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Victorian Railways NA class
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Victorian Railways NA class
The Victorian Railways NA class is a 2-6-2T built for their four 2 ft 6 in (762 mm) gauge branch lines.
In the mid-1890s the Victorian Railways were considering construction of narrow gauge railways around the state in order to reduce construction costs. These were originally intended to be built to a gauge of 2 ft (610 mm), and quotations were obtained from an assortment of British locomotive engineering companies who advised delivery times of 11 to 18 months. Before construction had started the specification changed to 2 ft 6 in (762 mm), and the Baldwin Locomotive Works in the United States was awarded a tender for two engines to be supplied at a cost of £3,880 supplied the first two 2-6-2Ts, as well as a range of spare parts. The engines were a new design for Baldwin, based on prior work but with enough changes that whole new drawings were necessary.
These two engines were delivered on the Amana in August 1898, and numbered 1A and 2A. Both were placed in service for construction of the Wangaratta to Whitfield line in the North East of Victoria in September 1898. Correspondence originally referred to the engines as "Narrow Gauge A" class; this later changed to "NA", although with a few exceptions in the early preservation era this code was never reflected on the engines themselves. The spare parts from the Baldwin Locomotive Works were used to construct locomotives 3A and 4A at Newport Workshops in 1900 for the Upper Ferntree Gully to Gembrook Line, with further examples of the class entering service up to the last, number 17A, in 1915. Engines 2 and 4 used Vauclain compound high- and low-pressure cylinders, while the rest of the class used simple expansion cylinders.
The engines brought with them the full range of Baldwin standard design features, including a fully-enclosed cab with side doors, sliding windows on the sides, hinged windows on the front, smaller windows at the rear above the coal bunker, and a roof ventilator; but the cabs were small enough that a different type of shovel was needed for the fireman, smaller than the usual type.
The boiler and firebox were lagged (insulated) with magnesia sections, and the outer boiler shell was steel with brass boiler bands. The small cab necessitated use of a 12 in (30 cm) shovel blade, in lieu of the normal 18 in (46 cm) shovel blade. Thus, the average shovelfull of coal was reduced from 10 lb (4.5 kg) to only 5.5 lb (2.5 kg), and the engines required around 3.5 to 5 scoops of coal per minute. The small firebox grate resulted in a significant quantity of coal passing through the firebox unburnt, being ejected as cinders.
The saturated (unsuperheated) steam at 180 psi (1,200 kPa) reached temperatures of 379 °F (193 °C), but by the time the steam had reached the cylinders the temperature would have dropped by at least 120 °F (49 °C), with some water condensing in the system. In the Compound engine design the loss was only around 75 °F (24 °C). The engines were also less likely to pull cinders from the firebox through the chimney when working hard.
Above the boiler were dual sand domes either side of the central steam dome, pop-type safety valves. The boiler was fed by a pair of Sellers "Monitor" injectors, which drew from the side tanks. On the original engines the tanks had a capacity of 600 US gal (2,271.25 L) total, but this was later increased to 780 US gal (2,952.62 L). It is not clear whether 3A and 4A started with lower-capacity tanks or not. These were the first Victorian engines fitted with double blast pipes of 2 in (51 mm) diameter, excepting 8A (and possibly 12A) which had a single 3.1 in (79 mm) diameter blast pipe.
The engines used outside bar frames with extended axles for the wheel cranks, Stephenson's valve gear between the frames, and for the Simple engines, actuated flat D valves above the cylinders actuated by rocker arms. To work around sharp curves the centre driving wheels were flangeless, and the five axles were grouped in two sets of compensated springs (leading two, rear three). The front and rear trucks had side movement controlled by a system of levers, and the leading and trailing wheels were of a wrought iron spoked design. Additionally, the engine cabs had a roof ventilator, a horizontal throttle arm set up for right-hand-drive (the inverse of normal Victorian practice), and a hand reverse lever. They were fitted with large wooden cowcatchers at each end, extending some distance beyond the couplers. The extended smokeboxes featured horizontal-grid spark arrestors and high blast pipes. Steam admission to gauges, the Westinghouse pump and the cylinders was controlled through a Nathan pattern sightfeed displacement type lubricator, mounted above the firebox. There was also a steam manifold that fed auxiliary systems like the compressor and the pair of Friedmann Minotr no.5 live steam injectors.
