Mexican Railway 4-6-0 Locomotives in Mexico


Class Details by Steve Llanso of Sweat House Media

Class F-1 (Locobase 15929)

Data from FCM 1920 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange and DeGolyer, Volume 11, pp. 54. Works numbers 6555-6559 in January 1883. (Campeche had the lowest boiler number.)

Ordered at the same time as the four engines described in Locobase 6956, this quartet had smaller drivers. The specification shows that the original plan was to fit 48" drivers, but an 18 June 1882 note shows the figure crossed out and the 51" written in.

Delivered with 19" cylinder bores, these engines later had their cylinders bushed to 18" diameter, perhaps because the cylinder volume overmatched the boiler's ability to create steam. All were delivered with names Nautla, Campeche, Coatspec, and Zongolica.


Class F-1-53 (Locobase 6956)

Data from FCM 1920 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. See also DeGolyer, Volume 11, pp. 54 and 212. Works numbers 6199 in May 1882; 6337, 6342 in August; 6364 in September; and 6811-6812 in June 1883.

Relatively old Ten-wheeler with a long, straight boiler over unevenly spaced driving axles, firebox between the last two axles (which were 8 1/2 feet apart), steam dome over the front two driving axles (which were 5 feet apart), and straight stack. Note that 54 & 57 (at least) had tenders with 2,327 US-gallon oil capacity.

Delivered with 19" cylinder bores, these engines later had their cylinders bushed to 18" diameter, perhaps because the cylinder volume overmatched the boiler's ability to create steam. All were delivered with names Tepeyac, Zempoala, Anahuac, Mexico, Meztitlan, and Cuatalapanga and all were renumbered several times.

Four more with smaller drivers were delivered at the same time; see Locobase 15929.


Class F-3- 21 (Locobase 6955)

Data from FCM 1920 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange.

Although the diagram is the only illustration available to Locobase, it seems to depict a Belpaire firebox. Although only three were left in 1920, the builder's numbers order suggests that at least 4682-4685 were produced as a batch for the Mexicano.


Class F-4 (Locobase 6734)

Data from MexRy 1939 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange.

Pittsburgh supplied the first 2 in 1900 and Dickson added 4 more in 1902.


Class F-5 (Locobase 6735)

Data from Degolyer, Volume 29, p. 85. See also MexRy 1939 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. Works numbers were 28163-28164 in May 1906.

This pair of Ten-wheelers followed a couple of earlier Baldwins shown in Locobase 6736. Although evaporative heating surface increased, the grate area dropped appreciably. This may not have mattered as much with oil-firing as it would have with coal.

In a later year, the MR reduced the boiler's tube count by 30, which trimmed total evaporative heating surface to 2,342 sq ft.

The pair served the Mexicano for almost 50 years. 40 retired in 1960.


Class F-5 - 37 (Locobase 6736)

Data from DeGolyer, Volume 27, p. 133; and MexRy 1939 Locomotive Diagrams supplied in May 2005 by Allen Stanley from his extensive Rail Data Exchange. Works numbers were 24791 and 24799 in November 1904

These Ten-wheelers were similar to the Alcos that had preceded them onto the MR. The boiler was a bit bigger, but the other principal measurements differed little except for the driver diameter. The pair burned soft coal when they arrived on the railway, but were converted to oil-burning some time later.

They went to the Nacional de Mexico in 1950 as that railroad's F-35 class.


Class F-5 / F-35 (Locobase 13640)

Data from Baldwin Locomotive Works Specification for Engines as digitized by the DeGolyer Library of Southern Methodist University Volume 27, p.133. Works numbers were 24791, 24799 in November 1904 and 28163-28164 in May 1906.

Not long after they took delivery of 6 Consolidations with Belpaire fireboxes (Locobase 13640), the Mexican took on 2 4-6-0s with essentially identical boilers and power dimensions. Only the drivers were different, although only by 4".

