From D1 to TOPS

Like many railway systems around the World, British Railways and its masters were seduced by the claims of diesel loco manufacturers. Suddenly steam was old hat, and was disposed of in great haste. Many of the British Standard locomotives went to the scrapyard (or into preservation) with less than 10 years service on the clock. The last steam engine built at Swindon, for example, worked less than 7 years before withdrawal. Having said that, the last diesel built there spent only 3½ years on BR metals. Withdrawing thousands of steamers meant their replacement by thousands of diesel locos. It might have been thought that some effort would have been made to organise a structured numbering system, but then, this was BR after all! BR did have a code for each type, but it was essentially meaningless to all.

To begin with, diesels were classified rather in the manner of steam engines, that is, by power. This gave the operating authorities some idea when it came to matching locomotives to the trains they had to pull. For example, an ex-LNER A4 and an ex-LMS Coronation were classified as 8P, the BR 2-10-0s as 9F, and a B1 as 5MT (P – Passenger, F – Freight, MT – Mixed Traffic). The higher the number, the more powerful the locomotive. Diesels were thus classified according to their horsepower.

Type 1 – 800 – 1,000
Type 2 – 1,000 – 1,365
Type 3 – 1,500 – 1,750
Type 4 – 2,000 – 2,750
Type 5 – 3,000+

To identify individual types, professionals and amateurs alike referred to the maker of the loco along with its power type. Thus, engines numbered D200 – D399 were known as E.E. (English Electric) Type 4s. The major manufacturers of main line locomotives were:

Beyer Peacock
Birmingham Railway Carriage and Wagon Co (Birmingham R.C. & W.)
British Railways (BR)
British Thomson-Houston (BTH)
Brush
Clayton
English Electric (E.E.)
Metropolitan Vickers (Metrovick)
North British Loco. (NB)

Some of the above produced only one type of locomotive, and thus there was no need to refer to its power type. Metrovick produced a class of Type 2 with a curious arrangement of a 6 wheel bogie at one end, but only a 4 wheeler at the other. The term ‘Metrovick’ (or Co-Bo) thus referred to this particular type of loco. Similarly, Clayton built an attractive centre-cab Type 1 which ran to 117 units, but this was to be their only BR locomotive, and thus a Clayton’ could refer to only one type of engine. Last in this group were the 101 Type 3s built by Beyer Peacock. They had hydraulic transmission of the Mekhydro type, and were thus always known as the ‘Hymeks’. And very attractive they were too, in my opinion! Finally, some locomotives were known by the name given to the first of the class. The BR type 4 is a case in point. The first (D1) was called Scafell Pike, and the following nine also received names of high tops in England and Wales. Accordingly, the entire class of 193 was known as ‘Peaks’. The NB Type 4s on the Western Region were generically known as ‘Warships’, whilst the BR Type 4 hydraulics were the ‘Westerns’. Equally, no-one would have dreamed of ever referring to an EE Type 5, they were simply the ‘Deltics’, after the prototype. Enthusiasts did conjure up nicknames for certain classes, such as ‘Whistlers’, ‘Growlers’, and ‘Hoovers’. However, such names are outwith the scope of this article, and I never used the terms anyway! BR locomotives were built in BR’s own shops, such as Derby, Crewe, or Doncaster. However, repeat orders were sometimes put out to the private sector.

To complete the fist part of this article, the following table identifies running numbers and classes. The word ‘hydraulics’ refers to the transmission system.

D1 – D193 BR Type 4 (the Peaks)
D200 – D399 EE Type 4
D400 – D449 EE Type 4 (second series – the 400s)
D600 – D604 NB Type 4 (hydraulics A1A – A1A bogies – Warships)
D800 – D832 BR Type 4 (hydraulics – Warships)
D866 – D870
D833 – D865 NB Type 4 (hydraulics – Warships)
D1000 – D1073 BR Type 4 (hydraulics – the Westerns)
D1100 – D1111 Last dozen Brush type 4s
D1200 Brush prototype named ‘Falcon’ and originally D0280
D1500 – D1999 Brush Type 4.
D5000 – D5299 BR Type 2. Class continued D7500 – D7677
D5300 – D5415 B’ham RC&W Type 2
D5500 – D5699 Brush Type 2 or 3. Class continued D5800 – D5862
D5700 – D5719 The Metrovicks D5900 – D5909 EE Type 2. (The Baby Deltics)
D6100 – -D6157 NB Type 2
D6300 – D6357 NB Type 2 (hydraulic transmission)
D6500 – D6597 B’ham RC&W Type 3
D6700 – D6999 EE Type 3 Class continued D6600 – D6608
D7000 – D7100 Beyer Peacock Type 3 (always known as the Hymeks)
D8000 – D8199 EE Type 1. Class continued with D8300 – D8327
D8200 – D8243 BTH Type 1
D8400 – D8409 NB Type 1
D8500 – D8616 Clayton Type 1
D9000 -D9021 EE Type 5 (always known as the Deltics)
D9500 – D9555 BR Type 1. An 0-6-0 hydraulic meant for trip working.

BR had other locos on its books, including a number built around Nationalisation or just after. This included the pioneer LMS 10000. A number of prototypes were also to be seen on BR metals, although they were not in BR stock. Finally, there were varieties of electric locomotive. On the ex-LNER Woodhead line, two types worked at 1,500 volts dc. Southern Region had three large early BR types, a class of straight electrics , and a number of hybrid electro-diesels, all using 660 volts dc, and working off the third rail. (The straight electrics also had pantographs for yard working). Finally, the private sector, and then BR, built a couple of hundred engines for the WCML, and running under the wires at 25 kilovolts ac. From this morass BR finally decided to reorganise the numbering of their stock, to give some order to the chaos.

