to transfer spoil to trucks at LeBreton then it's possible to do it near Hurdman too.