Another group of 25 Class K-60 "Mikados" was delivered by Baldwin in 1913. This group was assigned road numbers 2550-2574. The specifications were identical to the previous Class K-60 Baldwin-built locomotives. A final group of Class K-60 2-8-2s came from ALCO in 1918. These 20 locomotives were similar to the 1913 "Mikados" and were assigned road numbers 2575-2590.
During World War I the USRA allocated twenty USRA "Mikado-Light" locomotives to the CRI&P. Baldwin built nine of them (road numbers 2300-2308) and ALCO built the other eleven (road numbers 2309-2319). These locomotives were designated as Class K-55 on the CRI&P.
In 1923, Baldwin and ALCO each delivered 24 more of the Class K-60 "Mikados. The Baldwin-built locomotives were given road numbers 2591-2618 and the ALCO group was assigned road numbers 2619-2642.
Later in 1923, another 36 ALCO-built 2-8-2s were Added to the roster. These locomotives were similar to the Class K-60 but had a 210 psi boiler pressure which increased its Tractive effort to 66,640 pounds. They were designated as Class K-60b and were assigned road numbers 2643-2678.
In 1926, the CRI&P bought another 10 "Mikados" from ALCO. These locomotives were similar to the Class K-60b and were designated as Class K-64b and assigned road numbers 2679-2688.
A final group of 2-8-2s were delivered by ALCO in 1927 and were similar to the Class K-64b. They were classified as Class K-67K and were given road numbers 2689-2731.
There are no surviving CRI&P 2-8-2 "Mikado" type locomotives.
|Class||Qty.||Road Numbers||Year Built||Builder||Notes|
|K-60||40||2500 - 2539||1912||Baldwin|
|10||2540 - 2549||1912||ALCO|
|25||2550 - 2574||1913||Baldwin|
|20||2575 - 2594||1918||ALCO|
|K-55||9||2300 - 2308||1919||Baldwin||USRA allocated "Mikado-Light" locomotives|
|11||2309 - 2319||1919||ALCO||USRA allocated "Mikado-Light" locomotives|
|K-60||24||2595 - 2618||1923||Baldwin||Four of these locomotives were sold to the Soo Line in 1941|
|24||2619 - 2642||1923||ALCO|
|K-60b||36||2643 - 2678||1923||ALCO|
|K-64b||10||2679 - 2688||1926||ALCO|
|K-67b||25||2689 - 2713||1927||ALCO|
As part of the USRA's distribution of Mikados, Baldwin built the first 9 of the Rock Island's batch of 20 and Alco produced the latter 11. Locobase has several examples of as-built light Mikes, so this entry shows the Rock's firebox reconditioning in which 28 sq ft of arch tubes was replaced by 77 sq ft of thermic syphons.
Numbers Builder Date Valve gear
2500-2539 Baldwin 1912 Baker
2540-2549 Alco 1912 Walschaerts
2550-2574 Baldwin 1913 Baker
2575-2594 Alco 1918 Walschaerts
48 more followed after World War I.
Piston valves were of a generous 16" diameter and the engines were delivered with brick arches and 29 sq ft of arch tubes. WJ Tollerton, Chief Mechanical Superintendent said in Railway Age (9 January 1914) that they'd proven to be "excellent steamers; there is experienced no difficulty in maintaining full boiler pressure at all times and the absence of black smoke at the stack is evidence of their boiler efficiency." Per 1000 gross ton miles on the Herington-Pratt, Kansas section (126 miles at a ruling grade of 0.8%), the Mikes dropped coal consumption from 96 lb to 66 lb compared to the earlier 2-8-0s while raising the average train load from 1,650 tons to 2,400 tons.
Tenders held either 16 tons of coal or 3,200 to 4,400 gallons of oil. Boiler pressure in these engines began at 180 psi; the earlier ones were raised to 190 psi and later engines were delivered at 200-210 psi. Many had firebox updates in which the arch tubes were replaced by 82 sq ft of thermic syphons, which increased direct heating surface to 361 sq ft. Some even received roller bearings.
Clearly a prized workhorse that soldiered on to the end of steam on the Rock.
The Rock Island continued building after World War I a line of Mikados that it first procured in 1912, but wrought several important changes. Both the direct heating surface and the superheater surface areas were increased, the former being accomplished by including 116.7 sq ft thermic syphons and the later by increasing the number of flues. The postwar class of 48 can be further subdivided by the number of tubes and a consequent difference in evaporative heating surface. The first two batches, which arrived in 1920 and 1922, were as shown in the specs. The last 24 are depicted in Locobase 7233.
