Following the reconstruction of Paddington station and the introduction of larger locomotives and new routes, the Great Western Railway (GWR) required a larger depot than that at the 1855 constructed Westbourne Park, at which to service its locomotives and carriages.

In 1901, a site was acquired in South Acton, south of the Grand Union Canal and on the upside of the mainline.
Taking four years to layout and build, designed by G.J. Churchward, it was the largest depot on the entire GWR system, and set the pattern for similar depots throughout the GWR including Tyseley.

It had four 65 feet (19.8 m) undergirder turntables, under six-spans of  east-west aligned northern-light pitched roofs.
The shed covered a total area of 360 feet (110 m) (six bays of 60 by 444 feet or 18.3 by 135.3 metres} (six bays of 74 feet or 22.6 metres).
The roofs were made of wood and steel rafters covered in Welsh slate tiles, supported on steel or cast iron columns, with solid London Brick Company walls.
Laid out in an interconnecting 4-square pattern under the roof, each electrically operated turntable was fully boarded, and had 28 tracks spanning from it, able to accommodate locomotives up to 75 feet (22.9 m) in length.

The associated repair shop, termed The Factory, was allocated to the northeast front of the depot, with 11 roads approached over an electric traverser, and a 12th road direct from the depot throat.
Built in a similar style to the depot, it was 195 feet (59 m) by 110 feet (34 m) in size, and housed a 30-long-ton (30.5 t; 33.6-short-ton) crane.
There were also separate blacksmiths and carpenters workshops, a stores and a general office.

The approach to the shed housed a standard GWR pattern coal stage, again the largest on the system.
It was approached via a 1:50 gradient brick-arch supported ramp, with 1:80 beyond the stage.
In 1938, the approach roads to and from the coal stage were doubled, and in 1942 an ash shelter constructed to protect from Nazi Luftwaffe bombing.
The four water tanks housed over the stage held 290,000 imperial gallons (1,300,000 l; 350,000 US gal) of water, while sand was supplied from a separate sand furnace.

The whole depot came into operation from 17 March 1906, and became the head of the GWR London operating division.
Following the reconstruction of Paddington station and the introduction of larger locomotives and new routes, the Great Western Railway (GWR) required a larger depot than that at the 1855 constructed Westbourne Park, at which to service its locomotives and carriages.
In 1901, a site was acquired in South Acton, south of the Grand Union Canal and on the upside of the mainline. Taking four years to layout and build, designed by G.J. Churchward, it was the largest depot on the entire GWR system, and set the pattern for similar depots throughout the GWR including Tyseley.
It had four 65 feet (19.8 m) undergirder turntables, under six-spans of  east-west aligned northern-light pitched roofs. The shed covered a total area of 360 feet (110 m) (six bays of 60 by 444 feet or 18.3 by 135.3 metres} (six bays of 74 feet or 22.6 metres). The roofs were made of wood and steel rafters covered in Welsh slate tiles, supported on steel or cast iron columns, with solid London Brick Company walls. Laid out in an interconnecting 4-square pattern under the roof, each electrically operated turntable was fully boarded, and had 28 tracks spanning from it, able to accommodate locomotives up to 75 feet (22.9 m) in length.
The associated repair shop, termed The Factory, was allocated to the northeast front of the depot, with 11 roads approached over an electric traverser, and a 12th road direct from the depot throat. Built in a similar style to the depot, it was 195 feet (59 m) by 110 feet (34 m) in size, and housed a 30-long-ton (30.5 t; 33.6-short-ton) crane. There were also separate blacksmiths and carpenters workshops, a stores and a general office.
The approach to the shed housed a standard GWR pattern coal stage, again the largest on the system. It was approached via a 1:50 gradient brick-arch supported ramp, with 1:80 beyond the stage. In 1938, the approach roads to and from the coal stage were doubled, and in 1942 an ash shelter constructed to protect from Nazi Luftwaffe bombing. The four water tanks housed over the stage held 290,000 imperial gallons (1,300,000 l; 350,000 US gal) of water, while sand was supplied from a separate sand furnace.
The whole depot came into operation from 17 March 1906, and became the head of the GWR London operating division.
Old Oak Common TMD