Iowa Central / Minneapolis & St Louis 4-6-0 "Ten-wheeler" Locomotives of the USA


Class Details by Steve Llanso of Sweat House Media

Class G-7 (Locobase 12401)

Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University, Volume 22, p. 265 Works numbers were 17595-17596 in March 1900, 176350-17636, 17656-17657 in April.

These were essentially identical to the Reading's 1898 batch of Ten-wheelers shown in Locobase 12272. Most were served the Heartland for over three decades and took on two more series of numbers on the Minneapolis & St Louis Railway after that line took over the IC in 1912. It does not appear as if the class was ever rebuilt as simple-expansion engines, but a boiler update significantly changed the heating surface areas; see Locobase 9025.

235 (works 17636) ended its career in a wreck in 1926 and was scrapped in December. The others were all scrapped in 1935.


Class G1-19 (Locobase 9018)

Data from M&StL 1934 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Raildata collection. Works numbers 2234-2235. Iowa Central info from http://www.cashgroth.com/iacent.html, accessed 1 January 2008. Works numbers were 1201-1204 in January 1891.

Known as the "Hook & Eye", the Iowa Central "...was said to have poor equipment and a high turnover of men", according to Lyndon "Cash" Groth, webmaster of the Minneapolis & St. Louis - Iowa Central - Chicago & Northwestern Website (http://www.cashgroth.com/). On the other hand, the 28 April 1899 issue of Railway Age (p. 818), featured an assessment of the "Regeneration of the Iowa Central, that noted much new construction, railway rehabilitation, the retirement of floating debt, and the payment of dividends."

This class was delivered with 17" (431 mm) cylinders, but were later modified to take the larger cylinders shown in the specs.

201 was retired in 1932, scrapped in 1933. The other three went in 1935.


Class G2-20 (Locobase 9019)

Data from M&StL 1934 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Raildata collection. Works numbers 2234-2235. Iowa Central info from http://www.cashgroth.com/iacent.html, accessed 1 January 2008. Works #1761-1766.

Six years after the quartet of Pittsburgh Ten-wheelers shown in Locobase 9018 arrived in Iowa, the Hook & Eye returned to the builder for this group of six. Although not significantly bigger in the boiler, the engine had a bigger grate and 18" x 26" cylinders. At some later date, the IaC bushed the cylinders to a 17" diameter. They were followed in the next year by much larger engines; see Locobase 9021.

Most of this class was retired in 1931.


Class G2-26 (Locobase 14083)

Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University, Volume 45, p. 284. Works numbers were 33501-33502, 33518-33519 in June 1909.

This class was later superheated; see Locobase 9024.


Class G3-22 (Locobase 9021)

Data from M&StL 1934 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Raildata collection. Works numbers 2234-2235. Iowa Central info from http://www.cashgroth.com/iacent.html, accessed 1 January 2008. Works numbers were 1881-1884 in November 1898.

Pittsburgh sent four more engines to the Iowa Central the year after it delivered the 101s. In the interim, the entire design grew considerably. The boiler had more tubes, the grate grew, the drivers were taller and carried more weight ...this was a different design for a different service. Only firebox heating surface remained nearly the same and it included 18 sq ft (1.67 sq m) of arch tubes. Steam was now admitted through 10"(254 mm)-diameter piston valves.


Class G4-25 (Locobase 9022)

Data from M&StL 1934 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Raildata collection. Works numbers 2234-2235. Iowa Central info from http://www.cashgroth.com/iacent.html, accessed 1 January 2008. Works numbers 1300-1301 in January 1892; 1302-1303 in February.

A year after Pittsburgh supplied the IaC with some freight-friendly Ten-wheelers (Locobase 9018), it produced a second quartet with even smaller drivers, slightly more boiler pressure and cylinder volume and, consequently, more tractive effort. The much larger grate allowed more steam to be generated and the firebox heating surface area included 13 sq ft (1.21 sq m) of arch tubes.

The class remained essentially unchanged, although all four had their boilers' "factor of safety" increased in 1914-1916 for a cost of $225 eaach.

