Data from the Twelfth Annual Report of the American Railway Master Mechanics' Association, May 13th-May15th, 1879, page 84. See also DeGolyer, Volume 8, pp. 76 and 247 and "Our Locomotives Abroad", Railway Age, Volume 3 (7 March 1878), p. 130.. NB: Boiler pressure is an estimate and the heating surface of the tubes is measured from inside the tube plates. Works numbers were 4074 in May 1877 and 4398 in August 1878.
The first engine's tender held 1,800 imperial gallons of water (shown in the specs in US gallons). The second locomotive trailed a tender holding 2,300 US gallons (1,917 Imp gal).
Edward H Williams of the Baldwin Works contributed to a discussion of boilers by providing the relatively sketchy details shown in the specs and commenting that British engines used smaller fireboxes and more tubes. He then observed that the American engines had pulled a greater number of cars and showed better fuel economy.
Of the first engine, the RA was pleased to quote from the Times of London's letter from Sydney, Australia about trials conducted on the NSWGR: "The sample locomotive engine which was furnished by the firm of Messrs. Baldwin & Co., of Philadelphia. has just passed through its oflicial trial on the steep grades and sharp curves of our railway across the Blue Mountains. The result is said to be that it sits the line more easily and rounds the curves with less friction than the more rigid rolling stock imported from England. These are considerations not to be despised, and are superadded to the equally substantial one that the cost is about +600 less than the English locomotive."
The NSWGR's interest in replacing round-top boilers with square-shoulder Belpaires on this class design's firebox heating surface was later increased to 94 sq ft (8.75 sq m). The museum also notes the short, straight, free-steaming boiler, raked smokebox, slightly inclined outside cylinders, tall thin stack, brass steam dome, and circular windows in the cab as delivered. In the 1890s, a refit introduced the Belpaire firebox and an upright smokebox
OS Nock (RWC II, pl 30) points out that the leading truck wasn't a bogie that turned around a central pivot. Instead the four-wheel Bissell truck was carried on a radial arm that pivoted from a point just ahead of the leading driving axle.
Noting their long service (as much as 80 years), Hollingsworth concludes that their simplicity --"the steam locomotive's trump card" -- was the key. This "classic" design, he says, "came near the ultimate in this respect."
John Forsythe (Archive Officer, Transport House), Steam Locomotive Data, Public Transport Commission of NSW [New South Wales], July 1974, p. 78, archived at [], last accessed 12 March 2015. See also Powerhouse Museum web exhibit -- [], last accessed 2 June 2006, (Many thanks to Brett Fitzpatrick for his 11March 2015 email supplying the link to the CoalsToNewcastle website.)
Hollingsworth (1982) says that 68 engines were supplied: 30 from Beyer, Peacock in 1877 and 1879 (works numbers 1620-1637 in 1876-1877 and 1765-1776 in 1878), 26 from Dubs & Company, 4 more from Beyer, Peacock in 1881 (works numbers 2060-2063), and a final 4 from Atlas Engineering of Sydney.
The Powerhouse Museum notes the short, straight, free-steaming boiler, raked smokebox, slightly inclined outside cylinders, tall thin stack, brass steam dome, and circular windows in the cab as delivered. According to Powerhouse's entry on their survivor, "The 79 class engines were the mainstay of the expanding New South Wales railway system for about 20 years. They took over all the through passenger and mail trains, were free steaming and became very popular with the crews. However, the introduction of new more powerful engines and their inability to cope with gradients greater than 1:40 saw the 79 class locomotives moved to the more easily graded branch lines or used as assistant engines."
P-6 4-6-0s (Locobase 2410) replaced them in their original service.
OS Nock (RWC II, pl 30) points out that the leading truck wasn't a bogie that turned around a central pivot. Instead the four-wheel Bissell truck was carried on a radial arm that pivoted from a point just ahead of the leading driving axle.
