A West Australian engineering firm has been fined $16,000 over the collapse of an 80-tonne crane.

The incident occurred during test loading in April 2013.  The company was prosecuted by the Department of Mines and Petroleum.

Etschmann Engineering pleaded guilty in the Perth Magistrates Court on Thursday to failing to ensure the equipment complied with the Australian Standard.

The company was also ordered to pay $5000 in court costs.

State mining engineer Andrew Chaplyn said the outcome was a watershed for the department, which had not previously prosecuted a designer.