The Clacton express stock originally was 10-car, formed 2 x 4-car and 1 x 2-car. Arriving at Colchester the rear 2-car was dropped off and did all stations, including the reversal through Colchester Town, through to Clacton. The remaining 8 ran on nonstop to Thorpe-le-Soken, where the train divided again, the front set without the buffet went to Walton, and the rear one, with buffet, went to Clacton. So there were two off-peak services an hour to Clacton, compared to the current one.
After a period the Colchester division stopped, the local stations being served by a separate connecting train, and six cars went fast to Clacton, and four to Walton. There were later changes again, a series of Open Seconds were converted from hauled stock, and replaced the buffet cars and augmented the 2-car units up to 4. The current arrangement where the local connects with a different Liverpool Street train, precedes the express to Thorpe, waits there to connect, and then provides the Walton service, is more recent, and in all truth reflects the all-year demand better.