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Victorian Railways NA class
The Victorian Railways NA class is a 2-6-2T built for their four 2 ft 6 in (762 mm) gauge branch lines.
In the mid-1890s the Victorian Railways were considering construction of narrow gauge railways around the state in order to reduce construction costs. These were originally intended to be built to a gauge of 2 ft (610 mm), and quotations were obtained from an assortment of British locomotive engineering companies who advised delivery times of 11 to 18 months. Before construction had started the specification changed to 2 ft 6 in (762 mm), and the Baldwin Locomotive Works in the United States was awarded a tender for two engines to be supplied at a cost of £3,880 supplied the first two 2-6-2Ts, as well as a range of spare parts. The engines were a new design for Baldwin, based on prior work but with enough changes that whole new drawings were necessary.
These two engines were delivered on the Amana in August 1898, and numbered 1A and 2A. Both were placed in service for construction of the Wangaratta to Whitfield line in the North East of Victoria in September 1898. Correspondence originally referred to the engines as "Narrow Gauge A" class; this later changed to "NA", although with a few exceptions in the early preservation era this code was never reflected on the engines themselves. The spare parts from the Baldwin Locomotive Works were used to construct locomotives 3A and 4A at Newport Workshops in 1900 for the Upper Ferntree Gully to Gembrook Line, with further examples of the class entering service up to the last, number 17A, in 1915. Engines 2 and 4 used Vauclain compound high- and low-pressure cylinders, while the rest of the class used simple expansion cylinders.
The engines brought with them the full range of Baldwin standard design features, including a fully-enclosed cab with side doors, sliding windows on the sides, hinged windows on the front, smaller windows at the rear above the coal bunker, and a roof ventilator; but the cabs were small enough that a different type of shovel was needed for the fireman, smaller than the usual type.
The boiler and firebox were lagged (insulated) with magnesia sections, and the outer boiler shell was steel with brass boiler bands. The small cab necessitated use of a 12 in (30 cm) shovel blade, in lieu of the normal 18 in (46 cm) shovel blade. Thus, the average shovelfull of coal was reduced from 10 lb (4.5 kg) to only 5.5 lb (2.5 kg), and the engines required around 3.5 to 5 scoops of coal per minute. The small firebox grate resulted in a significant quantity of coal passing through the firebox unburnt, being ejected as cinders.
The saturated (unsuperheated) steam at 180 psi (1,200 kPa) reached temperatures of 379 °F (193 °C), but by the time the steam had reached the cylinders the temperature would have dropped by at least 120 °F (49 °C), with some water condensing in the system. In the Compound engine design the loss was only around 75 °F (24 °C). The engines were also less likely to pull cinders from the firebox through the chimney when working hard.
Above the boiler were dual sand domes either side of the central steam dome, pop-type safety valves. The boiler was fed by a pair of Sellers "Monitor" injectors, which drew from the side tanks. On the original engines the tanks had a capacity of 600 US gal (2,271.25 L) total, but this was later increased to 780 US gal (2,952.62 L). It is not clear whether 3A and 4A started with lower-capacity tanks or not. These were the first Victorian engines fitted with double blast pipes of 2 in (51 mm) diameter, excepting 8A (and possibly 12A) which had a single 3.1 in (79 mm) diameter blast pipe.
The engines used outside bar frames with extended axles for the wheel cranks, Stephenson's valve gear between the frames, and for the Simple engines, actuated flat D valves above the cylinders actuated by rocker arms. To work around sharp curves the centre driving wheels were flangeless, and the five axles were grouped in two sets of compensated springs (leading two, rear three). The front and rear trucks had side movement controlled by a system of levers, and the leading and trailing wheels were of a wrought iron spoked design. Additionally, the engine cabs had a roof ventilator, a horizontal throttle arm set up for right-hand-drive (the inverse of normal Victorian practice), and a hand reverse lever. They were fitted with large wooden cowcatchers at each end, extending some distance beyond the couplers. The extended smokeboxes featured horizontal-grid spark arrestors and high blast pipes. Steam admission to gauges, the Westinghouse pump and the cylinders was controlled through a Nathan pattern sightfeed displacement type lubricator, mounted above the firebox. There was also a steam manifold that fed auxiliary systems like the compressor and the pair of Friedmann Minotr no.5 live steam injectors.
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