Class E-4 (Locobase 13666)

Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University, Volume 35, p. 10 Works numbers were 35894-35898 in January 1911.

Almost identical to the CB&Q O-1 Mikes shown in Locobase 474 but fitted with 57" drivers. these were the only 2-8-2s to be bought by the C&S. These had 14" (356 mm) piston valves.

The Emerson superheater was not satisfactory and was soon replaced by a Schmidt setup. See Locobase 1339 for the later upgrade with Schmidt superheater and Elesco feedwater heaters.

Leased to the Burlington from 1933-1947, retired in 1960.

Class E-4-A (Locobase 1339)

Data from C & S 7 -1939 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. Works numbers were 35894-35898 in January 1911.

Locobase 13666 describes the original version as delivered in 1911 with an Emerson superheater. This entry describes the later upgrade with Schmidt superheater and Elesco feedwater heaters.

Leased to the Burlington from 1933-1947, retired in 1960.

Class O-1 (Locobase 474)

Corbin & Kerka (1960, p. 111), confirmed and supplemented by CB&Q Assorted Steam Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. See also DeGolyer, Volume 35, pp. 1+. Works numbers were 35609-35616 in November 1910; 35685-35688, 35735-35752 in December; 35874-35893 in January 1911; 36998-37002 in September; 37025-37029 in October

First CB&Q mikes, 60 of which were delivered in 1910-1911 with tapered boilers, inside-admission 14"(356 mm) piston valves, Emerson superheaters in 24 flues. Baldwin estimated superheater area as 845 sq ft (78.5 sq m), but the CB&Q calculated the area as shown above in the specs. Firebox heating surface area included 32.4 sq ft (3.01 sq m) of arch tubes.

According to Baldwin's "Hereafter" note in its specifications, the railroad complained on 19 April 1911 that the installed cylinder heads were breaking. "Hereafter," the note said,"back cylinder heads to be cast steel."

Among the first American locomotives to be delivered with superheaters, these engines would soon be dwarfed by their two-years-younger brothers shown in Locobase 2902.

Upgrades were confined to such appliances as a Worthington #3 feed water heater. But the Burlington retained the rarely used Emerson superheater until the end of their days.

With the exception of 5008 scrapped in September 1927 (wrecked?), two scrapped in 1933 (5051, 5053) and in 1934 (5017, 5033), operated the entire class until the late 1940s. Some held on a little longer with 5023 and 5059 being scrapped in August 1950; 5055 in September; 5036 in February 1951; 5006, 5022, 5049 in April; and 5045 in May.

Class O-1A - 1917 (5060) (Locobase 11020)

Data from Corbin & Kerka (1960) and from locomotive diagram published on Vernon Beck's website -- [] (accessed 22 March 2003). See also DeGolyer, Volume 56, pp. 21+ and 39+ and Volume 67, pp. 54; 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 number were:

1917

March 45359-45360; April 45463, 45521-45523; May 45621, 45636, 45664; June 45702-45703, 45759-45761, 45792

1918

June 48725-48726, 48904, 48949, 48994, 49072-49073; July 49228-49229, 49301, 49358, 49409-49410; August 49543-49544. 49640, 49653-49654; October 50130, 50362; November 50677; December 50787, 50942, 50988-50989

1920

November 54137; December 54170-54175

1921

January 54290-54292, 54362-54367

1922

April 55352; May 55400-55404, 55380-55381, 55454-55462; July 55497-55503, 55533-55539

Improved O-1s delivered in two batches: 88 in 1917-1922 (5060-5147), 60 more in 1923 (4940-4999); the latter engines are shown in Locobase 10.

Unlike the O-1s (Locobase 474), these had outside-admission 14" (356 mm) piston valves. Equipped with wagon-top boiler with radially stayed fireboxes and a short combustion chamber that reduced tube length by 2 1/2 feet (762 mm). To accommodate ten more flues for an enlarged superheater installation, the boiler sacrificed 21 small tubes. At a later date, the boiler pressure was raised from 180 psi (12.4 bar) to 200 psi. Some of the O-1As adopted a taller forward sand dome and 5144 was delivered with Young radial valve gear.

