[Hamuko]

>Typhoon class has a displacement of 48000 tons.

That's quite massive.

The Japanese I-400-class submarines/submersible aircraft carriers, which I believe are still the largest diesel submarines built, were under 7000 tons.

[hu3]

Here's a nice picture comparing their sizes: https://inteng-storage.s3.amazonaws.com/images/import/2017/0...

Source: https://interestingengineering.com/uncovering-i-400-japanese...

[masklinn]

> which I believe are still the largest diesel submarines built

According to the internet you seem to be right, the Qing-class gets very close but not quite there: wiki lists 6628t, versus 6670t for the for the I-400.