Class 4 article

12V was a voltage standard for LEGO Trains sets from 1969 until 1991 and complemented the older battery powered 4.5V standard. The power of the 12V system came from a mains powered DC Transformer delivered by add-on center conductor rails. TECHNIC also offered a 12V motor in the form of 880 12 Volt Motor which ran from 1977 to 1982.

In order to reach the newer 12V standard, the older – but still co-existing – 4.5V Trains system could be upgraded by using different 12V Trains accessories.

The second generation "gray" system introduced in 1980 brought much more functionality and expansion options, with the system able to support functioning lights inside the trains, remote controlled signals, power operated points/switches, decouplers and level crossings.

No further 12V sets were released after 1986, and the 12V powered trains were replaced by 9V trains in 1991. Spare parts and accessories for the 12V system (but not complete sets) remained on sale via LEGO mail order service until 1993.


Leaflet explaining the transition from 12V to 9V made in 1993 (in French)

12V Powered Sets[]


Trains Accessories[]

Service Packs[]

Complete List[]

Image#SetNumber of piecesMinifiguresPriceRelease
11-Locomotive Traction Tires11Locomotive Traction Tyres8 1977
11041104Battery Cables  1981
11-Locomotive Traction Tires1111Rubber Rims for Locomotive Wheels8 1977
12-Wheel Bearings for Locomotives1112Train Sliding Wheel Blocks2 1977
1119 Locomotive Piston Assemblies1119Locomotive Piston Assemblies6 1977
11-Locomotive Traction Tires1138Replacement Rubber Wheel Treads for Trains8 1981
1140-1-911824257114012V Light Brick2 1981
1146-1-91182448511464 Pushrods, 2 Cylinder Housings6 1981
1147-1-91182391011472 Light Prisms, Light Prism Holder, 2 Red and 2 Yellow Light Covers7 1981
1150 Replacement Motor 12V1150Replacement Motor 12V1 1977
12-Wheel Bearings for Locomotives12Wheel Bearings for Locomotives2 1977
123911239Remote Control for Electric Points  1985
19-Locomotive Piston Assemblies19Locomotive Piston Assemblies6 1977
26-12V Motor2612V Motor1 1977
506950692 Lighting Bricks 12 V2 1987
5083-15083Remote Control for Crossing 12V1 1989
5084-15084Lighting Bricks 12V for Signals1 1989
0703-170312V Replacement Motor1 1969
0704-170412V Sleeper (Track) Contacts2 1969
0705-1705Motor Bushings4 1970
0706-1706Rail Contact Wires1 1970
0708-17082m Extension Cord for Points1 1970
0722-272212V Electric Train with 2 Wagons151 1970
0723-1723Diesel Locomotive95 1970
0724-172412V Diesel Locomotive with Crane Wagon and Tipper Wagon155 1972
0725-2725Freight Train Set4252 LEGOLAND Minifigures 1974
0726-1726Western Train2873 LEGOLAND Minifigures 1976
0727-1727Locomotive134 1977
0741-174112V Transformer1 1974
0742-174212V Transformer - for 100V Mains1 1970
0750-1750Straight Conductor Rails8 1969
0751-1751Curved Conductor Rails8 1969
753 Automatic Right Electric Switch753Automatic Right Electric Switch4 1969
754-Automatic Left Electric Switch754Automatic Left Electric Switch4 1969
0755-1755Left and Right Points12None 1974
756-1756Electric Crossing5 1974
7715-17715Push-Along Passenger Steam Train4495$49.501985
7725 Box7725Electric Passenger Train Set4851 1981
7727-1-17727Freight Steam Train Set5702 1983
7730-17730Electric Goods Train Set5122 1980
7735-17735Freight Train Set5092 1985
7740-17740Inter-City Passenger Train Set78610 1980
7745774512 Volt High Speed Train73610 1985
7750-17750Steam Engine with Tender2632 1980
7755-17755Diesel Heavy Shunting Locomotive1641 1983
7760-1-17760Diesel Shunter Locomotive1502$29.991980
7823-17823Container Crane Depot4872$45.001986
7834-17834Level Crossing911 1980
7839-17839Car Transport Depot3402$39.001986
7850-17850Straight Rails32$$9.251980
7851-17851Curved Rails32$9.251980
7854-17854Straight Electric Rails8 1980
7855-17855Curved Electric Rails8 1980
7856-17856Electric Points16 1980
7857-17857Electric Crossing5$8.751980
7858-17858Remote Controlled Points Right 12V12 1980
7859-17859Remote Controlled Points Left 12V12 1980
7860-17860Remote Controlled Signal24 1980
7861-17861Lighting Set Electric 12V28 1980
7862 Box7862Remote Controlled Decoupling16 1981
7863-17863Remote Controlled Point Motor 12V7 1980
7864-17864Transformer / Speed Controller 12V33 1980
7865-17865Motor Replacement Unit for Battery or Motor-Less Trains 12V19 1980
7866-1-27866Remote Controlled Road Crossing 12V1911 1983
7867 Box78674 Lighting Standards Electric 12V52 1983