Data from [], Steamindex's summary of Great Northern locomotive practice. See also George Frederick Bird, The Locomotives of the Great Northern Railway 1847-1910 (London: Locomotive Publishing Company, 1910), p. 79-80.
This was a new wheel arrangement for the Great Northern and was a modification of the underground 0-4-2T engine that had entered service years earlier. The longer wheelbase improved stability and made it, so Bird said, "...a much easier riding engine." More than half of the locomotives were delivered with larger tanks and bunkers.
The class was delivered over a 9-year period from 1872 (2) to 1881 (4).
Data from Richard Marsden, from his LNER Encyclopedia at [] (January 2004); and Graham Glover, British Locomotive Design 1825-1960 (London: George Allen & Unwin Ltd, 1967)
Although the 0-4-2 passenger engines using this boiler were considered to have fallen a little short, the shorter runs of Patrick Stirling's tanks probably made better use of the steaming qualities found in this design. Glover (1967) notes that the relatively great spacing between the latter coupled axle and the lead bogie axle -- 10 ft 3 in -- was noteworthy, but not uncommon in the arrangement and reflected " the freedom accorded to designers in providing an adequate firebox with this form [tank] of locomotive."
Richard Marsden's LNER site -- [] (Jan 2004) show the slightly larger domeless Ivatt boiler fitted to the surviving 25 members of this class between 1902 and 1919 as each locomotive came up for boiler renewal. In a boiler enlarged to 53" in diameter, total heating surface increased to 1,119 sq ft, of which 103 sq ft was firebox heating surface. The grate and the power machinery remained the same.
Although 9 remained in service long enough to be grouped and be classed by the LNER, withdrawals of the last 9 were done in 1927.
Richard Marsden's LNER site -- [] (Jan 2004) for date. This was the earlier of Patrick Stirling's bogie tanks, a class that was divided into ten for the Bradford area and six for London suburban service. By the turn of the century, the London locomotives had joined the others.
A relatively small design, both in size and numerically, the class shrank over the years until only six were left to be designated G2 by the LNER at the 1923 Grouping. At that, they retained their old numbers until their retirement in 1924-1926.
Data from Marsden, LNER Encyclopedia, [] (last accessed 31 January 2009) and George Frederick Bird, The Locomotives of the Great Northern Railway 1847-1910 (London: Locomotive Publishing Company, 1910), p. 201-203.
Locobase 9926 sketches out a brief history of the motor coach concept and describes the GNR's home-grown pair. This entry shows the larger and more powerful pair delivered by Kitson to Ivatt's order. Trailing a coach body supplied by the Birmingham Carriage & Wagon Works, the motor had a Belpaire firebox flanked by small coal bunkers. In light of the smaller heating surface area, firebox must have been quite shallow.
By 1917, all 6 had been taken out of service. The coach portions were later converted into twin composite brake carriages and and numbered 44161-44162 by the LNER.
Data from Marsden, LNER Encyclopedia, [] (last accessed 31 January 2009) and George Frederick Bird, The Locomotives of the Great Northern Railway 1847-1910 (London: Locomotive Publishing Company, 1910), p. 201-203.
Locobase 9926 sketches out a brief history of the motor coach concept and describes the GNR's home-grown pair; 9927 describes the Kitson pair delivered in the same year. This entry details Avonside's pair of motor coaches, which had the largest grate and firebox heating surface.
By 1917, all 6 had been taken out of service. The coach portions were later converted into twin composite brake carriages and and numbered 44141-44142 by the LNER.
