[Mobhack]

http://members.tripod.com/~nigelef/37inchowsheet.htm

The 3.7-inch How was designed before WW1 but did not enter service until about 1916, and was used in Palestine and East Africa with both British and Indian mountain batteries. Between the wars they were used on the NW Frontier of India and developed a reputation for accurate and consistent shooting. Designed as pack artillery they could be disassembled and carried by mules or towed by short draught (no limber). In the 1930s they were further adapted for vehicle towing, the Mk 2P carriage. During WW2 they had some use in European and African theatres and initially with airborne batteries, being generally but not entirely replaced by 75-mm M1. However, they were widely used in Burma, mainly by Indian mountain batteries but also by British field batteries and continued to serve on India's NW Frontier. A few were also used in Guadacanal by RNZA and New Guinea by RAA. Production was transferred to India and during WW2 798 carriages and 805 ordnances were manufactured there together with some 2.7 million HE rounds.

(found within 2 minutes using Google with "3.7 inch australian" as the search term)

Cheers
Andy