Commonwealth Engineering

Commonwealth Engineering (Com-Eng) was a major Australian engineering firm that designed and built railway rolling stock. While best known for their work on standard and broad gauge passenger stock for state railways, they produced a significant number of diesel locomotives for the Queensland sugar industry during the transition from steam to internal combustion power in the 1950s and 1960s.

History

Com-Eng entered the sugar cane locomotive market in the mid-1950s. Their locomotives were manufactured at their Rocklea works in Brisbane, Queensland. The company established a classification system to denote the various models they produced, initially using a single letter code, and later a two-letter code where the first letter indicated the general type and the second indicated engine or transmission variations.

The company ceased production of cane locomotives as the market saturated and other builders like E.M. Baldwin and Clyde Engineering became dominant in the heavier horsepower categories.

Models and Classification

The Com-Eng classification system for sugar industry locomotives is as follows:

• Type A: 0-6-0 Diesel Mechanical or Diesel Hydraulic. These were typically 14 to 18 tonnes with power output ranging from 150 to 205 hp.
• Type C: 0-4-0 Diesel Hydraulic. A lighter shunting unit weighing 9 to 12 tonnes with approximately 112 hp.
• Type F: 0-6-0 Diesel Hydraulic. A heavier unit for the time, weighing 19 to 25 tonnes with 250 to 277 hp.
• Type G: 4-wheel Diesel Mechanical. Very small units weighing 4 to 8 tonnes with 76 hp.
• Type N: B-B Diesel Hydraulic.

Production Notes

Until 1959 (up to serial number 35), classification was by the initial letter only. Later, a more complex scheme was introduced, and these codes were often applied retrospectively. The numbering system typically used the first two digits to denote the variant code (starting from 10) and the final digits as the serial number.

Significant Allocations

Com-Eng locomotives were found at mills right across the state, from the Southern districts to the Far North. Notable examples include the fleets at South Johnstone Mill and Mulgrave Mill, where they served as the backbone of the diesel fleet before the introduction of larger bogie locomotives.

