According to famous British naval constructor Reed could Russian popovkas oppose Turkish ironclad Mesudiye according to the Dutch newspaper Algemeen Handelsblad dated 2 June 1877

Popovka

Mesudiye

The famous British naval constructor sir E. Reed (1) described in 1877 the Russian and Turkish fleets. He discussed also the circular ironclads Novgorod and Admiraal Popoff (2) lying in the Black Sea for protection of the mouth of the Dnjepr and the coastlines of the Sea of Azov. The Novgorod had a diameter of 101’ and a draught of 12”. The armament consisted of 2-27 ton guns and she was protected by a 11” thick armour. Propelled by six screws was her speed 7 knots. The Admiraal Popoff had a diameter of 121, protected by a 18” armour and armed with 2-40 ton guns. Reed believed that if Russia possessed just a dozen of these ships she was able to stop the Turkish fleet on the Black Sea. With just two available the only task could be coast defence for which purpose they were designed. If Turkey intended to blockade the Russian Black Sea harbours and control the Russian popoffkas needed she 5 or 6 armoured ships. Her largest ship was the Mesoudieh with a measurement of 8.994 tons, an armour of 12” thickness and an armament of 12-18 ton guns. While the popovkas had the heaviest guns and the thickest armour was the Mesoudieh needed on the Black Sea. If she however decided to go the Mediterranean to oppose the Russian fleet could Turkey expect huge problems on the Black Sea. Reed expected that the popovkas would attack the 4-5 armoured Turkish ships and he believed that the Turkish would loose the confrontation.

Notes
1. Edward James Reed (20 September 1830 Sheerness, England-30 November 1906 London, England), chief constructor of the British Royal Navy between 1863 and July 1870 (as a result of the HMS Captain-affaire) and member of the House of Commons 1874-1906.
2. 1. Together with her sister ship Rear Admiral Popov (ex-Kiev) designed by Andrei Alexandrovich Popov (21 September Russia-6 March 1898 Russia)to be circular shaped shallow draught vessels to serve in coastal waters. The Novgorod was armed with 2-11”26 ton guns placed on revolving turntables which could operate independently from each other. She was from far the stable platform Popov projected. It were pitching, rolling, slow and worse manoeuvring ships. Using the guns the ship started spinning. Propelled by six screws and fitted out with one rudder. The Novgorod was laid down at St. Petersburg, Russia on 17 December 1871,disassembled and transported to Nikolayev, launched on 21 May 1873, commissioned in 1874, reclassified as coastal defence armor-clad in 1892, stricken in 1900, decommissioned on 4 July 1803, became a store and finally broken up in 1912. With a displacement of 2.491-2.671 (full load) tons and as dimensions 30,8 (diameter) x 3,75 (draught( metres. The 8-coal fired boilers supplied 2.000 ihp allowing a speed of just 7 knots. Her crew numbered 2-11” guns, 2-4pd guns and 16-3,7cm guns. The armour consisted of a 23cm thick belt and a 6cm thick deck. Her sister ship - built at Nikolaiev in 1874- was somehow larger with a diameter of 36,3 metres and a displacement of 3.550 tons and heavier armed with 2-12.2” guns.
3. Central-battery ironclad Mesudiye. Laid down at the British shipyard Thames Iron Works (and Shipbuilding Company Limited, Leamouth Wharf, England in 1872, launched in 1874, commissioned in December 1875, rebuilt as a pre-dreadnought at Genoa, Italy in 1903 and finally sunk by the British submarine B-11 on 13 December 1914. The original armament consisted of 10” muzzle loading rifled guns.