Yesterday, after receiving the big update, I took a 166 on a spin from West Ealing to Paddington. I turned on the safety systems upon departure from West Ealing, with the DSD and Vigilance isolated. The TPWSIS isolation switch was left in the Normal position. As I was getting close to London, I did not decrease speed. Instead, I kept going at 80 mph. The train passed over several TPWS grids on the approach to Paddington. I was expecting these to put me to a stop as I would be overspeeding, but nothing happened. I applied the emergency breaks just before reaching the platforms but it was too late: I crashed into the buffer stops at 35 mph, derailing my train. Therefor my question: does GWE have TPWS OSS loops, anywhere? Does the 166 know what to do with them? And did I do something wrong (apart from overspeeding in the first place, of course!) by isolating something?