Several ships were converted to escort destroyers in late 1942–early 1943 for duty in the North Atlantic and many others were assigned there for extended periods of time where they sank two German submarines.

The destroyers carried a maximum of 470–480 long tons (480–490 t) of fuel oil that gave them a range of 6,350 nautical miles (11,760 km; 7,310 mi) at 15 knots (28 km/h; 17 mph).

[3] All of the ships had the same main armament, four quick-firing (QF) 4.7-inch (120 mm) Mark IX guns in single mounts, designated 'A', 'B', 'X', and 'Y' from front to rear.

[5] For anti-aircraft (AA) defence, they had two quadruple mounts for the QF 0.5-inch Vickers Mk III machine gun on platforms between the funnels.

The stern of the minelayers was fitted with a pair of sponsons that housed part of the mechanical chain-conveyor system and to ensure smooth delivery of her mines.

[6] To compensate for the weight of her Mark XIV mines, their rails, two 4.7-inch guns, their ammunition, both sets of torpedo tubes, their whalers and their davits had to be removed.

Four to eight QF 20 mm Oerlikon cannons were added to the surviving ships, usually replacing the .50-calibre machine gun mounts between the funnels.

The 12-pounder was removed to allow for the installation of a Huff-Duff radio direction finder on a short mainmast and for more depth charges.

Express's modifications differed somewhat in that 'B' gun was replaced by a twin-gun QF 6-pounder Hotchkiss mount and a split Hedgehog installation.

[6] For the first time since the A class of the 1927 programme, the flotilla leaders were built to an enlarged design, being lengthened to incorporate an additional QF 4.7-inch gun between the funnels.

[11] Their turbines were 2,000 shp (1,500 kW) more powerful than the private ships, which made them 0.5 knots (0.93 km/h; 0.58 mph) faster; their propulsion machinery was otherwise identical.

Two Oerlikons were later added on the forward part of her aft superstructure and a quadruple QF two-pounder "pom-pom" mount replaced 'Q' gun between the funnels.

In mid-1939, newly commissioned J-class destroyers began to replace the E-class ships and they were reduced to reserve for lack of manpower.

Increasing tensions with Nazi Germany in August, caused the British to mobilize the Navy's reserves, which allowed the ships to be manned again and assigned to the 12th Destroyer Flotilla of the Home Fleet.

[16] When the war began on 3 September, the E-class ships, except for the two minelayers, Esk and Express, were assigned to the Western Approaches Command (WAC) for convoy escort and patrolling duties, while the Fs remained with the Home Fleet, performing the same sorts of tasks.

Esk and Express were assigned to the specialist 20th Destroyer Flotilla shortly after the war began, together with the four I-class destroyer-minelayers, and were busy laying mines in the North Sea and off the English coast through April–May 1940.

[22] On the night of 31 August/1 September, Esk, Express and three other minelaying destroyers laid a minefield off the Dutch island of Texel.

[19] On 13 September, Force H met a convoy that was carrying troops intended to capture Dakar from the Vichy French that was escorted by Inglefield, Eclipse, Echo, Encounter, and Escapade.

The following day, Firedrake together with the destroyer Wrestler and two Royal Air Force flying boats sank the Italian submarine Durbo.

A month later, Fearless was crippled by Italian bombs on 23 July while escorting a convoy to Malta and had to be scuttled by her sister Foresight while Firedrake was badly damaged by near misses and had to return to Gibraltar for repairs.

Encounter was transferred to the Mediterranean Fleet in April and spent several months under repair as she was badly damaged by bombs at Malta.

[25] Express and Electra were half of the escorts for Prince of Wales and Repulse as they sailed north on 9 December, but could do little as the Japanese bombers sank the two capital ships other than help to rescue the 3,000-odd survivors.

[26] Express did not participate in any of these battles because she'd been damaged by a boiler room fire in early February and her repairs did not begin until April.

[27] On 27 March, Fury, Eclipse and the light cruiser Trinidad were escorting Convoy PQ 13 in the Arctic when they were intercepted by three German destroyers.

Two days later, they were attacked by three German destroyers which badly damaged Foresight and Forester and put another torpedo into Edinburgh, crippling her.

While being repaired, Fame was converted into an escort destroyer and was assigned to the WAC, joining her sister, Fearless, upon its completion in September.

Fury, and Eclipse were detached to augment the escorts of the WAC in March–May 1943, joining their sisters, Fame and Escapade, when German submarine attacks reached their peak.

[31] Faulknor, Fury, Echo, and Eclipse were transferred to the Mediterranean Fleet to escort the covering force during the invasion of Sicily in July and the subsequent landings in mainland Italy.

Faulknor, Fury, and Eclipse participated in the Dodecanese Campaign after the surrender of Italy in September and the latter ship sank after hitting a mine on 24 October.

[32] Echo began a long refit at Malta in December and was loaned to the Royal Hellenic Navy upon its completion in April 1944.