Class F-3-A (Locobase 6757)

Data from C&S 7 -1939 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange.

Firebox heating surface included 31.4 sq ft of arch tubes.

In 1922-25, the C&S rebuilt its quintet with new cylinders and superheaters and added Elesco feedwater heaters and new tender trucks in 1929. They also raised working steam pressure by 40 psi (2.76 bar).

Except for 354, which was totalled in a February 1938 wreck, the class carried on into the late 1940s, the last locomotive retiring in 1951.

---

Class F-3-B (Locobase 9385)

Data from C & S 7 -1941 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange; and DeGolyer, Volume 56, pp. 1+. Works numbers were 48261 in April 1918; 48731 in May; 49071 in June.

This trio was part of a batch of S-3s (Locobase 1186) originally supplied to the Burlington Road in 1918. Although they had the same layout as the earlier S-3s, the heating surfaces varied slightly. In July 1919, the Burlington leased 2965, 2970, 2973 (48261, 48731, 49071) to the C&S (and sold them outright in December 1920).

Locobase chose to highlight them to show the differences from the earlier S-3 batches.

---

Class F-3-C (Locobase 6758)

Data from C & S 7 -1939 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. See also DeGolyer, Vol 67, pp. 6+. Works numbers were 55569-55571 in July 1922.

These were substantial Pacifics based on the Burlington's S-3 (Locobase 1186) with a generous increase in direct heating surface over the 1911 F-3-As (Locobase 6757). The boiler's dimensions reflected the then-current thinking that tube length was less important than truly hot heating surfaces. So the tube length was cut by 30" (762 mm) and that "savings" was invested in a combustion chamber that contributed 59 sq ft (5.5 sq m) to the firebox heating surface. This augmented the 36.7 sq ft (3.4 sq m) in the arch tubes. Piston valves diameter was a relatively generous 14 inches (356 mm).

Although never truly express locomotives -- the 69" drivers were more realistic given the profile over which C & S passenger trains would run -- these were quite satisfactory engines and remained in service into the 1950s. 375 was scrapped in April 1954, 373 in May 1955, and 374 went in November 1960.

---

Class S-1 - Stephenson (Locobase 156)

Data from "Prairie and Pacific Locomotives," American Engineering and Railroad Journal, Volume 80, No 8 (August 1906), p. 300-302. (Many thanks to Chris Hohl for his 22 September 2017 email reporting unlikely boiler pressure values for 177 entries. A Locobase macro caused the error .) 70 built by Alco and Baldwin from 1906 to 1909.

The first 45 had Stephenson gear off inside 12" (305 mm) piston valves; the data for these are shown above. At the time the class was introduced, AERJ described them as ranking "...among the heaviest and most powerful of the type in our records."

The last 25 also had inside valves but Walschaert valve gear and fewer boiler tubes; see Locobase 13506.

Most of the class was rebuilt during the 1920s as S-1A (see Locobase 5474) with piston valves and valve gear moved outside, superheaters, and feedwater heaters.

---

Class S-1 - Walschaert (Locobase 13506)

Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University, Volume 33, p. 86. Baldwin works numbers were 33441-33449 in May 1909; 33450-33452; 33471-33472, 33485-33493 in June; 33523-33524 in July.

Locobase 156 shows the first 45 engines delivered to this basic design in 1906-1907. Supplied by Alco and Baldwin, these had Stephenson valve gear and slightly bigger boilers.

Most rebuilt during the 1920s as S-1A (see Locobase 5474) with piston valves and valve gear moved outside, superheaters, and feedwater heaters.

---

Class S-1A (Locobase 5473)

Data from locomotive diagram published on Vernon Beck's website -- [] (accessed 22 March 2003).

This was the made-over S-1 design; the original saturated-boiler variants are shown in Locobase 156 and 13506.. The firebox had 33 sq ft of arch tubes. Tractive effort didn't change much, but the locomotive had drier, hence more potent steam. Interestingly, those that had Stephenson gear retained it, possibly because they'd been delivered with piston valves.

