On 9 February 1964, both ships arrived at
Jervis Bay for post-refit trials. During the day of 10 February the ships operated independently, or exercised with the British submarine . That evening, while south-east of Jervis Bay,
Melbourne was performing night flying exercises, while
Voyager was acting as the carrier's
plane guard escort; tasked with rescuing the crew from any aircraft that crashed or ditched. This required
Voyager to maintain a position astern of and to
port of
Melbourne at a distance of . As aircraft carriers head into the wind to provide maximum assistance for takeoffs, their course can vary widely and on short notice; bridge teams aboard escorting destroyers must thus remain alert at all times. During the early part of the evening, when both ships were manoeuvring together,
Voyager had no difficulty maintaining her position. After the series of course changes which began at 20:40, intended to reverse the courses of both ships onto a northerly heading of 020° for flight operations,
Voyager ended up ahead and to
starboard of
Melbourne. At 20:52,
Voyager was ordered to resume her plane guard station. According to
Melbournes ship log the order to resume plane guard, sent as Foxtrot Corpen 020, was sent at 20.54.
Voyager acknowledged the order and began turning a minute later. It was expected that
Voyager would turn away from
Melbourne, make a large circle, cross the carrier's stern, then advance towards
Melbourne on her port side.
Voyager did turn to starboard, away from
Melbourne, but then unexpectedly turned to port. It was initially assumed by
Melbourne bridge crew that
Voyager was "fishtailing", conducting a series of
zig-zag turns to slow the ship before swinging behind
Melbourne, but
Voyager did not alter course again. Recent investigations have demonstrated
Melbournes bridge crew correctly interpreted
Voyagers action as a fishtail manoeuvre. Due to Justice Spicers report in 1964 it has been written that on
Voyager's bridge, the
officer of the watch and the navigator had become distracted, and Stevens was reading navigational charts, impairing his
night vision. Recent investigations challenge this opinion by providing direct testimony of the three survivors from
Voyager bridge who gave evidence at the first royal commission. There was no such distraction; the officer of the watch and navigator on
Voyager were manoeuvring
Voyager into position. The officer of the watch remained at the
pelorus from the first to the last four signals and was watching
Melbourne through the entire exercise with his binoculars. Captain Stevens was also seen by one witness to come out from the chart area at 20.54, several minutes before the collision, and was seen to return to his chair or near his chair before suddenly moving and giving the order "full ahead, hard astarboard" 20 seconds before the collision. The port bridge lookout had come on duty while
Voyager was turning to starboard, and raised the alarm when the swing back to port brought
Melbourne back into view around 20:55.
Melbourne navigation officer ordered the carrier's engines to half speed astern around the same time, which Captain Robertson increased to full astern a few seconds later. At the same time, Stevens gave the order "Full ahead both engines. Hard a-starboard," before instructing the destroyer's quartermaster to announce that a collision was imminent. Both ships' measures were too late; at 54 seconds from impact, the ships were less than apart and
in extremis –physically unable to alter their speed or course enough to avoid a collision. Recent investigations have asserted the time of alert for both ships was 40 seconds. Captain Robertson himself was adamant that
Voyager appeared to be doing a legitimate manoeuvre by fishtailing to get into station, that the arrival of danger was sudden and irreversible, and that
Melbournes bridge crew did not see
Voyagers port light till 20 seconds before the collision.
Melbourne struck
Voyager at 20:56, with the carrier's bow cutting into the forward
superstructure of the destroyer just aft of the bridge and
operations room. The senior officers on the bridge were killed on impact. The mass of the oncoming carrier rolled
Voyager to starboard before cutting the ship in two, with the bow passing down
Melbourne port side, and the stern down the starboard.
Voyager forward boiler exploded, briefly starting a fire in the open wreckage of the carrier's bow before it was extinguished by seawater. The destroyer's forward section sank in 10 minutes, due to the weight of the two gun turrets. The aft section did not begin sinking until half an hour after the collision, and did not completely submerge until 00:18. In the messages that were sent immediately to the Fleet Headquarters in Sydney, Robertson underestimated the extent of the damage to
Voyager and as a result the Captain Cook Graving Dock at
Garden Island was ordered to clear the troopship from the dock to make room for
Voyager, and the salvage ship, , began sailing south to tow the destroyer to Sydney.
Melbourne launched her boats almost immediately after the collision to recover survivors, and the carrier's wardroom and C Hangar were prepared for casualties. One
cutter was able to rescue 40 people before beginning to take on water. The cutter was commanded by Leading Seaman M. A. W. Riseley, who rescued as many survivors as he could despite the weight limit of the rescue boat. The
admiral's barge was damaged by debris. Eight helicopters were also launched, but it was then deemed too dangerous to have so many active in such a small area, and they were limited to two at a time. Most of the sailors in the water were unable or unwilling to be rescued with the helicopters' winches, so the helicopters were reassigned to provide illumination of the site with their landing lights. At 21:58,
Melbourne was informed that five minesweepers (HMA Ships , , , , and ), two
search-and-rescue (SAR) boats from ( and ), and helicopters from
Naval Air Station Nowra, had been dispatched. The
destroyer escort was also being prepared to sail. Arriving just before 22:00,
Air Nymph collected 34 survivors and attempted to transfer them to
Melbourne, but swells pushed the boat up under the carrier's flight deck and damaged two communications aerials, and the SAR boat was sent back to
Creswell to offload the survivors. Another 36 were recovered by
Air Sprite and transported ashore. Sea searches continued until 12 February, and aircraft made occasional passes over the area until 14 February, looking for bodies. From the 314 personnel aboard
Voyager at the time of the collision, 14 officers, 67 sailors, and one civilian dockyard worker were killed, including Stevens and all but two sailors of the bridge crew. The majority of those killed had been in the forward section of
Voyager when the collision occurred, off duty and relaxing or sleeping. Only three bodies were recovered, one of them being that of Stevens. They were buried on 14 February, and the missing were
declared dead on 17 February. Memorial services were held around Australia on 21 February. There were no casualties aboard
Melbourne. == Repairs and replacement ==