It must be a decade or more since I last looked at anything to do with steam locomotives, but the recent acquisition of the Eugene Huddleston book “Uncle Sam’s Locomotives” got me thinking again about standardization, derivatives of standard locomotives, etc., and long unanswered questions.
In the chapter “World War II Parallels” Huddleston mentions how under the aegis of the WPB and its “no new designs” restriction, the 1929 Rock Island 4-8-4 was used as the basis for locomotives built successively for the D&H, the Milwaukee and then for the Rock Island itself.
These activities are fleshed out in Richard Steinbrenners’s Alco book, wherein the term Alco standard WWII 4-8-4 is used.
But the curious thing is that in some respects, there was quite a jump between the original Rock Island R-67b and the D&H K-62 that seem to go beyond the detail changes that the WPG typically allowed, such as valve gear choice and trading off between boiler pressure and cylinder diameter.
In particular, the firebox size increased, with grate area going from 88.3 to 96.2 ft², although in other dimensions the boiler seemed to be unchanged. The tubes were shorter and the combustion chamber was longer, but I would think that this would fall into the detail change class. With the longer firebox, overall wheelbase was increased, and the driving wheelbase went from 19’3” to 19’9” to allow the use of 75” driving wheels. I can’t think of any other WPB case where this level of change was allowed, and one imagines that there might have been quite a bit of design work required to get from the R-67b to the K-62, so this case does look to be anomalous.
But perhaps there is another connection?
Using mostly the information available in the “Train Shed Cyclopedia” series, to my eyes the Lehigh Valley (LV) T-2 class 4-8-4 looks to be same locomotive as the Rock Island R-67B, apart from some detail changes, including slightly higher boiler pressure, 255 instead of 250 lbf/in², and 70” instead of 69” drivers. However, this connection is not mentioned by Steinbrenner, or in fact in any other literature that I have encountered.
If it is the case that the T-2 was the R-67b in disguise, then that the LV acquired the T2b in 1943, essentially as an updated, but dimensionally unchanged T-2 makes the K-62 et seq look even more anomalous. Had the WPB been sticking closely to its own rules, then one may argue that the T2b would have been the locomotive that was also supplied to the D&H, Milwaukee and the Rock Island in the 1943-44 period, maybe with 74 inch drivers, which the basic design could accommodate.
Anyway, back to the LV connection, treating the T-2 as being essentially the Rock Island R-67b makes the very similar LV T-1 its Baldwin counterpart, with the typical Baldwin differences including the short wheelbase, equal wheel diameter trailing truck and 27” x 30” rather than 26” x 32” cylinder dimensions; Baldwin seemed to be staying with 4-8-2 era precepts in this regard. One might say that the T-1 and T-2 are to each other as is the L&N 2-8-4 to its Van Sweringen cousins.
Allowing the LV T-1 into the lineage then also brings in the Baldwin-built T-3. This was essentially the T-1 stretched to accommodate 77” drivers, and with boiler pressure increased to 275 lbf/in² to compensate. But the firebox was lengthened to allow a grate area of 96.5 ft², with the boiler being otherwise unchanged. And that seems to be the missing link. Apart from a small fractional difference in length, the K-62 firebox was the same as that on the T-3.
Thus one may conclude that although the K-62 differed from the R-67b in non-trivial ways and so might have been viewed as being outside of the WPB guidelines, the basic elements already existed, and it was more a case of a different combination of existing elements than a major redesign, just enough so to be allowed by the WPB.
One more possible connection is the Lima-built Soo Line O-20 class 4-8-4. That looks very much as if its design was informed largely by the R-67b. It had the same boiler and firebox dimensions, although a different arrangement of flues and tubes. It also had the 16’9” driving wheelbase that accommodated 75” drivers, so even this design element of the K-62 had an apparent family precedent.
Whilst the foregoing seems logical on the basis of the available information, it does concern me that the LV connection to the R-67b is not mentioned in the literature. Thus maybe I have missed something in my analysis, which is essentially an attempt to provide a post facto rationale for what appears to be a WPB anomaly.
WPB or not, the K-62 managed to embody much of Alco’s current thinking, perhaps via the D&H J-95 Challengers and evidently related to Alco’s work with the UP with the FEF-2, Big Boy and “big” Challengers. Thus in respect of its running gear, it had lateral motion devices on three driving axles, and auxiliary coil springs at the suspension anchor points.
Now looking back to the front end of this design sequence, was there a prior design, a 4-8-2 perhaps, that partially at least informed the original R-67b? The DL&W Q-1 and Q-2 are mostly different, although share the same firebox dimensions and grate area. But these firebox numbers go back at least to the USRA Heavy 2-10-2, so are not really all that defining. Perhaps the 1927 MoPac MT-73 4-8-2 was an antecedent of sorts? I think that it has similar boiler dimensions to the R-67b, albeit with a smaller grate area (84.3 ft²). The 1927 model was much larger and heavier than the first MoPac MT-73, which was essentially a slightly stretched USRA Light 4-8-2 with 73” drivers. Thus indirectly the MoPac might have arrived at a notional 73” driver derivative of the USRA Heavy 4-8-2. (I don’t think that any of the other 73/74” driver 4-8-2s developed from 1922 onwards would have qualified, but 4-8-2 development in that period looks to be a complex topic, so I can’t be sure.) Continuing this theme, perhaps the R-67b is as close as it got to a logical 4-8-4 successor to the USRA Heavy 4-8-2. On the other hand the USRA Light 4-8-2 did have a definite 4-8-4 successor in the form of the NC&StL J-1 class, which design effectively became the Alco standard light 4-8-4.
