first occurrence, in September 2006, led to the suspension of operations by the patrol boats for a month, and the engineering controls were redesigned. The problem occurred again in January 2007, and led to an 'operational pause' while Austal redesigned the fuel system, engineering procedures were altered, and fuel quality criteria were tightened. The five ships yet to be completed were fitted with the modified fuel system during construction, while the active ships were refitted over the course of 2007. As of December 2007, no further fuel problems have occurred. A 20-berth auxiliary accommodation compartment (the 'austere' compartment) was included in the design, for the transportation of soldiers, illegal fishermen, or unauthorised arrivals; in the latter two cases, the compartment could be secured from the outside. However, a malfunction in the sewage treatment facilities aboard in August 2006 pumped hydrogen sulphide and carbon monoxide into the compartment, non-fatally poisoning four sailors working inside resulting in use of the compartment as accommodation being heavily restricted across the class.McPhedran, The navy's patrol boat fleet is over worked and under maintained according to a new report In 2010, allegations were made to The Australian that a sailor working in the austere compartment on a different vessel had been gassed with hydrogen sulphide, and carbon monoxide was regularly detected in the enclosed space. Following publication of the allegations, Chief of Navy Russ Crane claimed that there was no record of the alleged gassing incident, and while there were ongoing incidents of poisonous gasses detected in the compartment, the sensors were set to trigger well below dangerous levels, and modifications were being made to the sewerage and ventilation systems. In 2014, the navy reported the recurrence of hull cracking around the engine spaces, which has been attributed to a combination of design issues related to the aluminium hull, and the high tempo of operations. By 2015, several patrol boats were confined to port because of structural, mechanical, and corrosion issues. In response, the Department of Defence threatened to cancel DMS' maintenance contract based on the company's poor performance in maintaining the Armidales (but did not go ahead due to the political repercussions from potentially losing local jobs). Defence and Serco (the parent company of DMS) later agreed to end the contract in 2017, with the Australian government to tender for a new in-service support contract during 2016. The patrol boat fleet began a mid-life refit