Surprising to me how little attention the whole TGF effort has received outside Francophone circles -- I have yet to see an English-language article on it.
A reasonable background on the technological alternatives for Montreal-QC (en francais) is here
When will the monorail advocaes realize that is a very slow speed type of transportation ? Reports that the disney monorail ride is getting very rough ?
I think someone in the Quebec legislature has run into Lyle Lanley:
https://www.youtube.com/watch?v=ZDOI0cq6GZM
Greetings from Alberta
-an Articulate Malcontent
Now hold on a moment, read up on the idea before invoking Lyle:
Overmodow hold on a moment, read up on the idea before invoking Lyle: http://www.trensquebec.qc.ca/english
Sounds very optimistic and ambitious. The suspended monorail systems on rubber tires I know of have a maximum speed of 50 mph (80 kph). But 155 mph (250 kph) on these tires? I have my doubts.
Light system is relative. When I was project manager (structural design) on the rebuilding site of the burned down Duesseldorf Airport we had to implement the columns of the Siemens Sipem people mover into our construction: https://ic.pics.livejournal.com/barmashev/70799644/66973/66973_600.jpg
IIRC the monorail weighed around 0.7 kips/ft at 30 mph (50 kph) and 100 ft (30 m) span. That is about the lane load in US and Canadian bridge design codes. Not to mention the weight of columns and their fixing moments.
In my opinion there is no way to use a Highway bridge without loosing a traffic lane.
With 131 ft (40 m) span and 155 mph (250 kph) the monorail's weight will possibly more than double.
I think the shown open H-section as monorail is less than ideal in curves at high speed.
It would be interesting to learn what the cost estimate was based on.
Without further information it is not more than an eye catcher for me.
Now THESE are correct considerations 'against' the monorail, and it is significant that they come from a practicing engineer with distinctive competence in precisely this area of design.
There is a certain amount of handwaving involving the vertical compliance and damping of the 'power wheel' bogies, and in some fairly critical lateral concerns (for the intended speeds). These don't seem to me fundamentally 'insoluble' ... but Volker is right to note that for all the work done to put up this Web site in so many languages these critical aspects of the design should have been addressed.
Likewise I was struck, and not too impressed, with the apparent lack of rack bracing in the depicted structure, perhaps in more planes than longitudinal. It reminded me a little of the track support systems for 'telepomps' more than a century ago, and is a curious oversight for a physicist like Confort to make.
It will be interesting to see how, even with full and effective algorithms for nonslip acceleration and regenerative braking to a stop, the monorail accommodates the need for any given 'module' to make required TGF stops and still achieve low trip times without interfering with other traffic running at other speeds. This being reasonably easy to accomplish with switchable conventional bi-rail...
Can someone, not necessarily Volker, look at published structure for the St. Lawrence bridge in particular and determine how and where it would have to be 'beefed up' to take the monorail in whatever safe configuration would accommodate it? I am thinking that speed restrictions across this span would constitute a reasonably small percentage of trip time increase, but it might be prudent to design for inadvertent overspeed mistakes 'anyway'.
Which St. Lawrence bridge do you think of? The bridge under construction for the St. Lawrence Corridor Project?Regards, Volker
Does the Quebec Bridge not cross the St. Lawrence? I was pretty sure it did (between Sainte-Foy and Levis?) but there may have been watercourse changes in the intervening years.
They have both 'video' and a discussion of this crossing, which has nothing to do with the proposed Rive Nord TGF as far as I know but is an illustration of how a historic asset might be used for new transit.
Overmod Does the Quebec Bridge not cross the St. Lawrence? I was pretty sure it did (between Sainte-Foy and Levis?) but there may have been watercourse changes in the intervening years. They have both 'video' and a discussion of this crossing, which has nothing to do with the proposed Rive Nord TGF as far as I know but is an illustration of how a historic asset might be used for new transit.
Johnny
I only looked superficially into the Quebec Bridge's design.
The portal design forces the monorails to the outside of the trusses
The Quebec Bridge is pin-connected. So hopefully the trusses are able to carry the additional loads. I not you can strengthen eye bar by welding a cut-out steel plate fitting the head of the eye bar and weld rods to the plate.
Problem: Can the old steel get welded? Are the pins able to carry the additional loads? Here perhaps more modern analysis methods for eye bar/pin connections might help. Possible but not sure.
Strengthening of riveted chord can be done if you find flanges or webs not full of rivets.
The post that will have to carry the monorail loads directly are not designed to carry any bending moments. To avoid this the monorail supports will have to be on two common channels right and left of the post that reach completely across the bridge width.
A lot depends on how many reserves were calculated into the bridge structure.
Steel bridges stand a lot better chance to get strengthened than concrete bridges though it can be done. On long spans like the Quebec Bridge strengthening when possible seems more economic. On shorter spans a new bridge might be better especially if the existing bridge is concrete
Strengthening is never cheap.Regards, Volker
http://trn.trains.com/news/news-wire/2018/06/28-four-companies-will-vie-to-build-new-via-equipment
Bombardier, Siemens, Stadler and Talgo are the four.
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