Thompson non-gangwayed coaches
Thompson started with steel-panelled gangwayed designs in 1946 and proceeded to the secondary stock the following year where the need was greater with vast numbers of pre-Grouping carriages still ploughing furrows. After so many different varieties under Gresley when the Areas and Sections called the tune, Thompson established genuine standard designs with only 4 Diagrams. All were 52'4" long, only slightly longer than Gresley's 51'1 1/2" designs:
It may be added that the Wikipedia article about Thompson contains misleading personal bias (I take no sides myself) and the part about his carriages is flimsy and completely wrong. Other accounts have missed key points. There is a tendency to hate Thompson and much of the historical record could be better.
This is going to take time to build up and the sequence, when all have been worked up, will be:
1 - Basic concepts 2 - CL 1st/3rd lavatory composite 3 - T 3rd 4 - BT(4) 3rd brake 5 - F 1st 6 - BC 1st/3rd brake 7 - BT(5) 3rd brake 8 - On the WR Culm Valley branch
New additions placed here temporarily:
A group of pictures showing Thompson carriages in a variety of services on the NE Region:

J21 No 65047 (Kirkby Stephen) passes Tanwath with a cross-country Ordinary Passenger train between Penrith-Darlington on a rainy Tuesday 30th May 1950. The leading three carriages are modern Thompsons but there's what looks like an ex-GNR Gresley carriage on the rear:
BT |
3rd brake |
Thompson |
52'4" |
CL |
1st/3rd lavatory composite |
Thompson |
52'4" |
BT |
3rd brake |
Thompson |
52'4" |
BC? |
1st/3rd brake |
ex-GNR Gresley |
58' 1 1/2" |
It's another example showing how common were mixtures of old and new carriages, and that modellers' description of these carriages as "suburban" is misleading. Photo: SLS No 18558
Click on the image for an enlargement

Middlesbrough's V1 No 67677 is shunting what may be a 5-set in the early 1950s at an unidentified location. Once again, the carriages are a mixture of the old and new:
BT |
3rd brake |
Thompson |
52'4" |
CL |
1st/3rd lavatory composite |
Thompson |
52'4" |
C |
1st/3rd |
ex-NER |
|
T |
3rd |
ex-NER |
|
BT? |
3rd brake? |
Thompson? |
52'4"? |
Only a fraction of the last carriage in the photo can be seen but it looks like a Thompson and a BT is a reasonable estimate. Photo: R.K. Blencowe collection.
Click on the image for an enlargement