Noting their long service (as much as 80 years), Hollingsworth concludes that their simplicity --"the steam locomotive's trump card" -- was the key. This "classic" design, he says, "came near the ultimate in this respect."
In the 1890s, a refit introduced the Belpaire firebox and an upright smokebox; this upgrade is shown in Locobase 2400.
Data from Leon Oberg, The Locomotives of Australia - 1854-2007 (, 2008, 4th ed), pp. 55-56. See also John Forsythe (Archive Officer, Transport House), Steam Locomotive Data, Public Transport Commission of NSW [New South Wales], July 1974, p. 78, archived at [], last accessed 12 March 2015. (Many thanks to Brett Fitzpatrick for his 11 March 2015 email supplying the link to the CoalsToNewcastle website.) Works numbers 2150-2155.
These were built to offer better speed than the Class 79 5 1/2 footers (Locobase 2400), but, says Oberg, the class proved unable to cope with the 1 in 40 (2 1/2%) grades as well as being a bit unstable due to a short-wheelbase Bissell-design bogie. 24 follow-on Dubs-built 261-class engines had 18"-diameter cylinders. Still later in 1884, Dubs added seventeen 334-class engines that had outside Joy valve gear and a 6-foot wheelbase Adams bogie.
Nevertheless, the 255s had been paid for and thus remained in service for decades. Between 1901-1909, they were fitted with Belpaire fireboxes; see Locobase 15982.
Ten later built for the 5' 3" gauge Victorian.
Data from John Forsythe (Archive Officer, Transport House), Steam Locomotive Data, Public Transport Commission of NSW [New South Wales], July 1974, p. 78, archived at [], last accessed 12 March 2015. (Many thanks to Brett Fitzpatrick for his 11March 2015 email supplying the link to the CoalsToNewcastle website.)
The Highflyer Sextet (not a musical group as will be seen in Locobase 1105) joined several other NSWGR classes in trading in their round-top boilers for Belpaire boilers that pitched the fireboxes higher to clear the driving axles and widen the grate.
John Forsythe (Archive Officer, Transport House), Steam Locomotive Data, Public Transport Commission of NSW [New South Wales], July 1974, p. 66, archived at [], last accessed 12 March 2015. (Many thanks to Brett Fitzpatrick for his 11 March 2015 email supplying the link to the CoalsToNewcastle website.)
Larger passenger engines with a slightly longer stroke than the Z12 and a much larger grate. The specifications given in the 1974 handbook show internal inconsistencies. Calculating the heating surface area of the 196 small-diameter tubes yields an figure 350 sq ft (32.4 sq m) or 32% less than the number shown in the book. Even if one assumes that the 1 3/8" given in the databook is an inside dimension (which Brett Fitzpatrick and I both suspect is true), the outside diameter would have to be 2" to generate the area used by the NSW.
According to the description written for the State Rail Heritage authority (found on http://www . staterail.nsw.gov.au/Heritage/2b/1709.htm), this class "represented an unsuccessful attempt to improve upon the very successful Z12 class." The historical notes state that the Hs were meant to challenge the steep gradients of the short north and south coast lines. "Compared to the earlier C79 class," the report notes,"the H373 class were dogged by design flaws such as high axle loading, low factor of adhesion, and rough riding." (Such a combination of flaws suggests an over-muscled locomotive for the railway.)
With all its faults, the class still represented available motive power, so the railway included the class in its program of replacing the round-top boiler with a Belpaire design in 1905-1906; see Locobase 15987.
John Forsythe (Archive Officer, Transport House), Steam Locomotive Data, Public Transport Commission of NSW [New South Wales], July 1974, p. 66, archived at [], last accessed 12 March 2015. (Many thanks to Brett Fitzpatrick for his 11 March 2015 email supplying the link to the CoalsToNewcastle website.)
As noted in Locobase 2402, this class was quite unsuccessful in their passenger-service role. But as they were in service, the railway made the best use they could with the engines and , keeping them in service until 1934 (first retirement) to 1957 (last retirement).
