fanoftoronto said:
These aren't cheap purchases for Toronto, ranging around $20 million per TBMs these days. Why do we not buy used? Why can't we reuse them between our projects?
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And considering that the cost of the projects that use them are measured in the multiple billions of dollars, the savings of reusing the TBMs would be measured as fractions of a single percentage point on the whole project.

It seems penny-wise and pound-foolish considering the risks involved in reusing them.

Dan
 
smallspy said:
And considering that the cost of the projects that use them are measured in the multiple billions of dollars, the savings of reusing the TBMs would be measured as fractions of a single percentage point on the whole project.

It seems penny-wise and pound-foolish considering the risks involved in reusing them.

Dan
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What are these risks, though? If it’s constantly being resold for use in other countries it definitely works. The article mentions that TBMs last for 20 km of tunnelling. Rexy and Renny have tunnelled only 6.3km or 32% of its design life. It shouldn’t need drastic refurbishment at 32% design life! Even if it’s dismantled and refurbished for $2 million and reused for Ontario Line, it’s $18 million in savings per TBM.

Also, it’s this sort of penny-wise and pound foolish thought process that’s landed us in this high cost situation for transit projects. How is reusing TBMs pound foolish? Transit projects in Europe do not cost upwards of $400 million per km of transit. There are a thousand inefficiencies that are happening in Toronto transit projects that all need to be addressed.

We need to be looking at efficiencies in order to reduce costs. And at the end of the day $36 million is still an exorbitant amount of savings of taxpayer dollars!

It’s not about penny wise and pound foolish, it’s about making the most using the available money.
 
fanoftoronto said:
What are these risks, though? If it’s constantly being resold for use in other countries it definitely works. The article mentions that TBMs last for 20 km of tunnelling. Rexy and Renny have tunnelled only 6.3km or 32% of its design life. It shouldn’t need drastic refurbishment at 32% design life! Even if it’s dismantled and refurbished for $2 million and reused for Ontario Line, it’s $18 million in savings per TBM.

Also, it’s this sort of penny-wise and pound foolish thought process that’s landed us in this high cost situation for transit projects. How is reusing TBMs pound foolish? Transit projects in Europe do not cost upwards of $400 million per km of transit. There are a thousand inefficiencies that are happening in Toronto transit projects that all need to be addressed.

We need to be looking at efficiencies in order to reduce costs. And at the end of the day $36 million is still an exorbitant amount of savings of taxpayer dollars!

It’s not about penny wise and pound foolish, it’s about making the most using the available money.
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They may be designed to "last" 20 km of tunnelling - or whatever the number may be, depending on type - but that doesn't mean that they don't need maintenance. Main bearings only last a quarter of that distance or even less. Hydraulic lines fail, cylinders give up the ghost, conveyors wear thin, bearings need to be replaced, the list goes on. They are machines that operate in extremely harsh conditions, and their cost can not be equated to just their purchase. The risk with a used machine is that it will not be as reliable as a new one, and with that comes the potential for increased costs - be it in terms of repairs, or in terms of delays.

Newer machines are faster, and more automated. What required a crew of 50 people 20 years ago only needs 25 today. That number may be reduced further into the future. Speed increases aren't as substantial, but according to people in the field machines today are about 10% or 15% faster than those 20 years ago.

I frankly fail to see how you can equate the cost of a $36mil machine - which is designed to be disposable - with the vast ongoing costs of everything else involved in building a subway. $100mil or $400mil per kilometer, either way the foregoing of the cost of one brand new TBM doesn't save you the cost of one kilometer. There are far better places to save real dollars on a project.

Dan
 
smallspy said:
They may be designed to "last" 20 km of tunnelling - or whatever the number may be, depending on type - but that doesn't mean that they don't need maintenance. Main bearings only last a quarter of that distance or even less. Hydraulic lines fail, cylinders give up the ghost, conveyors wear thin, bearings need to be replaced, the list goes on. They are machines that operate in extremely harsh conditions, and their cost can not be equated to just their purchase. The risk with a used machine is that it will not be as reliable as a new one, and with that comes the potential for increased costs - be it in terms of repairs, or in terms of delays.

Newer machines are faster, and more automated. What required a crew of 50 people 20 years ago only needs 25 today. That number may be reduced further into the future. Speed increases aren't as substantial, but according to people in the field machines today are about 10% or 15% faster than those 20 years ago.

I frankly fail to see how you can equate the cost of a $36mil machine - which is designed to be disposable - with the vast ongoing costs of everything else involved in building a subway. $100mil or $400mil per kilometer, either way the foregoing of the cost of one brand new TBM doesn't save you the cost of one kilometer. There are far better places to save real dollars on a project.

Dan
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The TBMs are rated for 20 kms as stated in the article I linked in my post. If you had a tunnel of 12km, would you argue to buy a second TBM once you hit 6km with the first TBM just because increased maintenance is required?

It is extremely cost effective to reuse capital equipment such as TBMs. I'm not saying keep these machines for 20 years. Wouldn't it be good to reuse Rexy and Renny for the Ontario Line which should be starting tunnelling in the next year or so? TBM technology isn't going to advance by that much in the next year or two.

