Class 123 Swindon Inter-City 4 car sets

These were the final batch of "First Generation" units, and were built by BR Swindon. As with the first DMUs it built, back in 56, they were designated as "Inter-City" sets. They also had as much in common with BR standard coaching stock as they did with other DMUs, having long underframes, buckeye couplings, Pullman gangways, BR4 bogies, oval coach buffers and interior finishes based on hauled stock.

Ten four car sets were built, each providing seating for 24 first class and either 144 or 176 second class depending on whether it was one of the five buffet sets. Gangways at the outer ends of the sets allowed a buffet set to be attached to a non-buffet set giving access throughout. A maximum of three sets could be joined.