Kelson
New Member
More (on the ground) shots if West Don Crossing
- Thread starter JasonParis
- Start date
hawc
Senior Member
Where's the 'cut-off' for you guys in terms of windspeed. I don't really like anything about 35km/h.
I mean obviously you fly out into the wind so you know you can get back, but it's hard to do shots (especially straight down) when it's really windy. Keeps blowing it around.
I had one incident with the MINI 4 Pro last year where I couldn't get back because the wind was too strong and I had to do an emergency landing on a parking pad and drive over and pick the drone up.
That spooked me for windy days.
urbancog
Active Member
Anyone know if the electricity system operator (ieso.ca) has de-energized the transmission circuits beside those cranes? If a crane failed or experienced unexpectedly high wind loads it could come into contact with a conductor - establishing a path to earth for ~140,000V. That would be fatal for the crane operator and might cause a large scale outage in Toronto.
Tim MacDonald
Senior Member
For me, the important things are:
1. Sustained wind speed "in the 30s" and it depends on where I am and the direction of the wind. IF it's a strong north wind, I don't want to be too close to the lake so I'll be cautious if I'm shooting Lakeview or Brightwater. There were some gusts today but so long as I am above any obstructions, the Mini3pro will recover without smashing into something.
2. I always plan the mission to fly into the wind on the outbound and have a tailwind on the return.
3. Power consumption will be higher on windy days so that might impact where I fly as a lot of my flights seem to be long distance.
4. I plan my takeoff and landing on the sheltered side (other side of the car or sometimes I'll act as a windbreak) of the wind so it doesn't drift too much as it is transitioning from ground to flight. Chipped a prop on my Phantom 4 pro as it got blown over in gusty conditions once. Not quite as important with the Mini series but you could still have it drift into a parking curb and bust a prop.
Today I was shooting the Hurontario at QEW and flying north into the wind about another KM to shoot the hospital construction at Hurontario and The Queensway. I had some wind warnings but it was still moving along at 6.1m/s on the outbound and 10.0m/s on the return.
Man, that must have been a drag having to play fetch with the Mini4. Certainly a lot better than losing it to an inaccessible location.
hawc
Senior Member
I'd be curious to know that too.
Also interesting once the line is built and operational the trains look like they will be running mere metres from those lines. I mean I know they could never touch them, but it looks super close.
Kelson
New Member
Kotsy, what report is that graphic from? I don't see that one in the most recent thorncliffe park msf press conference slides.
kotsy
Senior Member
The West Don Crossing & Walmsley Brook Crossing updates show up in the Flemmingdon & Don Valley slides, but I can't seem to find the specific presentation featuring that graphic right now.
Flemingdon Park & Don Valley Station CLC
Meeting materials for the Flemingdon Park & Don Valley Station Construction Liaison Committee
www.metrolinx.com
hawc
Senior Member
Snug as a bug in a rug.
I guess the concrete needs to be kept warm (or at a constant temperature, maybe not warm) as it cures.
Lot of extra work to keep it all wrapped up during the winter months it looks like.
West Don Crossing.
I guess the concrete needs to be kept warm (or at a constant temperature, maybe not warm) as it cures.
Lot of extra work to keep it all wrapped up during the winter months it looks like.
West Don Crossing.
urbancog
Active Member
Triggered review of Concrete for Engineers course materials (from 1982, so practice may have evolved!).
- Temperature of concrete should be kept above 0 C at all times
- The water and/or the course aggregate may be heated in the concrete batching process to prevent freezing during transport and at point of placing into formwork
- Heat dissipates through unprotected surfaces and un-insulated formwork, so forms may have added insulation and open surfaces should be closed off with tarps or insulation
- Curing cement generates heat within the concrete, counteracting heat lost to the environment
- Concrete strength develops more quickly at higher temperatures
- Temperature of concrete shouldn't exceed 80 C during curing otherwise design strength will never be achieved
- Too steep a temperature gradient through the body of the concrete before it develops early strength will cause cracks to form, so external heating can be provided - but not so much that the internal temperature exceeds 80 C.
- Water loss can also prevent development of concrete strength and is related to the temperature difference between the air and the concrete, to wind speed, and to relative humidity of the air. So, exposed surfaces should be protected from the wind, particularly on cold, dry, windy days.
hawc
Senior Member
^^^ Nice!
Also I think I read somewhere that concrete never 'fully' cures. So even stuff built hundreds of years ago is still technically curing.
Also I think I read somewhere that concrete never 'fully' cures. So even stuff built hundreds of years ago is still technically curing.
YongeBloor
Active Member
Nice end of year progress video on a lot of the stations.
www.linkedin.com
#proudtobeotg #ontariotransitgroup | Ontario Transit Group - Ontario Line - Southern Civil, Stations & Tunnel
Crews continued to make steady progress on the Ontario Line Southern Civil, Stations & Tunnel project, with major work underway at station sites highlighted in the latest and last Sizzle Reel for 2025. Watch the video to see the latest progress and stay tuned for the next updates in 2026...
www.linkedin.com
Westey
New Member
Officially it's 70C.
Somehow if these temps are achieved then the concrete crystal is altered and expansion forces develop and slowly create cracking. Look up Delayed Ettringite Formation (DEF), which needs a PhD to understand.
The temperature differential allowed is only 20C. There are thermocouples added and this is the difference of ones near the surface and in the core.
This is one issue Contractors have with MTO - thinking this is way to restrictive.
There is a whole temperature control plan developed for the pour, using fancy modelling to predict concrete temperatures. Silica Fume and FlyAsh (supplementary cementing materials, SCMs) create strength without the heat, but there are limits on them as well.
Cement nowadays is ground finer than the old days, so most the reaction happens relatively early (28 to 56 days). Previously it was true that the hydrations continued for decades, although the actual strength gain after a couple of years was not much.
Northern Light
Superstar
Ontario Line Construction update to the January meeting of TEYCC:
Its quite lengthy with lots of slides, I don't have the time to extract them all just at the moment so anyone who wants to, please feel free.
I will offer a link from within the above to the Pape Station construction update for December:
Lots of other items are also linked from within the main report.
Its quite lengthy with lots of slides, I don't have the time to extract them all just at the moment so anyone who wants to, please feel free.
I will offer a link from within the above to the Pape Station construction update for December:
Lots of other items are also linked from within the main report.
generalcanada
Senior Member
only notable thing i found.
everything else is in CLC meeting decks
i remember people noting the dufferin bridge was being inspected.
Also the tree removals in the don valley
kotsy
Senior Member
They just put out new Thorncliffe Park meetings slides and I see now that West Don Crossing is covered in it. I went back and found that the graphic was from the August presentation.
I'll post the construction update slides here: