Disc Headcodes

Many of the locos hauling trains along the North Wales coast were Class 24s and 40s built before the 4 character headcodes displays were introduced, and fitted with the disc type of headcode. The discs gave no indication of route - just of train classification.

24082 at Shrewsbury 16/07/7724082 shows the disc layout: 4 discs repeating the pattern used on steam locos. When open, the disc showed a white face, with a light shining through a hole in the lower half of the disc. Closed, by folding the top half down, the white face and light were obscured. The disc could also be folded up, obscuring the face but leaving the light visible. The lights were independently switched.

I had always assumed that the arrangement of disc codes matched that previously used for steam. However, when putting together this page, it became apparent that was not the case. Headcodes were revised in 1962 to allow for the numeric classification of trains, and there was then a major revision in 1969. Finally, in 1977 the use of different headcodes was abandoned. The various headcodes used from 1962 onwards are shown below.

Pass your mouse over these links to see the disc headcode and train classification description

1962-1969: Class [1] [2] [3] [4] [5] [6] [7] [8] [9] [0] [Royal]
1969-1977: Class [1] [2] [3] [4] [5] [6] [7] [8] [9] [0] [Royal]

 

Here are some example pictures of Class 24s and 40s showing various headcodes

40025 at Bangor 07/11/75

One unmistakeable headcode is this one - all four discs showing together - the code for the Royal Train. Often seen at open days and the like, this is the genuine article. 40025 works the stock of the Royal train out of Bangor on the 7th November 1975.

40013 at Llandudno Junction 24/07/76

Here is 40013 on 24th July 1976 working 5D74 Empty Coaching Stock from Llandudno to Holyhead, and displaying the correct Class 5 headcode. Seen at Llandudno Junction where it ran round.

24080 at Llandudno Junction 27/07/76

24080 works the afternoon trip from Llandudno Junction to Mold Junction on 27th July 1976. This is train 8T30, and the headcode is the correct one for a Class 8 train.

24091 at Llandegai 03/09/76

24091 works 17:55 Bangor-Crewe Parcels on the 3rd September 1976. This is train 4K53, showing the Class 4 headcode.

24081 at Bangor 06/09/76

24081 shows the "Light Engine" headcode as it waits in Platform 4 at Bangor on trip 50, the Bangor shunt. Train reporting code 0T50. 6th September 1976.

24063 at Chester 23/04/77

From mid-1977 onwards, it became policy that the "Class 1" code of two white discs would be used for all trains. 24063 shows this code on Chester shed on 23rd April 1977. However, unlike the conversion to showing '0000' headcodes which had a very definite implementation date, the use of the various disc headcodes only gradually stopped between March and June 1977.