Data from A R Bennett (M.I.L.E), Volume XXXIII [32],No 422 (15 October 2027), pp. 327-329.
In 1891, the MR sought more power for its 7-mile (11.3 km) railway and order returned to Manning Wardle for two Prairie tanks. Built to specifications and designs prepared by the Crown Agents for the Colonies, the engines certainly delivered more tractive effort.
Unfortunately, A R Bennett wrote, "On being set to work [the 5] was found that she was extremely trying to the light permanent way." Concluding that one trailing radial axle bore too much weight, the Hamrun Works fitted a trailing bogie supplied by Manning Wardle, converting the 5 to a 2-6-4 layout. Engine wheelbase increased to 25 ft (7.62 m) to accommodate the longer bogie, weight grew to 41 tons (91,840 lb), but bunker capacity shrank by 90 US gallons to allow for an inspection aperture.
"The changes resulted," Bennett conceded, "in acute disappointment." He pointed to the leading axle's "advanced postion" and the water tanks placed "an excessive weight on the coupled wheels." The 6, delivered by MW with the rear bogie last served in 1914 and 5 went idle in 1920.
Both engines were unsatisfactory to such an extent that they spent most of their time in the Hamrun sheds.
| Principal Dimensions by Steve Llanso of Middle Run Media | |
|---|---|
| Class | 1 |
| Locobase ID | 21303 |
| Railroad | Malta Railways |
| Country | Malta |
| Whyte | 2-6-2T |
| Number in Class | 3 |
| Road Numbers | 1-3 |
| Gauge | Metre |
| Number Built | 3 |
| Builder | Manning Wardle |
| Year | 1891 |
| Valve Gear | Stephenson |
| Locomotive Length and Weight | |
| Driver Wheelbase (ft / m) | 8.50 / 2.92 |
| Engine Wheelbase (ft / m) | 21.50 / 2.92 |
| Ratio of driving wheelbase to overall engine wheelbase | 0.40 |
| Overall Wheelbase (engine & tender) (ft / m) | 21.50 / 2.92 |
| Axle Loading (Maximum Weight per Axle) (lbs / kg) | |
| Weight on Drivers (lbs / kg) | / 22,353 |
| Engine Weight (lbs / kg) | 87,360 / 22,353 |
| Tender Loaded Weight (lbs / kg) | |
| Total Engine and Tender Weight (lbs / kg) | |
| Tender Water Capacity (gals / ML) | 1320 / 1.59 |
| 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) | 39 / 1041 |
| Boiler Pressure (psi / kPa) | 140 / 820 |
| High Pressure Cylinders (dia x stroke) (in / mm) | 15" x 20" / 267x457 |
| Tractive Effort (lbs / kg) | 13,731 / 6228.28 |
| Factor of Adhesion (Weight on Drivers/Tractive Effort) | |
| Heating Ability | |
| Tubes (number - dia) (in / mm) | |
| Flues (number - dia) (in / mm) | |
| Flue/Tube length (ft / m) | |
| Firebox Area (sq ft / m2) | 71 / 7.80 |
| Grate Area (sq ft / m2) | 10 / 0.42 |
| Evaporative Heating Surface (sq ft / m2) | 754 / 30.10 |
| Superheating Surface (sq ft / m2) | |
| Combined Heating Surface (sq ft / m2) | 754 / 30.10 |
| Evaporative Heating Surface/Cylinder Volume | 184.32 |
| Computations Relating to Power Output (More Information) | |
| Robert LeMassena's Power Computation | 1400 |
| Same as above plus superheater percentage | 1400 |
| Same as above but substitute firebox area for grate area | 9940 |
| Power L1 | 2467 |
| Power MT | |