Why is "Archer-class sloop" trending?

Wikipedia Overview

On 26 March 1846, two vessels were ordered from Deptford Dockyard as Rifleman-designed gunvessels named Archer and Parthian. However, on 9 September 1846 the orders for both vessels were suspended prior to the vessels being laid down. On 25 April 1847 two vessels were ordered to the improved Rattler-type screw sloops as designed by John Edye of the Surveyor's Department from Deptford Dockyard. The first vessel, Archer may have been the change of the build from the Rifleman type to the sloop design. The second vessel, Wasp, appears to be a new vessel as the build for the Parthian remained on the books at Deptford until June 1849, when it was cancelled. Archer received the machinery from the gunvessel Rifleman, which resulted in an increase of speed over Wasp. Wasp's hull was sheathed in Muntz metal to retard marine growth. Their armament would increase from 12 to 15 guns over their careers. Both vessels would participate in the Russian War of 1854–1855. Both would be broken by 1869.