Rollingstock

Name	Builder	Model	Serial	Year	Current Mill	Notes
Mossman	Commonwealth Engineering	AA	1719	1957	Out of service	Operational - ANGRMS Woodford
Cook	Commonwealth Engineering	AL	3372	1964	Out of service	Purchased by South Johnstone. Stored at Mourilyan Loco Shed
Ivy	Commonwealth Engineering	AL	4181	1965	Out of service	Purchased by South Johnstone. Stored at Mourilyan Loco Shed
Douglas	Commonwealth Engineering	AL	2562	1963	Out of service	Private Owner - Victoria
Faugh-a-Balugh	Commonwealth Engineering	AL	4190	1965	Out of service	Private Owner - Victoria
Cattle Creek	Commonwealth Engineering	AA	B1724	1957	Out of service	Transferred to Mossman for parts in 2003. Sold to South Johnstone Mill in 2024. Current location unknown.
3	Commonwealth Engineering	AA	A1003	1955	Out of service	Retired 2018
5	Commonwealth Engineering	AA	A1005	1955	Mulgrave Mill
6	Commonwealth Engineering	AA	A1006	1955	Mulgrave Mill
7 / Highleigh	Commonwealth Engineering	AA	B1010	1955	Mulgrave Mill
8 / Charringa	Commonwealth Engineering	AA	A1926	1958	Mulgrave Mill
9 / Meerawa	Commonwealth Engineering	FC	FC3473	1964	Mulgrave Mill
1	Commonwealth Engineering	AA	A1821	1957	South Johnstone Mill	Was Josephine at Babinda
10	Commonwealth Engineering	AA	A2027	1958	South Johnstone Mill	Was Russell
6	Commonwealth Engineering	AG	C2234	1959	South Johnstone Mill	Paired with 7. Was Allison
4	Commonwealth Engineering	AD	AD1138	1960	South Johnstone Mill	Was Harvey at Babinda
7	Commonwealth Engineering	AD	AD1239	1960	South Johnstone Mill	Paired with 6. Was Morrison
5	Commonwealth Engineering	AH	AH22460	1962	South Johnstone Mill	Was Bramston at Babinda
9	Commonwealth Engineering	AH	AH3979	1964	South Johnstone Mill	Was Bartle-Frere
No. 6	Commonwealth Engineering	AA	AA1543	1960	South Johnstone Mill
7	Commonwealth Engineering	AJ	AJ2359	1962	Lautoka Mill	Last seen 2020
DL15 Nerada	Commonwealth Engineering	AA	B1111	1956	Out of service	Unknown location
26 / Meringa	Commonwealth Engineering	AK	AK3675	1964	Mulgrave Mill	Was South Johnstone #2
12 / Riverstone	Commonwealth Engineering	AD	AD1452	1961	Mulgrave Mill	Was South Johnstone #23
27	Commonwealth Engineering	AI	AA1544	1975	South Johnstone Mill	No markings.
28	Commonwealth Engineering	AA	AI57111	1960	Out of service	Stored derelict. 2020.
31	Commonwealth Engineering	AB	C1125	1957	Out of service	Stored for parts. 2008.
16	Commonwealth Engineering	AA	A1102	1955	South Johnstone Mill
39	Commonwealth Engineering	AH	AH4688	1965	South Johnstone Mill	Paired with 38
38	Commonwealth Engineering	AH	AH4695	1965	South Johnstone Mill	Paired with 39
10	Commonwealth Engineering	AD	AD1341	1960	Tully Mill	Navvy duties. 2025.
Tully 11	Commonwealth Engineering	AD	AD1347	1960	Tully Mill	Paired with Tully 16. 2024
Tully 12	Commonwealth Engineering	AD	AD1351	1961	Out of service	Stored at Tully Mill. 2025
Tully 14	Commonwealth Engineering	AK	AK2663	1963	Tully Mill	Navvy duties. 2025
Tully 16	Commonwealth Engineering	AH4484	AH	1964	Tully Mill	Paired with Tully 11. 2024.
Tully 17	Commonwealth Engineering	AH	AH42100	1966	Out of service	Stored at Tully Mill. 2025
Tully 18	Commonwealth Engineering	AO	AO60113	1977	Tully Mill	Navvy duties. 2025
2	Commonwealth Engineering	AA	A1001	1955	Out of service	Preserved - Atherton Herberton Historic Railway
4	Commonwealth Engineering	AA	A1004	1955	Mulgrave Mill
Tully 15	Commonwealth Engineering	AK	AK3574	1964	Out of service	Stored at Tully Mill. 2025
Dunethin	Commonwealth Engineering	AC	H1022	1968	Lautoka Mill	Now #118. Transferred 2019.
DL14 Johnstone	Commonwealth Engineering	AA	B1112	1958	Out of service	Was Jamaica at Moreton Mill. Stored - Private owner
Tegege	Commonwealth Engineering	HD	FD4799	1966	Millaquin Mill
Thistle	Commonwealth Engineering	AA	A1207	1955	Millaquin Mill	Stored at Millaquin
Invicta	Commonwealth Engineering	AA	A1513	1956	Bingera Mill	Navvy duties.
Sharon	Commonwealth Engineering	AE	A1935	1959	Millaquin Mill	Stored at Millaquin
Wattle	Commonwealth Engineering	FD	FD4789	1965	Bingera Mill	Used as backup for breakdowns. Last seen in service Oct 2025.
Burnett	Commonwealth Engineering	AH	AH2967	1963	Bingera Mill	Stored? Last seen in service 2024
Eric. M. Plomley	Commonwealth Engineering	AD	G1023	1958	Lucinda Bulk Sugar Terminal	Rebuilt 2017
Haughton	Commonwealth Engineering	AH	AH3878	1964	Invicta Mill
D4	Commonwealth Engineering	FA	FA1037	1960	Plane Creek
D7	Commonwealth Engineering	FC	FC3775	1964	Plane Creek Mill	Stored - Backup duties
22 Pinnacle	Commonwealth Engineering	AN	AN5849	1975	Racecourse Mill	Rebuilt 1975 from ComEng, AA, AA1549
Eton	Commonwealth Engineering	FB	FB3170	1963	Farleigh Mill	Navvy Duties
Septimus	Commonwealth Engineering	AE	A2128	1958	Out of service	Stored at North Eton Depot
Barcoo	Commonwealth Engineering	FB	FB4383	1965	Out of service	Stored at North Eton Depot
47 Pioneer	Commonwealth Engineering	AI	AI2358	1962	Out of service	Stored at North Eton Depot
48 Carlisle	Commonwealth Engineering	AI	AI3271	1963	Out of service	Stored at North Eton Depot
Richmond	Commonwealth Engineering	AA	A1308	1955	Out of service	Stored at North Eton Depot
Finch Hatton	Commonwealth Engineering	NA	NA59112	1977	Out of service	Only BB ComEng Loco. Stored at North Eton Depot
Keebah	Commonwealth Engineering	AF	C2231	1958	Inkerman Mill
Osborne	Commonwealth Engineering	AH	AH2866	1963	Inkerman Mill
Koolkuna	Commonwealth Engineering	AM	AM4993	1965	Inkerman Mill
Alma	Commonwealth Engineering	FE	FE56110	1975	Out of servic
Delta	Commonwealth Engineering	FD	FD5094	1965	Kalamia Mill
Barratta	Commonwealth Engineering	AD	AH4098	1965	Kalamia Mill
Northcote	Commonwealth Engineering	AH	AH4091	1965	Kalamia Mill
Chiverton	Commonwealth Engineering	AB	C1030	1958	Kalamia Mill
Kalamia	Commonwealth Engineering	AA	A1409	1955	Out of service
Inkerman	Commonwealth Engineering	FB	FB3169	1963	Pioneer Mill
D8	Commonwealth Engineering	FC	FC3777	1964	Pioneer Mill
Clare	Commonwealth Engineering	AB	C1015	1957	Out of service	Converted to brake van.
Clare	Commonwealth Engineering	AH	AH4080	1964	Out of service	Converted to brake van
17 / Deeral	Commonwealth Engineering	AD1453	AD	1961	Mulgrave Mill
7	Commonwealth Engineering	GA	GA1148	1961	Out of service	Unknown location
3	Commonwealth Engineering	FA	FA1036	1959	Out of service	Unknown location
7	Commonwealth Engineering	FC	FC3776	1964	Out of service	Unknown location
3	Commonwealth Engineering	AL	AL4892	1965	Out of service
Ashbyrton	Commonwealth Engineering	AA	A1614	1956	Out of service
Ivahoe	Commonwealth Engineering	GA	GA1042	1960	Out of service
Airdmillan	Commonwealth Engineering	AH	AH3068	1963	Out of service
Invicta	Commonwealth Engineering	CA	CA1040	1960	Out of service	Preserved at mill entrance
No. 17	Commonwealth Engineering	AH	AH52100	1966	Out of service
Alex S. Hamilton	Commonwealth Engineering		F1018	1957	Out of service
(Blank)	Commonwealth Engineering		F1029	1958	Out of service	3'6" Gauge. In storage at Southern Downs Steam Railway

Sources

• Light Railway Research Society of Australia (LRRSA).
• Notes on Locomotive Classification and Numbering (Historical Document).
• Zelmer, L. (2004). Australian Canefield Locomotives.