3642's driver awaits the re-boarding of tour passengers at a photostop at Helensburgh Tunnel in 1967.

3642 staging a spectacular comeback at the head of a special RTM 'delivery' tour seen here at Colo Vale in 1982.

LOCOMOTIVE 3642

Presented here are extracts from a detailed article, 'Meet the Exhibits - Locomotive 3642' by Peter Berriman & Ray Love, which appeared in the NSWRTM's journal Roundhouse, May 2007.

Even when still in regular service, 3642 was a popular tour engine - seen here near Helensburgh on a tour in 1967.

Locomotive 3642 is one of three survivors of the class of 75 locomotives introduced as express passenger engines in 1925. Following its withdrawal from revenue service, locomotive 3642 was used by the NSWRTM for steam tours. Then after it received a replacement boiler in 1981, it was used by the State Rail Authority for tours as its 'Steam Excitement' locomotive, until 1989, when it reverted to an NSWRTM tours engine. Its last tour was in 1996, after which it failed a boiler inspection and it has since been on static display at Thirlmere.

Because of its heritage value, its popularity with members and in the rail enthusiast community, and the NSWRTM's moral and material investment in this locomotive in terms of work already done, the engine has been selected as the next steam locomotive to be restored.

Locomotive 3642 is an excellent example of the 36 Class, an important development of express passenger power on the New South Wales Government Railways and the penultimate class of mainline steam passenger locomotive in NSW. On introduction, the 36 Class became the principal motive power for all major expresses, and accelerated long distance passenger timetables leading to new levels of service in the pre World War II period.

The 36 Class was the first NSW mainline design to use 'modern' Walschaerts valve gear and turret tenders and was the mainstay of passenger expresses for over 20 years before the advent of the 38 Class. The class was used extensively for performance testing, and thus the development and trial of a number of technical improvements.

 

Origins & Development

The 36 Class of steam locomotives was a relatively minor development of the 35 Class express passenger locomotive (introduced in 1914 as the NN Class - later designated as the 35 Class).

The design was therefore a development of the British-inspired narrow-firebox 4-6-0 type, following the successful P (later 32) Class, the not so successful N (later 34) Class, and the 35 Class. The design continued the large (5' 9") driving wheels of the 35 Class, but with only slightly greater tractive effort.

The major areas of improvement were the outside Walschaerts valve gear - much easier to service and maintain, an improved ash pan design, a self-cleaning smokebox and a much larger tender, of the 'turret' type; this was the first application of a 'turret' type tender on the NSWGR.

Ten of the class (Nos. 3601 to 3610) were built by the NSW Railway Workshops at Eveleigh, the remaining 65, including 3642, by Clyde Engineering.

As superheating had by 1923 been firmly established as an essential design parameter for main-line locomotives, the whole class of 75 locomotives were superheated from the outset. In a departure from the practice established by the-then CME William Thow with his P Class express passenger locomotive in 1892, the 36 Class in original form had a round-top boiler rather than the Belpaire type. In the early to mid-1950s, the majority of the 36 Class locomotives were rebuilt with new, all-steel Belpaire boilers and re-designed cabs.

 

The design was a response to the increased loading of express trains and public demand for shorter journey times, as well as to the need for reduced servicing and lower maintenance costs. The addition to the fleet of a substantial number of large express passenger locomotives with higher availability, enabled older classes to be retired or relegated to lesser trains.

Typical of the technology of the day, the riveted steel boilers originally fitted to the class had copper inner fireboxes, fire-tubes and superheater flues. The replacement Belpaire boilers fitted in the 1950s had steel fireboxes, tubes and flues, in line with US practice and later NSWGR policy. This change was no doubt based on considerations of cost and longevity, as although copper provides superior heat transfer, it promotes a galvanic reaction resulting in the 'wasting' by corrosion of some steel boiler components such as crown stays and front tubeplates.

A noteworthy feature of the class was their outside Walschaerts valve gear, by then well-established in Britain and Australia and valued for its ease of lubrication and maintenance. The 36 Class was the first mainline locomotive design in NSW to be so fitted, and all subsequent steam classes continued the trend.

Walschaerts steam locomotive valve gear in operation on a US locomotive.
3642's centre driving wheels are spoked and not of the Boxpok style as shown here.
Animation used by courtesy of its author, Robert A. Booty.

The class were fitted with plate frames, as had been standard British practice at the time, although the shortcomings of this technology had already been recognised in the NSWGR. In common with other NSWGR classes with plate frames, the 36 Class suffered to some degree from frame cracking, and most members of the class needed frame repairs at some stage.

As left hand drive had been the standard on the NSWGR since the introduction of the P Class express loco in 1892, the 36 Class was therefore so fitted, with screw reversing gear as per standard British practice. All were fitted with Westinghouse air brake equipment and both engine and tender handbrakes. Originally, all of the class were fitted with 'Detroit' hydrostatic lubricators, typical of the period.

