The former Victorian Railways, the state railway authority in Victoria, Australia, built a number of experimental narrow-gauge lines around the beginning of the 20th century. Although all were closed by the early 1960s, parts of two have been reopened as heritage railways.

Background A depression in the early 1890s brought a halt to the rapid expansion of railways in Victoria. Politicians promoted narrow-gauge lines as a way to link remote communities, particularly in hilly country, without the expense of the railways. Railway officials opposed them, citing the inconvenience and expense of a break-of-gauge.

The Parliamentary Standing Committee on Railways examined 14 regions for potential railways: Bass River District: Without recommending a specific route, the Committee considered a narrow gauge line through the Bass River district to exploit timber resources along the river, coal deposits around Kilcunda and farming around Wonthaggi, eventually recommending examination a low cost broad gauge option. Instead the Wonthaggi railway line was built as broad gauge in 1910. Beech Forest District: From Colac to Beech Forest. Carrajung District: From Traralgon to Alberton via Carrajung. Gembrook District: From Ferntree Gully to Gembrook. Gunbower and Cohuna District: From Rochester or Elmore to Gunbower or Cohuna. Instead the Cohuna railway line was built as broad gauge in 1915. King River District: From Wangaratta to Whitfield. McDonald's Track District: From Nyora or Monomeith to Thorpdale. The broad gauge Strzelecki railway line partly covered this district in 1922. Mitta Mitta River District: From Tallangatta to Eskdale. Moondarra and Walhalla District: From Moe to Walhalla. Orbost and Snowy River District: An isolated line from Cunninghame to Orbost as an alternative to proposed extension of the broad gauge Gippsland line from Bairnsdale to Orbost via Bruthen. Instead the broad gauge line was extended to Orbost in 1916. Poowong East District: From Drouin or Warragul to Korumburra via Poowong. Tolmie District: The Committee stated that the suggested line to Whitfield must, at some future time, be extended to Tolmie and Mansfield. Upper Murray District: Tallangatta to Cudgwea and Towong, or from Bethanga to Walwa. Instead the broad gauge railway from Tallangatta was extended to Cudgewa between 1916 and 1921. Wandin and Warburton District: From Croydon to Warburton.

In considering the McDonald's Track and Poowong East Districts together, the committee also examined shorter routes from the existing Thorpdale railway line and Mirboo North railway line to Leongatha.

The Committee recommended that four experimental lines be built. They were: Croydon to Warburton Wangaratta to Whitfield Upper Ferntree Gully to Gembrook Colac to Beech Forest

The Warburton line was built in broad gauge, however authority was given for the construction of the other three lines. Subsequently, a further two lines were built, the Moe to Walhalla line, and an extension from Beech Forest to Crowes.

Initial plans were for the railways to be constructed in gauge, but following correspondence with British railway engineer Everard Calthrop, amongst others, a change was made to gauge.

None of the lines constructed ever made a profit. Freight rates were the same for broad and narrow-gauge railways, despite higher direct costs. Most of the loadings were goods such as timber, potatoes and lime, which were charged at a low rate. Most freight was outbound, so many trains travelled towards the terminals almost empty. And despite originating the traffic, the lines were only credited with a portion of the freight charge. The amount credited to the lines did not cover the cost of running trains, and the more traffic the larger the loss. However, particularly in the 1920s, the traffic generated by the narrow-gauge lines was appreciated by the railways and the lines survived for up to 60 years before closure.

Operations

Alignments A number of studies were made of overseas narrow-gauge railways such as the Darjeeling Himalayan Railway in India and the Ffestiniog Railway in Wales. An initial decision to build the lines in gauge was changed to gauge for the Victorian lines. This gauge was being adopted on other lines in the British Empire at this time, such as the Kalka-Shimla Railway and the Sierra Leone Government Railway. The railways were constructed using rail, initially obtained from broad-gauge lines that were being upgraded. A maximum grade of 1 in 30 (3.33%) was adopted, while the minimum radius of curves was 2 chains i.e. .

Safeworking Apart from a couple of experiments with other systems, all lines were operated by the Staff and Ticket method of safeworking, as was standard Victorian Railways practice for this system.

Loading gauge The maximum dimensions for rolling stock, when loaded, on the narrow gauge lines was from the railhead at the centreline, decreasing to at the sides; the maximum width was up to from the wagon floor ( from the railhead), with an extra either side permitted above that height.

Vehicle weights In 1916, 1926 and 1939 (among other years), weights for various train consist arrangements were published. The assumption was that each passenger carriage would weigh an additional when fully loaded.

Weight (plus goods load) Empty, on goods train On Passenger or Mixed train NC NAB, NB with lavatory NB saloon NB compartment NBC NBH NQR with canopy and seats by 1916 by 1926 NQR / NQ NUU / NU NMM / NM NTT / NT NH NQ 61, 72, 74, 79, 80 (sheep frame) by 1926 by 1939 by 1926 by 1939

Locomotives and rolling stock

Seventeen locomotives and two Garratt locomotives, plus a range of passenger and goods vehicles, were built to operate on the narrow-gauge lines. Six of the locomotives, including one of the Garratt locomotives, as well as at least one example of each type of rolling stock, have been restored to working order on the Puffing Billy Railway.

