The TEV Rangatira was a roll-on/roll-off vehicle and passenger ferry launched in 1971 for the Union Steam Ship Company of New Zealand.

From 1986 onwards, she passed through a succession of owners who renamed her three times and registered her under three different flags of convenience: as Queen M in 1986,[1][3] Carlo R in 1990[1][3] and Alexander the Great in 2001.

She was delivered to Union Steam Ship Company (UK) Ltd in January 1972[3] and sailed from England on 16 February carrying a cargo of motor cars.

[1] The new Rangatira had turbo-electric transmission, with twin turbo generators and electric propulsion motors built by AEI of Manchester.

[3] Compared with the more common reduction gearing between steam turbines and propeller shafts, turbo-electric transmission has lower energy conversion efficiency and an inferior power-to-weight ratio.

[3] However, on 18 September Rangatira developed a serious fault with her port turbine, reached Wellington at reduced speed two and a half hours late[3] and had to be taken out of service for repairs.

[1][3] The Maori was quickly re-equipped and on 20 September was returned to service until Rangatira's repairs were complete and she able to resume duty on 16 October.

[3] On 30 October 1973 Rangatira was en route from Lyttelton to Wellington when her starboard turbine suffered damage to a thrust bearing and a rotor.

In 1962 New Zealand Railways had introduced its Cook Strait rail ferries on the 55-nautical-mile (102 km) route between Wellington and Picton, offering a much shorter sea crossing for freight and cars.

Domestic aviation between the two islands was also expanding and becoming more affordable, especially after the National Airways Corporation (now part of Air New Zealand) introduced Boeing 737-200 aircraft in 1968.

The perception created by the loss of the Wahine that the Lyttelton to Wellington ferry service was a less safe option hastened the decline of passenger numbers.

Rangatira's long route and the high fuel consumption of her turbo-electric propulsion made her uncompetitive from the start.

[1] on 3 March 1976 Ministry of Transport renewed the charter "for a short period" until a more affordable replacement ship could be brought into service.

[1][3] On 18 March 1978 in Loch Kishorn the coastal tanker BP Springer collided with her, causing minor damage.

[1] Rangatira was then repaired and altered for a four-year charter as an accommodation ship for the building of the Sullom Voe Terminal in the Shetland Islands.

All her cabins were converted to single berths, a gymnasium and indoor games facilities for snooker and table tennis were installed and television lounges were built on her upper car deck.

[1][3] On 9 May 1981, Queen Elizabeth II officially opened Sullom Voe terminal, and afterwards dined aboard Rangatira.

Rangatira underwent sea trials for the UK Ministry of Defence, which on 15 May 1982 chartered her for possible service as a hospital ship.

[1] Her lower car deck was equipped with 14 freezer containers, holding enough food to feed 1,200 people for six months.

She sailed from Southampton, England on 19 June and reached Port Stanley in the Falklands on 11 July,[1][2][3] where she spent the next 14 months as a barracks.

On 26 September 1983[2][3] Rangatira left Port Stanley and on 18 October she arrived back at HMNB Devonport, where her Ministry of Defence equipment was removed.

[1] In 1994 Alimar chartered Queen M to Horizon Sea Lines of Greece who ran her between Ancona and Çeşme on the Aegean coast of Turkey.

[1] In 1995 Egnatia Line planned to charter Carlo R for a route across the Tyrrhenian Sea linking Trapani in Sicily with Livorno and Naples.