Data from "Four-Coupled Tank Engine, G N R, Ireland," The Locomotive & Railway Carriage & Wagon Review, Vol IV (January 1899), p. 5. Dundalk works numbers ran 16-18 , 20, and 23-24.
The data apply to 3rd and 4th of the 6 locomotives to be built to the same general design at the railroad's shops. Sutton (93 - built in 1895) and Howth (94 - 1896) had 140-psi boilers.
Aster & Crocus followed in 1898. The class was completed by Tulip (13) & Viola (14), which were built in 1902 with 175-psi boilers and 17" x 22" cylinders.
They filled the bill for commuter service for decades, operating first out of Dublin, then on the Dundalk. Newry and Greenore Railway which was taken over in 1933. Four were scrapped between 1955-1957, 93 was withdrawn in that period and preserved at the Ulster Folk & Transport Museum, and 91(ex-13) operated until 1963.
| Principal Dimensions by Steve Llanso of Middle Run Media | |
|---|---|
| Class | JT |
| Locobase ID | 10107 |
| Railroad | Great Northern |
| Country | Ireland |
| Whyte | 2-4-2T |
| Number in Class | 2 |
| Road Numbers | 18, 20 |
| Gauge | 5'3" |
| Number Built | 2 |
| Builder | Dundalk |
| Year | 1898 |
| Valve Gear | Stephenson |
| Locomotive Length and Weight | |
| Driver Wheelbase (ft / m) | 7 / 2.13 |
| Engine Wheelbase (ft / m) | 20.50 / 6.25 |
| Ratio of driving wheelbase to overall engine wheelbase | 0.34 |
| Overall Wheelbase (engine & tender) (ft / m) | 20.50 / 6.25 |
| Axle Loading (Maximum Weight per Axle) (lbs / kg) | 29,680 / 13,463 |
| Weight on Drivers (lbs / kg) | 57,344 / 26,011 |
| Engine Weight (lbs / kg) | 102,256 / 46,383 |
| Tender Loaded Weight (lbs / kg) | |
| Total Engine and Tender Weight (lbs / kg) | 102,256 / 46,383 |
| Tender Water Capacity (gals / ML) | 1200 / 4.55 |
| Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | |
| Minimum weight of rail (calculated) (lb/yd / kg/m) | 48 / 24 |
| Geometry Relating to Tractive Effort | |
| Driver Diameter (in / mm) | 66 / 1676 |
| Boiler Pressure (psi / kPa) | 160 / 1100 |
| High Pressure Cylinders (dia x stroke) (in / mm) | 16.5" x 22" / 419x559 |
| Tractive Effort (lbs / kg) | 12,342 / 5598.24 |
| Factor of Adhesion (Weight on Drivers/Tractive Effort) | 4.65 |
| Heating Ability | |
| Tubes (number - dia) (in / mm) | 214 - 1.75" / 44 |
| Flues (number - dia) (in / mm) | |
| Flue/Tube length (ft / m) | |
| Firebox Area (sq ft / m2) | 84.50 / 7.85 |
| Grate Area (sq ft / m2) | 13.95 / 1.30 |
| Evaporative Heating Surface (sq ft / m2) | 1067 / 99.16 |
| Superheating Surface (sq ft / m2) | |
| Combined Heating Surface (sq ft / m2) | 1067 / 99.16 |
| Evaporative Heating Surface/Cylinder Volume | 195.97 |
| Computations Relating to Power Output (More Information) | |
| Robert LeMassena's Power Computation | 2232 |
| Same as above plus superheater percentage | 2232 |
| Same as above but substitute firebox area for grate area | 13,520 |
| Power L1 | 4815 |
| Power MT | 370.23 |