John, I am by no means an authority, but as no one else has attempted a response here goes for what I know. The SVRy 16, 17, and 18 were reported by Earl Emlaw, SVRy chief engineer, to carry 6 and 12 cords of wood. He did not list the wood cap. for 19 and 20. The 19 and 20 tenders are listed as having a light weight of 74,000 lbs., while the 16-18 tenders are shown with a light weight of 31,511 lbs. What is curious to me is that the 16-18 tenders have a water cap. of 4000 gal. while the heavier 19-20 tenders hold 3500 gal. Evidently the 19-20 tenders are of much heavier construction and perhaps they could carry more fuel. I'll be at McEwen this Sunday and if I have time I'll do some measuring of the 20 tender and see if I can estimate what the wood cap. would be.
On the question about the pine slab fuel, I've not heard of any problems with the boilers. There are about 21 in the Denver pub. lib. Otto Perry collection of the SVRy taken in July 1938 which can be viewed on the internet. One of these pictures shows the engineer and fireman loading wood on to 19 by hand. As far as loco ratings, the SVRy timetable #60, effective Aug. 1, 1937, (reprinted and available in our depot), rates all the Mikes the same even though the TE for 19 and 20 is slightly higher. From Baker to Thompson M.P. 13.2, 350 tons. Grade in this section is about 1%. From Thompson to McEwen M.P. 22.5 rating is 300 tons. Grade in this section is about 1.5%. From McEwen to S. Wye M.P.30.2 350 tons, with a grade of 1.53%. This grade is based on a track profile averaged to Sumpter and the grade is considerably steeper from S. Wye into Sumpter a distance of 1.1 miles. I presume the decreased tonage on the lighter grade is due to the many sharp curves in that section. From S Wye to Larch M.P34.7, tonnage is 130 up a grade of 4%. From Whitney M.P. 43.4 to Tipton M.P. 51, tonnage is 170, with ruling grade to the summit of what I've been told was again 4%. The above were for westward trains, for eastward movement the ratings to the two summits were 170 tons. The east side of Larch is a 3.5%.
I have no info on how helpers were used. One article I've read mentioned 18 doubling the 3.5% grade from Whitney to Larch, and the first cut of loaded cars was 15, but don't know what the total # of cars was, but one assumes 29 or 30. One of the Otto Perry pics. show a train at Austin with I believe 17 in the lead with 19 on the rear as a pusher. I have a similar photo over my desk taken at the wye at White Pine with a loco in the lead and a pusher on the rear. Can't make out which locos though. I wish we had as much archival info to rely on out here in Oregon as the folks in Colorado do! Thanks none the less for asking the questions!
