[Goose]

I'm a bit surprised we haven't seen a more systemic targeting of electrical substations used to power rail transit. I could be wrong, but that seems a weak link in the rail transport chain relative to targeting tracks or hard targets like bridges. Maybe they are too numerous or just not enough muntiions to get that far down the list, but they should also be more poorly defended.

The reason for this is twofold. First, the transformers themselves and associated electrical equipment are quite rugged. Most drones don't carry large enough payloads to reliably destroy this equipment. This equipment, unlike munitions depots and oil storage tanks does not in general explode and catch fire. If you miss, you won't get any sympathetic detonations. Cluster type munitions which work well on fuel dumps don't work well on substations. They don't catch fire easily.

The second problem is that the electrical wiring itself (and its supports) often deflects or detonates the incoming suicide drone/warheads. These obstacles are located well above the actual substation itself. They will be damaged/destroyed, but they are relatively easy to repair and use material that is normally associated with railway maintenance and therefore readily available. Long range drones, being larger, will often hit these obstacles with parts of their structure (like wings and arms supporting lift fans). The collision usually knocks the drone down well away from its objective. These are not FPV drones so the pilot can't avoid such obstacles. Even FPV drones would have a tough time threading their way through the wiring :-).

Ukraine thinks it has better targets for its drone force.

Thanks Goose, I had wondered the same thing.  I still think the transformers can be hard to replace, but if they are really hard to hit, there have to be better targets.

You are correct that the transformers are difficult to replace. It is a relatively major engineering task. Moving and unloading the replacement transformer isn't easy. They are very heavy. In many cases road transport is unavailable to the substation site. In that case the transformer and the crane to lift it has to be brought in by rail. The most impactful problem is that even if an exact replacement transformer exists (and can be located) it will take weeks (at a minimum) to replace the transformer. This is not something the Maintenance of Way (MOW) crews do. You need the specialized railway construction crews to do it. Organizing and scheduling the effort is a major undertaking. During all this time the rail line will be down. If synchronized with a major Ukrainian offensive that can have serious effects on the defense.  Since these transformers last quite long, often several decades, it is common that no direct replacement is available. In that case the mounting structure and electrical layout may need to be re-designed to accommodate what is easily available. This will add even more down time to the line.

It must also be noted that some railroads are "over engineered". Their power stations are placed on the line at much more frequent intervals than actually required. Any given power station can be removed from service and the line can continue to operate, possibly at lower speeds and/or reduced capacity. On high volume lines this is often the case. I doubt the lines in the Kursk area fall into this category.

There are two "normal" means of replacing transformers that are getting old, perhaps leaking fluid (used to be PCB laden) and not performing to spec. One is to manufacture an exact replacement, schedule the work, get all the people to the site and swap the transformer as quickly as possible. If well coordinated the actual swap can often be done in 48 hours or less. The planning and manufacturing may have taken months but the line downtime is only the "cut-over" interval.

The second approach is to install a new transformer (whose form factor and power rating may differ from the original) right next to the existing transformer. This can be done only if there is space available near the existing transformer. The required engineering and procurement can be done at somewhat leisurely pace, keeping the old transformer in service. When all is ready, the wiring will be moved from the old transformer to the new. This can usually be done quite quickly. All railroads have daily MOW intervals where no trains are allowed on specific sections of the line. This rapid cut-over usually is folded into a normal MOW interval and no down time is introduced. When using this method it is common to install bus bars that will allow either the "old" or the "new" transformers to power the line. Next time a transformer needs replacement, it is easy. There is already the infrastructure in place to do it. The "old" transformer sometimes isn't pulled out until it is time to replace its successor. In many "modern" electric railroads today two transformers are normally in place. If one needs to be taken offline for any reason, the switch to the other is fast, sometimes requiring no manual operations at all. Of course, if both are damaged the railroad is back to the original crash program of replacement.

[Goose]

I'm a bit surprised we haven't seen a more systemic targeting of electrical substations used to power rail transit. I could be wrong, but that seems a weak link in the rail transport chain relative to targeting tracks or hard targets like bridges. Maybe they are too numerous or just not enough muntiions to get that far down the list, but they should also be more poorly defended.

The reason for this is twofold. First, the transformers themselves and associated electrical equipment are quite rugged. Most drones don't carry large enough payloads to reliably destroy this equipment. This equipment, unlike munitions depots and oil storage tanks does not in general explode and catch fire. If you miss, you won't get any sympathetic detonations. Cluster type munitions which work well on fuel dumps don't work well on substations. They don't catch fire easily.

The second problem is that the electrical wiring itself (and its supports) often deflects or detonates the incoming suicide drone/warheads. These obstacles are located well above the actual substation itself. They will be damaged/destroyed, but they are relatively easy to repair and use material that is normally associated with railway maintenance and therefore readily available. Long range drones, being larger, will often hit these obstacles with parts of their structure (like wings and arms supporting lift fans). The collision usually knocks the drone down well away from its objective. These are not FPV drones so the pilot can't avoid such obstacles. Even FPV drones would have a tough time threading their way through the wiring :-).

Ukraine thinks it has better targets for its drone force.

Thanks Goose, I had wondered the same thing.  I still think the transformers can be hard to replace, but if they are really hard to hit, there have to be better targets.

You are correct that the transformers are difficult to replace. It is a relatively major engineering task. Moving and unloading the replacement transformer isn't easy. They are very heavy. In many cases road transport is unavailable to the substation site. In that case the transformer and the crane to lift it has to be brought in by rail. The most impactful problem is that even if an exact replacement transformer exists (and can be located) it will take weeks (at a minimum) to replace the transformer. This is not something the Maintenance of Way (MOW) crews do. You need the specialized railway construction crews to do it. Organizing and scheduling the effort is a major undertaking. During all this time the rail line will be down. If synchronized with a major Ukrainian offensive that can have serious effects on the defense.  Since these transformers last quite long, often several decades, it is common that no direct replacement is available. In that case the mounting structure and electrical layout may need to be re-designed to accommodate what is easily available. This will add even more down time to the line.

It must also be noted that some railroads are "over engineered". Their power stations are placed on the line at much more frequent intervals than actually required. Any given power station can be removed from service and the line can continue to operate, possibly at lower speeds and/or reduced capacity. On high volume lines this is often the case. I doubt the lines in the Kursk area fall into this category.

There are two "normal" means of replacing transformers that are getting old, perhaps leaking fluid (used to be PCB laden) and not performing to spec. One is to manufacture an exact replacement, schedule the work, get all the people to the site and swap the transformer as quickly as possible. If well coordinated the actual swap can often be done in 48 hours or less. The planning and manufacturing may have taken months but the line downtime is only the "cut-over" interval.

The second approach is to install a new transformer (whose form factor and power rating may differ from the original) right next to the existing transformer. This can be done only if there is space available near the existing transformer. The required engineering and procurement can be done at somewhat leisurely pace, keeping the old transformer in service. When all is ready, the wiring will be moved from the old transformer to the new. This can usually be done quite quickly. All railroads have daily MOW intervals where no trains are allowed on specific sections of the line. This rapid cut-over usually is folded into a normal MOW interval and no down time is introduced. When using this method it is common to install bus bars that will allow either the "old" or the "new" transformers to power the line. Next time a transformer needs replacement, it is easy. There is already the infrastructure in place to do it. The "old" transformer sometimes isn't pulled out until it is time to replace its successor. In many "modern" electric railroads today two transformers are normally in place. If one needs to be taken offline for any reason, the switch to the other is fast, sometimes requiring no manual operations at all. Of course, if both are damaged the railroad is back to the original crash program of replacement.