thompson and gresley coaches

[bignose27]

what are the differences between Thompson and gresley coaches? They look the same to me.

[silverfox]

In What respect?

Gresley were mostly wood construction
Thompson Steel

Thompson toilet windows were oval
Gresley were square

Thompson used a lot of the plans of Gresley esp in the local 52ft? carriages
Thompson did not used articulation

Willing to be put right on any of that as carriages not my strong point

[jwealleans]

I think that largely covers it. Gresley vestibuled carriages have domed roof ends - the roof curves down to meet the end at just above cantrail level while Thompson ones continue at a level and the end rises to meet them.

Gresley steel non-corridor stock was 51' or 54' and has deeper trussing than Thompson, which was, I believe only to 51'.

A look at the website of the LNER Coach Association will probably be informative.

[greenglade]

hi

If this question is in regards to the 'Flying Scotsman' model that you was seeking info on the train make up for, then the 'Thompson' coaches are probably not suitable for the locomotive in that guise as they are from a later era. I'm not clued up on when Thompson first built his carriages, others here will know better but unless he built these between 1941 and 1943 ( he took over from Gresley after his death in IIRC late 41) and they were actually pulled by the 'scotsman' in that short window (possible if in existence) then they are not suitable. 4472's livery changed to wartime black from 43.

Pete

[Darryl Tooley]

The first two prototypes of the Thompson stock appeared in 1945; volume production didn't start until the following year, so as far as the LNER goes Thompson carriages would principally be associated with locomotives carrying their new numbers after the 1946 renumbering.

D

[robertcwp]

The vast majority of Thompson stock was not built until after Thompson had retired and much of it did not appear until after nationalisation. Although steel-panelled, in other respects the body construction was largely timber-framed.

[gobbler]

I believe the early Thompson coaches had square windows. This was found to gather moisture in the corners and corroded easily. That's when the design changed to windows with a radius in each corner.

[sawdust]

I believe the early Thompson coaches had square windows. This was found to gather moisture in the corners and corroded easily. That's when the design changed to windows with a radius in each corner.

Is there evidence to support this? It could just be a fashion design change, remember steel panelled Gresley carriages had been constructed quite some time earlier than the square cornered Thompson's. The change appears to have come in during 1949, so that didn't give very long for problems with the first batches to show themselves.

Sawdust.

[65447]

It has always been reported as the reason in the accepted works on the subject, primarily those by Michael Harris who thoroughly researched the relevant LNER C&W records in what is now the National Archives.

With real teak-bodied stock laying enough varnish into the corners would help, but I must admit to wondering about the streamlined, tourist and later Gresley steel-panelled stock. Other companies did build steel-bodied carriages with square-cornered windows but comparatively not as many types.

The change would have come under Peppercorn. Did Thompson require a different window frame detail and fitting to that used by Gresley?

The fact that later modifications to deal with the problem were also round-cornered insert frames does tend to support corrosion as the problem.

[sawdust]

The principal changes, besides the extra steel in the corners of the window openings on the steel panels, were brass corners added to sliding vents, the use of cast brass bottom glazing beads in passenger compartments (with integral round corners), separate round corner beads elsewhere and trims with round corners. In all cases the glass retained square corners.

It is worth mentioning that some of the Gresley buffet cars also gained round corners during BR mid life refurbishments, which has to be entirely down to fashion.

Lastly Thompson CL 88339 doesn't seem to have had any particular problem with the corners of the windows in the steel panels since it was re-skinned in the early 80s.

Sawdust.

[65447]

It occurs to me that the quality of the steel may be a relevant factor. Gresley and his team understood the differing properties of steel when combined with other metals, e.g. for increasing strength whilst reducing the weight of reciprocating masses in locomotive valve gear or by undertaking trials of differing steels in the construction of hopper wagons to assess durability and resistance to corrosion. The early coaching stock constructed with steel bodies did not suffer from corrosion other than where rainwater collected at the bottom of doors with opening lights.

Post WW2, steel was rationed and it may well be that the types of steel available were what had to be used and those were less resistant to corrosion.

Sawdust noted that a re-skinned Thompson CL has not had any particular problem over the 30ish years since being so treated. Was a different grade of steel used?

[65447]

Gresley steel non-corridor stock was 51' or 54' and has deeper trussing than Thompson, which was, I believe only to 51'.

Thompson stock had the deeper trussing and also a lower bottom window line and the standard non-vestibule underframe was 52' 2.5". Whilst there was only a minor difference in the profile of the sides it is still noticeable in photographs of trains of mixed stock.

The lower window line and deeper trussing are the most obvious indicators of a 'Thompson' carriage.

[bernhard s]

Re; I believe the early Thompson coaches had square windows. This was found to gather moisture in the corners and corroded easily. That's when the design changed to windows with a radius in each corner. Quote
In the 1980s I wrote to the Model railway magazine and the late K. Hoole replied that they rusted badly in the 90 degree corners- I still have his letter somewhere. . . .

[sawdust]

Re; I believe the early Thompson coaches had square windows. This was found to gather moisture in the corners and corroded easily. That's when the design changed to windows with a radius in each corner. Quote
In the 1980s I wrote to the Model railway magazine and the late K. Hoole replied that they rusted badly in the 90 degree corners- I still have his letter somewhere. . . .

I refer the honourable gentleman to my previous answer.

Just because things are written down and repeated does not make them fact! Mike Trice of this parish has recently demonstrated this with the height of carriage lettering over the gold.

Some photographic evidence to support this assertion that the window design was changed because of corrosion would be nice.

My final comment is that 1950 built (and therefore round cornered) CK 18477 had patches around the windows on the corridor to cover corrosion when we striped the skin off that side.

Sawdust.

[john coffin]

Worth remembering that around 1950, De-Havilland had such problems with the Comet jet which caused the UK to lose its premier place
at the time in jet passenger planes.

paul