It goes faster than that of a regular train.
I am actually year 5. 10 years old but in my school we are learning about Victorians and Victorian trains. I think they could go about 30 miles an hour (top speed) and thank you for writing this...
The speed that a train can go depends on the speed limit for a specific segment of track.
300km/h for passenger ones and over 400km/h for cargo.