On diesel loco numbering, why was there no classes 61 to 65?

Question

We had the 60s in the early 90s; the next new locos were the American built Class 66s so why the large gap?

Answer 1

It was due to TOPS being unable to handle duplicate numbers.  When the class 60s were built, the one remaining Hastings DEMU had to have its end cars renumbered in order to allow the class 60s to occupy 60001 to 60100.

Now that we have numerous private operators, it doesn't matter so much as it's only duplication within an operator or leasing company that would cause problems.

So there are now 2 57301s running about for example, One of them is a class 57 locomotive, the other is a class 153 DMU.

Answer 2

At a guess, it's because vehicle numbers in the 61xxx to 65xxx ranges were already in use for EMUs, and TOPS/GEMINI/GENIUS would get horribly confused if you had duplicate numbers.

Answer 3

The numbering of UK locomotives go'es back to the modernisation plan in 1955.

Type 1 locomotives in 1000BHP (or less) to 1999BHP

Type 2 locomotives in 2000BHP-2999BHP range

Type 3 locomotives in 3000BHP-3999BHP range

Type 4 locomotives in 4000BHP-4999BHP range

BHP=brake horse power.

Later there were more powerful locomotives in the Type 5 power range.

Locos were allocated numbers prefixed with a letter denoting power type...Dxxxx for diesel Exxxx for electric.

Originally steam locos were going to be Sxxxx but this was dropped.

During the 1970's British Rail intoduced a computerised data base to keep track of all it's rail assets.

T.O.P.S  Total Operating Prossesing Sytstem.

This meant all Locomotives and rolling stock (coaches and waggons) were re-numbered.

Type 1 locos became 0-19

Type 2 ..20-29   etc

i.e a more powerful loco gets a higher number

With the introduction of class 60(would've been therefore a Type 6 loco) and class 66 there are powerbands available for locomotive to be introduced inbetween them.

(Proposed but not built).

T.O.P.S can be used for the re-introduction of powerband classes with have been withdrawn in the past...i.e class 13 or 28,but preserved locomotives acually reintroduced to the mainlines are classified 97XXX...Ex LNER loco "flying scotsman" would be 97472 as the only the last 3 digits of it's original number are used.

Answer 4

Class 61 was originally earmarked for what became the Class 66*.

Class 62 was allocated to proposed General Motors Trainload Coal Co-Co Type 5 in 1990, plan scrapped in 1991

Classes 63 & 64 were never allocated*

Class 65 issued for proposed 4,000hp Co-Co freight loco for use on liner trains using Mirrlees V-16 engine - cancelled

*Why this should be the case, in each instance, I have been unable to find out

Answer 5

You must be in the U.K.?Here in the states EMD has progressed with the SD50,SD60,SD70 and SD90 series locomotives.