Valeriy
The later B&M 4-8-2s and ATSF 3460 class 4-6-4s did indeed have Baldwin Disc wheels.
(the ATSF 3400 class were 4-6-2s and they and the 3450 class 4-6-4s were fitted with Universal Disc wheels, only the 3460 class 4-6-4s had Baldwin Disc wheels)
On page 153 of the Kalmbach Cyclopedia, there is a very clear view of the “large hole” version of the BoxPok wheel, fitted to C&NW Pacific 2908. These were also on the NP A3 class 4-8-4 and are similar to the Japanese type.
M636C
Although Valeriy hasn’t asked any further questions, and neither has anyone else, all of the photos referred to made me look more closely at things I had taken for granted. In the Kalmbach Cyclopedia there is a photo of ATSF 4-8-4 2925 with three BoxPok driver sets as built, but the trailing coupled set appears to be a Baldwin disc set (or possibly a Universal set).
It was at this stage I realised that while early Baldwin Disc wheels were clearly identifiable, with narrow holes and prominent stiffening ribs between the holes as applied to the ATSF 1937 locomotives of classes 3460, 3765 and 5001, those fitted to the Wartime 3776 class 4-8-4s, and some other early 1940s types had larger holes and lacked the stiffening ribs.
The still later 5011 class and 2900 both had BoxPok wheels, at least as built.
The early Universal wheels had a large blank area around the crank pin and smaller holes, but later Universal wheels look generally similar to later Baldwin Disc wheels, but with rather fewer larger holes.
I should like to hear from anyone who can confirm my ideas about these late Baldwin Disc Wheels.
M636C
Please, help me to find sectional views of different types of driving wheel centers.
Valeriy.
I think the best place to look would be one of the Simmons Boardman “Locomotive Cyclopedias” of the 1930s and 1940s. Kalmbach reprinted the 1942 Cyclopedia some years ago. One of these might appear in Amazon or in EBay.
To bring up an earlier point, I note that the large German Passenger locomotives of class 01 and 03 had webbing around the spokes near the crank pin, but not on the remaining spokes. But these would date back to 1925.
M636C