WMATA to Stop Operations Tomorrow

I was looking at the video from March showing the damaged shunt cables connecting the third rail. What I can not understand is this,

The cable has insulation cracked but I did not see any signs of excessive heat(ie melted insulation). What I saw looks more like something hit the cable and tore the insulation. Also is it standard practice to have the shunt cable on the same side that the third rail shoe travels on? It occurs to me that if the third rail shoe caught a piece of debris it could very easily have torn the insulation.

Further I have to wonder aloud about the porcelain insulators. The pictures I saw of the old insulators showed dirty insulators. Another words no one was on occasion cleaning them. Fibreglass is made with resin which given a chance will burn. Porcelain has already been fired in the manufacturing process.

Not sure what else to say.

My possibly warped understanding is that the apparently conductive debris allowed the third rail to arc to the metal post holding the insulator, melting it. Fiberglass insulators are supposed to handle heat better, but the real solution is for Metro to actually clean their tunnels.

The bad insulators are a separate problem. The original concern, and the reason for the one-day shutdown, was for insulating boots on feeder cables that were either not installed properly or were at the risk of failing due to wear or other reasons.

The insulator problem is a separate problem. These are the ceramic pedestals that hold the third rail and were quickly replaced only at every station because of a high-profile video which shows a fireball showering the tracks and part of the station platform with sparks and fire just after a train departed the station. The insulators in the tunnels are still in the process of being replaced but the insulators inside the stations were a priority for obvious reasons. Most of these insulators are original and many are 30-40 years old.