Data from "MAV 40 sorozat" in Wikipedia at [] (translated by Google), last accessed 2 October 2025. Works numbers were 1782-1788 in 1908.
Seven Mikado engines fitted with the Abt rack-system duplicated many of the specifications of the four 0-8-4RTs originally delivered in 1896 (Locobase 1541). Like those, their rack cylinder diameters measured 420 mm (16.54" ), driving the inside gearing when engaging the centrally aligned rack on the Karánsebes-Orvállajja rack railway section. To enhance the design's ability to negotiate tight curves, leading and trailing trucks used the Adams radial system. The MAV set rod-driven operation maximum speed at 40 kph (25 mph). On the rack, a TIVc rated a 12 kph (7.5 mph) speed.
Reorganization of class IDs in 1911 led to these engines falling in Class 40. After the armistice ending World War I and the collapse of the Austro-Hungarian Empire, the 40's operating area came under Romanian control.
After it was retired, class member 40.006 languished until a group restored the engine to operating condition in 2014.
| Principal Dimensions by Steve Llanso of Middle Run Media | |
|---|---|
| Class | TIVc/40 |
| Locobase ID | 1540 |
| Railroad | Magyar Allamvasutak (MAV) |
| Country | Hungary |
| Whyte | 2-8-2RT |
| Number in Class | 7 |
| Road Numbers | 4291-4297/40.001-007 |
| Gauge | Std |
| Number Built | 7 |
| Builder | Floridsdorf |
| Year | 1908 |
| Valve Gear | Heusinger |
| Locomotive Length and Weight | |
| Driver Wheelbase (ft / m) | 14.12 / 4.30 |
| Engine Wheelbase (ft / m) | |
| Ratio of driving wheelbase to overall engine wheelbase | |
| Overall Wheelbase (engine & tender) (ft / m) | |
| Axle Loading (Maximum Weight per Axle) (lbs / kg) | 31,107 / 14,110 |
| Weight on Drivers (lbs / kg) | 107,744 / 48,872 |
| Engine Weight (lbs / kg) | 157,189 / 71,300 |
| Tender Loaded Weight (lbs / kg) | |
| Total Engine and Tender Weight (lbs / kg) | |
| Tender Water Capacity (gals / ML) | |
| Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | |
| Minimum weight of rail (calculated) (lb/yd / kg/m) | |
| Geometry Relating to Tractive Effort | |
| Driver Diameter (in / mm) | 41.30 / 1049 |
| Boiler Pressure (psi / kPa) | 174 / 1200 |
| High Pressure Cylinders (dia x stroke) (in / mm) | 19.7" x 19.7" / 500x500 |
| Tractive Effort (lbs / kg) | 27,379 / 12418.92 |
| Factor of Adhesion (Weight on Drivers/Tractive Effort) | 3.94 |
| Heating Ability | |
| Tubes (number - dia) (in / mm) | |
| Flues (number - dia) (in / mm) | |
| Flue/Tube length (ft / m) | |
| Firebox Area (sq ft / m2) | |
| Grate Area (sq ft / m2) | 25.82 / 2.40 |
| Evaporative Heating Surface (sq ft / m2) | 1784 / 165.80 |
| Superheating Surface (sq ft / m2) | 568 / 52.79 |
| Combined Heating Surface (sq ft / m2) | 2352 / 218.59 |
| Evaporative Heating Surface/Cylinder Volume | 256.70 |
| Computations Relating to Power Output (More Information) | |
| Robert LeMassena's Power Computation | 4493 |
| Same as above plus superheater percentage | 5571 |
| Same as above but substitute firebox area for grate area | |
| Power L1 | |
| Power MT | |