|Total Number of Engines Built||12|
|First Engine Built||1948|
|Last Engine Built||1952|
|First Engine Written Off||1966|
|Last Engine Written Off||1969|
These engines were an “improved” version of the D17 Class incorporating modern features including roller bearings, longer travel valves and self cleaning smokeboxes
All engines were attached to Mayne depot and, like their predecessors, were restricted to the Brisbane suburban area. Initially they were used exclusively on the “Northside” suburban passenger and a few local goods trains. Increasing numbers of 1720 Class DEL saw them eliminated from these passenger workings in August 1967. After the closure of Wooloongabba depot in September 1967, a few made appearances on the “Southside” passenger trains until the dieselization of those services later the following year.
Between 1953 and 1956 the class suffered a number of embarrassing failures in traffic due to broken driving axles and fractured coupling rods. Fortunately none of these incidents resulted in seriously consequences. The defect was overcome with fitting of “Vibroc” steel axles and altering the horn cheeks. After these alterations, they then established a reputation for reliable service that was not surpassed until they were replaced by diesels.
Prototype N°949 entered service painted black. The second engine, N°950 was the 200th locomotive constructed at Ipswich Shops and was exhibited at the first Queensland Industries Fair in May 1949. It was painted in a dark Royal blue livery with red and silver trim. When N°951 to 954 were completed later that year, they also appeared in the same colour scheme. N°949 was similarly repainted in October 1949. The second batch (N°1046 – 1051) entered service painted “Midway” blue – midway between Royal and sky blue. The first six were later similarly repainted. This colour scheme earned them the nick name “Blue Babies”.
N°1047 worked an ARHS excursion to Toowoomba and return on 2 October 1966. This trip involved the engine being re-coaled by hand at Helidon.
N°1048 was the first member of the class to be withdrawn and was written off in November 1966. N°952 and N°953 followed in 1967 with a further seven engines in 1968. N°1046 and N°1049 survived until the following year.
N°1051 was the last engine to be constructed at Ipswich and was preserved statically. It was overhauled and restored to working order by Ipswich Workshops in August 1993.
* N°1051 fitted with Davies & Metcalfe B.V.
Ipswich – Ipswich Workshops
ZZR – Zig Zag Railway, Lithgow NSW