Simplify the following text for a Grade 6 native English-speaking person.
Original: Unlike the 1967 Tube Stock , the trains are built 40 m wider to take advantage of the Victoria line 's slightly larger than normal loading gauge compared with the other deep-level tube lines .
Simplified: The new trains are being built 40 m wider than the current 1967 Tube Stock . This is because the Victoria line has a larger than normal loading gauge compared to the other deep level tube lines . .