The BTC was not convinced that the future of diesel traction lay down the hydraulic transmission path of the Western Region, and concentrated on diesel-electric designs.

Based on the success of these initial 20 locomotives an order for 270 was made, which was later revised upwards a number of times to reach the final total of 512.

D1702 to D1706, were fitted with a Sulzer V12 12LVA24 power unit and classified as Class 48s; the experiment was not deemed a success, and they were later converted to standard 47s.

This enabled a number of easily recognisable sub-classes to be created, depending on the differing equipment fitted.

The original series were based on train heating capability and were as follows;[13] However, this numbering system was later disrupted as locomotives were fitted with extra equipment and were renumbered into other sub-classes.

[17][19] They were all fitted with slow speed control for working MGR coal trains (as were a number of Class 47/0s).

[21] The sub-type remained stable until withdrawals started, although an "extra" 47/3, 47300, was created in 1992 when 47468 had its train heating equipment removed and was renumbered.

However, no more were constructed in this way until 1967 when the final two Brush-built locomotives, D1960 and D1961,[18] were fitted with a new type of electric heat system using an AC alternator.

[18] After being severely damaged in a derailment near Peterborough in 1974, locomotive 47046 was selected to be a testbed for the projected Class 56, and was fitted with a 16-cylinder Ruston 16RK3CT engine rated at 3,250 bhp (2,420 kW) for assessment purposes.

[16] In the late 1970s, BR authorities identified a need to replace the ageing trains operating the Glasgow to Edinburgh shuttle services, in order to increase speed and reliability.

The locomotives would be known as Class 47/7 and would be fitted with TDM push-pull equipment[27] and long-range fuel tanks, and be maintained to operate at 100 mph (160 km/h).

At the same time, further locomotives were fitted with extra fuel tanks and renumbered; the series eventually reached 47854.

[18] After the privatisation of British Rail, the locomotives in the 47/8 number range were mainly used by Virgin CrossCountry on cross-country work until the introduction of Class 220 Voyager trains.

These duties have kept them maintained in serviceable condition, allowing them to remain operational longer than the majority of their classmates.

[29] However, with work for the class declining due to the introduction of new rolling stock and spare parts becoming difficult to source, some inroads started being made.

[29] During the decline in passenger work a number of locomotives were painted in "celebrity" colours, depicting various liveries that the type had carried during its history.

[32] West Coast Railways is currently the largest operator of the type,[33] though they began scrapping their stored locomotives in January 2023.

[62] In 2013, a BR Blue version of D1662 Isambard Kingdom Brunel was commissioned by Modelzone, based on Bachmann's OO gauge model.

[64] In 2010, Bachmann issued a British N gauge model of 47474 Sir Rowland Hill in Parcels Sector red and grey livery.

[65] Between 1963 and 1966, ten locomotives similar to the British Rail Class 47 were supplied to Ferrocarriles de Cuba (Cuban National Railways).