Rastrick was born in Morpeth, Northumberland, to John Rastrick and Mary. He attended local public schools; at age 15, in 1795 he was apprenticed in his father's engineering practice. In 1802 he was hired by the Ketley Ironworks in Shropshire.
Hazeldine & Rastrick
After five years at Ketley, Rastrick partnered with John Hazledine, in Bridgnorth, Shropshire. While at Bridgnorth, Rastrick helped Richard Trevithick develop his ideas for the high pressure steam engine and locomotive, and he later testified in a parliamentary enquiry that he had built the locomotive that had been demonstrated in London in 1808. He also produced much equipment for Trevithick's abortive South American adventure. On 1 April 1814, he was awarded UK patent number 3,799 for his steam engine design. Rastrick oversaw the construction of the Wye bridge at Chepstow, which opened in 1816. The partnership between Rastrick and Hazledine was a troubled one, ending in a dispute in 1817. He worked independently for a short period, but in 1819 he formed a partnership with James Foster, and he moved his family to Stourbridge.
Foster Rastrick & Co.
The new company manufactured an extensive range of products from blast furnaces, and rolling mills, wrought iron rails, 'bearers' for some of the famous buildings of the age, etc. In 1822 Rastrick became the engineer for the Stratford and Moreton Tramway, an early horse-drawn line. The partnership was also responsible for the first steam locomotives for the Delaware and Hudson Canal Company, the Stourbridge Lion in 1829.
In 1829 Rastrick was commissioned with James Walker to report on the economics of using either rope haulage or locomotives on the new Liverpool and Manchester Railway. After extensive travels to view the early railways of the age their report favoured rope haulage on economic grounds. They did however include the rider that there were some benefits to locomotive haulage not least their probable technical improvement. Given such a marginal judgement, the directors of the company decided to hold a competition to test the locomotives on offer. Rastrick was one of three judges at the Rainhill Trials of 1829 which conclusively proved the benefits of Stephenson's Rocket locomotive. Rastrick's diaries and notebook of the trial are valuable records of the performance of locomotives of that era.
During his partnership with John Hazledine, Rastrick married Sarah Jervis on 24 December 1810 at Codsall, Staffordshire. He had seven children: Joseph, born June 1808; John, born 10 April 1811; Sarah, baptised 2 June 1813; Mary, baptised 30 January 1818; Henry, baptised 30 January 1818; Frederick James born c1820; George, baptised 10 June 1821. Joseph emigrated to New Zealand and founded a line of builders, engineers and architects.