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.

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.

[5][7] Throughout its GWR and early BR operational life, the depot remained fairly intact and similar to its original layout.

The only major difference by the early 1960s was the addition of a pre-war diesel refuelling stage just north of the repair shop, for use by GWR railcars.

[5] Within a year the majority of the GWR 1906 depot was demolished, with only "The Factory" repair shop, furthest western turntable and parts of the stores remaining.

[5] The main service building had 3 tracks, each holding two locos, with inspection pits, fuel supply points and a washing plant on the approach road.

Just south of the residual GWR buildings, in the 1960s BR built what was initially the storage depot for the Blue Pullman trains, what later became known as the Coronation Carriage Sidings.

In the late 1970s, south of this and almost adjacent to the Great Western Main Line (GWML), BR built a depot for the new InterCity 125 fleet.

On the privatisation of BR, the buildings were allocated to English Welsh & Scottish, and latterly operated by its commercial subsidiary Axiom Rail.

From 2000 onwards, developments were focused on the southern section of the former GWR site, either side of the 1970s BR High Speed Train depot.

All the remaining GWR Factory buildings and the Coronation Carriage Sidings were demolished by mid-2011, with the former northwestern shed turntable donated to the Swanage Railway.

In December 2017, maintenance of the Night Riviera was transferred to Penzance Long Rock Depot with the stock laying over at Reading TMD at its northern end.