Queensland Railways steam locomotive classification explained

Between 1864 and 1958, Queensland Railways ordered 47 types of locomotives for purposes such as freight, passenger and mail train use.

Classification

Until 1889, each of the isolated sections of the Queensland Railways adopted its own locomotive numbering system. With the impending joining of most of the sections, in 1890 a new centralised classification system was adopted to eliminate duplications. Locomotives on the Southern & Western Railway retained their existing numbers, with locomotives on other networks renumbered where there was a duplication.^{[1] [2]}

The classification system consisted of a letter, indicating the number of driving axles, followed by a number, indicating the cylinder diameter in inches and factions of inches. This was confusing for two reasons:

• it differed from the international system
• it could lead to several classes having the same classification number

Where classification numbers were duplicated, the classes were usually distinguished by the name of the builder, e.g. A10 Baldwin, A10 Fairlie, A10 Neilson.^{[1] [2]}

In the case of tank locomotives, the number of driving wheels was added as a prefix, e.g. the 6D16 class had six driving wheels. With all four wheel tank locomotives, the prefix was dropped, thus the 6D16 class became the D17 class.^{[1] [2]}

Number of driving axles	International classification	QR classification
1	A	-
2	B	A
3	C	B
4	D	C
3 (Tank locomotive)		D

Improved versions of a similar class were given a second identical letter. For example, the improved version of the D17 was the DD17.

Classes

Classification
Image	Years built	Whyte notation	Designation	Cylinder diameter (inches)	Driving axles	Type	Number in Class
	1864	2-4-0	A10 Avonside	10		2	Freight	4
	1865-1866	0-4-2	A10 Neilson class – Originally B class	10		2	Mixed	13
	1867	2-6-0	B11 class – Originally C class	11		3	Freight^[3]	4
	1867	0-6-6-0	Double boilered Cross class	17		6	Freight
	1874-1882	2-6-0	B12 class – Originally E class	12		3	Mixed use^[4]
	1874		0-4-4-0	8D11 class	11		4	Tank
	1877	2-4-0	A10 Fairlie – Originally A class	10		2	Freight^[5]
	1877	2-4-0	A10 Ipswich	10		2	Freight
	1878	2-4-0	A11 class – Originally Large A class	11		2	Mixed^[6]
	1878		4-4-0	A12 (small) class – American Passenger class	12		2	Passenger	3
	1879		4-4-0	A10 Baldwin – Originally American Passenger class	10		2	Passenger^[7]
	1879		2-8-0	C13 Baldwin class	13		4	Freight^[8]
	1879		2-8-0	C15 class – Originally Small Consolation class	15		4	Mixed^[9]
	1880		2-6-0	B11 Baldwin class	11		3	Freight, then shunting^[10]
	1881		2-4-2T	4D9 class	9		2	Tank (Mixed use)
	1882-1891		4-4-0	A12 class – Originally American Passenger class	12		2	Passenger^[11]
	1882	0-6-0T	6D11½ Motor class	11 1/2		3	Tank (Freight)^[12]
	1882		0-6-2T	6D13 – formerly F-class	13		3	Tank (Freight)^[13]
	1882		2-8-0	C16 Baldwin class – Large Consolidation class	15		4	Freight^[14]
	1883-1895	4-6-0	B13 class	13		3	Mixed use^[15]
	1883		2-8-0	C13 Dubs class	13		4	Freight^[16]
	1884-1885	2-4-2T	4D10 class	10		2	Tank (Passenger)^[17]
	1884		2-8-2T	8D15 class	15		4	Tank (Heavy Freight)^[18]
	1889-1899	4-6-0	B15 class	15		3	Freight^[19]
	1894-1895	4-4-0	A14 class	14		2	Passenger^[20]
	1898	0-4-2T	4D11½ Abt class	11		2	Tank (Rack Freight)^[21]
	1899-1926	4-6-0	PB15 class	15		3	Passenger, Shunter^[22]
	1900-1923		0-6-0T	6D8½ class	8 1/2		3	Tank (Passenger)
	1900-1915		0-6-0T	6D13½ Abt class	13 1/2		3	Tank (Rack Freight)^[23]
	1901-1902		4-6-2T (originally), 4-6-4T (after rebuild)	6D16 class	16		3	Tank (suburban passenger)^[24]
	1902		0-6-0ST	6D11½ Crane class	11 1/2		3	Saddle Tank (Inspection)^[25]
	1903-1918		4-8-0	C16 class	16		4	Poison trains, mail trains, goods trains^[26]
	1904-1905	0-6-0T	6D13½ later B13½ class	13 1/2		3	Tank (Shunter)^[27]
	1908	4-6-0	B13 Baldwin class	13		3	Freight
	1911		4-6-0	B17 class	17		3	Express Passenger^[28]
	1914		4-8-0	C18 later CC19 class	18 (then 19)		4	Express passenger^[29]
	1918		2-6-2	B16½ class	16 1/2		3	Passenger
	1920-1953	4-8-0	C17 class	17		4	Mail trains, suburban passenger, freight trains and passenger^[30]
	1922-1935		4-8-0	C19 class	19		4	Express passenger^[31]
	1923-1927	0-6-2	B9½ class	9		3	Freight
	1924-1942		4-6-4T	6D17 later D17 class	17		3	Tank (suburban passenger)	30
	1926-1947	4-6-2	B18¼ class	18 1/4		3	Express passenger, suburban passenger, mail trains and heavy freight	83
	1943	2-8-2		16		4	Mixed use^[32]	20
	1943-1945		4-8-2+2-8-4 2′D1′+1′D2′		14.5		8	Heavy freight^[33]	57
	1948-1952	4-6-4T	DD17 class	17		3	Suburban passenger	12
	1950-1958	4-6-2	BB18¼ class	18 1/4		3	Express passenger, mail trains, suburban passenger and heavy freight trains^[34]	55
	1950-1951	4-8-2+2-8-4	Beyer-Garratt class	13 3/4		8	Freight^[35]	30