Direct heating surface area included 59 sq ft (5.5 sq m) from the combustion chamber and 33 sq ft (3.07 sq m) from arch tubes. 5060-5115 used a horizontal-type coal pusher and 5116-5147 were fitted with a slope-sheet type.

Like all of the Burlington's Mikados, these operated well into the 1950s with a few evading the ferro-knacker until 1960.

Class O-1A - 1923 (4940) (Locobase 10)

Data from Corbin & Kerka (1960) and from locomotive diagram published on Vernon Beck's website -- [] (accessed 22 March 2003). See also DeGolyer, Volume 67, pp. 97+; "Grand Canyon 4960" on Martyn Banes's Modern Steam Locomotive website at [], last accessed 15 May 2021; "Grand Canyon Railway 4960" in Wikipedia, also last accessed 15 May 2021; and William Vantuono, "Steam Power Returns to Grand Canyon Railway", Railway Age (17 February 2021) . (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. Hohl's 2 April 2021 email provided information about the Grand Canyon Railway's tender. ) Works numbers in 1923 were:

May 56572-56576

July 56704-56713; 56804-56818

August 56931-56932, 56968-56972

September 56973-56975, 57073-57077, 57096, 57105-57114

October 57245-57248

This was the second order of Improved O-1s; the first 88 are described in Locobase 11020. 60 more in 1923 (4940-4999). Unlike the O-1s (Locobase 474), these had outside-admission 14" (356 mm) piston valves. The later group shown here were ten short tons (9,072 kg) heavier on the drivers and weighed 19 tons (17,237 kg) more overall.

The 4940s had a tapered boiler with Elesco or Worthington #3 feed water heater; boiler pressure raised from 170 psi (11.7 bar) to 200 psi. Radially stayed fireboxes were fitted with either B K or Martin stokers. The direct heating surface included 33 sq ft (3.05 sq m) of arch tubes and 59 sq ft of combustion chamber (5.48 sq m). Others had 58 sq ft (5.39 sq m) of thermic syphons instead of the arch tubes,

The 4960 later went on to serve the Grand Canyon Railway beginning in 1996 after age and wear in excursion service had led to a complete rebuilding.. Other changes included eight transverse arch tubes to increase water circulation and a smaller smokebox that Wikipedia reports led to a 30% decrease in back pressure. A 1999 custom-built injector delivered faster water flow. In 2005, the GCR replaced the original six-limbed Kiesel star nozzle with a Lempor exhaust that was reported to have worked well.

Wikipedia's entry said that the 1993 makeover meant the 4960 "has been so heavily modified, it now has an appearance of a 1940s era locomotive, instead of a 1920s locomotive it originally appeared as [sic]." Locobase thinks that OK because many locomotives were overhauled extensively, either because fads fade to be replaced by other fads or, more often, newer technology offers benefits deemed to be worth the cost..

Chris Hohl traced the 4960's tender history back to the Soo Lines' N-20 4-8-2 #4005 (Locobase 226). Tender number 4056 was modified by changing the fuel from 22 tons of coal to 3,600 US gallons (13,626 litres) of Waste Vegetable Oil (WVO). Railway Age reported that the 4960 was nicknamed "The Green Machine" for its use of WVO, for the snow melt water in its boiler, which is jacketed in dark green to match the tender's color.

Class O-2 (Locobase 2902)

Corbin & Kerka (1960, 114) and data from locomotive diagram published on Vernon Beck's website -- [] (accessed 22 March 2003). See also "Mikado Locomotives for the Burlington," Railway Age Gazette, Volume 53, No 22 (29 November 1912), p. 1045; and DeGolyer, Volume 46, pp. 212+.

Works numbers were

1912

August 38176-38177, 38205-38210; September 38229-38231, 38285-38289, 38365-38370, 38387-38392; October 38428-38433, 38501-38516; November 38768-38771, 38874-38889; December 38929-38932, 38973-38983

1913

January 39040-39041, 39071-39083.

