Why 24-inch torpedoes were a different weapon

What is the practical difference between 21-inch and 24-inch torpedoes?

The larger torpedo is far heavier and offers substantially greater range and destructive potential, demanding a different launch platform and doctrine.

The British heavy weapon was a 24.5-inch torpedo, a substantial increase over the standard 21-inch size. It weighed about 2.6 tons, compared with roughly 1.5 tons for a later 21-inch Mark VIII. The heavy torpedo could run about 20,000 yards at 30 knots or 15,000 yards at 35 knots, while the cited 21-inch weapon managed roughly 7,000 yards at 41 knots. That is an exceptional reach for a weapon rooted in 1920s technology. The comparison explains its anti-capital-ship appeal and the substantial space, handling, and hull penalties imposed on any ship or submarine carrying it.