Data from John Forsythe (Archive Officer, Transport House), Steam Locomotive Data, Public Transport Commission of NSW [New South Wales], July 1974, p. 59, archived at [], last accessed 12 March 2015. (Many thanks to Brett Fitzpatrick for his 11 March 2015 email supplying the link to the CoalsToNewcastle website.) Works numbers were 1909-1914 in 1880.
Originally built as tank engines, these were converted to tender-engine 4-4-0s in 1910. The tender weighed 50,512 lb (22 t 11 cwt) when filled with 2,400 US gallons (2,000 Imperial gallons) of water and 4.95 short tons (4 1/2 long tons) of coal. Moving fuel and water reduced adhesion weight to 55,480 lb (24 t 16 cwt 2 q) and engine weight to 81,424 lb (36 t 7 cwt).
When the Commonwealth Railways bought them in 1912 it was to support construction of the Kalgoorlie-Port Anthony line. Soon after they entered CR service, the six locomotives in the D class developed problems with blown firetubes and water gauges. In fact, these seem to have been lemons. But they carried on anyway, once all the broken stays were repaired and boilers retubed, and operated until the late 1950s as yard goats.
Principal Dimensions by Steve Llanso of Middle Run Media | |||||
---|---|---|---|---|---|
Class | 105 | C- 79//C12/Z12 | C- 79//C12/Z12 | D-255 Highflyers | D-255 Highflyers |
Locobase ID | 9520 | 2400 | 15983 | 1105 | 15982 |
Railroad | New South Wales | New South Wales | New South Wales | New South Wales | New South Wales |
Country | Australia | Australia | Australia | Australia | Australia |
Whyte | 4-4-0 | 4-4-0 | 4-4-0 | 4-4-0 | 4-4-0 |
Number in Class | 2 | 65 | 68 | 6 | 6 |
Road Numbers | 105, 130 | 79-92, 118-126+ | 79-92, 118-126+ | 255-260 | 255-260 |
Gauge | Std | Std | Std | Std | Std |
Number Built | 2 | 68 | 6 | ||
Builder | Burnham, Parry, Williams & Co | NSWGR | several | Beyer, Peacock | NSWGR |
Year | 1877 | 1901 | 1877 | 1882 | 1901 |
Valve Gear | Stephenson | Stephenson | Stephenson | Stephenson | Stephenson |
Locomotive Length and Weight | |||||
Driver Wheelbase (ft / m) | 8.50 | 8.04 / 2.45 | 8.04 / 2.45 | 8 / 2.44 | 8 / 2.44 |
Engine Wheelbase (ft / m) | 21.50 | 19.50 / 5.94 | 19.50 / 5.94 | 19.75 / 6.02 | 19.77 / 6.03 |
Ratio of driving wheelbase to overall engine wheelbase | 0.40 | 0.41 | 0.41 | 0.41 | 0.40 |
Overall Wheelbase (engine & tender) (ft / m) | 36.65 / 11.17 | 36.65 / 11.17 | 38.90 / 11.86 | 38.90 / 11.86 | |
Axle Loading (Maximum Weight per Axle) (lbs / kg) | 30,688 / 13,920 | 28,448 / 12,904 | 28,224 / 12,802 | 29,904 / 13,564 | |
Weight on Drivers (lbs / kg) | 49,000 | 59,920 / 27,179 | 56,784 / 25,757 | 55,104 / 24,995 | 58,016 / 26,316 |
Engine Weight (lbs / kg) | 74,000 | 91,056 / 41,302 | 87,472 / 39,677 | 84,112 / 38,153 | 90,048 / 40,845 |
