Streamlining on A4s

Seeing 'Duchess of Hamilton' with the streamlined casing fitted prompts me to wonder about the A4s.

If it was seen as a good idea to remove the streamlining from the 'Duchesses' after WWII why wasn't this also done to the A4 class?

Was the A4 streamlining more integral to the boiler, etc., & therefore more difficult to remove, or was there less benefit in doing so?

Or was it simply that the LNER/ER had a different view to the LMS/LMR?

 

The A4 streamlining was part of the complete design of the locomotive, as can been seen by the curve of casing over the wheels. The skirting (sometimes called valances) over the wheels was removed during the war (between June 1941 and September 1942) as a time saver for motion and 2 to 1 conjugated valve gear gear maintainence. According to the 'bible' (RCTS Part 2a) the front end design was perfected from wind tunnel experiments, although there was a rumour that a draughtsman error gave the shape a 12 foot radius as opposed to the 14 foot one Gresley had ordered. The mistake was never noticed, apparently. Either way, the shape proved to be very effective at lifting smoke and steam from the drivers vision.

The valances were not re-fitted after the war. In my opinion the loco's looked much better in their final condition, without valances and wearing double chimneys

 

Fully agree with that as in their final condition they perfomed better - and still do - than when originally built. Witness their final days on the 3 hour Glasgow - Aberdeen trains.

 

Whilst the Gresley A4 streamlining was a basic component of the design - thus an integral part of it - the design was also a good publicity image hence the application of the streamlining to the 2 GER Royal Train locos to maintain the publicity value of the concept.

This obviously upset the LMS which was always a strong competitor of the LNER especailly as both were competing for the lucrative Anglo-Scots traffic and therefore publicity was always an important element of the weaponry used in the war for custom.

As I understand it the streamlining proved such a publicity coup that the LMS redrew its Coronation designs to incorporate the streamlining as this had not been an original part of the design. This in one way made it easier to redesign the locomotives when it was decided to dispense with streamlining for later batches of th class and also to rebuild the streamlined locomotives when the streamlining was removed.

 

OOOO I did Eightpot! Scottish Railrovers in Aug/Sept 1965 and June 1966 Footplate rides on 60019/24/34 - unbelievable now - but fantastic memories

 

The wedge nose in particular on the A4 was a very effective exhaust lifter, one reason behind keeping the streamlining in BR days. I have read that the Duchess streamlining was much less effective as an exhaust lifter and the flat top to the casing could cause low pressure on the leeward side in a cross wind and this pulled the exhaust down. Maybe one reason why it was removed.

 

Gresley consulted Bugatti IIRC and the designs were tested in the wind tunnels to gain the best profile - hence the reference to Bugatti nose - as it was based on the style adopted for the famous racing cars of the time.

 

That is totally correct.

 

As far as I know, the removal of the streamlining was never even considered.

 

Not to my knowledge. I always thought the B17 'Royals' were 'Sandringham' and 'Royal Sovereign' (after Thompson re-build to a B2). Could be wrong though!

 

Having had my memory banks adjusted I have checked my oracle - Nigel Gresley Locomotive Engineer by FAS Brown

He records that Gresley was a friend of Ettore Bugatti - the racing car constructor who built the French railcars. They were reported by observers to part the air with minimum resistance and power-wasting eddies and even less slipstream effect when standing close to one as it passed through the platform thus Gresley sampled them running between Deauville and Paris.

So yes the A4 wedge came directly from the railcars but they were presumably based on the earlier racing car designs from the same source - i.e. Bugatti.

Honours even - I presume.

As to the streamlining of the 2 B17s - that arose because of the use of 2 engines dedicated to the East Anglian Express which had recently been provided with stock to the same design as the Coronation trainset. More for publicity value than any efficiency benefits 2859 was named East Anfglia and 2870 City of London and both were streamlined in September 1937 for this prestigious East Anglian service. The streamlining had sufficient value that it was decided to remove it when 2870 went into Doncaster for overhaul in 1950 but the works left it streamlined thus it was only at its next overhaiuul at Gorton that the streamlining was removed

Mea Culpa - and apologies for relying solely on memory - but the 2 B17s were for the East Anglian service as noted above although presumably might be the GER section choice for Royal duties.

 

What does an A4 look like without its cladding ? I don't believe I have ever seen a photo, even in the workshop

 

I never knew that - I thought the 'streamlined coaching sets' were limited to the 'Silver Jubilee/Coronation/West Riding' services.
:-k