This should have hit me like a ton of bricks long before now. It's hitting me like a tons of bricks now though, so at least it's happening.
Civil (water) engineer here. I have long wondered why "life cycles" are assigned to structures like power plants and other capital assets. Why do we not design for "perpetuity" as our forebears such as the Romans did. Furthermore, why do our materials not seem to last like theirs did - our concrete mixes, for example, do not seem capable of lasting two millenia.
Your article (I think) unlocked it for me. As with all things in the US, we have constructed a system where total replacement at the end of the service life will always be more cost effective than ongoing O&M. Do we design for degradation? I don't know, but we would seem to allow, at least, for book value to reach such a degraded value at the end of the service life and to be so low that when we anticipate a new analysis to be done that compares ongoing annualized maintenance costs added to a constantly depreciating asset it never makes sense not to just "re-invest" in a new facility. We are designing and building to literally match a straight-line depreciation curve and knowing that we intend to just dump capital assets at time t in the future. I guess what I'm saying is that it hits me that it's all deliberate, as least here in the States. Capital budgeting and planning is a premeditated act of short to mid-term planning and completely ignores any alternative that might plan for effective O&M to keep a facility such as an power plant or wastewater plant operational long after we're dead.
As engineers, could we be accused of borderline abuses of ethics in allowing and facilitating such wasteful practices?
Excellent question, there is an old saying "engineers let their mistakes burry others".
I would say this though, the structures that the Romans Built won't pass modern serviceability limit states, and most of what remain today are static loads.
My sense is that part of the problem with design lifes is that we don't really understand fatigue behaviour and long term degradation. France in the last 10 years did a lot of diagnostics and root cause analysis on their structures and they have now engineered those errors out for the new upgrades. That should be the way to do it.
I would also argue that modern Project Life Cycle Management should tell you when to replace what critical component of a plant and (hopefully) someone will act.
Another side story, the romans used a binder called Pozzolana, and when I worked with a team in Uganda a few years ago they had the exact same material in their cement, it has this weird behaviour where the plaster looks entirely dry and if you just move it a bit with the trowel then it starts flowing again.
"My sense is that part of the problem with design lifes is that we don't really understand fatigue behaviour and long term degradation. France in the last 10 years did a lot of diagnostics and root cause analysis on their structures and they have now engineered those errors out for the new upgrades. That should be the way to do it."
What sort of errors did they uncover and eliminate? I don't feel like American engineers pay any attention to this. Maybe, but I'm not a structural engineer and am not up on the literature.
So it's a plasticizer and a water reducer, AND reduces the amount of Portland cement that's required? We use Pozzolanic admixtures here too but are busy trying to eliminate the source (coal combustion >> fly ash) as quickly as we can by shutting down coal fired power stations. I can't speak to whether our pozzolans increase workability to that extreme degree. Very interesting, thanks for sharing.
South Africa should consider not only bringing back abandoned coal power stations, but that the leadership should unapologetically make a commitment in law to continue the investment in coal, at least for two decades.
The authors’ reasons include but are not limited to: coal being most cost-effective and abundant utilizing proven combustion technology, coal being the most important source of power in SA and globally, coal demonstrates geopolitical stability, coal does not depend on weather coal is able to ramp up and down quickly with little efficiency loss, coal has “less climate impact” than LNG, and the newest coal power technology can reduce substantially the environmental impact.
The potential overhaul of South Africa’s entire coal fleet has incredible benefits for traditional social democratic development.
Fully functional after 90 years. That is impressive.
This should have hit me like a ton of bricks long before now. It's hitting me like a tons of bricks now though, so at least it's happening.
Civil (water) engineer here. I have long wondered why "life cycles" are assigned to structures like power plants and other capital assets. Why do we not design for "perpetuity" as our forebears such as the Romans did. Furthermore, why do our materials not seem to last like theirs did - our concrete mixes, for example, do not seem capable of lasting two millenia.
Your article (I think) unlocked it for me. As with all things in the US, we have constructed a system where total replacement at the end of the service life will always be more cost effective than ongoing O&M. Do we design for degradation? I don't know, but we would seem to allow, at least, for book value to reach such a degraded value at the end of the service life and to be so low that when we anticipate a new analysis to be done that compares ongoing annualized maintenance costs added to a constantly depreciating asset it never makes sense not to just "re-invest" in a new facility. We are designing and building to literally match a straight-line depreciation curve and knowing that we intend to just dump capital assets at time t in the future. I guess what I'm saying is that it hits me that it's all deliberate, as least here in the States. Capital budgeting and planning is a premeditated act of short to mid-term planning and completely ignores any alternative that might plan for effective O&M to keep a facility such as an power plant or wastewater plant operational long after we're dead.
As engineers, could we be accused of borderline abuses of ethics in allowing and facilitating such wasteful practices?
Excellent question, there is an old saying "engineers let their mistakes burry others".
I would say this though, the structures that the Romans Built won't pass modern serviceability limit states, and most of what remain today are static loads.
My sense is that part of the problem with design lifes is that we don't really understand fatigue behaviour and long term degradation. France in the last 10 years did a lot of diagnostics and root cause analysis on their structures and they have now engineered those errors out for the new upgrades. That should be the way to do it.
I would also argue that modern Project Life Cycle Management should tell you when to replace what critical component of a plant and (hopefully) someone will act.
Another side story, the romans used a binder called Pozzolana, and when I worked with a team in Uganda a few years ago they had the exact same material in their cement, it has this weird behaviour where the plaster looks entirely dry and if you just move it a bit with the trowel then it starts flowing again.
Thanks Mr. Kruger.
"My sense is that part of the problem with design lifes is that we don't really understand fatigue behaviour and long term degradation. France in the last 10 years did a lot of diagnostics and root cause analysis on their structures and they have now engineered those errors out for the new upgrades. That should be the way to do it."
What sort of errors did they uncover and eliminate? I don't feel like American engineers pay any attention to this. Maybe, but I'm not a structural engineer and am not up on the literature.
So it's a plasticizer and a water reducer, AND reduces the amount of Portland cement that's required? We use Pozzolanic admixtures here too but are busy trying to eliminate the source (coal combustion >> fly ash) as quickly as we can by shutting down coal fired power stations. I can't speak to whether our pozzolans increase workability to that extreme degree. Very interesting, thanks for sharing.
South Africa should consider not only bringing back abandoned coal power stations, but that the leadership should unapologetically make a commitment in law to continue the investment in coal, at least for two decades.
The authors’ reasons include but are not limited to: coal being most cost-effective and abundant utilizing proven combustion technology, coal being the most important source of power in SA and globally, coal demonstrates geopolitical stability, coal does not depend on weather coal is able to ramp up and down quickly with little efficiency loss, coal has “less climate impact” than LNG, and the newest coal power technology can reduce substantially the environmental impact.
The potential overhaul of South Africa’s entire coal fleet has incredible benefits for traditional social democratic development.