The first major step was the removal of the ‘D’ prefix from almost all diesel numbers. This was really useful, and must have cost a lot of money in paint and painters’ time. Secondly, TOPS was introduced. TOPS (Total Operations Processing System) was a computerised form of classification, pinched from the Southern Pacific Railroad in the USA. It was introduced in the late 1960s, and was not immediately successful. However, with modification, the system was made to work, and now includes multiple units as well as locomotives. It should be pointed out, however, that several classes that were allocated TOPS classification never actually carried the new numbers, whilst there was a major cull of locomotives around this time, which mean that several locomotives were never even given a classification. What TOPS did manage to do was to differentiate the different versions of classes of locomotive. For example, within the same body shell might lurk two or three variations of the basic locomotive. These variations might refer to horsepower, the type of engine unit, the size of the shell, or whether or not the particular locomotive was fitted with certain types of equipment. Under BR, the Peaks were looked upon as one class. However, the first 10 were rated at 2,300 hp, whilst the remainder were 2,500 hp. The Brush Type 2 or 3 body contained a single engine unit that ran at different speeds. This gave power outputs of 1,250, 1,365, and 1,600 hp, whilst one loco was temporarily uprated to 2,000 hp – technically a Type 4. Again, the last dozen B’ham RC&W Type 3s were slightly thinner, to fit the tunnels on the Hastings line, and so on.

The basic TOPS structure worked as follows. Each class of locomotive was given a class number. This related closely to the Type classification. Type 3s, for example, were classed in the range 30 – 39. After the class number came the locomotive number. All the EE Type 3s became Class 37, and locomotives were numbered 37 001 and upwards. However, a refinement meant that some locomotives lost their train heating boiler, rendering them useless for pulling steam-heated passenger coaches. These locos became sub. class 37/3, and their running numbers began 373xx. The replacement of the steam heating boiler with electrical train heating equipment mean a further reclassification as 37/4, and a new number series beginning 374xx. This gave the operators a much clearer idea of what locomotives would be suitable for each particular train. The class ranges were as follows:

TOPS Class Power Classification

01 to 09 Shunters below 600 hp
10 to 20 Type 1
21 to 29 Type 2
30 to 39 Type 3
40 to 52 Type 4
53 to 55 Type 5
56 to 69 New types not already in existence
70 to 79 Electro-diesels and other electrics not working on 25kv
80 to 99 Existing and new electrics.

The following table lists the locomotives that BR owned up the end of the 1960s that were given TOPS classification. As mentioned, several did not exist long enough to actually carry their new numbers. Classes that have appeared since that time are rather outwith the scope of this article, as they have always been known by their TOPS classification. I have ignored shunters, again as I have been concentrating on what Americans would refer to as ‘road’ engines, main line locomotives not tied to small or marshalling yards.

TOPS Original Classification

14 BR Type 1 0-6-0 (numbers D9500 – D95)
15 NB Type 1
16 BTH Type 1
17 Clayton Type 1
20 EE Type 1
21 NB Type 2
22 NB Type 2 (hydraulic, numbers D6300 – D6357)
23 EE Type 2, the Baby Deltics (numbers D5900 – D5909)
24 BR Type 2 (numbers D5000 to D5150)
25 BR Type 2 (numbers D5151 – D5299 and D7500 – D7677)
26 B’ham RC&W Type 2 (numbers D5300 – D5346)
27 B’ham RC&W Type 2 (numbers D5347 – D5415)
28 Metrovicks (numbers D5700 – D5719)
29 NB Type 2 (re-engined by Paxman, numbers D6100-03/06-08/12- 14/16/19/21-23-24/29-30/32-33/37)
30/31 Brush Type 2 and 3. Class 30 was reserved for those locos that were still fitted with the original Mirrlees engine unit. Class 31 was for those re-engined with an EE power plant. However, by the time TOPS was on its way, almost all had the new engine, and it is doubtful if any loco ever received a 30xxx number. (Original numbers D5500 – D5699 and D5800 – D5862)
33 B’ham RC&W Type 3 (numbers D6500 – 6597)
35 The Hymecks (numbers D7000 – D7101)
37 EE Type 3 (numbers D6700 – D6999 and D6600 – D6608)
40 EE Type 4 (numbers D200 – D399) 41 NB Warship (numbers D600 – D604)
41 Also – the two prototype HST ‘locomotives’ were classified thus.
42 BR Warships (numbers D800 – D832/D866 – D870) 43 NB Warships (numbers D833 – D865)
43 Production IC125 power cars
44 BR Peaks (numbers D1 – D10) 45 BR Peaks (numbers D11 – D137)
46 BR Peaks (numbers D138 – D193).
47 Brush Type 4 (numbers D1500 – D1999/D1100 – D1111)
50 EE Type 4 – the 400s (numbers D400 – D449)
52 BR Westerns (numbers D1000 – D1073)
55 EE Type 5 – the Deltics (numbers D9000 – D9021)

Within the list above, certain classes have several sub groups, depending upon electrical equipment, train heating, etc. As noted many classes never actually carried their TOPS code. Locos deemed non-standard were ruthlessly cleared out by the early 1970. This included al the hydraulics, with the exception of the Westerns. However, with cast metal numberplates it was considered a waste of money to renumber them also. If there is a demand, I’ll produce a follow-up article to look at the electrics that were renumbered, and also at what has happened to some of the survivors of the fleet from the 1950s and 1960s. For further information or questions that arise, please feel free to contact the writer at the website.

By Ken McKee

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