Blaydon's V1 No 67639 runs into Newcastle c1955 with a train from Peckhill & Consett. There are no longer any pre-Grouping carriages in this train and further modernisation can be seen by deployment of a BR Mk.1 3rd brake:
BT |
3rd brake |
Thompson |
52'4" |
CL |
1st/3rd lavatory composite |
Thompson |
52'4" |
BT |
3rd brake |
BR Mk.1 |
57' |
BG |
bogie van |
ex-LMS |
50' |
Note the bogie van on the rear, in this case a Stanier BG, many of which found themselves in the NE Region. It's worth adding that 3rd class wasn't redesignated 2nd class until June 1956. Photo: P. Ransome-Wallis.
Click on the image for an enlargement
1. Basic concepts
Some say that these were among Thompson's best arrivals, especially where they ousted ageing pre-Grouping carriages, in the West Riding for example where modernisation had ground to a halt and they came after the War as a welcome breath of fresh air. Unlike the gangwayed carriages for expresses where there were some radical departures, the secondary carriages followed Gresley's steel-panelled designs of the 1930s and '40s quite closely.
The differences were relatively minor. To begin with, leg room in the compartments was increased by a couple of inches and this led to a small increase in overall length from 51'1 1/2" to 52'4". They were still short compared with other companies' carriages and can be hard to distinguish from Gresley's SP designs because the external differences were so minor, except for where a lavatory was provided with an elegant oval window. The brake-ended coaches differed most for the guard's end was no longer recessed and the ducket was dropped. Common to all were these external changes in detail:
- grab handles - were slightly longer with the door handles positioned off-centre. - solebar step - was positioned slightly higher (and is a good identifier in a train containing both designs). - trussing - was deeper, same as in the gangwayed carriages. - battery boxes were on one side only.
Introduction was:
1947 D.338 - CL D.339 - T 1948 D.340 - BT D.341 - F
Later developments
Three years later, BR(E) saw fit to add two more designs:
1951 D.360 - BC D.361 - BT
The last Diagram was for a BT(5), many of which were for the Scottish Region, others for the NE Region, and was only built that year. One senses that standardisation of only one design of BT - a BT(4) - was not viewed kindly and that a brake with a larger passenger capacity was required. A BT(5) was thus added.
The same year saw introduction of a brake composite with even more seats as a BC(2,4). The reason was a desire for a carriage with a smaller number of 1st Class seats than in the CL and minimal van space for use in short trains, and as a response for continuing fall in demand for 1st Class seats in secondary services in less well built up areas. Indeed, construction of large numbers of the F was questionable and conversion began to composites. Thompson had retired in 1946 and these last, more practical designs should be attributed to Peppercorn.
The last ones were built in 1953. In the process, the window design was revised from square to round corners. As far as I can tell this took place over the winter of 1948/49.
2. CL - 1st/3rd semi-corridor lavatory composite
Thompson's version of the CL came first and was a minor departure from the past because the handing was reversed; the man wanted his stock to look different although many people were only aware of the different grab handles and a more modern interior, and on the CL, where there had been a rectangular window, an oval window was provided. The LMS made a similar change at the time but with "porthole" type windows. Thompson's design was more pleasing.

Click on the image for an enlargement
The Diagram of the CL, which needed a lot of repair, shows the corridors on both sides of the coach (and, incidentally, why the term "corridor coach" is so misleading when applied to gangwayed stock). Note the deeper upholstery and armrests in the 1st Class compartments, their width increased by the odd inch compared with the Gresley version, the 3rd by two inches. The toilets benefitted most, by almost 5", which enabled a small corner table to be added. Diagram: Author's collection.
Running numbers were:
1947 - 88327-83
1948 - 88384-426
1950 - 88427-49
1952 - 82716-96

CL No E88412 was captured on 9.6.56 at Sutton-in-Ashfield (between Nottingham and Lincoln), eight years old and still carrying the original simulated teak livery, but with an E suffix added to the running number. It was built in 1948 with square corners to the windows so it's safe to say that the ones built in 1950 and 1952 received rounded corners.
Livery - when describing Thompson's gangwayed carriages I noted how the simulated teak was more elegant than teak panelling had been and in place of a chequerboard arrangement to try and harmonise wide differences between panels, a painted finish could achieve a pleasing uniformity and it's evident here. Indeed, in a b&w image it's hard tell between it and the crimson painted BR Mk.1 coach next to it. On the other hand, modellers may like to note the colourful mixture of liveries so common when liveries were changed (some would say that they were always changing) and so often hard to see in a b&w image. Photo: H.C. Casserley.
Click on the image for an enlargement
In service
Introduction by Thompson of numbering by Diagram meant that the regional prefixes were lost so it's hard to identify where the carriages were deployed. It is known that many were used in East Anglia, the Nottingham district, the West Riding conurbation (see link), and the North East, and that they were mixed with the immediately preceding types, Gresley teak-panelled and steel-panelled. Here are some examples:

N1 69430 is at Wilsden midway between Keighley and Queensbury in 1956. The 1st class passengers were provided with a Thompson CL, behind which was a Gresley steel-panelled 3rd brake to BT(6). Note the minor differences described above between the types. Photo: G.B. Blakelock.
CL |
1st/3rd lavatory composite |
Thompson |
52'4" |
BT |
3rd brake |
Gresley |
51' 1 1/2" |

This view on the NE region in 1958 shows a Goathland-Whitby train arriving at Ruswarp behind ex-NER A8 No 69861. It's another two-coach formation but made up with two Thompsons. Photo: Michael Mensing.
Click on the image for an enlargement