Also, $36 million is still $36 million! Just because it's peanuts when compared to the total cost of the project doesn't diminish the cost savings of $36 million. For reference, that's the yearly tax revenue from roughly 4,500 Ontario tax payers.
 
the TBMs are rated for 20km? Not 19.4 or 20.6, but 20? And at all depths and soil conditions? And without supplementary charge for support after a TBM extract reinsert, and no difference to insurance premiums? And with no cost to properly store it if the second project TBM portal is delayed?

IMG_1142.jpeg
 
I would be a lot happier if we looked for opportunities to use cut and cover methodologies which don't require the deep (and therefore expensive) station shafts. Wasting the remaining life in a pre-owned TBM is spare change compared to adopting TBM designs where cut and cover is doable.

- Paul
 
The irony is not at all lost on me that both Toronto and NYC were capable of making widespread use of cut and cover technology in their downtowns without destroying them, but vast, sprawling suburbs with much more space and much less to worry about destroying need deep tubes. We're moving backwards.
 
dowlingm said:
the TBMs are rated for 20km? Not 19.4 or 20.6, but 20? And at all depths and soil conditions? And without supplementary charge for support after a TBM extract reinsert, and no difference to insurance premiums? And with no cost to properly store it if the second project TBM portal is delayed?

View attachment 566239
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I took the 20km service life referenced from a TTC tender document as found in the article I linked to. You can take it up with TTC whether it's 19.4 or 20.6km.

TBMs are regularly extracted and reinserted and run without any issues. It happened twice on the Crosstown during tunneling, once at Yonge-Eglinton and once at Eglinton West station where they met the existing subway. Didn't have to worry about insurance premiums for those times right? Also, it's not supplementary charges, they have to remove the old TBM anyway and they have to insert a new TBM anyway. Again, you can take it up with the TTC on how they were able to do it for Crosstown.

I mean, the storage was happening anyway at TTC cost while they were waiting for buyers for the TYSSE TBMs. Again, as listed in the article, they were being stored in the Keele Valley Landfill site. You can take it up again with the TTC how they can store TBMs for sale but not for reuse in Toronto.

The only item you have brought up that I didn't have an answer for is soil types, but even that could be mitigated by different cutter heads if anything. Added on, the article mentions that the TYSSE cannot be reused for Line 2 Scarborough extension only because of the 6 year gap. Seems like soil type wasn't an issue between TYSSE and Bloor extension, just the age.

I don't understand why there's a need in this thread to defend Metrolinx and TTC wasting money.
 
I think people are pointing out that this solution doesn’t address your larger concern: the spiraling cost of transit expansion in NA. If you wanted to solve that, you’d actually have to tackle:

* P3s and private financing
* Lack of public sector technical and project management expertise
* Huge construction contracts as opposed to smaller ones that can attract more competition
* Political dithering and flip-flops
* A stop (for a long time) and restart philosophy when it comes to transit expansion, causing institutional knowledge to be lost
* Too little land banking for transit
* A transit-last philosophy, where we don’t build transit in the cheapest way possible while a neighborhood is still being built (Portlands)
* Too much kowtowing to loud voices, leading to expensive technical decisions

All of these would be more impactful than reusing a TBM. And some of these may result in a TBM being reused anyways (imagine if we’d already figured out the airport expansion and GTAA terminal).
 
dowlingm said:
Your certainty that they are is what is grinding people’s gears.
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I do agree that sometimes it's not possible to reuse TBMs.

I'm only trying to possit that in this case, Metrolinx could reuse them. We have evidence of sale of TBMs from Toronto to other countries and projects. If those countries and projects can reuse the Toronto's TBMs given the myriad of problems that have been identified, why can't Toronto?
 
allengeorge said:
I think people are pointing out that this solution doesn’t address your larger concern: the spiraling cost of transit expansion in NA. If you wanted to solve that, you’d actually have to tackle:

* P3s and private financing
* Lack of public sector technical and project management expertise
* Huge construction contracts as opposed to smaller ones that can attract more competition
* Political dithering and flip-flops
* A stop (for a long time) and restart philosophy when it comes to transit expansion, causing institutional knowledge to be lost
* Too little land banking for transit
* A transit-last philosophy, where we don’t build transit in the cheapest way possible while a neighborhood is still being built (Portlands)
* Too much kowtowing to loud voices, leading to expensive technical decisions

All of these would be more impactful than reusing a TBM. And some of these may result in a TBM being reused anyways (imagine if we’d already figured out the airport expansion and GTAA terminal).
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Oh, you're completely correct and I totally agree! We need a bottom up look of how transit projects are planned, bidded, and executed.

But that isn't going to happen overnight. Toyota came up with the continuous improvement strategy. Don't wait for massive projects and re-evaluations to cut cost. Do it small and easy-to-implement. This could be one of those CIs. Fair?
 
T3G said:
The irony is not at all lost on me that both Toronto and NYC were capable of making widespread use of cut and cover technology in their downtowns without destroying them, but vast, sprawling suburbs with much more space and much less to worry about destroying need deep tubes. We're moving backwards.
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Sure but in a world where political careers are made and lost based on how quickly surface traffic moves, most folks don't care about the incomprehensible sums it actually requires to move tunneling far deeper. Politicians are too-often spineless chum and we all end up paying for it (both literally and metaphorically).
 
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