#2938
SR Class 4-DD
🇬🇧 United Kingdom ·built by Unknown builder· from 1949· class of 2 four-car Double Deck electric multiple units
5 photos from Wikimedia Commons · credits & licences
- 1. Class 4DD no 4902 at Ashford Steam Centre: Hugh Llewelyn· CC BY-SA 2.0
- 2. BR Class 4DD DMBC no. 13004 pic1: T-j-l1234· CC BY-SA 4.0
- 3. BR Class 4DD DMBC no. 13004 pic2: T-j-l1234· CC BY-SA 4.0
- 4. BR Class 4DD DMBC no. 13004 side on: T-j-l1234· CC BY-SA 4.0
- 5. Class 4DD double decker coach: Paul Miller· Attribution
what is it?
The SR Class 4-DD was an experimental double-decker electric multiple unit built in 1949 and operated by the Southern Region of British Railways until 1971. Conceived by Oliver Bulleid for the Southern Railway's commuter line from London Charing Cross to Dartford, the two trains were the only double-decker trains to be used on the mainline railway network in Britain. Whilst commonly used in continental Europe and North America, the restrictive railway loading gauge in the United Kingdom prohibits normal double-decker trains with two fully separated decks.
who runs it
base stats
Bars compare against all trains: 600 km/h (maglev), 1,700 seats; power, weight and number built on a log scale up to 20 MW, 1,000 t and 20,000 built.
fun facts
- First built 77 years ago, in 1949.
- Weighs about as much as 23 African elephants (~6 t each).
- 78.3 m long: about 17 cars parked nose to tail.
- Seats 552: 11 full city buses (~50 seats each).
- Served for 22 years (1949–1971).
multiple unit: A self-propelled train: motors are spread under the passenger cars, so no separate locomotive.
spec sheet
- built
- 1949
- in service from
- 1949
- retired
- 1971
- status
- retired
- number built
- 2
- kind
- multiple unit
- traction
- electric
- origin
- 🇬🇧 United Kingdom
- builders
- Unknown builder
- operators
- British Rail
- top speed
- —
- power
- —
- gauge
- 1,435 mm standard gauge
- electric system
- 750 V DC
- formation
- DMBT, Driving Motor Brake Third-TT, Trailer Third-TT-DMBT
- length
- 78.3 m
- weight
- 135 t
- capacity
- 552 passengers
From the Wikipedia infobox and Wikidata. Blank means the sources don't say.
Sources: Wikidata Q2207682, Wikipedia: SR Class 4-DD (CC BY-SA 4.0).Updated 2026-10-25.