A detail view is methinks, overdoing things! The formation is interesting, though:
CL |
1st/3rd lavatory composite |
Thompson |
52'4" |
|
BT |
3rd brake |
Thompson |
52'4" |
- The BT(5) version of 1951 and the last design. |
Click on the image for an enlargement
3. T - 3rd
I don't have a portrait of the Thompson 3rd but here is the Diagram and some construction notes:

This, the second Diagram to be introduced, was quite basic and shows how the overall length of 52'4" was derived - eight compartments 6'4" wide. The drawing shows the original design with square-cornered windows; later ones built from the winter of 1948-9 received rounded corners. Quite a vast quantity was built and running numbers were:
1947 - 82643-74
1948 - 82675-85/5-91
1949 - 82683-4/91
1950 - 82693-715
1951 - 82716-890
1952 - 82891-3
Click on the image for an enlargement
In service
The following illustrations concentrate on relatively short formations. Where only two coaches were required and both were brake-ended there was no need for a 3rd but if three coaches were required there were two options, depending on the route and if lavatories were required:
(BT,CL,BT) or (BC,T,BT).
- often a mixture of Gresley and Thompson types.

Seen in the early 1950s at Sunderland is A8 4-6-2T No 69863 (Sunderland) with a partly modernised 3-set comprising a Gresley teak-panelled and two Thompson steel-panelled.
Click on the image for an enlargement

A closer view shows the formation:
BC |
1st/3rd brake |
52'4" Thompson |
T |
3rd |
52'4" Thompson |
BT(3) |
3rd brake |
51'1 1/2" Gresley |
Evidently aimed at short distance trips in the North East conurbation, there were no lavatories and only two compartments for 1st class passengers. Photo: author's collection.

Seen in 1957 at Bishop Auckland is the same formation in Link B behind Sunderland's G5 0-4-4T No 67320. Photo: author's collection.
Click on the image for an enlargement

This example shows a cross-country Ordinary Passenger c1957 with L1 No 67765 in charge (it moved between Middlesbrough and Whitby) and a 4-set has been provided with lavatories and more space for 1st class passengers. The location is crossing the River Esk at Ruswarp on the line between Grosmont and Whitby and the train has probably taken the long circuitous route from Middlesbrough via Picton and Battersby. The formation is:
vanfit |
||
BC |
1st/3rd brake |
52'4" Thompson |
T |
3rd |
52'4" Thompson |
CL |
1st/3rd lavatory |
51'1 1/2" Gresley |
BT(4) |
1st/3rd brake |
52'4" Thompson |
The loco may look scruffy but the coaches look fine. The ventilated vanfit may have been part of a fish roster returning to Whitby. Photo: SLS ref: 3332.
Click on the image for an enlargement
4. BT(4) - 3rd brake
Thompson continued genuine standardisation by only designing a single 3rd brake and it was a BT(4), unlike during the Gresley era when there had been four different versions: BT(3), BT(4), BT(5) and BT(6). In fact the ER relented and in 1951 - deep in BR days - a batch of BT(5) was produced (more on this later). The brake-end designs followed on from the Gresley steel-panelled ones with only minor changes, as described above. Most significantly, a ducket for the guard was dispensed with, a featured which Gresley had abandoned in the 1920s and then reinstated. Under Thompson it was gone for good. Details included a slightly different horizontal grab rail at the guard's end - a pleasing flourish.
Like the other designs the passenger windows were square-cornered at first, radiussed, later. The toplights at the guard's end were so slim that when radiussed, they effectively had round ends.