Following closely on the heels of the O-1s (Locobase 474), the 100 O-2 Mikados had substantially larger, straight-top boilers and grates. The latter's firebox heating surface included 34 sq ft (3.15 sq m) of arch tubes. They were designed for "long, hard freight runs", according to the AERJ account, and were supplied with 14" (356 mm) piston valves with 1/4" (6.35 mm) lead, Ragonnet power reverse. All drivers were flanged, but provided with sufficient lateral play so as to negotiate 20-deg curves.

43 O-2a and 12 O-2bs were rebuilt O-2s; see Locobase 9461. The other 45 were scrapped in the 1920s and 1930s.

Class O-2A/O-2B (Locobase 9461)

Data from CB&Q - 1953 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange.

Locobase 2902 shows the O-2 class it entered service in 1912. When the Burlington remade this large class of Mikados in the middle 1920s, it didn't take half-measures. In addition to a new frame, new cylinders, Ragonnet power reverse, Duplex or DuPont stoker and other frills, the shops reworked the boiler. They introduced a combustion chamber that added 59 sq ft (5.48 sq m) to the firebox heating surface. 43 O-2As had 34 sq ft (3.16 sq m) of arch tubes; 12 O-2Bs did not. Inside the boiler, 79 tubes were removed to make room for 15 more flues for the Schmidt superheater. Each tube was shorter by the length of the combustion chamber.

The consequent heating surface area was considerably less, but the superheater ratio climbed to well over 20% of the total. All of the changes netted 12 tons of additional weight for the engine, much of it settling on the drivers as increased adhesion weight.

All in all, a worthy set of alterations that stood the O-2 and the Burlington in good stead for almost three more decades.

Class O-3 (Locobase 5441)

Data from table in May 1916 issue of Railway Mechanical Engineer (RME) and from locomotive diagram published on Vernon Beck's website -- [] (accessed 22 March 2003). See also DeGolyer, Volume 56, pp. 60+; 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 42126-42131, 42145-42149, 42162-42165

1917

March 45361-45362; April 45525-45527; May 45577-45579, 45630, 45637, 45665-45667; June 45712-45713, 45756, 45762-45764, 45794-45796, 45831-45833

1919

February 51264, 51275-51276, 51347, 51446; March 51480-51481, 51519-51521, 51631; April 51665, 51709-51710, 51742-51743; May 51760

The O-3s were the first Chicago, Burlington & Quincy Mikes delivered with a combustion chamber, brick arch and Schmidt superheater. The firebox heating surface included 69 sq ft (6.4 sq m) in the combustion chamber and 35 sq ft (3.25 sq m) of arch tubes . The first 15 were delivered with a pressure set to 180 psi (12.4 bar). The later engines came pressed to 200 psi. Piston valves measuring 14" (356 mm) in diameter admitted steam to the cylinders.

Otherwise they were derived from the earlier O-2s (Locobase 2920), which in turn were later modified along lines very similar to those of the O-3.

Class O-4 (USRA) (Locobase 9462)

Data from CB&Q - 1953 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange;and DeGolyer, Volume 58, pp. 96+. Works numbers were 51552-51553, 51585-51588, 51613-51621 in March 1919.

Very simply, these were fifteen USRA Heavy Mikados that went into service with the Burlington. These government engines were a bit smaller than the other CB&Q Mikes and had slightly less cylinder volume as well. Firebox heating surface area included a short combustion chamber presenting 51 sq ft (4.74 sq m) and four arch tubes contributing 28 sq ft (2.60 sq m). 14" (356 mm) piston valves supplied steam to the cylinders.

Later additions featured either Du Pont or Duplex mechanical stokers and either Worthington or Elesco feed water heaters.

But very few operators of the USRA Heavy Mike threw theirs away in any sort of haste and the Burlington kept its stud in service until the mid-1950s.