New South Wales Z11 class locomotive

The Z11 class (formerly the M40 class) was a class of steam locomotives built for the New South Wales Government Railways in Australia.

Built by Beyer, Peacock and Company of Manchester, they entered suburban traffic in Sydney in 1891.

They were primarily intended for use on the steeply-graded Strathfield-Hornsby and Milson's Point-Hornsby sections, hence their hefty weight which served to hinder them later in their careers. Because of this, they were never noted for spectacular performance.

Between 1906 and 1910, they were rebuilt with Belpaire boilers. They were soon superseded by the S636 class 4-6-4Ts and were promptly used on Newcastle suburban services for a period. In 1924, all were renumbered as part of the Z11 Class.

No. 50 was sold to Australian Iron & Steel Ltd., No. 51 to the South Maitland Railway, No. 1104 to the Nepean Sand & Gravel Company and No. 1111 to the Southern Portland Cement Company of Berrima. The remainder were sold for scrap between 1925 and 1927.

None are preserved.