Principal Dimensions by Steve Llanso of Sweat House Media

ClassF-1F-1-53F-3- 21F-4F-5
Locobase ID15929 6956 6955 6734 6735
RailroadMexican RailwayMexican RailwayMexican RailwayMexican RailwayMexican Railway
CountryMexicoMexicoMexicoMexicoMexico
Whyte4-6-04-6-04-6-04-6-04-6-0
Number in Class46462
Road Numbers50-53/55-5847-49, 2, 61-62/53-5821-2469-70 / 31-3639-40
GaugeStdStdStdStdStd
Number Built46462
BuilderBurnham, Parry, Williams & CoBurnham, Parry, Williams & CoNeilson & CoseveralBurnham, Williams & Co
Year18831882189419001906
Valve GearStephensonStephensonStephensonStephensonBaker
Locomotive Length and Weight
Driver Wheelbase (ft / m)13.50 / 4.1113.50 / 4.1112.50 / 3.8112 / 3.6612.50 / 3.81
Engine Wheelbase (ft / m)23.65 / 7.2123.52 / 7.1723.12 / 7.0523 / 7.0123.08 / 7.03
Ratio of driving wheelbase to overall engine wheelbase 0.57 0.57 0.54 0.52 0.54
Overall Wheelbase (engine & tender) (ft / m)46.25 / 14.1046.08 / 14.0550.21 / 15.3051.75 / 15.7748.33 / 14.73
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)71,905 / 32,61671,905 / 32,616106,769 / 48,430109,257 / 49,558115,447 / 52,366
Engine Weight (lbs / kg)91,755 / 41,61991,755 / 41,619128,219 / 58,159137,619 / 62,423146,107 / 66,273
Tender Loaded Weight (lbs / kg)69,268 / 31,41969,268 / 31,41999,089 / 44,94687,486 / 39,68387,304 / 39,600
Total Engine and Tender Weight (lbs / kg)161,023 / 73,038161,023 / 73,038227,308 / 103,105225,105 / 102,106233,411 / 105,873
Tender Water Capacity (gals / ML)2600 / 9.852600 / 9.853500 / 13.265000 / 18.945000 / 18.94
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT)2402 / 90922402 / 90922055 / 77782500 / 94632680 / 10,144
Minimum weight of rail (calculated) (lb/yd / kg/m)40 / 2040 / 2059 / 29.5061 / 30.5064 / 32
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)51 / 129557 / 144860 / 152460 / 152454 / 1372
Boiler Pressure (psi / kPa)150 / 10.30150 / 10.30175 / 12.10175 / 12.10200 / 13.80
High Pressure Cylinders (dia x stroke) (in / mm)19" x 24" / 483x61019" x 24" / 483x61018.5" x 26" / 470x66020" x 26" / 508x66020" x 26" / 508x660
Tractive Effort (lbs / kg)21,660 / 9824.8219,380 / 8790.6322,061 / 10006.7125,783 / 11694.9932,741 / 14851.09
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.32 3.71 4.84 4.24 3.53
Heating Ability
Tubes (number - dia) (in / mm)154 - 2.25" / 57154 - 2.25" / 57232 - 1.75" / 44243 - 2" / 51330 - 2" / 51
Flues (number - dia) (in / mm)
Flue/Tube length (ft / m)12.23 / 3.7312.25 / 3.7311.49 / 3.5013 / 3.9613.37 / 4.08
Firebox Area (sq ft / m2)125.60 / 11.67125.60 / 11.67123 / 11.43164 / 15.24163.20 / 15.16
Grate Area (sq ft / m2)17.76 / 1.6517.76 / 1.6524 / 2.2332.50 / 3.0233.20 / 3.09
Evaporative Heating Surface (sq ft / m2)1215 / 112.921215 / 112.921328 / 123.421817 / 168.872460 / 228.62
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)1215 / 112.921215 / 112.921328 / 123.421817 / 168.872460 / 228.62
Evaporative Heating Surface/Cylinder Volume154.19154.19164.15192.28260.32
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation26642664420056886640
Same as above plus superheater percentage26642664420056886640
Same as above but substitute firebox area for grate area18,84018,84021,52528,70032,640
Power L129823333420348836240
Power MT274.29306.57260.36295.59357.48

Principal Dimensions by Steve Llanso of Sweat House Media

ClassF-5 - 37F-5 / F-35
Locobase ID6736 13640
RailroadMexican RailwayMexican Railway
CountryMexicoMexico
Whyte4-6-04-6-0
Number in Class24
Road Numbers37-3837-40
GaugeStdStd
Number Built24
BuilderBurnham, Williams & CoBurnham, Williams & Co
Year19041904
Valve GearStephensonStephenson
Locomotive Length and Weight
Driver Wheelbase (ft / m)12.50 / 3.8112.50 / 3.81
Engine Wheelbase (ft / m)23.08 / 7.0323.08 / 7.03
Ratio of driving wheelbase to overall engine wheelbase 0.54 0.54
Overall Wheelbase (engine & tender) (ft / m)48.33 / 14.7348.12 / 14.67
Axle Loading (Maximum Weight per Axle) (lbs / kg)
Weight on Drivers (lbs / kg)115,352 / 52,323116,500 / 52,844
Engine Weight (lbs / kg)146,008 / 66,228147,500 / 66,905
Tender Loaded Weight (lbs / kg)87,302 / 39,60080,000 / 36,287
Total Engine and Tender Weight (lbs / kg)233,310 / 105,828227,500 / 103,192
Tender Water Capacity (gals / ML)5000 / 18.944000 / 15.15
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT)2680 / 10,144
Minimum weight of rail (calculated) (lb/yd / kg/m)64 / 3265 / 32.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)54 / 137254 / 1372
Boiler Pressure (psi / kPa)180 / 12.40180 / 12.40
High Pressure Cylinders (dia x stroke) (in / mm)20" x 26" / 508x66020" x 26" / 508x660
Tractive Effort (lbs / kg)29,467 / 13366.0229,467 / 13366.02
Factor of Adhesion (Weight on Drivers/Tractive Effort) 3.91 3.95
Heating Ability
Tubes (number - dia) (in / mm)235 - 2.25" / 57237 - 2.25" / 57
Flues (number - dia) (in / mm)
Flue/Tube length (ft / m)13.42 / 4.0913.37 / 4.08
Firebox Area (sq ft / m2)167 / 15.51162.70 / 15.12
Grate Area (sq ft / m2)33.20 / 3.0933.20 / 3.08
Evaporative Heating Surface (sq ft / m2)2023 / 188.012018 / 187.48
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)2023 / 188.012018 / 187.48
Evaporative Heating Surface/Cylinder Volume214.07213.54
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation59765976
Same as above plus superheater percentage59765976
Same as above but substitute firebox area for grate area30,06029,286
Power L148994854
Power MT280.89275.57

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