What was changed in 56 of the original 70 was the boiler contents -- fewer tubes, superheater flues added. What's shown above is the 32-tube variant. Some may have been upgraded twice. Beck's book (diagrams supplied by Ray Buhrmaster and Joe Douda) shows an "S-1" modification with 24 flues, 171 tubes pressed to 185 psi and either retaining the 22" cylinders or fitted with 25". But all of the engines listed on the S-1a page had either 30 flues for an Emerson superheater and 158 tubes or the combination shown in the specs. Cylinder diameters could be 23, 24, or 25", but boiler pressure was always 200 psi.

---

Class S-2 (Locobase 9384)

Data from CB&Q Assorted Steam Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. See also DeGolyer, Volume 33, pp. 103+. Works numbers were 34511-34516, 34583-34588, 34599-34600, 34605-34606 in April 1910; 34619-34624, 34685-34689, 34706-34707, 34736, 34737-34738 in May; 34757-34760, 34811-34812, 34850-34855, 34868-34869 in June; 34913-34916 in July

50 engines built with Emerson fire-tube heaters Note that the class was delivered with boilers set at a low 160 psi (11.0 bar). Piston valve diameters measured 12" (305 mm). Although delivered with 69" drivers, most received 74" drivers soon after they entered service.

The big rebuilding occurred during the 1920s; see Locobase 1185.

---

Class S-2A (Locobase 1185)

Data as shown in the locomotive diagram published on Vernon Beck's website -- [] (accessed 22 March 2003) and CB&Q 3 - 1953 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange.

When the Burlington rebuilt the S-2s described in Locobase 9384, they overhauled the entire heating system. They kept the 12" (305 mm) piston valves, but moved the valve gear outside. The original superheaters were replaced by a 30-flue Schmidt installation, and the shops installed feedwater heaters as well. Firebox heating surface included 33.2 sq ft of arch tubes.

As in the S-1As, three different cylinder diameters (23", 24", and 25") were fitted as well.

This class was retired beginning in 1933, the last leaving in 1955.

---

Class S-3 (Locobase 1186)

Data from the locomotive diagram published on Vernon Beck's website -- [] (accessed 22 March 2003), as amended by the CB&Q 3 locomotive diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. Corbin & Kerka (1960, p 104 and 218). See also DeGolyer, Volume 51, pp. 91+ and Volume 56, p. 1+; and "New Locomotives for the Burlington, Colorado and Southern, and the Ft. Worth and Denver", Railway and Locomotive Engineering, Volume XXVIII [28], No 8 (August 1915), pp.262-264. Works numbers were

1915

June 42150-42161, 42171-42173

1918

April 48261-48262; May 48570-48571, 48674, 48731; June 48886-48887, 49071, 49075

25 engines built in batches by Baldwin (15 in 1915, 10 in 1918). They represented a revamped Pacific design with a new shorter boiler, combustion chamber, and brick arch. The combustion chamber contributed 62.4 sq ft (5.8 sq m) and the four arch tubes added 32.6 sq ft (3 sq m) to the firebox heating surface. Steam admission came through 14" (356 mm) piston valves.

Other improvements were lighter, heat-treated steel alloy reciprocating parts, hollow-bore piston rods (which weighed 557 lb/253 kg each) and crank pins (front, main, and back crank pins weighing 125 lb/57 kg, 295 lb/134 kg, and 130 lb/59 kg, respectively), and the Laird suspended crosshead (414 lb/188 kg each). The main rods weighed 870 lb (395 kg) each. Each front crank pin carried 158 lb (63 kg) of the front side rod's weight with each main crank pin bearing side rod weights totalling 490 lb (222 kg) and each back crank pin bore 168 lb (76 kg) of the rear side rod.

Additional equipment included Ragonnet power reverser, and eventually a Worthington or Elesco feedwater heater. As with other designs, this class was fitted with cylinders of three different diameters - 25" (40,200 lb tractive effort), 26" (43,400 lb), and 27" as shown in the specs.

The last five fleshed out rosters on the Fort Worth & Denver (two oil burners; Locobase 9854) and the Colorado & Southern (three 69"-driver engines with a 45,300 lb tractive effort; see Locobase 6758). The C & S also procured 3 of this class from the Burlington in July 1919.

Retirements began in 1951 and ended in 1958.