Tender Loaded Weight (lbs / kg) | 49,224 / 22,328 | 49,224 / 22,328 | 59,024 / 26,773 | 56,784 / 25,757 | |
Total Engine and Tender Weight (lbs / kg) | 140,280 / 63,630 | 136,696 / 62,005 | 143,136 / 64,926 | 146,832 / 66,602 | |
Tender Water Capacity (gals / ML) | 2160 | 2400 / 9.09 | 2400 / 9.09 | 2400 / 9.09 | 2400 / 9.09 |
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | 4.95 / 5 | 4.95 / 5 | 4.95 / 5 | 4.95 / 5 | |
Minimum weight of rail (calculated) (lb/yd / kg/m) | 41 / 20.50 | 50 / 25 | 47 / 23.50 | 46 / 23 | 48 / 24 |
Geometry Relating to Tractive Effort | |||||
Driver Diameter (in / mm) | 63.50 / 1575 | 66 / 1676 | 66 / 1676 | 72 / 1829 | 72 / 1829 |
Boiler Pressure (psi / kPa) | 120 / 830 | 140 / 970 | 140 / 970 | 150 / 1030 | 150 / 1030 |
High Pressure Cylinders (dia x stroke) (in / mm) | 18" x 24" / 457x610 | 18" x 24" / 457x610 | 18" x 24" / 457x610 | 17" x 26" / 432x660 | 17" x 26" / 432x660 |
Tractive Effort (lbs / kg) | 12,491 / 5665.83 | 14,020 / 6359.37 | 14,020 / 6359.37 | 13,306 / 6035.51 | 13,306 / 6035.51 |
Factor of Adhesion (Weight on Drivers/Tractive Effort) | 3.92 | 4.27 | 4.05 | 4.14 | 4.36 |
Heating Ability | |||||
Tubes (number - dia) (in / mm) | 187 - 2" / 51 | 195 - 1.875" / 48 | 191 - 1.875" / 48 | 195 - 1.875" / 48 | |
Flues (number - dia) (in / mm) | |||||
Flue/Tube length (ft / m) | 10.05 / 3.06 | 10.58 / 3.22 | 10.58 / 3.22 | 10.33 / 3.15 | 10.58 / 3.22 |
Firebox Area (sq ft / m2) | 94 / 8.73 | 87 / 8.08 | 89 / 8.27 | 96 / 8.92 | |
Grate Area (sq ft / m2) | 17.25 / 1.60 | 14.75 / 1.37 | 14.75 / 1.37 | 16.75 / 1.56 | 16.90 / 1.57 |
Evaporative Heating Surface (sq ft / m2) | 1121 / 104.14 | 1074 / 99.78 | 1049 / 97.45 | 1123 / 104.33 | |
Superheating Surface (sq ft / m2) | |||||
Combined Heating Surface (sq ft / m2) | 1121 / 104.14 | 1074 / 99.78 | 1049 / 97.45 | 1123 / 104.33 | |
Evaporative Heating Surface/Cylinder Volume | 158.59 | 151.94 | 153.58 | 164.41 | |
Computations Relating to Power Output (More Information) | |||||
Robert LeMassena's Power Computation | 2070 | 2065 | 2065 | 2513 | 2535 |
Same as above plus superheater percentage | 2070 | 2065 | 2065 | 2513 | 2535 |
Same as above but substitute firebox area for grate area | 13,160 | 12,180 | 13,350 | 14,400 | |
Power L1 | 3466 | 3288 | 3937 | 4224 | |
Power MT | 255.05 | 255.31 | 315.03 | 321.03 |
Principal Dimensions by Steve Llanso of Middle Run Media | |||
---|---|---|---|
Class | H/Z17 | H/Z17 | Q-158 |
Locobase ID | 2402 | 15987 | 4186 |
Railroad | New South Wales | New South Wales | New South Wales |
Country | Australia | Australia | Australia |
Whyte | 4-4-0 | 4-4-0 | 4-4-0T |
Number in Class | 12 | 12 | 8 |