The Diagram shows the general layout with square corners to the windows; details like this were generally considered too minor for a new Diagram to be issued. Incidentally, Harris doesn't give any details for construction of D.340 in 1946 or 1947.
A note in passing about terminology which often vexes modellers' minds. The CL was titled as a "Corridor" coach, because of course, it was. The BT was titled "Ordinary", the LNER's long-standing term for non-gangwayed carriages. The word was often abbreviated to "O" which has led some people to designate them wrongly as "open". Diagram: Author's collection.
Click on the image for an enlargement
Known running numbers were:
1948 - 86009-87054/6/7
1949 - 870558-127
1951 - 87128-77, 87228-97

Seen at Thornton Jc. in June 1967, SC87129E built by Metro-Cammell in 1951, was on the point of withdrawal after a service life of only 16 years - a fate shared by many other non-gangwayed carriages as BR replaced them with the DMU and EMU. Note that this Scottish coach was lined, as are other Thompson carriages in this siding. Body colour now may have been maroon. Photo: N.D. Mundy
Click on the image for an enlargement
In service
The first two views show 1951-built BT(4)s with radiussed corners to the windows:

A 1950s view at St.Botolphs (renamed Colchester Town in 1991) of a train about to depart behind an N2 is useful for showing some of the details described above. The number appears to be E87276E of 1951. It's also a wake-up call to modellers who might think that steel-panelled coaches lack detail! Photo: R.S. Carpenter.
Click on the image for an enlargement

In an undated view at Grantham from the 1950s, station pilot C12 No 67397 is at the head of Thompson and Gresley carriages with BT(4) No E87270E built at York in 1951 leading. Livery was probably BR crimson. Photo: author's collection.
Click on the image for an enlargement

A fairly typical example of how new carriages were blended with the old so that all the sets got modernised gradually. In this undated view at Little Weighton near Hull, ex-NER G5 No 67337 (based at Dairycoates until early 1957) has what looks like a secondary 3-set strengthened on the rear. Leading is a Thompson BT, the whole formation comprising:
BT |
3rd brake |
Thompson |
52'4" |
CL |
1st/3rd lav compo |
Gresley SP |
51 1'1 1/2" |
BT |
3rd brake |
Thompson |
52'4" |
T |
3rd |
Ex-NER |
52' |
Note how the strengthener, possibly on market day, was an old banger from c1910 and getting on for fifty years old. Photo: Author's collection
Click on the image for an enlargement

Another example of old and new carriages rubbing shoulders, in this case at Harrogate in the 1950s where N1 No 69434 (a West Riding loco at Bradford Hammerton St. and then Copley Hill) is moving a train ECS. It's a tidy 4-set made up with carriages from four decades:
BT |
3rd brake |
Ex-GCR Robinson matchboard |
56' |
C |
1st regraded to a 1st/3rd composite |
Gresley |
51' 1 1/2" |
CL |
1st/3rd lavatory composite |
Gresley |
51' 1 1/2" |
BT |
3rd brake |
Thompson |
52'4" |
The Thompson BT is on the rear. Note how the ex-GCR carriage, a BT(6) had been built around the time of the Great War and was to a decent length (the GCR also built 60' secondary carriages). Photo: Author's collection
Click on the image for an enlargement

A damp day in the Pennines sees N1 No 69443 at Laisterdyke with a West Riding Ordinary 3-set (after the war many Gresley and Thompson steel-panelled carriages were introduced and in short trains like this they were a mixture of both designs, or all one or the other). This is an all-Thompson set:
BT |
3rd brake |
Thompson |
52'4" |
CL |
1st/3rd lavatory composite |
Thompson |
52'4" |
BT |
3rd brake |
Thompson |
52'4" |
In short (BT,CL,BT) with one of the brakes marshalled inside out (awfully common, modellers please note)!
No date but clearly the 1950s when this was a Bradford Hammerton St. loco. The train has come from Bradford Exchange and is in the centre roads, destination Leeds Central or Wakefield. There used to be many lines here. Photo: N. Harrrop.
Click on the image for an enlargement
6. BC - 1st/3rd brake
The brake composite was one of the two final designs not generated until 1951 in BR days. I don't have a portrait of the coach but here is the Diagram and some service views:

By now all new construction had round corners to the windows. The lower class seated five a side. Two batches were built to D.360:
1951 80332/91 1952 80392/421
Diagram: author's collection
Click on the image for an enlargement

