The Diesel Electric Multiple Unit (DEMU) was a uniquely Southern Region solution to the changes brought about by the British Railways era. This part of the site looks briefly at the reasons behind this and in more depth at the Hampshire (Class 205) and Sussex (Class 207) versions.
The class 205 and 207 Diesel-Electric Multiple Units were the last design of the successful Southern region units, based on the BR standard Mk1 coach, that were introduced from 1957. These multiple units were introduced to meet the 1955 British Transport Commission's requirement to modernise the railway and eliminate steam haulage. With an extensive electrified network, the Southern Region had considerable experience in Electrical engineering. It also had plenty of experience with English Electric diesel generators from the pioneer Southern Railway diesel electric locomotives, and also the LMS pioneer main line diesel electric locomotives which were allocated to the Southern Region for a while. Therefore, the case for the Southern Region to have electric transmission instead of the predominantly mechanical transmission adopted by other regions was accepted by the commission, (there were a few Diesel Mechanical Units with "hydraulic" transmission but they were even rarer than Diesel-Electric Multiple Units).
In recent years, some of the units were modified for use as departmental units, performing duties like applying Sandite to the rails during the leaf fall season. Click here to see more.
Now, fifty years later, the last of the DEMUS have now been replaced from their final duties on the Ashford to Hastings and East Croydon to Uckfield routes by the next generation units. The DEMUs had made these lines their own being the last lines that were never electrified or had new units ordered for. The reason for this is tied up at least in part over protracted deliberations as to whether or not to electrify these lines. However, new class 170 diesel units have now taken over and the remaining Hampshire and Sussex units have been withdrawn.
The leasing company, Porterbrook, which owned the remaining DEMUs, decided to sell off redundant units to Hertitage Railways for a nominal sum. Thus it is that many Heritage Railways around the country now own a DEMU. However, these units had many more years in service, and ran many more miles, than the unit currently being preserved by H&SUPS. Most of them have been put straight back into service, with just a quick repaint, in contrast to the thorough restoration work being carried out on our unit. Click here to see more about the unit being preserved by H&SUPS.
Click here to see more about the Class 205 units.
Click here to see more about the Class 207 units.
Click here to see more about the Departmental units.
A mixture of Hampshire and Sussex Units, parked for the weekend at Tunbridge Wells West
Photo: Copyright John Smerdon 2005