Motor Rail

Motor Rail (formally the **Motor Rail & Tram Car Co Ltd**) was a British locomotive manufacturer based in Bedford, England. Best known for their "Simplex" brand of internal combustion locomotives, the company played a pivotal role in the mechanisation of the Queensland sugar cane railways. The Simplex was often the first internal combustion locomotive acquired by many mills, marking the transition away from steam and animal power for lighter duties.

Origins

The company was founded in 1911, initially exploring internal combustion railcars. However, the outbreak of World War I created a massive demand for light logistical transport on the Western Front. The British War Department (WD) required a simple, robust tractor capable of operating on the 600mm (2 foot) gauge trench railways.

Motor Rail produced a design featuring a transverse-mounted engine and a unique gearbox, which allowed for equal speeds in both forward and reverse. These were produced in 20hp and 40hp variants. The 40hp models were often armoured and nicknamed "Tin Turtles", while the "Open" protected type became the standard for general haulage. Following the Armistice in 1918, hundreds of these locomotives became war surplus.

Impact on the Queensland Industry

The 600mm gauge used by the War Department was compatible with the 2 foot (610mm) gauge standard of the Queensland cane fields. In the early 1920s, agents began importing surplus Simplex locomotives to Australia, offering them to sugar mills at a fraction of the cost of new steam locomotives.

The "Navvy" Locomotive

While they lacked the tractive effort to haul heavy cane rakes during the crushing season compared to the larger Fowler or Hudswell Clarke steam engines, the Simplex found a niche as a "navvy" or maintenance-of-way locomotive.

Mills such as Mulgrave, Mossman, and Marian utilised them for:

• Hauling bridge gangs and track maintenance crews.
• Delivering portable rail (jumper track) to the harvesting fields.
• Shunting rolling stock in the mill yards during the slack season.
• Powering pumping equipment via a belt drive take-off.

The ability to start instantly without the lengthy firing-up process required for steam made them ideal for these intermittent duties.

Technical Features

The defining feature of the early Simplex locomotives was the transverse engine layout. The driver sat sideways to the direction of travel, which provided excellent visibility in both directions—a critical safety feature for shunting work.

• Engine: Originally fitted with 2 cylinder (20hp) or 4 cylinder (40hp) petrol engines manufactured by W.H. Dorman & Co.
• Transmission: The patented Dixon-Abbott gearbox. This utilised heavy chain drives to the axles, which provided flexibility on uneven temporary track often found in the paddocks.
• Frame: The early models featured a distinctive "bow frame" or curved chassis rail, which remains a key recognition point for historians.

Dieselisation

As diesel technology matured in the 1930s to 1950s, many mills re-engined their Simplex fleets. The original petrol Dorman engines were often replaced with more fuel-efficient diesel units from manufacturers such as Gardner or Perkins. Motor Rail themselves transitioned to producing diesel-powered Simplex locomotives (the "Di-Simplex" range) in the post-war era, which were purchased new by mills like Racecourse and Pleystowe.

Preservation

Due to their small size, mechanical simplicity, and widespread use, a high number of Simplex locomotives survive in Queensland. They are a staple of heritage collections and park railways.

• Navvy (Mulgrave Mill): A 1954 built diesel Simplex, preserved operationally.
• Netherdale (Marian Mill): A classic Motor Rail product utilised for line maintenance, now preserved.
• Various Private Collections: Numerous ex-War Department 20hp and 40hp models (often heavily modified with locally built cabs) remain in private ownership across the state.

