I don’t understand why they would think this to have low drag.

- Displaced volume wouldn’t be lower than that of a traditional ship (likely even quite a bit higher because the wheels would add mass and the hull would have to be stronger than one that rests on the water)

- Surface area would be higher than that of a single hull.

Also, looking at this as a variant on the paddle steamer (https://en.wikipedia.org/wiki/Paddle_steamer#Seagoing_paddle...), didn’t we already know in 1897 that screw propellers are a lot more efficient? SS Archimedes (https://en.wikipedia.org/wiki/SS_Archimedes) was built in 1839.

So, what was the thinking? It being easier to have low rpm in steam driven engines, and that compensating for those disadvantages?