#3529

British Rail Class 121

🇬🇧 United Kingdom ·built by Pressed Steel Car Company· from 1960· class of single-car diesel multiple units

10 photos from Wikimedia Commons · credits & licences

1. 19880827-Paddington-Class121: Copyright © 1988-2009 K. Krallis Sv1xv· CC BY-SA 3.0
2. 121L124: Murgatroyd49· CC BY-SA 4.0
3. Class 121 Diesel Bubble Car Railcar at Didcot Great Western Railway Centre (7881328066): Andrew Bone from Weymouth, England· CC BY 2.0
4. Class 121 Diesel Bubble Car Railcar at Didcot Great Western Railway Centre (7881334832): Andrew Bone from Weymouth, England· CC BY 2.0
5. Class 121 Diesel Bubble Car Railcar at Didcot Great Western Railway Centre (7881341740): Andrew Bone from Weymouth, England· CC BY 2.0
6. Class 121 Diesel Bubble Car Railcar at Didcot Great Western Railway Centre (7881348608): Andrew Bone from Weymouth, England· CC BY 2.0
7. Class 121 diesel railcar (2830738441): Timitrius from Great Britain· CC BY-SA 2.0
8. Class 121 L102 and a Class 33 at Reading in 1979: The Basingstoker· CC BY-SA 2.0
9. Class 121 L128 at Oxford in 1979: The Basingstoker· CC BY-SA 2.0
10. GWR AEC Railcar W22 with Class 121 DMU Bubble RailCar at Great Western Railway Centre in Didcot (7881320994): Andrew Bone from Weymouth, England· CC BY 2.0

what is it?

The British Rail Class 121 diesel multiple units were built by Pressed Steel from 1960 to 1961. Sixteen driving motor vehicles were built, numbered 55020–55035, which were supplemented by ten single-ended trailer vehicles, numbered 56280–56289 (later renumbered 54280–54289). They have a top speed of 70 mph (113 km/h), with slam-doors and vacuum brakes.

who runs it

British Rail Network SouthEast Regional Railways Silverlink Railtrack Network Rail Arriva Trains Wales Chiltern Railways Western Region of British Railways

base stats

seats 65passengers
built 16made in total

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 66 years ago, in 1960.
Still in service after 66 years.

multiple unit: A self-propelled train: motors are spread under the passenger cars, so no separate locomotive.

spec sheet

built: 1960
in service from: 1960
status: in service
number built: 16
kind: multiple unit
traction: diesel
origin: 🇬🇧 United Kingdom
builders: Pressed Steel Company
operators: British Rail, Network SouthEast, Regional Railways, Silverlink, Railtrack, Network Rail, Arriva Trains Wales, Chiltern Railways, Western Region of British Railways
top speed: —
power: —
formation: Single car (with trailer), DMBS (+DTS)
capacity: 65 passengers

From the Wikipedia infobox and Wikidata. Blank means the sources don't say.

Sources: Wikidata Q3307596, Wikipedia: British Rail Class 121 (CC BY-SA 4.0).Updated 2026-10-25.