Just to highlight although it's been linked to above,mInhavent read the report and am just replying to what has been posted here.
Okay, I can see what was meant now no what was intended by his actions. However, activating the TT wires frequently would not have prevented traction current being recharged. The controller/PCRO would not know that they had been operated a second time within the initial 7 mins, so if they had been activated again at the 5 min mark, a recharge would have still been attempted at the 7 min mark, some 2 mins later. After traction current had been recharged, however, using the TT wires would again have tripped traction current - provided they had not been over-ridden because of an assumed fault.
Yes and no - but it's only confusing because the TT wires weren't being used fully anyway. The SCD's purpose is designed to, as the name suggests, create a short circuit, either tripping out the current feed or creating such an indication that it could be determined that an SCD had been laid, and current therefore requiring discharge. However, an SCD aims by no means a guaranteed method of discharge or assurance that a recharge won't occur.
The only way of ensuring that traction current will not be recharged would be to speak to the service controller.