I hear the term “Pre-War” and “Post-War” when discussing Pennsylvania RR 4-6-2 Pacific K-4. Can anyone tell me what differentiates the two locomotives?
There were metal restrictions during the war and locos were made heavier using the old cast iron frames vs stronger steel ones. The war board only authorized certain plans as well…
That’s a quick answer.
John
So John, you described war time K4’s. Did pre-war and post war K4’s have steel frames then?
To be honest I knew more of the restrictions than about those engines. Materials that were required for war got priorities. For specifics I’d trust a Pennsy historian over my thoughts.
John
If it’s still on the Accucraft site, they made both versions and had pictures you can compare. This was in 1:29, the AML line.
Greg
According to Wikipedia;
Equipment on the prototype, built in 1914, was conservative and included a screw reverse (power reverse would soon be added), a small 70-P-70 tender holding only 7,000 US gallons (26,000 l) of water and 12½ tons of coal set up for hand firing, a wooden cowcatcher pilot, a square-cased, old-fashioned headlight and piston tailrods (soon to go).
A World War I era prototype had distinctive “chicken coop” slat pilots, while the Post-War versions had modern pilots.
Boosters
K4s numbers 3676, 5399, and 5436 were fitted with booster engines on the trailing trucks in 1941.
Roller Bearings
K4s numbers 20 and 5371 were fitted with roller bearings.
Poppet Valves
K4s 5399 was rebuilt by Lima in 1939, with, among other improvements, poppet valves actuated by Franklin oscillating cams. K4s 5436 was fitted with stem actuated valves in 1940. They were designed by Lloyd Jones, the Engineer of tests at the Altoona Works. in 1945, K4s 3847 was given a front-end throttle and Franklin rotary-actuated poppet valves. All performed well, but were difficult to maintain.
K4sa
K4s numbers 612, 1985, 5405, 5481 and 5484 were converted with 15" piston valves, higher steam domes and circulators, and front-end throttles.
Other then that, the references I can find say that the design didn’t change (much) during the production of all of the K4s. So the tenders were upsized, headlights moved, and various appliances changed and upgraded.
No cast iron frames?
I think I mis-read the question and spoke of war time production, not the pre or post. (http://www.largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-embarassed.gif)
Aw shucks.
John
It seams that wartime production was concentrated on the Mikados. So a few K4s were built before the war, and many were built after the war. At least that is what I have turned up on the net. I am not a PRR nor K4 expert, and I also did not spend the night in a Holiday Inn Express.