Australian Post Office
Telephone No. 33MW

This phone was introduced in 1910, and in bulk purchases from 1918 as a post-War emergency measure until the Telephone No. 35MW could be delivered in quantity. It was made by Stromberg Carlson in the United States and was fitted with the solid back transmitter. The APO seems to have bought in a range of phones around this time, probably looking for a replacement for the elderly Tele No 1, the Commonwealth Ericsson. This phone is a typical U.S. style, big and boxy. It featured an adjustable lightning arrestor on the right hand side on the pre-War models. In most respects it is similar to the Western Electric Model No. 317, but is slightly taller due to the higher generator.

As well as the Australian Post Office, the Commonwealth National Railways also purchased the phone for the Trans-Australia line, completed in 1918.

During the 1930's many No. 33MW's were rebuilt in the PMG workshops and fitted with an insert transmitter and a standard receiver.  This version was reclassified as the No. 133MW .

During WWII some 33MW and 133MW were rebuilt in the PMG workshops and fitted with a No.164 handset.  This version was reclassified as the 233MW (shown below).

With experience with the phone, the APO redesigned the phone and issued the No. 133. It had the new Inset transmitter and no lightning arrestor but was otherwise similar. It must have been a fairly good phone, because the APO ordered large numbers. Purchases continued during World War 1, but by the end of the war the APO had decided to standardise on the British Ericsson (Telephone No. 35).

This telephone could also be fitted with a control lock.  This was a key operated lock which was fitted above the generator on the right hand side of the telephone.

Taken from Bob's Old Phones

Source: Substation Equipment Handbook 1951

233MW

Last revised March 15, 2026

FM2