As the run of Mikados described in Locobases 2796 and 7232 came to its conclusion in 1923, Brooks rang one more change on the boiler. Ten more tubes were deleted in favor of two more superheater flues, which resulted in a still higher percentage of superheater area in relation to overall heating surface. The firebox heating surface remained the same and still included 116.7 sq ft of thermic syphons.
Firebox had thermic syphons. One of a series of Mikado classes built for the Rock Island before and after World War I. Boiler pressure was later raised to 215 psi and the class redesignated K-68B to signify the increased tractive effort. A 14,000-gallon tender added later put 237,600 lb on the rails.
Firebox had 82 sq ft of thermic syphons. These were the last Mikados delivered to the Rock Island and differed from the K-64B from Brooks (Locobase 11) only in steam pressure and having 2 fewer boiler tubes.
|Specifications by Steve Llanso|
|Railroad||Rock Island (CRI & P)||Rock Island (CRI & P)||Rock Island (CRI & P)||Rock Island (CRI & P)||Rock Island (CRI & P)||Rock Island (CRI & P)|
|Valve Gear||Walschaert||Baker or Walschaert||Baker||Baker||Baker||Baker|
|Locomotive Length and Weight|
|Ratio of driving wheelbase to overall engine wheebase||0.46||0.48||0.48||0.48||0.47||0.47|
|Overall Wheelbase (engine & tender)||71.37'||67.04'||72.98'||73'||73'||73'|
|Axle Loading (Maximum Weight per Axle)|
|Weight on Drivers||216950 lbs||238200 lbs||249053 lbs||246000 lbs||257000 lbs||263000 lbs|
|Engine Weight||284300 lbs||318850 lbs||337240 lbs||331000 lbs||347000 lbs||355000 lbs|
|Tender Light Weight||200600 lbs||189900 lbs||190000 lbs||188000 lbs||196000 lbs||199500 lbs|
|Total Engine and Tender Weight||484900 lbs||508750 lbs||527240 lbs||519000 lbs||543000 lbs||554500 lbs|
|Tender Water Capacity||10000 gals||9000 gals||9000 gals||10000 gals||10000 gals||14000 gals|
|Tender Fuel Capacity (oil/coal)||5000 gals||16 tons||16 tons||3600 gals||16 tons||4550 gals|
|Minimum weight of rail (calculated) on which locomotive could run||90 lb/yard||99 lb/yard||104 lb/yard||103 lb/yard||107 lb/yard||110 lb/yard|
|Geometry Relating to Tractive Effort|
|Boiler Pressure||200 psi||190 psi||200 psi||200 psi||200 psi||210 psi|
|Cylinders (dia x stroke)||26" x 30"||28" x 30"||28" x 30"||28" x 30"||28" x 30"||28" x 30"|
|Tractive Effort||54724 lbs||60293 lbs||63467 lbs||63467 lbs||63467 lbs||66640 lbs|
|Factor of Adhesion (Weight on Drivers/Tractive Effort)||3.96||3.95||3.92||3.88||4.05||3.95|
|Firebox Area||335 sq. ft||259 sq. ft||388.70 sq. ft||388.70 sq. ft||339 sq. ft||339 sq. ft|
|Grate Area||66.70 sq. ft||63 sq. ft||63 sq. ft||63 sq. ft||63 sq. ft||63 sq. ft|
|Evaporative Heating Surface||3697 sq. ft||4276 sq. ft||3600 sq. ft||3443 sq. ft||3506 sq. ft||3485 sq. ft|
|Superheating Surface||882 sq. ft||819 sq. ft||900 sq. ft||914 sq. ft||992 sq. ft||1036 sq. ft|
|Combined Heating Surface||4579 sq. ft||5095 sq. ft||4500 sq. ft||4357 sq. ft||4498 sq. ft||4521 sq. ft|
|Evaporative Heating Surface/Cylinder Volume||200.54||200.00||168.38||161.04||163.98||163.00|
|Computations Relating to Power Output (More Information)|
|Robert LeMassena's Power Computation||13340||11970||12600||12600||12600||13230|
|Same as above plus superheater percentage||15875||13885||15120||15246||15372||16273|
|Same as above but substitute firebox area for grate area||79730||57084||93288||94065||82716||87564|