 

The 36 Class in Service

Once 'run-in,' 36 Class locomotives were placed in express passenger service, initially on the premier Sydney-Newcastle trains, then later on Southern and Northern expresses and mail trains. The much-increased range of the class was trialled early on, with through trips from Sydney to Albury, a distance of some 400 miles, without changing the engine. By the late 1920s, 36 Class engines were in regular use on the Melbourne Limited and Melbourne Express, generally with only four servicing stops en-route.

Locomotive 3617 standing at Picton with the Royal Train in 1927

As the NSWGR's latest and finest, several 36 Class locomotives were used in 1927 to haul the Royal Tour train during the visit of the Duke and Duchess of York when they came to Australia to open the new Parliament House in Canberra. Later that year, the class was used on the first Broken Hill expresses (though not all the way) following the opening of the line through to the 'Silver City.'

On the Main North, 36 Class engines worked trains as far as Armidale, and on the North Coast, to South Grafton. Following the opening of the bridge over the Clarence River at Grafton, the class worked all the way to South Brisbane. By the late 1930s, the 36 Class had displaced the 35 Class on most expresses, including on the Western line - and on prestige trains such as the Caves Express and The Fish, as well as on mail and express trains generally. When the Riverina Express and the Northern Tablelands Express were introduced in 1941, the 36 Class was naturally rostered. Even after the introduction of the more powerful 38 Class in 1943, 36 Class locomotives were still used on the Newcastle Express, until c.1945 when enough 38s had entered service to cope with the traffic. However by the 1950s, the 38 Class had taken over all major expresses, and the 36 Class were generally used on slower passenger services and mail trains, including to Albury, Narrandera, Dubbo, Parkes, Thirroul, Armidale and South Brisbane and local stopping trains on the 'Short North' to Newcastle. On all the lengthy runs to the extremities of the system, the engines were 'relayed' at specific locations.

By the end of 1968, locomotive 3642 could mostly be found working trains between Gosford and Newcastle. Here, 3642 assists Beyer-Garratt 6016 on an Express Goods train, heading north near Narara.

Following electrification of the Western line to Lithgow in 1957, 36 Class locomotives were based at Lithgow, Bathurst and Parkes, and with the introduction of diesel-electric locomotives, were beginning to be used on goods trains as the diesels took over the more important passenger trains. As well as providing a faster service, useful for more perishable goods, the rostering of the 36 Class on freight workings allowed the withdrawal of numbers of Standard Goods locomotives. By the 1960s, withdrawal of the 36 Class (along with other steam loco classes) had begun as more diesels became available, but a number were temporarily returned to traffic in late 1966, to work wheat trains after a record harvest.

 

Locomotive 3642

In common with 65 of the class, locomotive 3642 was built by The Clyde Engineering Company Limited at Granville, as Works No.376 and entered service in 1926. Throughout its service life, it received the various modifications common to the class.

The class was progressively withdrawn in the late 1960s, and 3642 was officially withdrawn (from Broadmeadow Depot) in September 1969. Its distance recorded in service was 1,837,716 miles. It was retained for preservation and allocated to the
NSWRTM collection in 1970.

Locomotive 3642 was returned to operation, based at Broadmeadow, in December 1970, to assist in moving crowds for the visit of Pope Paul IV, along with locomotives 3801, 3813, 3820 and 3214. The next major duty for 3642 was the 'Pirinari Whyalla' tour in 1972, to celebrate the opening of the standard gauge link between Port Augusta and Whyalla, in which it was accompanied by 3801 from Sydney to Port Augusta.

3642 paired with the World's most famous locomotive, ex-LNER Flying Scotsman, for a tour in 1989 - seen here at Aylmerton, near Mittagong in the Southern Highlands.

In 1973, the locomotive was discovered to have a cracked foundation ring in the firebox, resulting in its being placed out of traffic pending re-boilering. A number of 36 Class boilers in good condition were identified and available, although the cost of boiler change then was estimated at over $20,000.

In 1976, locomotive 3642 (along with many other items) was included in the formal agreement made between the Public Transport Commission and the Museum, known as the 'Deed of Gift' (this agreement was replaced in 1978 by a formal custody agreement). Then, following its overhaul and fitting of its replacement boiler in 1981, locomotive 3642 was operated for several years by the State Rail Authority on steam tours as its 'Steam Excitement' locomotive. The Museum maintained the locomotive under contract for the SRA, and it was also used to haul the Museum's own heritage trains. In 1989, the SRA's 'Steam Excitement' tours ceased and the locomotive was subsequently operated only on Museum tours until 1996, when it failed a boiler inspection. It was then placed on static display.

