From Wikipedia:
"A
cowcatcher, also known as a
pilot, is the device mounted at the front of a
locomotive to deflect obstacles on the track that might otherwise damage or
derail it or the train.
"In the UK, small metal bars called
life-guards,
rail guards or
guard irons are provided immediately in front of the wheels. They knock away smaller obstacles lying directly on the running surface of the railhead. Historically, fenced-off railway systems in Europe relied exclusively on those devices and cowcatchers were not required, but in modern systems cowcatchers have generally superseded them.
"Instead of a cowcatcher,
trams use a device called a
fender. Objects lying on the tram track come in contact with a sensor bracket, which triggers the lowering of a basket-shaped device to the ground, preventing the overrunning of the obstacles and dragging them along the road surface in front of the wheels."
Train derailments would happen every day without devices to clear debris, and a human body is very light debris compared to the mass of a train. You can do further research on this if you like. You're making comments about a "100% method" while you have almost no knowledge of trains. You should do your own research, your ideas about this method are based on a fantasy world idea rather than being based on real knowledge. YOU should spend hours researching trains and attaempted suicides by them, then you will know there is know way to get this close to 100%.