Madrid, Zaragoza & Alicante 4-6-4 Locomotives in Spain


Class Details by Steve Llanso of Sweat House Media

Class 620/232-0201 (Locobase 3364)

Data from [], the web site of the Spanish National Railway and Maurice Demoulin, Locomotive Actuelle ... (Paris: Librairie Polytechnique Ch.Beranger, 1906), p 286.

Pere Comas, whose Paleontologia Vaporosa posts on the family tree of Spanish 4-8-0s are referenced in Locobase 3382, says MZA expresses still suffered from a shortage of power on the better than 1% grades they encountered. Such grades and the growing weight of the trains demanded double-heading by the 4-6-2 Pacifics and these "small, but strong" (pequenos pero bravas) "Cercanius Maffeirensis" tanks, which operated on the suburban Catalonian lines. The greater demands eventually led to the introduction of the 4-8-2 Mountains.

Demoulin describes the design, noting that it has a Belpaire firebox.


Class 632/232-0221 (Locobase 3365)

Data from [], the web site of the Spanish National Railway.

Pere Comas, whose Paleontologia Vaporosa posts on the family tree of Spanish 4-8-0s are referenced in Locobase 3382, says MZA expresses still suffered from a shortage of power on the better than 1% grades they encountered. Double-heading required by the 4-6-2 Pacifics and these "small, but strong" (pequenos pero bravas) "Cercanius Maffeirensis" tanks, which operated on the suburban Catalonian lines. The greater demands eventually led to the introduction of the 4-8-2 Mountains.

Principal Dimensions by Steve Llanso of Sweat House Media

Class620/232-0201632/232-0221
Locobase ID3364 3365
RailroadMadrid, Zaragoza & Alicante (MZA)Madrid, Zaragoza & Alicante (MZA)
CountrySpainSpain
Whyte4-6-4T4-6-4T
Number in Class1210
Road Numbers620-631/232-0201 a 232-0212632-641/232-0221 a 232-0230
Gauge5'6"5'6"
Number Built1210
BuilderMaffeiMaffei
Year19031911
Valve GearWalschaertWalschaert
Locomotive Length and Weight
Driver Wheelbase (ft / m)10.83 / 3.3010.83 / 3.30
Engine Wheelbase (ft / m)33.14 / 10.1033.14 / 10.10
Ratio of driving wheelbase to overall engine wheelbase 0.33 0.33
Overall Wheelbase (engine & tender) (ft / m)33.14 / 10.1033.14 / 10.10
Axle Loading (Maximum Weight per Axle) (lbs / kg)28,660 / 13,00033,069 / 15,000
Weight on Drivers (lbs / kg)85,980 / 39,00099,208 / 45,000
Engine Weight (lbs / kg)167,683 / 76,060171,960 / 78,000
Tender Loaded Weight (lbs / kg)
Total Engine and Tender Weight (lbs / kg)167,683 / 76,060171,960 / 78,000
Tender Water Capacity (gals / ML)2112 / 82508 / 9.50
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) 3.90 / 4 3.90 / 4
Minimum weight of rail (calculated) (lb/yd / kg/m)48 / 2455 / 27.50
Geometry Relating to Tractive Effort
Driver Diameter (in / mm)60.80 / 154460.80 / 1544
Boiler Pressure (psi / kPa)171.10 / 11.80171.10 / 11.80
High Pressure Cylinders (dia x stroke) (in / mm)17.32" x 24.8" / 440x63017.32" x 24.8" / 440x630
Tractive Effort (lbs / kg)17,796 / 8072.1417,796 / 8072.14
Factor of Adhesion (Weight on Drivers/Tractive Effort) 4.83 5.57
Heating Ability
Tubes (number - dia) (in / mm)204 - 2.362" / 60204 - 1.969" / 50
Flues (number - dia) (in / mm)
Flue/Tube length (ft / m)13.45 / 4.1013.45 / 4.10
Firebox Area (sq ft / m2)129.17 / 12129.17 / 12
Grate Area (sq ft / m2)30.68 / 2.8530.68 / 2.85
Evaporative Heating Surface (sq ft / m2)1402 / 130.271402 / 130.27
Superheating Surface (sq ft / m2)
Combined Heating Surface (sq ft / m2)1402 / 130.271402 / 130.27
Evaporative Heating Surface/Cylinder Volume207.31207.31
Computations Relating to Power Output (More Information)
Robert LeMassena's Power Computation52495249
Same as above plus superheater percentage52495249
Same as above but substitute firebox area for grate area22,10122,101
Power L152505250
Power MT403.85350.00

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