| Regimental number | 6375 |
| Place of birth | Elmhurst Victoria |
| Religion | Presbyterian |
| Occupation | Horse driver |
| Address | Canning Mills, Western Australia |
| Marital status | Single |
| Age at embarkation | 35 |
| Next of kin | Father, Robert James Orrock, Elmhurst, Victoria |
| Enlistment date | 2 October 1916 |
| Date of enlistment from Nominal Roll | 5 September 1916 |
| Rank on enlistment | Private |
| Unit name | 28th Battalion, 18th Reinforcement |
| AWM Embarkation Roll number | 23/45/3 |
| Embarkation details | Unit embarked from Fremantle, Western Australia, on board HMAT A34 Persic on 29 December 1916 |
| Rank from Nominal Roll | Private |
| Unit from Nominal Roll | 28th Battalion |
| Fate | Returned to Australia 5 April 1918 |
| Family/military connections | Brother: 6621 Driver John Harold ORROCK, 4th Field Artillery Brigade, died of wounds, 18 November 1916. |
