Those aren’t tubes, they’re whole tubular tires, essentially an integrated tube and tire in one unit that is glued to the rim. Changing a flat first required peeling the old one off before the new tire could be stretched (they fit tight!) onto the rim.

Tubulars are still used regularly by at least one world tour team (French, naturally), but these days a flat is fixed by swapping the wheel or even the whole bike for a spare carried by the team car. That wasn’t allowed in the early days.