However they had variable - pitch propellers , developed by Maugas , obviating the need for a reversing engine .
The Farfadets were single - hulled , and powered by electric motors only , limiting their range and surface performance compared to the contemporary Sirene class .
Farfadets had variable - pitch propellers , developed by Maugas , obviating the need for a reversing engine .
The Farfadets were single - hulled , and powered by electric motors only , limiting their range and surface performance compared to the contemporary Sirene class .