Principal Dimensions by Steve Llanso of Middle Run Media | |||||
---|---|---|---|---|---|
Class | 120 | G1 (LNER) | G2 (LNER) | Steam motor coach | Steam motor coach |
Locobase ID | 9667 | 3210 | 5903 | 9927 | 9928 |
Railroad | Great Northern | Great Northern | Great Northern | Great Northern | Great Northern |
Country | Great Britain | Great Britain | Great Britain | Great Britain | Great Britain |
Whyte | 0-4-4T | 0-4-4T | 0-4-4T | 0-4-4T | 0-4-4T |
Number in Class | 46 | 29 | 16 | 2 | 2 |
Road Numbers | 5-6 | 7-8 | |||
Gauge | Std | Std | Std | Std | Std |
Number Built | 46 | 29 | 16 | 2 | 2 |
Builder | Doncaster | several | GNR | Kitson & Co | Avonside |
Year | 1872 | 1889 | 1881 | 1905 | 1905 |
Valve Gear | Stephenson | Stephenson | Stephenson | Walschaert | Walschaert |
Locomotive Length and Weight | |||||
Driver Wheelbase (ft / m) | 7.25 / 2.21 | 7.25 / 2.21 | 7.25 / 2.21 | 8 / 2.44 | |
Engine Wheelbase (ft / m) | 22.50 / 6.86 | 22.50 / 6.86 | 22.50 / 6.86 | 53.75 / 16.38 | |
Ratio of driving wheelbase to overall engine wheelbase | 0.32 | 0.32 | 0.32 | 0.15 | |
Overall Wheelbase (engine & tender) (ft / m) | 22.50 / 6.86 | 22.50 / 6.86 | 52.42 / 15.98 | 53.75 / 16.38 | |
Axle Loading (Maximum Weight per Axle) (lbs / kg) | 32,928 / 14,936 | 39,872 / 18,086 | |||
Weight on Drivers (lbs / kg) | 58,772 / 26,659 | 78,792 / 35,739 | 89,824 / 40,744 | ||
Engine Weight (lbs / kg) | 91,252 / 41,391 | 119,728 / 54,308 | 112,448 / 51,006 | 90,692 / 41,137 | |
Tender Loaded Weight (lbs / kg) | |||||
Total Engine and Tender Weight (lbs / kg) | 91,252 / 41,391 | 119,728 / 54,308 | 112,448 / 51,006 | ||
Tender Water Capacity (gals / ML) | 1200 / 4.55 | 1200 / 4.55 | 1200 / 4.55 | ||
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | 1.70 / 2 | 3.30 / 3 | |||
Minimum weight of rail (calculated) (lb/yd / kg/m) | 49 / 24.50 | 66 / 33 | 75 / 37.50 | ||
Geometry Relating to Tractive Effort | |||||
Driver Diameter (in / mm) | 67 / 1702 | 67.50 / 1715 | 62 / 1575 | 43 / 1092 | 44 / 1118 |
Boiler Pressure (psi / kPa) | 170 / 1170 | 160 / 1100 | 170 / 1170 | 200 / 1380 | 200 / 1380 |
High Pressure Cylinders (dia x stroke) (in / mm) | 17.5" x 24" / 445x610 | 18" x 26" / 457x660 | 17.5" x 24" / 445x610 | 10" x 16" / 254x406 | 10" x 16" / 254x406 |
Tractive Effort (lbs / kg) | 15,852 / 7190.35 | 16,973 / 7698.83 | 17,130 / 7770.05 | 6326 / 2869.43 | 6182 / 2804.11 |
Factor of Adhesion (Weight on Drivers/Tractive Effort) | 3.71 | 4.64 | 14.20 | ||
Heating Ability | |||||
Tubes (number - dia) (in / mm) | 174 - 1.75" / 44 | 180 - 1.6" / 41 | 180 - 1.6" / 41 | ||
Flues (number - dia) (in / mm) | |||||
Flue/Tube length (ft / m) | 10.50 / 3.20 | ||||
Firebox Area (sq ft / m2) | 81 / 7.53 | 92.25 / 8.57 | 94 / 8.74 | 46.20 / 4.29 | 60 / 5.58 |
Grate Area (sq ft / m2) | 16.25 / 1.51 | 16.25 / 1.51 | 9.80 / 0.91 | 10.30 / 0.96 | |
Evaporative Heating Surface (sq ft / m2) | 887 / 82.43 | 929 / 86.31 | 924 / 85.87 | 506 / 47.03 | 390 / 36.25 |
Superheating Surface (sq ft / m2) | |||||
Combined Heating Surface (sq ft / m2) | 887 / 82.43 | 929 / 86.31 | 924 / 85.87 | 506 / 47.03 | 390 / 36.25 |
Evaporative Heating Surface/Cylinder Volume | 132.76 | 121.32 | 138.30 | 347.90 | 268.14 |
Computations Relating to Power Output (More Information) | |||||
Robert LeMassena's Power Computation | 2600 | 2763 | 1960 | 2060 | |
Same as above plus superheater percentage | 2600 | 2763 | 1960 | 2060 | |
Same as above but substitute firebox area for grate area | 13,770 | 14,760 | 15,980 | 9240 | 12,000 |
Power L1 | 3671 | 3268 | 3665 | 7263 | 6958 |
Power MT | 275.41 | 182.88 | 356.52 |