Sorry if this came up earlier, but I couldn’t find any info on this by using the search bar.
I have read that for the N&W test runs of 1952 which compared steam engines to diesel, N&W Y-6b #2197 has been upgraded slightly. That included a booster or intercepting valve which increased dbhp and tractive effort. The same source states that by shopping all the other Y-6 engines they got that valve, too. My question is if that is correct, and if so, what were then the remaining differences between Y-6, Y-6a and Y-6b engines. To me it seems that N&W then had a large fleet of almost identical - also in power - 2-8-8-2s where different nomenclature appears senseless. Can someone help?
The Y5 thru Y6b classes were modified with the external reducing/booster valve and the addition of lead in the front engine frame. Afterwards for the most part they were all the same, at least as far as tonnage ratings on each district. With some number changes, these classes were then all in the 2100 series with the exception of the last Y6b #2200. They were then known in the N&W Employee Timetables as “Improved”. To the men they were “twenty one hundreds”. There was no such Y6c as one author would lead you to believe.
N&W was the last railroad in the US to take steam development seriously. But, even the most advanced steam power in the US was toast once they were unable to obtain compressors, feedwater heaters and other outside supplied appliances. Then, too the EMD GP9 and Alco RS11 were just good enough to make it all a matter of time for steam in North America.
The only visible diference that I’m aware of between the Y-6b and previous engines is that the Y-6b had a Worthington SA FW heater ahead of the stack and one air pump on either side along w/ a VERY slight forward tilt of the smokestack, while the earlier engines had a straight smokestack w/ a Worthington BL F/W heater on the left side and 2 airpumps on the right