| John Mervyn Dallas Wrench | |
| Honorific Suffix: | CIE |
| Birth Date: | 15 September 1883 |
| Birth Place: | Punjab, India |
| Death Date: | 31 August 1961 |
| Death Place: | Sherborne St John, England |
| Education: | Bedford Modern School |
| Nationality: | British |
John Mervyn Dallas Wrench (15 September 1883 – 31 August 1961) was Chief Engineer of the Great Indian Peninsular Railway and later Chief Controller of Standards of the Railway Board of India from 1929 to 1940.[1] [2] [3] [4] Also known as J. M. D. Wrench, he was made CIE in 1929.[5]
John Mervyn Dallas Wrench was born in Punjab, India, on 15 September 1883.[6] He was the son of John Mervyn Wrench and Fanny Julia van Zuylen van Nyevelt de Gaesebeke.[7] Wrench was educated in England at Bedford Modern School.[8]
Wrench entered the Indian State Railway Service in 1906 and steadily rose through the ranks.[1] During World War I he served in Mesopotamia from 1917 to 1919 attaining the rank of Major.[1] After the War he was appointed Locomotive Superintendent of the Indian State Railways in 1921.[8]
Wrench was made Chief Engineer of the Great Indian Peninsular Railway in 1923 and was later appointed Chief Controller of Standards of the Railway Board of India, a position he held between 1929 and 1940.[1] He was made CIE in 1929.[5]
Wrench married Elise Mackenzie-Hughes in 1908 with whom he had four daughters.[1] He died on 31 August 1961 at Sherborne St John, England.[7]