Cheers,
In the chapter “World War II Parallels” Huddleston mentions how under the aegis of the WPB and its “no new designs” restriction, the 1929 Rock Island 4-8-4 was used as the basis for locomotives built successively for the D&H, the Milwaukee and then for the Rock Island itself.
These activities are fleshed out in Richard Steinbrenners’s Alco book, wherein the term Alco standard WWII 4-8-4 is used.
But the curious thing is that in some respects, there was quite a jump between the original Rock Island R-67b and the D&H K-62 that seem to go beyond the detail changes that the WPG typically allowed, such as valve gear choice and trading off between boiler pressure and cylinder diameter.
In particular, the firebox size increased, with grate area going from 88.3 to 96.2 ft², although in other dimensions the boiler seemed to be unchanged. The tubes were shorter and the combustion chamber was longer, but I would think that this would fall into the detail change class. With the longer firebox, overall wheelbase was increased, and the driving wheelbase went from 19’3” to 19’9” to allow the use of 75” driving wheels. I can’t think of any other WPB case where this level of change was allowed, and one imagines that there might have been quite a bit of design work required to get from the R-67b to the K-62, so this case does look to be anomalous.
But perhaps there is another connection?
Using mostly the information available in the “Train Shed Cyclopedia” series, to my eyes the Lehigh Valley (LV) T-2 class 4-8-4 looks to be same locomotive as the Rock Island R-67B, apart from some detail changes, including slightly higher boiler pressure, 255 instead of 250 lbf/in², and 70” instead of 69” drivers. However, this connection is not mentioned by Steinbrenner, or in fact in any other literature that I have encountered.
If it is the case that the T-2 was the R-67b in disguise, then that the LV acquired the T2b in 1943, essentially as an updated, but dimensionally unchanged T-2 makes the K-62 et seq look even more anomalous. Had the WPB been sticking closely to its own rules, then one may argue that the T2b would have been the locomotive that was also supplied to the D&H, Milwaukee and the Rock Island in the 1943-44 period, maybe with 74 inch drivers, which the basic design could accommodate.
Anyway, back to the LV connection, treating the T-2 as being essentially the Rock Island R-67b makes the very similar LV T-1 its Baldwin counterpart, with the typical Baldwin differences including the short wheelbase, equal wheel diameter trailing truck and 27” x 30” rather than 26” x 32” cylinder dimensions; Baldwin seemed to be staying with 4-8-2 era precepts in this regard. One might say that the T-1 and T-2 are to each other as is the L&N 2-8-4 to its Van Sweringen cousins.
Allowing the LV T-1 into the lineage then also brings in the Baldwin-built T-3. This was essentially the T-1 stretched to accommodate 77” drivers, and with boiler pressure increased to 275 lbf/in² to compensate. But the firebox was lengthened to allow a grate area of 96.5 ft², with the boiler being otherwise unchanged. And that seems to be the missing link. Apart from a small fractional difference in length, the K-62 firebox was the same as that on the T-3.
Thus one may conclude that although the K-62 differed from the R-67b in non-trivial ways and so might have been viewed as being outside of the WPB guidelines, the basic elements already existed, and it was more a case of a different combination of existing elements than a major redesign, just enough so to be allowed by the WPB.
One more possible connection is the Lima-built Soo Line O-20 class 4-8-4. That looks very much as if its design was informed largely by the R-67b. It had the same boiler and firebox dimensions, although a different arrangement of flues and tubes. It also had the 16’9” driving wheelbase that accommodated 75” drivers, so even this design element of the K-62 had an apparent family precedent.
Whilst the foregoing seems logical on the basis of the available information, it does concern me that the LV connection to the R-67b is not mentioned in the literature. Thus maybe I have missed something in my analysis, which is essentially an attempt to provide a post facto rationale for what appears to be a WPB anomaly.
WPB or not, the K-62 managed to embody much of Alco’s current thinking, perhaps via the D&H J-95 Challengers and evidently related to Alco’s work with the UP with the FEF-2, Big Boy and “big” Challengers. Thus in respect of its running gear, it had lateral motion devices on three driving axles, and auxiliary coil springs at the suspension anchor points.
Now looking back to the front end of this design sequence, was there a prior design, a 4-8-2 perhaps, that partially at least informed the original R-67b? The DL&W Q-1 and Q-2 are mostly different, although share the same firebox dimensions and grate area. But these firebox numbers go back at least to the USRA Heavy 2-10-2, so are not really all that defining. Perhaps the 1927 MoPac MT-73 4-8-2 was an antecedent of sorts? I think that it has similar boiler dimensions to the R-67b, albeit with a smaller grate area (84.3 ft²). The 1927 model was much larger and heavier than the first MoPac MT-73, which was essentially a slightly stretched USRA Light 4-8-2 with 73” drivers. Thus indirectly the MoPac might have arrived at a notional 73” driver derivative of the USRA Heavy 4-8-2. (I don’t think that any of the other 73/74” driver 4-8-2s developed from 1922 onwards would have qualified, but 4-8-2 development in that period looks to be a complex topic, so I can’t be sure.) Continuing this theme, perhaps the R-67b is as close as it got to a logical 4-8-4 successor to the USRA Heavy 4-8-2. On the other hand the USRA Light 4-8-2 did have a definite 4-8-4 successor in the form of the NC&StL J-1 class, which design effectively became the Alco standard light 4-8-4.
Cheers,
