Iserlohn was a 4,667 GRT cargo ship that was built in 1909 by Reiherstieg Schiffswerfte & Maschinenfabrik, Hamburg, Germany.

Renamed Empire Defiance, she served until June 1944, when she was sunk as a blockship at Sword, Ouistreham, France in support of Operation Overlord.

[5] The ship was propelled by a triple expansion steam engine,[1] which had cylinders of 66 and 121 and 195 cm (26 and 47+5⁄8 and 76+3⁄4 in) diameter by 122 centimetres (48 in) stroke.

[2] She was operated under the management of the British-India Steam Navigation Co Ltd.[8] Iserlohn was allocated the Official Number 143916.

[8] In 1924, Union City was sold to J A Zachariassen & Co, Uusikaupunki, Finland and was renamed Wasaborg.

[11] In 1935, Wasaborg was sold to Achille Lauro & Co, Naples, Italy and was renamed Erica.

Five days later, Empire Defiance departed from Durban for Calcutta, India, arriving on 10 December.

The next day, Empire Defiance departed from St Thomas for Halifax, Nova Scotia, Canada, arriving on 27 July.

She departed from Halifax on 6 August for Sydney, Cape Breton, arriving the next day.

[17] Empire Defiance the sailed to Methil, where she joined Convoy FS 847,[17] which departed on 5 July and arrived at Southend, Essex two days later.

[23] Empire Defiance was a member of Convoy EN 116, which departed from Methil on 27 July and arrived at Loch Ewe two days later.

Empire Defiance departed from Trincomalee on 17 October but arrived back there three days later.

[17] Empire Defiance departed from Calcutta on 20 January 1943 for Madras, arriving three days later.

She was carrying a cargo of copra, mails and pig iron, as well as twelve passengers.

[27] The then joined Convoy XB 60, which departed from Halifax that day and arrived at the Cape Cod Canal, Massachusetts on 29 June.

Empire Defiance departed from New York on 4 July for the Hampton Roads, Virginia.

A return trip was made to Philadelphia, Pennsylvania before she returned to New York, from where she departed on 21 July for Boston, Massachusetts.Empire Defiance was a member of Convoy BX 75, which departed from Boston on 24 July and arrived at Halifax two days later.

[17] On 7 June 1944,[30] Empire Defiance was scuttled at Sword, Ouistreham, Calvados, France as part of Gooseberry 5.

On 21 August, Empire Defiance had to be beached off The Mole, Zeebrugge after developing a leak.