Small access points that house telecommunication cables and jointing equipment. Provide protection to cables/equipment from damage and access for maintenance. Designed for reach-in access rather than climbing access.

The pit is a moulded semi-enclosed housing usually inserted into ground with a removable lid inserted into the top at surface level. May be sited in publicly accessible soil, tarmac, verges, pathways, or on private property.

ACM pits were produced in a few different top surface shapes:  

• The smaller pits are (1m length) round ended with straight long edges or rectangular with rounded corners.
• The slightly larger are rectangular with rounded corners (650x400mm). These may be laid in twos over a single pit, usually end to end.
• The siding of the ACM pit is usually exposed at surface surrounding the lid.
• The lids are pre-cast concrete with one or two holes to provide access for lifting tools.
• The former Telecom Australia or PMG symbol is cast into the top.
• Distortion of shape may occur over time when in ground.

Manufactured by all the major AC manufacturers for the former Postmaster-General’s Department (PMG) and later Telecom Australia between the 1930s and the 1980s. Concrete cast pits were also installed throughout this period, as well as polyethylene moulded pits from the early 1980s to the early 2000s. During the 1980s cellulose cement moulded pits were installed at the same time as the ACM pits were being phased out. Telstra references both ACM and cellulose material as fibre cement (Telstra contractor guidance 2018).