This undated view from the early 1950s shows Northallerton's D20 No 62347 pausing at Hawes with an ordinary 2-set whose composition varied over the years:
BC |
1st/3rd brake |
Thompson 52'4" |
BT |
3rd brake |
Gresley 51'1 1/2" teak |
Prior to arrival of the Thompson coach an ex-GNR 58'1 1/2" BC had been used so this was an example of modernisation of the oldest carriage in the train. The teak panelled Gresley remained. Photo: JW Armstrong.
Click on the image for an enlargement

Click on the image for an enlargement
Another undated view of the same formation on the branch at Leyburn, this time behind J21 No 65038. This loco wasn't allocated to Northallerton until May 1952 so that's the earliest possible date for the picture. Photo: author's collection.
There's another view lower down of the BC in a more modern 2-set at Sandsend.
Click on the image for an enlargement

A later view from 30th May 1959 at Nottingham Victoria shows L1 No 67750 with a 3-set:
BC |
1st/3rd brake |
Thompson 52'4" |
CL |
1st/3rd lavatory |
Thompson 52'4" |
BT |
3rd brake |
Gresley 51'1 1/2" teak |
This is more modern than it may look for the Gresley brake on the far end is a BT(6) built just before WW2. Photo: PH Groom.
Click on the image for an enlargement
7. BT(5) - 3rd brake
As described under Later Developments, the last Diagram was introduced by BR in 1951 and only built that year and was for a 3rd brake with more seats and less van space for the NE and Scottish Regions.

The Diagram for the BT(5) shows a familiar arrangement with the later round-cornered windows. A BT(6) design, popular on the GC Section, could have been produced but was not. Diagram: author's collection.
Construction and running numbers were:
1951 - 87178-227, 87298-327) = 80
Click on the image for an enlargement
I don't have a carriage portrait but two service views show the design well, both on the NE Region:

A 1950s 3-set is seen near York behind one of York's many ex-NER B16s, No 61450 (BT,CL,BT). Photo: Author's collection.
Click on the image for an enlargement

This is quite an economical formation for a long distance working hauled by a tender loco and the 1st class is covered by a semi-corridor lavatory composite. On either side are the higher capacity 3rd brakes:
BT(5) |
3rd brake |
Thompson |
52'4" |
CL |
1st/3rd lavatory composite |
Thompson |
52'4" |
BT(5) |
3rd brake |
Thompson |
52'4" |
Click on the image for an enlargement

Seen near Sandsend is an all-Thompson train with L1 No 67784 heading a neat 2-set. The formation has little van space and comprises:
BT(5) |
3rd brake |
Thompson |
52'4" |
BC |
1st/3rd brake |
Thompson |
52'4" |
The date is probably 1956-57 when this L1 was a Middlesbrough loco, returning with a working along the coastal line from Whitby. Visible in the distance are Sandsend Viaduct and the station with three camping coaches in the siding. Photo: author's collection.
Click on the image for an enlargement
8. On the WR Culm Valley branch
A use was found for Thompson stock on the Culm Valley branch in Devon which was 7 miles long and the line speed insufficient to charge the batteries. After WW2, the WR provided ex-Barry Railway coaches which it retro-converted to gas lighting. As closure of the branch drew near, Thompson carriages with superior ability to re-charge were employed although, even then, it is said that a topping up run to Exeter was required once a week.

A view on the Culm Valley branch at Hemyock with ex-GWR No 1451 in charge of a Thompson BT(4). A single light is being carried over the left hand buffer while the loco shunts the milk tanks. 1962. Photo: R.K. Blencowe.

A single coach was the usual roster but for the last day of passenger service on 7th September 1963, two were employed, both BT(4). Seen at Tiverton Jc. This is not a "Mixed" train, by the way, it's a passenger train conveying passenger-rated (NPCS) milk tanks. I believe that goods trains were handled separately with a goods brake van. Photo: RG Turner.
Click on the image for an enlargement
To be continued...