Cathays railway works the Cardiff Valleys Division, under the Loans and Guarantees Act (1929): the track layout was improved; a new corrugated roof installed; and a new ramp added to the GWR standard-pattern single-road coaling stage. By 1950 under British Railways, the combined depots of Cathays and Radyr (Code:88A), had a complement of 82 locomotives, all tank-types: 2x2-8-2T; 62x0-6-2T; 15x0-6-0T; 3x0-4-2T. In 1959 the shed was divided to cope with the introduction of diesel multiple units. In 1961 the shed closed to steam, and all steam locomotives were moved to Radyr. The shed closed completely in November 1964, with the opening of the
Crown Buildings, Cathays Park twenty years. In 1934–8, the block now known as Cathays Park 1 (a.k.a. CP1 or old Crown Building) was built by P. E. Hanton, as offices for the Welsh Board of Health. It is a three-storey building in the Stripped Classical style, with of floorspace. It also has an attic and a basement. Cathays Park 2 (a.k.a. CP2 or new Crown Building) is a five-storey office building with of floorspace, including an underground car park and a central atrium housing a cafe for the office staff. The "Encyclopaedia of Wales" describes CP2, completed in 1979, as conveying an impression of