NMS Ardeal was a Temes-class river monitor originally named SMS Temes while in Austro-Hungarian Navy service.
Based on the lessons learned in previous designs, the two ships had to be capable of covering a 270° arc with their turrets, have light armament to defend against small arms fire from shore, and needed to have a very shallow draught.
Propulsion was ensured by two triple-expansion steam enginess generating 1,400 ihp (1,000 kW) which controlled two propellers and were powered by two Yarrow water-tube boilers giving the ship a maximum speed of 13 knots (24 km/h; 15 mph) and a range of 500 nmi (930 km; 580 mi) at a speed of 9.5 knots (17.6 km/h; 10.9 mph).
Light armament consisted of two quick-firing 37 mm (1.5 in)/L42 Vickers (British QF 1-pounder pom-pom guns) placed in the forward and aft sections on each side of the upper deck.
[5] On 8 September 1914, the monitors repelled a Serbian attempt to cross the Danube, however the Austro-Hungarian troops were forced to evacuate the city to avoid encirclement.
In the following days, the Sava monitor group under the command of Linienschiffsleutnant Olaf Richard Wulff supported the Krauss Division during the Srem Offensive.
While on a nighttime reconnaissance mission on the Sava River on 22/23 October, Temes struck a Serbian mine and sunk with the loss of 31-33 of her crewmen.
Following the negotiations at Saint-Germain-en-Laye, the final decision for the distribution of the ex-Austro-Hungarian river monitors was taken by the Naval Allied Commission for Disposal of Enemy Vessels (NACDEV) and Temes was reassigned to Romania along with Inn and Sava on 15 April 1920.
[10] On 27 June 1940, after the Soviet ultimatum, Ardeal received the order to move to Reni and protect the evacuation operations from Bessarabia.
[2] On 22 June 1941, NMS Ardeal along with three other monitors and two gunboats became part of the Galați River Naval Force within the Romanian Danube Flotilla.
The task of the Naval Force was supporting the flank of Romanian Fourth Army and conducting counter-battery fire against the Soviet artillery and monitors located in Giurgiulești and Reni.
At the start of Operation Barbarossa, Ardeal with another monitor and a gunboat occupied positions at the mouth of the Siret River.
[2] In the early morning of 22 June, as the German and Romanian batteries opened fire in the Giurgiulești-Reni sector, an aircraft was spotted flying at low altitude along the Danube and Ardeal engaged it with her heavy machine gun as instructed.
Organized in the 3rd River Group at Hârșova and commanded by Lieutenant-Commander Eustațiu Nicolau with Basarabia as the leading ship, Ardeal together with Bucovina and Lahovary departed for Giurgiu on the night of 26/27 August.
On 30 August, the Ardeal group, which was moving at a lower speed due to boiler problems, was instead ordered to the Călărași-Oltenița area to prevent the withdrawal of German soldiers from Bulgaria.