See also

• List of Australian diesel locomotives

Notes and References

1. Book: Armstrong, John. Locomotives in the Tropics Volume 1. 1985. Australian Railway Historical Society. Brisbane. 0 909937 13 3. 8.
2. Book: Clark, Peter. An Australian Locomotive Guide. 2012. Rosenberg Publishing. 9781921719554. 16.
3. Web site: B11 – Originally C Class « qrig.org – queensland railway's interest group. en. 2019-11-24.
4. Web site: B12 – Originally E Class « qrig.org – queensland railway's interest group. en. 2019-11-24.
5. Web site: A10 Fairlie – Originally A Class « qrig.org – queensland railway's interest group. en. 2019-11-24.
6. Web site: A11 – Originally Large A Class « qrig.org – queensland railway's interest group. en. 2019-11-24.
7. Web site: A10 Baldwin – Originally American Passenger Class « qrig.org – queensland railway's interest group. en. 2019-11-24.
8. Web site: C13 Baldwin Class « qrig.org – queensland railway's interest group. en. 2019-11-24.
9. Web site: C15 – Originally Large Consolation Class « qrig.org – queensland railway's interest group. en. 2019-11-24.
10. Web site: B11 Baldwin Class « qrig.org – queensland railway's interest group. en. 2019-11-24.
11. Web site: A12 – Originally American Passenger Class « qrig.org – queensland railway's interest group. en. 2019-11-24.
12. Web site: 6D11½ Motor Class « qrig.org – queensland railway's interest group. en. 2019-11-24.
13. Web site: 6D13 – Originally F – Class « qrig.org – queensland railway's interest group. en. 2019-11-24.
14. Web site: C16 Baldwin – Large Consolidation Classba « qrig.org – queensland railway's interest group. en. 2019-11-24.
15. Web site: B13 Class « qrig.org – queensland railway's interest group. en. 2019-11-24.
16. Web site: C13 Dubs – Originally Small Consolation Class « qrig.org – queensland railway's interest group. en. 2019-11-24.
17. Web site: 4D10 – Ipswich Class « qrig.org – queensland railway's interest group. en. 2019-11-24.
18. Web site: 8D15 Class « qrig.org – queensland railway's interest group. en. 2019-11-24.
19. Web site: B15 Class « qrig.org – queensland railway's interest group. en. 2019-11-24.
20. Web site: A14 Class « qrig.org – queensland railway's interest group. en. 2019-11-24.
21. Web site: 4D11½ Abt Class « qrig.org – queensland railway's interest group. en. 2019-11-24.
22. Web site: PB15 Class « qrig.org – queensland railway's interest group. en. 2019-11-24.
23. Web site: 6D13½ Abt Class « qrig.org – queensland railway's interest group. en. 2019-11-24.
24. Web site: 6D16 Class « qrig.org – queensland railway's interest group. en. 2019-11-24.
25. Web site: 6D11½ Crane Class « qrig.org – queensland railway's interest group. en. 2019-11-24.
26. Web site: C16 Class « qrig.org – queensland railway's interest group. en. 2019-11-24.
27. Web site: 6D13½ later B13½ Class « qrig.org – queensland railway's interest group. en. 2019-11-24.
28. Web site: B17 Class « qrig.org – queensland railway's interest group. en. 2019-11-24.
29. Web site: C18 later CC19 Class « qrig.org – queensland railway's interest group. en. 2019-11-24.
30. Web site: C17 Class « qrig.org – queensland railway's interest group. en. 2019-11-24.
31. Web site: C19 Class « qrig.org – queensland railway's interest group. en. 2019-11-24.
32. Web site: AC16 Class « qrig.org – queensland railway's interest group. en. 2019-11-24.
33. Web site: Australian Standard Garratt « qrig.org – queensland railway's interest group. en. 2019-11-24.
34. Web site: BB18¼ Class « qrig.org – queensland railway's interest group. en. 2019-11-24.
35. Web site: Beyer-Garratt Class « qrig.org – queensland railway's interest group. en. 2019-11-24.