There have been a number of
TOPS class numbers assigned to proposed
locomotives in the UK that have not been built for one reason or another.
Diesel locomotives
Type 1 locomotives
Class 18 – A proposed new Type 1 locomotive proposed in the mid 1980s. A 1988 proposal was for a 6-wheeled 800 hp locomotive with a maximum speed of 50 mph, similar in concept to
Class 14.[1] No prototype was constructed.
Type 3 locomotives
Class 38 – Projected classification for new generation of Type 3 freight locomotives in the 1980s. The Class 38 was dropped in favour of the
Class 60.
Type 4 locomotives
Class 41 – The third use of
Class 41 was for a proposed class of
Class 60 locomotives with 2,500 hp engines in the early 1990s.
Class 48 – The second use of
Class 48 was a proposal for a new class of locomotive for the 1990s, with gearing differences for slower freight work or higher speed loco-hauled for InterCity or parcels trains. The proposal included using proven technology for engines and electrical systems to avoid lengthy introduction and development costs associated with developing new technology.
Type 5 locomotives
Class 51 – Projected classification for the proposed "Super Deltic" locomotive intended as a follow on from the
Class 50 and
Class 55.[2][3][4][5]
Class 62 – Projected classification for proposed Type 5 coal train locomotives in the early 1990s.
Class 65 – Projected classification for proposed 4,000 hp freight working locomotive intended for liner trains.
Electro-diesel locomotives
Class 75 – Spare classification for projected "super electro-diesel" follow on from
Class 73 and
Class 74.
Electric locomotives
Class 88 – The first use of
Class 88 was for a proposed electric version of the
Class 58, powered through 25 kV AC from
overhead wire.
^Locomotive Rivals from Across the Pond. D. Clough. Rail (magazine), issue 805, Jul-Aug 2016.
^Haresnape, Brian (June 1984) [1982]. 3: Production Diesel-Electrics Types 4 and 5. British Rail Fleet Survey (2nd ed.). Shepperton:
Ian Allan. p. 6.
ISBN0-7110-1450-7. CX/0684.
Nock, O.S. (1985). British Locomotives of the 20th Century: Volume 3 1960-the present day. London: Guild Publishing/Book Club Associates. p. 75. CN9613.
There have been a number of
TOPS class numbers assigned to proposed
locomotives in the UK that have not been built for one reason or another.
Diesel locomotives
Type 1 locomotives
Class 18 – A proposed new Type 1 locomotive proposed in the mid 1980s. A 1988 proposal was for a 6-wheeled 800 hp locomotive with a maximum speed of 50 mph, similar in concept to
Class 14.[1] No prototype was constructed.
Type 3 locomotives
Class 38 – Projected classification for new generation of Type 3 freight locomotives in the 1980s. The Class 38 was dropped in favour of the
Class 60.
Type 4 locomotives
Class 41 – The third use of
Class 41 was for a proposed class of
Class 60 locomotives with 2,500 hp engines in the early 1990s.
Class 48 – The second use of
Class 48 was a proposal for a new class of locomotive for the 1990s, with gearing differences for slower freight work or higher speed loco-hauled for InterCity or parcels trains. The proposal included using proven technology for engines and electrical systems to avoid lengthy introduction and development costs associated with developing new technology.
Type 5 locomotives
Class 51 – Projected classification for the proposed "Super Deltic" locomotive intended as a follow on from the
Class 50 and
Class 55.[2][3][4][5]
Class 62 – Projected classification for proposed Type 5 coal train locomotives in the early 1990s.
Class 65 – Projected classification for proposed 4,000 hp freight working locomotive intended for liner trains.
Electro-diesel locomotives
Class 75 – Spare classification for projected "super electro-diesel" follow on from
Class 73 and
Class 74.
Electric locomotives
Class 88 – The first use of
Class 88 was for a proposed electric version of the
Class 58, powered through 25 kV AC from
overhead wire.
^Locomotive Rivals from Across the Pond. D. Clough. Rail (magazine), issue 805, Jul-Aug 2016.
^Haresnape, Brian (June 1984) [1982]. 3: Production Diesel-Electrics Types 4 and 5. British Rail Fleet Survey (2nd ed.). Shepperton:
Ian Allan. p. 6.
ISBN0-7110-1450-7. CX/0684.
Nock, O.S. (1985). British Locomotives of the 20th Century: Volume 3 1960-the present day. London: Guild Publishing/Book Club Associates. p. 75. CN9613.