Rollingstock

Name	Builder	Model	Serial	Year	Purchasing Mill	Current Mill	Notes
4	Motor Rail	4wDM	2090	1922	Hambledon Mill	Out of service	Former Hambledon #4 truck-shop locomotive; converted from petrol to diesel. Sold in working order to a buyer in Sydney in 1999.
7	Motor Rail	4wDM	3748		Hambledon Mill	Out of service	Motor Rail 3748; converted from petrol to diesel. Listed as Hambledon #7 in 1978; later disposition not established.
(Blank)	Motor Rail	32/42hp	10219	1950	Mourilyan Mill	Out of service	Ex Goondi/Mourilyan Motor Rail Simplex. Preserved at Illawarra Light Railway Museum, Albion Park NSW; arrived 9 March 2004 and recorded on fire-train duty in 2012.
(Blank)	Motor Rail	20hp	3668?	1924	Mourilyan Mill	Out of service	20hp Motor Rail locomotive, works number recorded as 3668?; ex Goondi Mill, transferred to Mourilyan in 1987. Later disposition not established.
2	Motor Rail	20hp	3717	1925	Victoria Mill	Out of service	Former Victoria Mill Motor Rail 3717. Transferred to Macknade in 1958, converted from petrol to diesel in 1958 and into a ballast plough in 1989. Recorded returning to Macknade from loan in the Burdekin on 21 June 2001; listed as Macknade #2 in the 2005 Herbert River roster.
4	Motor Rail	32/42hp	10232	1951	Macknade Mill	Out of service	Former Macknade Motor Rail 10232. Later stored at Victoria Mill; acquired by a Victoria Mill driver and removed to his property in the Seymour area in 2012.
Thunderbolt	Motor Rail	4wDM	11255	1964	Victoria Mill	Out of service	Ex Harwood Mill; transferred to Victoria Mill and named THUNDERBOLT in 1998. Recorded as a wreck at Macknade Mill in December 2003.
(Blank)	Motor Rail		21622	1957	Racecourse Mill	Out of service	Out of use by 1983 and later derelict. Acquired by Peter McFarlane for the Sugar Bowl Museum at Septimus in early 2003 after lying derelict for at least 13 years.
1	Motor Rail	4wDM	9577	1951	Pleystowe Mill	Out of service	Stored in the Mackay Sugar fleet (2024).
2	Motor Rail	4wDM	9861	1953	Pleystowe Mill	Out of service	Preserved; LRRSA recorded at Cobdogla Steam Friends Society, South Australia (2011).
Li'l Toot	Motor Rail	4wDM	21575	1956	Pleystowe Mill	Out of service	Worked at Pleystowe until 2000; later privately preserved in Queensland. Fully restored and arrived at Milang Railway Museum, South Australia, on 21 March 2023.
(Blank)	Motor Rail	4wDM	21503	1953	North Eton Central Mill	Out of service	Listed at North Eton Central Mill in the 1978 Australian Sugar Industry Locomotives register. Later disposition not established.
(Blank)	Motor Rail	4wDM	21512	1955	Marian Mill	Out of service	LRRSA recorded the locomotive preserved with Alan Finch, Horsham VIC. Later advertised with railway equipment at a clearing sale in 2015; subsequent disposition not established.
Seaforth Simplex	Motor Rail	4wDM	7369	1939	Farleigh Mill	Out of service	Preserved at Cobdogla Irrigation and Steam Museum, South Australia, where it operates as FARLEIGH. Recorded operational on passenger trains in 2018.
Phar Lap	Motor Rail	4wDM	21623	1957	Farleigh Mill	Out of service	Sold at the November 2003 Mackay Sugar auction to Zebra Truck Wrecking, Gracemere. Acquired by Errol Dennis, Jambin, in December 2005; offered for sale in 2008 without a bid. LRRSA subsequently recorded it preserved at Jambin.
(Blank)	Motor Rail	4wDM	21543	1956	Kalamia Mill	Out of service	Preserved at Dreamworld, Coomera; recorded on maintenance-train duties in 2013. Had not hauled passenger trains for 10-12 years as of 2018.
S1	Motor Rail	4wDM	10181		Victoria Mill	Out of service	Motor Rail works no. 10181 was recorded as Victoria Mill S1 in the 1978 Australian Sugar Industry Locomotives amendments. Later disposition not established.
S3	Motor Rail	4wDM	10381	1953	Victoria Mill	Out of service	Converted to an unpowered ballast plough; transferred from the Herbert district to the Burdekin region in 2019.
S2	Motor Rail	4wDM	10382	1953	Victoria Mill	Out of service	Remains recorded in Victoria Mill's scrap disposal area in 1978. Later disposition not established.
3	Motor Rail	4wDM	3365		Macknade Mill	Out of service	Partially dismantled at Macknade by 1977, with engine removed. Later disposition not established.
Amy	Motor Rail	4wDM	4207	1929	Mulgrave Mill	Out of service	Acquired from Mulgrave by RAILCO in 1997 and transferred to Ravenshoe; subsequently recorded with RAILCO at Atherton.