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 stay within the 10,000-ton limit, the STNC realized that using the same machinery from the previous class would cause ships to exceed the limit by 200 tons to achieve the desired 34 knot speed. Thus, the STNC put the machinery up for auction. AC Bretagne suggested an eight-boiler four-shaft solution generating 155,000 CV at normal displacement.