To maintain the 10,000-ton limitation the STNC determined that using the same machinery at the previous class would have put the ships at 200 tons over the limit to achieve the 34 knot speed desired. The STNC therefore put the machinery out for bid. AC Bretagne came up with an eight boiler four shaft solution producing 155,000 CV for  at normal displacement.
To meet the 10,000-ton requirement, the STNC determined that using identical machinery from the previous class would result in ships exceeding the limit by 200 tons to achieve the desired 34 knot speed. As a consequence, the STNC auctioned off the machinery. AC Bretagne presented an eight-boiler four-shaft proposal producing 155,000 CV at normal displacement.