Retirements came in September 1931 (204), April 1935 (205-206), and November 1936 (207).


Class G5-25 (Locobase 9023)

Data from M&StL 1934 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Raildata collection. Iowa Central info from http://www.cashgroth.com/iacent.html, accessed 1 January 2008. Works numbers were 2505-2508 in February 1900.

The Hook & Eye adopted 4-6-0s for all kinds of service from drag freight to passenger. This quartet from the small Paterson, NJ builder that would soon join several others in the American Locomotive Corporation were mixed-traffic engines of modest size.

A key rebuild increased the "factor of safety" in the boilers of 223-224 in 1917. The M&StL installed 8" (203 mm) piston valves in an Economy valve chest (a form and fit replacement of the original slide valves. 222 received the mod in May 1921, but others didn't get the new valves until December 1924 (224), April 1925 (223), and April 1927 (225) . Their firebox heating surface areas included 12 sq ft of arch tubes each.

Like most of the rest, they served the IaC and its successor Minneapolis & St Louis until the early-to-mid thirties.


Class G6-24 (superheated) (Locobase 9024)

Data from M&StL 1934 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Raildata collection. Thanks to Chris Hohl for his 8 August 2014 email resubmission of information about a decorative upgrade to at least two of the engines.

These Ten-wheelers were delivered as saturated-boiler engines and designated class G2-29; see Locobase 14083.

Beginning in December 1916 Their cylinders were supplied through 8" (203 mm) piston valves installed in a universal steam chest and the firebox heating surface included 25 sq ft (2.32 sq m) of arch tubes. Chris Hohl notes that the 227 and 229 had little raised decorative skirts fitted along the running boards. They may have retained them until their retirement.

The class remained in service until after World War II, with some retiring in 1946, others lasting until 1950.

NB: Superheater area is an estimate based on similar locomotives with identical setups.


Class G7-24 (Locobase 9025)

Data from M&StL 1934 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Raildata collection. See also DeGolyer, Volume 22, p. 265. Works numbers were 17595-17596 in March 1900, 17635-17636, 17656-17657 in April. Iowa Central info from http://www.cashgroth.com/iacent.html, accessed 1 January 2008.

Locobase 12401 describes the original Baldwin sextet of Ten-wheelers that arrived on the IC in 1900. This entry shows the results of a signficant boiler modification that deleted 60 tubes. Although the engines retained their Stephenson gear, it now operated 8" Economy piston valves in a universal steam chest, but the firebox heating surface area included only a modest 13 sq ft of surface area.

They were renumbered by the IaC in 1910 (with the first two receiving the highest two numbers, for some reason) and by the M & StL in 1912 when that railroad took over the IaC. 235 was wrecked in December 1926; the other engines were retired in groups of 3 (233-234, 231) in April 1935 and 2 (232, 230) in August of the same year.

