The most common carbon fiber composite is carbon fiber reinforcing an epoxy matrix. The carbon fiber, as individual fibers 5-10 microns in diameter (vs human hairs ~20-180 μm), and as tows or yarns of 3000-24,000 fibers are actually very flexible. I can take fibers or yarns and fold and crush them back on themselves without breaking (of course, other high-performance fibers such as Kevlar or Dyneema, can take even more such abuse).
It is the epoxy matrix that is brittle, and when it finally breaks under load, the load is concentrated at the fracture and breaks the fibers.
This is not an issue in high-performance fiber ropes, as they do not use an epoxy matrix. They have much higher fiber ratio (so much less matrix) and the matrix is of course highly flexible, e.g., some urethane formulation, and often a wear-protective jacket; the matrix is basically a binder to keep the rope/cable together. This is why composite fiber cables have replaced steel in high-performance yachting, tall elevators, racecar wheel tethers, and many other applications. The entire point is that they are much MORE resistant to breaking and wear than steel (and in some applications will work in long-length when the steel cables would literally break under their own weight).
That said, while I haven't done a full analysis, it is possible that Kevlar or Dyneema or even Zylon as the main cable reinforcement, sacrificing some strength-weight for increased toughness, may be better in that particular application. But any of the high-performance fibers will outclass steel.
Similarly, for the structure housing the suspended instruments, composites are a win on every parameter. First, reducing the suspended weight pays benefits across the whole system — lower weight to suspend reduces the requirements of the cables, which reduces their own weight, which reduces the loads on and so the weight of the towers, etc. This alone may overcome any initial cost differences. Moreover, lower weight means lower momentum generated fighting high winds, etc., composites are better vibration-damped, and more. Plus, composites don't corrode the way metals do. And, this is not a structure where we need to worry about impacts and brittleness (which can also be managed by reinforcement and matrix selection).
Doubt all you like, but composites would be a huge improvement in this application (and don't need active blow-drying, which seems unlikely to have been able to prevent the creep failure).
Source: I founded & run a high-performance composites design & mfg firm, with 20 years of direct hands-on experience designing & fabricating advanced composite components & products for motorsport, defense, aerospace, subsea, sport, & architectural applications.
And yes, some of your idea that carbon fiber is brittle may come from the fact that it has very low elongation and elongation at break, but this means that when it finally breaks, it will be a sharp event (e.g., compared to steel which starts by deforming), but that break is after far higher loads.
The most common carbon fiber composite is carbon fiber reinforcing an epoxy matrix. The carbon fiber, as individual fibers 5-10 microns in diameter (vs human hairs ~20-180 μm), and as tows or yarns of 3000-24,000 fibers are actually very flexible. I can take fibers or yarns and fold and crush them back on themselves without breaking (of course, other high-performance fibers such as Kevlar or Dyneema, can take even more such abuse).
It is the epoxy matrix that is brittle, and when it finally breaks under load, the load is concentrated at the fracture and breaks the fibers.
This is not an issue in high-performance fiber ropes, as they do not use an epoxy matrix. They have much higher fiber ratio (so much less matrix) and the matrix is of course highly flexible, e.g., some urethane formulation, and often a wear-protective jacket; the matrix is basically a binder to keep the rope/cable together. This is why composite fiber cables have replaced steel in high-performance yachting, tall elevators, racecar wheel tethers, and many other applications. The entire point is that they are much MORE resistant to breaking and wear than steel (and in some applications will work in long-length when the steel cables would literally break under their own weight).
That said, while I haven't done a full analysis, it is possible that Kevlar or Dyneema or even Zylon as the main cable reinforcement, sacrificing some strength-weight for increased toughness, may be better in that particular application. But any of the high-performance fibers will outclass steel.
Similarly, for the structure housing the suspended instruments, composites are a win on every parameter. First, reducing the suspended weight pays benefits across the whole system — lower weight to suspend reduces the requirements of the cables, which reduces their own weight, which reduces the loads on and so the weight of the towers, etc. This alone may overcome any initial cost differences. Moreover, lower weight means lower momentum generated fighting high winds, etc., composites are better vibration-damped, and more. Plus, composites don't corrode the way metals do. And, this is not a structure where we need to worry about impacts and brittleness (which can also be managed by reinforcement and matrix selection).
Doubt all you like, but composites would be a huge improvement in this application (and don't need active blow-drying, which seems unlikely to have been able to prevent the creep failure).
Source: I founded & run a high-performance composites design & mfg firm, with 20 years of direct hands-on experience designing & fabricating advanced composite components & products for motorsport, defense, aerospace, subsea, sport, & architectural applications.