Apart from light maintenance that could be done locally, the locomotives and rolling stock were maintained at the Victorian Railways' Newport Workshops in the suburbs of Melbourne, requiring the transport of the vehicles by broad-gauge flat wagons. The locomotives and other vehicles would be moved around the various narrow-gauge lines as appropriate, so that no equipment was dedicated to particular lines. However the G class Garratts were only used on the Crowes and Walhalla lines, while the NBH excursion coaches remained on the Gembrook line while that line was in operation.

Parameters The trains were all fitted with Westinghouse air brakes and, originally, with chopper couplers. In the mid-1920s the couplers were replaced with small MCB, or "knuckle" couplers.

Locomotives

Baldwin Locomotive Works in the United States supplied the first two locomotives, as well as parts for a further two locos. One each of the supplied locos and the parts kits was a simple loco, and the other a compound. The new class was classed "A", however confusion with the broad-gauge A, AA and A2 classes led to them being referred to as narrow-gauge A class for a short while, with a prefix "N" being applied to written records, making it the NA class. Victorian Railways' Newport Workshops assembled the parts to give an additional two locos, and subsequently built a further 13 of the simple cylinder version. The last one, number 17, was built in 1915.

The locomotives weigh and produce a tractive effort of , allowing them to haul loads of up grades of 1 in 30 (3.33%). Nos. 6, 7, 8, 12, and 14 have been restored and operate on the Puffing Billy Railway, and No. 3 is also on the Puffing Billy Railway, awaiting eventual restoration. The remaining locomotives have all been scrapped.

By the mid-1920s, traffic was growing with up to 7 trains a day on the Beech Forest line. To decrease train mileage and therefore costs, two G class Garratt locomotives were purchased from Beyer, Peacock & Company in England. Weighing 69 tons (70.1 t), these locomotives produce a tractive effort of , making them among the most powerful steam locomotives ever built for gauge. They were designated as the "G" class and given the numbers 41 and 42, and entered service in 1926. G41 spent its entire life on the Crowes line, whilst G42 was originally allocated to the Walhalla line, then transferred to the Crowes line, and is currently running on the Puffing Billy Railway. G41 was scrapped, after having been extensively cannibalised for parts to keep G42 running in the last years of the Crowes line.

Rolling stock

A range of passenger and goods vehicles were also built at Newport or by contractors. While most Victorian Railways broad-gauge goods vehicles of the time were 4 wheel trucks, all the narrow-gauge rolling stock were bogie vehicles and most were built on a standard underframe.

The initial stock were all built on a long underframe, with the carriages being the open saloon type with balconies for end loading. Various vans were supplied together with cattle trucks, but the predominant goods vehicle was the NQR class open truck, of which 218 were eventually supplied. Later some side opening carriages were built to cope with increasing traffic. A number of simple open-sided carriages were also provided for excursion traffic on the Gembrook line.

Transfer between workshops and lines Initially, rolling stock delivered from Newport Workshops was loaded on regular flat wagons, secured in place and railed to loading points at Wangaratta, Upper Ferntree Gully, Colac and Moe, unloaded, tested and brought into use.

Locomotive transfers were somewhat more complex. For the first thirty years or so, the process for transferring the NA class locomotives between sites required a pair of custom diamond-frame bogies with extended centre pins. The locomotives would be lifted by cranes (at Newport) or pushed along the loading ramps while supported by jacks (at the outer depots). While suspended the locomotive bogies were removed, and the broad gauge bogie king pins were installed in the leading truck swivel pin hole and the trailing truck's centre control pin hole. The cowcatchers, chopper couplers and whistle were all removed (the latter due to loading gauge limits), and temporary wooden headstocks were fitted to the locomotives with screw couplers and buffers for coupling to adjacent I or QR type wagons (which would also carry assorted tools and fittings, including the leading and trailing trucks). In this state the narrow gauge locomotive was functionally a regular goods wagon, through-piped with Westinghouse air brake but without its own brakes.

At Newport Workshops there was only limited space for shunting, so when an engine's maintenance was complete it had to be lifted from the short local length of narrow gauge track by crane onto its transfer bogies. At the terminal station the engine would be jacked up, with a timber support structure placed under the driving wheels as a safety precaution while the broad gauge bogies were disconnected and removed. Then the engine would be lowered onto the narrow gauge trucks, and when complete all the assorted suspension systems, cowcatchers and other fittings would be reconnected and restored. The engine was then lit up and given a test run in the yard; on completion the new engine would enter service on the line, and another engine scheduled for maintenance would take its place in the return trip to Newport.

Trains including locomotives for transfer were restricted to and accompanied by a repair crew in case of an incident en route, while the rest of the team followed on the next morning's passenger train to the same destination.

Q129 Q129 is a broad gauge wagon built in June 1926, initially to transfer the Garratt locomotives' engine units from Newport to Colac and Moe, and later used for the NA class engines as well.