Question on british renumbering?

[midrange]

My dad is going to be building a British set up. He was born and raised in England and recalled numbers (trainspotting) being for example, D3456. The D being for diesel etc i think.

We are looking into hornby items and notice that numbers have been changed from a D number to a class number followed by a train number.

We are curious to when they changed/started doing that type of numbering system.

Heres an example of a deltic D9009

 

[AndrewC]

Hi Midrange. BR numbering of diesel and electric originally started with a 4 digit number with either a D or E prefix to denote diesel or electric. Starting in 1972 these numbers were replaced with the TOPS coding. In the case of the Deltic in your picture it would be a class 55. Its new number was 55009.

Roughly speaking

class
1 - 10 = shunting locos
11-19 = small locos
20 - 29 = larger, etc

Until you get to 69 the higher the number the more powerful the loco.
70-79 was reserved for electro diesels. Locos that had pickups and a diesel engine.
80 - 95 are electric locos, and 96-99 are reserved for special locos.

Above 100 the class denotes the type of multiple unit.
1xx - diesel mechanica multiple units
2xx -diesel electric multiple units
3xx - electric units either dual voltage or 25kv overhead
4xx - Southern region 3rd rail units.
5xx - other 3rd rail units.

A complete list of locos/units and their tops codes are available at:
http://www.therailwaycentre.com/New TRC Main Pages/Resource Centre.html

Hope this helps. Just ask if you need more info.

 

[midrange]

Thanks Andrew.. That helps a lot.. I will show him this when hes here next time.

Cheers