 

Livery

When delivered, all of the 36 Class were painted in standard NSWGR unlined black. However for the 1927 Royal Tour of the Duke and Duchess of York, four of the class (3602, 3615, 3616 & 3617) were painted Royal Blue, with yellow and black lining. Then during the 1930s, a number of coloured locomotives of various Classes were assigned to named expresses. Initially, several 32 Class locomotives were painted in green or maroon for South Coast, Newcastle and Western expresses, and carrying name-plates such as Illawarra, Cambewarra, Hunter, Hawkesbury, Parramatta and Wyong. Some of the 36 Class inherited these name-plates when they took over the Newcastle Express. The named trains (with carriage sets also painted in attractive colours), the coloured engines and the name-plates appear to have been part of a marketing campaign - an attempt to increase customer appeal.

During the 1920s and 30s, the 36 Class was the pride of the passenger locomotive fleet and featured prominently in much of the Railways' advertising.

The first 36 Class locomotive (apart from the Royal Train engines in 1927) to be painted other than black was 3633. It appeared in green livery on the Southern Highlands Express in 1934. Subsequently, another 28 members of the 36 Class were painted green, including 3642. Of course at this stage, all members of the class were still in their original round-top form.

The intervention of World War II meant that no more steam locomotives were painted in colours other than black, and as the 36 Class became due for overhaul and re-paint, they reverted to plain black. After the war, no 36 Class locomotives in normal service were coloured, the 38 Class (after losing their coat of wartime grey) being the only locomotives to be painted green. (However, a couple of 12 Class, 4-4-0 tender engines retained green livery for a short period in the early 1950s).

Following its overhaul as a preserved locomotive (at Goulburn in 1981), 3642 was painted green, lined in red and straw, and has carried this livery ever since.

 

Locomotive 3642 - History & Details

The service career of locomotive 3642 (as a representative of the class) spanned some 43 years (1926 to 1969). In that time, its configuration and appearance (and even to some extent, its use, relegated in its latter years mainly to goods working)
changed in several respects. The significant milestones in the history of 3642 are as follows:

1926:		entered service, in its original form - round-top boiler number 3642 (with copper firebox and tubes), livery - unlined black.
c.1927:		fitted with electric lighting.
c.1932:		fitted with 'Rosebud' grates.
1933:		boiler 3602 fitted with new firebox and new piston rods and valve rods.
c.1934:		axle boxes converted to grease lubrication.
c.1936:		boiler 3602 fitted with new firebox and engine fitted with 'Cardew' water release valves.
1939:		boiler 3667 fitted with new firebox.
1942:		boiler 3673 fitted.
c.1943:		changes to draughting - blast pipe alterations and ashpan air openings.
1944:		boiler 3605 fitted.
1948:		boiler 3664 fitted.
1949:		fitted with mechanical lubricator.
1952:		boiler 3628 fitted.
1955:		fitted with new Belpaire all-steel boiler 3642A (200 lbs psi, the letter 'A' indicates that this was the new Belpaire boiler), smokebox regulator and new semi-enclosed cab.
1958:		boiler 3642B fitted.
1961:		out of service, repairs to cylinders.
1961:		out of service again, repairs finished in December 1961 at Chullora, fitted with cast steel cylinders and 12" Trick-ported valves.
1968:		fitted with power reverser, trailing sands and tender kit lockers.
1969:		withdrawn from service, placed with the NSWRTM for preservation.
1972:		in preservation - 'Pirinari Whyalla' tour.
1973:		in preservation - placed out of traffic due to boiler defects.
1981:		in preservation - re-boilered at Goulburn Railway Workshops; painted in lined green livery; operated by the State Rail Authority on steam tours as its 'Steam Excitement' locomotive.
1989:		in preservation - after cessation of 'Steam Excitement' tours, operated on tours by the NSWRTM, based at Thirlmere.
1996:		in preservation - failed boiler inspection and placed on static display at Thirlmere.
2007:		the locomotive's boiler overhaul is now complete, repairs to the frame, running gear, tender and mechanical components are underway, and work is on target for reassembly, trialling and painting of 3642 to be completed in February 2008.

Records show that locomotive 3642 was officially condemned on 28 November 1969.

A total of 37 different 'Light' to 'Heavy' overhauls were recorded until July 1964, being carried out at various workshops at Chullora, Eveleigh, Goulburn and Enfield. A total of eleven boilers have so far been fitted to this locomotive (as at June 2004).

The boiler fitted at Goulburn was boiler number 3646B, which has only recently been removed from the locomotive. The serviceable, overhauled boiler which will be fitted to the locomotive, is boiler 3632B. This boiler was fitted with a new front tubeplate, new flues and tubes at the State Dockyard/Hunter Valley Training Company in 1988.

Roundhouse™ magazine is the members' journal of the NSW Rail Transport Museum.

It's changed format several times during its long life, but ever since the very first issue appeared in December 1962, Roundhouse and its news section RTM Mail, have always delivered an interesting mix of the Museum's current affairs, Heritage Express  tour reviews and, historical articles including the popular 'Meet the Exhibits' pages.

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