BP# 6570-6571. Some data from Carlos Alberto Fernandez Priotti in Bryan Attewell ([] Steam Locomotive simulator program (April 2000) confirmed and supplemented by data from Gavin Hamilton's excellent compilation of Garratt data posted at []
(6 September 2005); and Data from Wiener, Articulated Locomotives (1930); and "Buenos Aires Midland Railway
-Design 1147", Beyer-Garrrat Patent Articulated Locomotives (Manchester, England: Beyer-Peacock & Company Limited, 1931), archived on flickr's Historical Railway Images at [], p. 32. Information about the class supplied in Coronel Gustavo Adolfo Tama'o, "Las Locomotoras Garratt en Argentina," in PDF.
BP's 1931 Survey claimed that the "4-6-2 type [of Garratt] is especially sweet running and permits a larger quantity of coal and water being carried." The Survey conceded that "[o]f course its draw-bar efficiency is slightly lower than the 2-6-2+2-6-2 type."
Fernandez commented that the pair's light axle loads led the Midland to lend these Pacific Garratts to the FC Santa Fe for its Santa Fe-Rosario main line. Indeed, says Tamano, on metre-gauge lines like these, the Garratts "...demonstrated a great superiority over those [engines with rigid wheelbase through their power, the steam-generating capacity of the boiler and [Belpaire] firebox suspended [between the bogies], low axle-loading, and aptitude for [negotiating] small-radius curves." Each one could trail 1,600 tons on a 0.4% grade combined with curves of 500 metres radius at 25 mph (40 kph).
Later Ferrocarril General Belgrano 9101-9102; retired by 1950.
| Principal Dimensions by Steve Llanso of Middle Run Media | |
|---|---|
| Class | H |
| Locobase ID | 529 |
| Railroad | Midland of Buenos Aires |
| Country | Argentina |
| Whyte | 4-6-2+2-6-4 |
| Number in Class | 2 |
| Road Numbers | 101-102 |
| Gauge | Metre |
| Number Built | 2 |
| Builder | Beyer, Peacock |
| Year | 1929 |
| Valve Gear | Walschaert |
| Locomotive Length and Weight | |
| Driver Wheelbase (ft / m) | 19 / 5.79 |
| Engine Wheelbase (ft / m) | 46 / 14.02 |
| Ratio of driving wheelbase to overall engine wheelbase | 0.41 |
| Overall Wheelbase (engine & tender) (ft / m) | 67.08 / 20.45 |
| Axle Loading (Maximum Weight per Axle) (lbs / kg) | 23,520 / 10,669 |
| Weight on Drivers (lbs / kg) | 141,120 / 64,011 |
| Engine Weight (lbs / kg) | 253,792 / 115,118 |
| Tender Loaded Weight (lbs / kg) | |
| Total Engine and Tender Weight (lbs / kg) | |
| Tender Water Capacity (gals / ML) | 4320 / 16.36 |
| Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | 5.50 / 5 |
| Minimum weight of rail (calculated) (lb/yd / kg/m) | 39 / 19.50 |
| Geometry Relating to Tractive Effort | |
| Driver Diameter (in / mm) | 48 / 1219 |
| Boiler Pressure (psi / kPa) | 188.50 / 1300 |
| High Pressure Cylinders (dia x stroke) (in / mm) | 15.5" x 22" / 394x559 (4) |
| Tractive Effort (lbs / kg) | 35,286 / 16005.48 |
| Factor of Adhesion (Weight on Drivers/Tractive Effort) | 4.00 |
| Heating Ability | |
| Tubes (number - dia) (in / mm) | |
| Flues (number - dia) (in / mm) | |
| Flue/Tube length (ft / m) | 12 / 3.66 |
| Firebox Area (sq ft / m2) | 152 / 14.12 |
| Grate Area (sq ft / m2) | 34 / 3.16 |
| Evaporative Heating Surface (sq ft / m2) | 1698 / 157.75 |
| Superheating Surface (sq ft / m2) | 335 / 31.12 |
| Combined Heating Surface (sq ft / m2) | 2033 / 188.87 |
| Evaporative Heating Surface/Cylinder Volume | 176.70 |
| Computations Relating to Power Output (More Information) | |
| Robert LeMassena's Power Computation | 6409 |
| Same as above plus superheater percentage | 7434 |
| Same as above but substitute firebox area for grate area | 33,236 |
| Power L1 | 8589 |
| Power MT | 805.08 |