HMNZS Otago (F111)

Otago took part in various Southeast Asia Treaty Organization (SEATO) deployments and took part in a protest against French nuclear tests at Mururoa Atoll in 1973. The protest voyage was opposed by the National Party Their leader, Jack Marshall called the deployment 'irresponsible' and a 'futile, empty gesture'[3] and RNZN officers, noting the Kirk Government approved the exercise on the day the International Labour Organisation and NZFOL called for stopping the French bomb tests [4] as an exercise ordered by FOL President Tom Skinner and the New Zealand Federation of Labour Executive[5] Otago, observed the "Euterpe" test carried out on 28 July 1973,[6] part of the 1971-74 nuclear test series.

In the weeks preceding the bomb test, HMNZS Otago was constantly monitored and tested by French Navy Lockheed 2PV-5 Neptune maritime patrol aircraft.[7][8] The instructions from the Cabinet, CNS and CDS were that Otago project authority, but not engage, if seriously challenged by French frigates, RNZN frigates should do everything to increase distance and not use weaponry. To avoid the embarrassment to the RNZN, its officers and ratings the frigate was fully armed with 4.5 shells (all fused on the voyage North, on the order of Cpt Tyrell with live shells in the loading hoppers[9] and extra shells in the turrets to overcome any problems with transfer belts for shells and charges from magazine below) to oppose any arrest or boarding effort by the French Navy, if all else failed, Seacat missiles fitted on the launcher while Otago was patrolling in French territory waters,[10] mortars, small arms and torpedoes) The Neptunes flew various patterns fully testing the Otago's radar, electronic warfare and IFF passive and active capabilities. HMNZS Otago was flying 3 RNZN battle ensigns, officially as an aid to recognition [11] and to signal this was a RNZN operational warship on a political not a protest mission. France may have considered it an act of war and it is unlikely the RN was approached on the right and wisdom of flying an associated battle ensign on this exercise. A couple of Soviet research ships were out of sight 25 nm distant and two large USN naval auxiliary and spy ships, USS Corpus Christi Bay and USS Wheeling (T-AGM-8). The Royal Navy had deployed an RFA tanker and an amphibious landing ship to allow for evacuating the Pitcairn Islands if the French conducted a much larger "megabomb" test but that didn't happen.[12] The objective was to lead a NZ government and world protest against 'illegal' atmospheric testing, demonstrate ability for 'innocent passage' in international waters, outside the French territorial 12-mile zone and, while avoiding confrontation, maintain the right to self defence. On the insistence of the PM , executive and CEO of Foreign Affairs (and possibly their Canberra counterparts, who reduced RAN involvement to HMAS Supply a Tanker with 6-10mm so the RNZN frigates in the vanguard would take any immediate retaliation)[13] only the Captain and operations officers were informed of the specific instructions, that in certain contingencies French action, fire and attempts to arrest or board the RNZN frigates would be arrested. Unaware with the specific instructions the wardroom of the Otago was increasingly concerned by the aggressive and unpredictable evolutions run by Cpt Tyrell in French waters.

The small French frigate force probably indicated only a small nuclear trigger test of 5.4 kilotons was likely. Otago observed it from 21.5 miles and the crew was held in the enclosed citadel for only 20 seconds before allowed on the upper deck to observe the nuclear cloud.[14] Cdr Tyrrell had witnessed the 1957 Christmas Islands hydrogen bomb test and saw the explosion as puny in comparison and well within safe limits for the crew at the distance.

The NZBC journalists, Shaun Brown and David Barber of New Zealand Press Association on Otago, saw it as an "angry... red fireball" and rising white mushroom cloud.[15]

In operations Otago needed the support of an RAN tanker due to the relatively short range of the Type 12 frigates[16] which was just sufficient for a one way trip from Auckland to Mururora or to operate for 36 hours at 25–30 knots (46–56 km/h; 29–35 mph) in all-out anti-submarine operations in the Greenland-Iceland-UK gap. The Rothesays were designed for such sweeps and as aircraft carrier escorts with fleet tankers in the group [17] sprinting and searching. A 50% fuel reserve was held at all times due to need to allow for emergency, weather and barnacle build-up on hull.[18][19] A solution became possible when the redesign of the Leander for the NZ in 1968-69 for HMNZS Canterbury; removal of the anti-submarine mortars giving more internal space below deck.

In 1960, the Royal Navy had seriously considered the Otago-class design as an alternative to the Rothesay Type 81 general purpose frigates for future development with a design that would have carried one or two Westland Wessex anti-submarine helicopters.[20] Proposals to fit a hangar and landing pad to Otago without complete reconstruction were rejected by RNZN CNS in the 1970s as jeopardizing the RNZN case for a new combat ship.[21] The Limbo mortars were finally removed after last firing on a recruitment cruise off Timaru in mid-1974, immediately before the frigates July 1974-November 75 mid life refit. [22][23]

Otago continued as the third combat ship in the three frigate fleet designated by the 1978 Defence Review. In the second half of 1979, the ship had another extensive refit, with its Seacat missile system repaired by using stored parts from HMNZS Taranaki's system. In early 1980, the ship deployed to Pearl Harbor and later the West Coast of the United States and Canada for extensive exercises with the United States Navy and Canadian Maritime Command firing hundreds of rounds of 4.5-inch shells. Under the command of Cmdr Karl Moen, who described Otago as the "one true fighting ship in the RNZN" [24] with Ltd Cmdr Robert Martin as his second. Martin assumed command during a final six-month refit, leaving the ship on 7 April 1982. Even at the time of the Falklands War, the Captain of Otago and the Minister of Defence, David Thomson, declared the ship to still be fully combat capable.[25]

• Gardiner, R. (1983), All the Worlds Fighting Ships 1947-1982: Pt 1. Western Powers, London: Conway Maritime Press
• Wright, G. (2008), Muroroa Protest. The Story of the Voyage of HMNZS Otago and Canterbury to Protest French Atmospheric Bomb test at Muroroa Atol 1973, Auckland

• HMNZS Otago Association
• Mururoa Veterans