Using the information from them three books listed below I was able to create this technical specifications table however some values were not mentioned and or I cannot deduce them. So I'm looking for help with the values with the ? values. Given that the boiler is pretty much identical to that of the production Class A1's would the values for the both the hearing surface secton, (ie: Firebox= 215sq.ft, Superheater= 525sq.ft, Flues= 835sq.ft, and Total= 3,455sq.ft) and the Grate area, (41.25sq.ft) be the same?
Books used: E. Fry's, (1973), "Locomotives of the .L.N.E.R. Parts 2a, Classes A1 to A10"; Brain Haresnape's, (1981), “Gresley Locomotives: A Pictorial History”; and Peter Townsend's, (1985), “East Coast Pacifics at Work”.
GCR11F wrote: ↑Sun Aug 15, 2021 10:32 pm
...Given that the boiler is pretty much identical to that of the production Class A1's would the values for the both the hearing surface secton, (ie: Firebox= 215sq.ft, Superheater= 525sq.ft, Flues= 835sq.ft, and Total= 3,455sq.ft) and the Grate area, (41.25sq.ft) be the same?...
That's a safe bet. The boiler and mechanism layout are near enough what went into the A1, it's just the double side window cab and four axle tender to advantageously garnish the splendid concept.
According to Norman Groves in the RCTS Great Northern Locomotive History Volume 3b the first production Pacifics were the same as the 1920 drawing save for, as Hatfield Shed mentions inter alia, the GER style cab, raised footplate, 8-wheel tender, reversion to swing-link bogie, and unspecified alterations to the smokebox. The tabulation that accompanies the text is relevant to the first Pacifics built under the GNR and provides the following data to fill in most of your blanks:
Heating Surface:
Firebox (with combustion chamber) 215 sq ft
Tubes (168x2.25") 1880 sq ft
Flues (32x5.25") 835 sq ft
Total evaporative 2930 sq ft
Superheater elements (32x1.25") 525 sq ft
Grand Total 3455 sq ft
Grate Area: 41.25 sq ft
Tractive effort (85%) 29,835 lb
Indicated Horsepower is not given, although the there is a statement to the effect that the cylinders were nominally 20" dia. x 26" stroke, with a calculated hp output of 1,946.
I do not understand your 'Max. Axle load: ? in Piston' statement nor what you are seeking in relation to 'Piston'?
The piston valves were reduced to 8" dia. to fit in the available (cramped) space, rather than the 10" used in Gresley's 2 cylinder locomotives
