Sorry, I though I’d included a link to the Google Books PDF download.
If that lunches for some reason, google Lawford Fry, “A Study of the Locomotive Boiler” and the Google Books link will be accessible from the first page of results.
Incidentally, you might appreciate some of the implicit analysis in the data accompanying Dawson’s (1975) analysis of Niagara road-testing (including discussion of 5500 that is not included in the 1947 report on motive power). Note the errata listed at the end carefully as you read.
https://nycshs.files.wordpress.com/2014/07/roadtestingniagaras.pdf
The Errata do not appear to correct any of the number in Table 4 on p 21 giving indicated and drawbar hp under the states steam flow and firing rage.
The 1500 hp spread between indicated and drawbar values suggests a speed of 70 MPG. The 4000 indicated hp suggests 2/3 of maximum power at that speed. 90 lbs/sq feet of grate firing rate is rather reasonable. How Dawson got 54.7 boiler efficiency out of 82.2 % combustion efficiency (the amount of lost coal, which seems reasonable for the firing rate given that 10% of the coal can end up in the ashpan droppings) and 80.1% absorption efficiency – should give .822 times .801 = 66 % boiler efficiency.
Where does the los number of 52,500 lbs steam through the blast pipe come from? Is the feedwater heater really drawing off that much from 15.8 times 4000 ihp = 63200 lbs steam/hr entering the cylinders?
The boiler efficiency, to the extent that the numbers could be reconciled seems reasonable. The 15.8 lbs/ihp-hr at 2/3 power seems a tad high in relation to the 16.7 lbs/ihp-hr I quoted from Alfred Bruce’s book at full power.
As to you-need-to-figure-on-drawbar-efficiency values, 3 times 2000 HP for E7’s to match the peak 6000 HP is about the same weight as Niagara and tender, although maybe you don’t need 3 E7s to make schedule on a trains pulled by a Niagara owing to the much higher low-end tractive effort? For comparable HP/weig