Road Numbers | 373-384 | 373-384 | |
Gauge | Std | Std | Std |
Number Built | 12 | 12 | 8 |
Builder | Vulcan Foundry | Vulcan Foundry | Beyer, Peacock |
Year | 1887 | 1887 | 1880 |
Valve Gear | Stephenson | Stephenson | Stephenson |
Locomotive Length and Weight | |||
Driver Wheelbase (ft / m) | 8.25 / 2.51 | 8.25 / 2.51 | 7.33 / 2.23 |
Engine Wheelbase (ft / m) | 22 / 6.71 | 22 / 6.71 | 18.71 / 5.70 |
Ratio of driving wheelbase to overall engine wheelbase | 0.38 | 0.38 | 0.39 |
Overall Wheelbase (engine & tender) (ft / m) | 41.12 / 12.53 | 41.12 / 12.53 | 18.71 / 5.70 |
Axle Loading (Maximum Weight per Axle) (lbs / kg) | 35,168 / 15,952 | 29,680 / 13,463 | 33,768 / 15,317 |
Weight on Drivers (lbs / kg) | 63,056 / 28,602 | 59,136 / 26,824 | 67,284 / 30,520 |
Engine Weight (lbs / kg) | 100,240 / 45,468 | 98,224 / 44,554 | 89,740 / 40,705 |
Tender Loaded Weight (lbs / kg) | 67,984 / 30,837 | 67,984 / 30,837 | |
Total Engine and Tender Weight (lbs / kg) | 168,224 / 76,305 | 166,208 / 75,391 | 89,740 / 40,705 |
Tender Water Capacity (gals / ML) | 2880 / 10.91 | 2880 / 10.91 | 1104 / 4.18 |
Tender Fuel Capacity (oil/coal) (gals/tons / Liters/MT) | 6.05 / 6 | 6.05 / 6 | 1.40 / 1 |
Minimum weight of rail (calculated) (lb/yd / kg/m) | 53 / 26.50 | 49 / 24.50 | 56 / 28 |
Geometry Relating to Tractive Effort | |||
Driver Diameter (in / mm) | 66 / 1676 | 66 / 1676 | 60.50 / 1537 |
Boiler Pressure (psi / kPa) | 140 / 970 | 140 / 970 | 152.30 / 1050 |
High Pressure Cylinders (dia x stroke) (in / mm) | 18" x 26" / 457x660 | 18" x 26" / 457x660 | 16" x 24" / 406x610 |
Tractive Effort (lbs / kg) | 15,189 / 6889.62 | 15,189 / 6889.62 | 13,147 / 5963.39 |
Factor of Adhesion (Weight on Drivers/Tractive Effort) | 4.15 | 3.89 | 5.12 |
Heating Ability | |||
Tubes (number - dia) (in / mm) | 196 - 1.375" / 35 | 219 - 1.875" / 48 | 176 - 1.875" / 48 |
Flues (number - dia) (in / mm) | |||
Flue/Tube length (ft / m) | 10.67 / 3.25 | 10.67 / 3.25 | 10.25 / 3.12 |
Firebox Area (sq ft / m2) | 112.50 / 10.45 | 125 / 11.61 | 77 / 7.15 |
Grate Area (sq ft / m2) | 20 / 1.86 | 20 / 1.86 | 14.75 / 1.37 |
Evaporative Heating Surface (sq ft / m2) | 1214 / 112.78 | 1287 / 119.57 | 945 / 87.79 |
Superheating Surface (sq ft / m2) | |||
Combined Heating Surface (sq ft / m2) | 1214 / 112.78 | 1287 / 119.57 | 945 / 87.79 |
Evaporative Heating Surface/Cylinder Volume | 158.53 | 168.07 | 169.20 |
Computations Relating to Power Output (More Information) | |||
Robert LeMassena's Power Computation | 2800 | 2800 | 2246 |
Same as above plus superheater percentage | 2800 | 2800 | 2246 |
Same as above but substitute firebox area for grate area | 15,750 | 17,500 | 11,727 |
Power L1 | 3573 | 3845 | 3657 |
Power MT | 249.84 | 286.69 | 239.65 |