The Centenary coaches were built to commemorate the 100th anniversary of the GWR in 1935. They were luxurious vehicles built to the maximum width of the loading gauge and were the first GWR coaches to feature large windows in the compartments. As a consequence entry was at the ends of the coaches only and due to gauge restrictions the doors were incorporated in an angled inset. The intermediate doors on the brake ended and catering vehicles were also inset. Initially the windows were of the wind down “Beclawat” type but these were replaced in 1938 with the more conventional 4 element sliding vents.
The standard set was of 10 coaches increased to a maximum of 13 when required. The formation used initially on the Cornish Riviera Express (later Limited) was, from the tender:-
BTK(LH van)/TK/TK/RTO/RF/CK/BTK(RH van)/TK/BCK/BCK
The maximum formation added a CK, BTK(RH van) and BCK. The vehicles behind the inner BTK were dropped off at intermediate destinations. The set formations lasted into the war years.
In 1947 the coaches were renovated internally and were subsequently seen on the Weston-super-Mare-Paddington trains and then cascaded to lesser workings. The dining pairs worked Paddington-Shrewsbury in the 1950s and in 1961 were on Weston-super-Mare, Wolverhampton and Plymouth trains.