Class 204 / 205
Hampshire / Berkshire DEMU
The first Diesel Electric Multiple Units on the Southern Region and indeed, the South Eastern Division, were the ‘’Hastings’’ formations, introduced during 1957 and 1958 to replace narrow-width steam-hauled stock on the Charing Cross to Hastings route via Tunbridge Wells Central. The second generation of DEMUs for the SR were this time destined for the South Western Division, to work short to medium-distance and branch line services in Hampshire. Hitherto, these had usually been operated by push-pull formations consisting of an ex-LSWR ‘’M7’’ Tank Engine, a parcels van, and two pre-nationalisation carriages. An initial batch of eighteen replacement two-vehicle DEMUs was assembled at Eastleigh during 1957, based on the prevalent suburban BR Mk 1 carriage design of the era. The advantage of DEMU operation over the customary mechanical drive of DMUs on other regions was that the SR was able to standardise components with the existing EPB third-rail fleet and the 2-Hap EMUs being introduced concurrently. The units became ''2H'' - referring to the number of vehicles and the the county of Hampshire - when introduced during 1958 on the Portsmouth to Salisbury line, and under the pre-TOPS system became Nos. 1101 to 1118. What the 2H Class DEMUs lost over their 2 EPB and 2 Hap counterparts was nearly half the seating capacity in one of the driving vehicles, space of which was required to house the 500 HP English Electric power unit. By the end of the decade, the units were also working between Alton, Southampton and Andover.
The type's South Eastern Division interest begins in 1958 with the construction of a second batch of two-vehicle units at Eastleigh, destined to replace steam traction on the bleak line across the Romney Marsh, between Hastings and Ashford. The light traffic loads on this route deemed it uneconomical for electrification and indeed, the line between Appledore and Ore was degraded to single-track working in September 1979. This batch was only four units strong - Nos. 1119 to 1122 - but this number was set to increase to eight later on in the year with the building of a further batch, Nos. 1123 to 1126. These four units had been bolstered with an additional trailer in-between the driving vehicles in response to increased passenger loads, and engines had been uprated from 500 HP to 600 HP. By the end of 1959, most steam-hauled services on the line had been totally replaced, although the Sunday mornings 06:50 Hastings to Ashford working remained with steam traction until Summer 1961. A third and final batch of seven units - Nos. 1127 to 1133 - saw construction in 1962, and again these consisted of three vehicles with the more powerful engine, but were instead bound for the Reading to Salisbury line and branches in Berkshire. These units and the original builds which had been strengthened, became ''3H''.
Steep gradients between Winchester and Alton did pose problems for strengthened units and the new three-vehicle builds. The class had been fitted with 90 MPH express gear ratios, which were proving unsuitable for the powerful acceleration required on this particular hilly route. Whilst the use of two-vehicle DEMUs was part of the solution, British Rail also initiated a bogie swap between ''Hampshire'' units and 4 EPBs: the latter had been fitted with 75 MPH gear ratios (65:16) from the outset. This was undertaken progressively throughout the 1970s, thus ''Hampshire'' units received 75 MPH gear ratios and a number of 4 EPBs received the express bogies. However, the EPB units involved in the bogie swap were still listed on paper as having a maximum speed of 75 MPH. This is an ideal example showing the advantages of standardisation across DEMU and EMU fleets. In addition to this modification, there have been numerous unit reformations, as class members have been reallocated to alternate areas, or withdrawn altogether and centre trailers re-used in active formations. In all the unit formations, two lavatories were situated within the Driving Trailer Composites (DTC) - one for First Class, one for Second Class. These units had no connecting corridors between vehicles, thus if one was in either the Driving Motor Brake Second Open (DMBSO) or Trailer Second Open (TSO), then the toilets could not be reached without disembarking onto the platform, then re-entering the train! Gangways then appeared in 3H (Class 205 under TOPS) unit No. 205011, when it was subject to an experimental refurbishment programme at Eastleigh. Internally, the unit received a wooden veneer and fluorescent lighting, whilst externally, high-intensity headlamps were fitted. Consequently, this member became the sole unit of the sub-class 205/1, being renumbered 205101. This then lost its centre trailer, but retained the same number, although in 1995 the set was again provided with a TSO, but this time from a refurbished 4 Cep (some of these units were being reduced to 3 Cep at the time), thus seeing it renumbered to 205205. By 1995, all three-car formations had connecting gangways, which had given rise to another sub-class: 205/2.
Central Division
Two-car unit No. 205001 is seen trailing behind three-car unit No. 205009 into London Bridge station
on 13th October 2004 with a service from Uckfield. Under TOPS, two-car units became Class 204 and
three-car units became Class 205. When the final two-car units were upgraded to three vehicles, all
units acquired the ''205'' prefix, but when these same units were degraded again to just the two vehicles,
the ''205'' number was retained. Interestingly, however, it appears that the pre-TOPs classification was
reversed - note above the left-hand buffer, the code ''2H''. David Glasspool
No. 205001 is seen pairing with No. 205009 once again, but this time on 4th December 2004 heading
London-bound through Gatwick Airport. The black triangle indicates to platform staff at which end of
the train the guard's / luggage area is located. This view gives a good impression of how much room the
engine compartment took up. David Glasspool
Following on from the first picture on this page, we see No. 205001 loading up for its return journey to
Uckfield. The head code blinds are yet to be rolled round: 13th October 2004. David Glasspool
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