The maintenance company accused over a fatal accident that saw a concrete boom collapse and kill a Canberra worker is investigating whether issues with United States-supplied bolts may provide an alternative explanation for the failure.
But Schwing Australia's attempt to delay the case by two months to look at 167 bolts and other outstanding evidence was rejected by Industrial Magistrate Lorraine Walker on Friday morning.
Instead, Ms Walker has entered pleas of not guilty to serious charges on behalf of the company and engineer Phillip James O'Rourke.
Ben Catanzariti was killed when the 39-metre boom from a concrete-pouring machine collapsed and struck him as he worked on the Dockside apartment development in Kingston in July 2012.
The boom had recently undergone an inspection.
Mr O'Rourke and Schwing were charged with criminal offences, and the case is now before the ACT Industrial Court.
Defence lawyer Sian Ryan asked the court for a seven-week delay, saying the defendants were still seeking outstanding material from the Director of Public Prosecutions.
Ms Ryan said they were also seeking access to the bolts for further investigation of an alternative theory for the collapse.
The defendant, the court heard, was also seeking footage showing the examination of the equipment, relied upon to form expert reports used by the prosecution.
Ms Ryan said the defendants were not ready to enter pleas.
The case has already been the subject of significant delays, and Ms Walker said she was entering not-guilty pleas on the defendants' behalf.
The case will return to court on December 18, when it will either be committed to the ACT Supreme Court or listed again in the Industrial Court.
The charges are the most serious of their type to be laid under nationally harmonised occupational safety laws.
Schwing Australia faces a maximum penalty of $3 million, and Mr O'Rourke faces a fine of up to $300,000 and a maximum of five years' imprisonment.