Victorian Railways B class 2-4-0 (1862)

The mainline passenger locomotives later classified as B class ran on the Victorian Railways between 1862 and 1917. Utilising a 2-4-0 wheel arrangement to allow greater traction on the heavily graded new lines to Ballarat and Echuca rather than the 2-2-2 arrangement previously selected for VR's Geelong line, these highly successful passenger locomotives are regarded as the first mainline VR locomotives.

History
The recently formed Victorian Railways, having purchased the struggling Melbourne, Mount Alexander and Murray River Railway Company in 1856 and more recently the Geelong and Melbourne Railway Company's line to Geelong in 1860, had begun the construction of two new mainlines to connect the booming gold-mining towns of Ballarat, Castlemaine and Sandhurst, as well as tap the lucrative Murray River trade at Echuca. These ambitious new railway projects, despite being engineered to very high (and very expensive) standards, traversed some difficult terrain and featured numerous gradients of up to 1 in 50. The 2-2-2 passenger locomotives VR had used to operate its relatively flat Geelong line proved to be unsuitable for heavy grades, and VR's fleet was already stretched to service the needs of its rapidly expanding network.

New locomotives were ordered in February 1861 from R and W Hawthorn in Newcastle upon Tyne, England, with a layout very similar to that of a successful 2-4-0 design previously been built for the Great Northern Railway, with modifications such as the fitting of cabs and steam domes.

Production
The initial order of seven 2-4-0 locomotives was followed by another order of seven of the same type from Beyer, Peacock and Company in April 1862, followed by two further orders of six locomotives each in October and the following January.

None of the locomotives had arrived in time for the opening of the Geelong to Ballarat line in April 1862, and passenger services on the line had to be worked by suburban saddle tank locomotives (later denoted as L class) until the arrival of the first of the new mainline locomotives in July 1862.

The success of the 2-4-0 mainline locomotives was such that, despite ongoing advances in locomotive technology, the design continued to be built. A further order of six locomotives was placed with Beyer Peacock in 1871, and a further two were built by the Phoenix Foundry of Ballarat in 1880.

The locomotives were initially unclassed, and were part of the initial numbering scheme, in which odd numbers were used for goods locomotives and even numbers for passenger locomotives, before being denoted as "B class" under the railways' 1889 reclassification. By that time, a new 4-4-0 express passenger locomotive had been introduced and took the "A class" designation.

Design features
The B class locomotives were easily recognisable by their use of external frames and bearings, and coupling rods mounted outside the frames, earning them the nickname "overarmers".

The B class locomotives featured an unusual design of firebox with two separate chambers, each with its own firedoor, divided by a water space that effectively acted as a thermic syphon, and joined at the tubeplate. The two fireboxes were designed to be worked separately, with one fire being built while the other was burning, and was designed to extract the maximum heat from the wood fuels the VR used in its early years. However, the last two locomotives, built in the 1880s, had a conventional single firebox.

Service Life
The B class' initial duties hauling passenger services on the new mainlines were to expand as the mainline network grew. B 88 had the honour of hauling the first VR train to Albury on 14 June 1883.

B 50 was selected to haul the first Victorian Railways Royal Train in 1867, taking Prince Alfred Duke of Edinburgh to Ballarat, Bendigo and Castlemaine. The Royal Train was recorded running the 45 mi between Melbourne and Geelong in as little as 52 minutes.

By 1894, the VR's Rolling Stock Branch Diagram Book noted their allocation around the state, with 2 at Stawell, 6 at Melbourne, 5 at Bendigo, 3 at Geelong, 6 at Ballarat, 4 at Benalla, and 3 at Seymour.

While the B class locomotives were highly successful on the expensively-engineered 1860s mainlines for which they were designed, they were less suited for the more cheaply built extensions to the VR system. Future VR express passenger locomotives were to use a four-wheel leading bogie to steer the locomotive, and from 1884 a class of 4-4-0 locomotives (later classed 'Old A') began to supplement, and eventually supersede the B class. Despite the delivery of the Old A, and the later and increasingly larger 'New A' and AA class 4-4-0s of 1889 and 1900 respectively, the entire B class (other than a couple of accident write-offs) lasted into the Twentieth century, with their roles ranging from double heading on express passenger trains down to shunting duties.

Design improvements
Given their long life and the considerable technological development of railways during that period, the B class locomotives saw a number of improvements.

As delivered, the only means of braking the locomotive was by operating a handbrake on the tender wheels. B 50 and B 108 were used in comparative trials of the Woods hydraulic and Westinghouse air brake systems in January 1884, with the Westinghouse system being later adopted as the standard.

During the 1880s, their boiler pressure was increased from 130 to 140 psi, and their cylinder bore increased from 16 to 17 inches, with those rebuilt after 1896 being fitted with 17.5 inch cylinders. These changes led to considerably increased tractive effort.

Their large spark-arresting chimneys were replaced with a straight chimney, with a conical spark arrestor being located in the smokebox.

The cab was also redesigned to provide greater amenity to the crew, with the original sheet metal structure, prone to vibration at speed, being replaced by one of wood, and a double roof was employed for greater comfort in Australian weather conditions.

Accidents
B 82 and B 92 were wrecked beyond repair in a head-on collision on the Geelong line between Little River and Werribee on 2 April 1884. On 18 August of the same year, B 72's boiler exploded at Warrenheip, although this locomotive was repaired and returned to service.

B 110 was involved in a spectacular mishap on 13 April 1904 when it pushed a rake of coal wagons off the end of the coal stage at Seymour and was left suspended by its tender and the wreckage of the wagons below.

Withdrawal and scrapping
Other than accident write-offs, the entire class lasted until 1904, when ten were withdrawn, many of which were by this stage over forty years old. Over the next ten years, the remainder of the class was gradually retired as mechanical condition dictated to the point where just two locomotives, B 56 and B 76, remained on the register.

These last two members of the class served out their final days shunting carriages at Spencer Street Station and North Melbourne yards, and were withdrawn for scrapping in May and June 1917.

None were preserved.