Specifications by Steve Llanso of Sweat House Media
ClassG-7G1-19G2-20G2-26G3-22
Locobase ID12,401 9018 9019 14,083 9021
RailroadIowa Central (MSL)Iowa Central (MSL)Iowa Central (MSL)Minneapolis & St Louis (MSL)Iowa Central (MSL)
CountryUSAUSAUSAUSAUSA
Whyte4-6-04-6-04-6-04-6-04-6-0
Number in Class641044
Road Numbers74-79/232-235, 230-23131-32, 50, 52/200-203100-105/ 208-213350-353/226-229106-109/214-217
GaugeStdStdStdStdStd
Number Built641044
BuilderBurnham, Williams & CoPittsburghPittsburghBurnham, Williams & CoPittsburgh
Year19001891189719091898
Valve GearStephensonWalschaertStephensonStephensonStephenson
Locomotive Length and Weight
Driver Wheelbase (ft)13.5014.5011.6715.8314
Engine Wheelbase (ft)25.252322.3326.9225
Ratio of driving wheelbase to overall engine wheebase 0.53 0.63 0.52 0.59 0.56
Overall Wheelbase (engine & tender) (ft)5048.9454.3151.81
Axle Loading (Maximum Weight per Axle) (lbs)
Weight on Drivers (lbs)103,00084,00094,100137,000115,500
Engine Weight (lbs)148,000114,300121,100182,000152,000
Tender Loaded Weight (lbs)86,00078,00092,000119,000102,200
Total Engine and Tender Weight (lbs)234,000192,300213,100301,000254,200
Tender Water Capacity (gals)45004000520065005000
Tender Fuel Capacity (oil/coal) (gals/tons)691011
Minimum weight of rail (calculated) (lb/yd)5747527664
Geometry Relating to Tractive Effort
Driver Diameter (in)6255626869
Boiler Pressure (psi)200165200200200
High Pressure Cylinders (dia x stroke) (in)14" x 26"18.5" x 24"17" x 26"21" x 26"18.5" x 26"
Low Pressure Cylinders (dia x stroke) (in)24" x 26"
Tractive Effort (lbs)20,85120,94620,60328,66521,924
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.94 4.01 4.57 4.78 5.27
Heating Ability
Firebox Area (sq ft)163137170175.60177
Grate Area (sq ft)30.301722.8042.5026.97
Evaporative Heating Surface (sq ft)22261405146226252269
Superheating Surface (sq ft)
Combined Heating Surface (sq ft)22261405146226252269
Evaporative Heating Surface/Cylinder Volume480.53188.17214.04251.85280.51
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation60602805456085005394
Same as above plus superheater percentage60602805456085005394
Same as above but substitute firebox area for grate area32,60022,60534,00035,12035,400
Power L146174234699576188968
Power MT296.47333.37491.65367.77513.53

Specifications by Steve Llanso of Sweat House Media
ClassG4-25G5-25G6-24 (superheated)G7-24
Locobase ID9022 9023 9024 9025
RailroadIowa Central (MSL)Iowa Central (MSL)Minneapolis & St Louis (MSL)Minneapolis & St Louis (MSL)
CountryUSAUSAUSAUSA
Whyte4-6-04-6-04-6-04-6-0
Number in Class4446
Road Numbers62-65/204-207/218-22170-73/224-227/222-225226-229230-235
GaugeStdStdStdStd
Number Built444
BuilderPittsburghCookeMSLMSL
Year1892190019201920
Valve GearStephensonStephensonWalschaertStephenson
Locomotive Length and Weight
Driver Wheelbase (ft)10.5012.1715.8313.50
Engine Wheelbase (ft)21.0422.6726.9223.25
Ratio of driving wheelbase to overall engine wheebase 0.50 0.54 0.59 0.58
Overall Wheelbase (engine & tender) (ft)48.1251.105454.25
Axle Loading (Maximum Weight per Axle) (lbs)
Weight on Drivers (lbs)92,000108,200133,000120,000
Engine Weight (lbs)114,000142,600167,000153,100
Tender Loaded Weight (lbs)80,30085,400120,00092,000
Total Engine and Tender Weight (lbs)194,300228,000287,000245,100
Tender Water Capacity (gals)4000500065005000
Tender Fuel Capacity (oil/coal) (gals/tons)8888
Minimum weight of rail (calculated) (lb/yd)51607467
Geometry Relating to Tractive Effort
Driver Diameter (in)51636763
Boiler Pressure (psi)170180185185
High Pressure Cylinders (dia x stroke) (in)19" x 24"19" x 26"20" x 26"19" x 26"
Tractive Effort (lbs)24,54822,79524,40923,428
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.75 4.75 5.45 5.12
Heating Ability
Firebox Area (sq ft)155176177192
Grate Area (sq ft)25.692842.5030
Evaporative Heating Surface (sq ft)1420158220801800
Superheating Surface (sq ft)450
Combined Heating Surface (sq ft)1420158225301800
Evaporative Heating Surface/Cylinder Volume180.30185.42220.02210.97
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation4367504078635550
Same as above plus superheater percentage4367504092785550
Same as above but substitute firebox area for grate area26,35031,68038,63935,520
Power L14027545415,3296284
Power MT289.50333.38762.28346.35


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