High-speed Sea Service or Stena HSS was a class of high-speed craft developed by and originally operated by Stena Line on European international ferry routes. The HSS 1500 had an in-service speed of 40 knots (75 km/h).
Several patents were registered to Stena Line in the development of the HSS, and four vessels were completed between 1996 and 1997. Stena Explorer, Stena Voyager and Stena Discovery were built to operate on the Irish Sea with Stena Carisma built for Scandinavian use. The newest of the craft was renamed HSS Discovery after being sold to a ferry company in Venezuela during 2009.
Currently, none of the four craft originally commissioned by Stena Line operate. Stena Explorer was the last of the vessels to be retired in 2015 when Stena Line cancelled the fast ferry service between Holyhead, Wales and Dún Laoghaire, Ireland. As of November 2019, one vessel is laid up (Stena Carisma in Gothenburg, Sweden, while in 2013 Stena Voyager (on the Belfast-Stranraer route between 1996 and 2011) was sent to Landskrona, Sweden to be scrapped. In 2016 Stena Explorer was sold and exported to Turkey to be converted into a floating office after spending a period of time laid up in Holyhead.
HSS 1500
Three larger vessels were purchased, each capable of transporting up to 1,520 passengers at a time: Stena Explorer (#404), 1996–04, IMO #9080194 Stena Voyager (#405), 1996–07, IMO #9080209 Stena Discovery (#407), 1997–06, IMO #9107590
HSS 900
Two HSS 900 vessels were originally ordered, but following bankruptcy of the shipyard where they were constructed, the second one was scrapped at only 30% complete. This left only one that entered service: Stena Carisma (#238), 1997–06–20, IMO #9127760
Routes
Until 2011, two identical 1500 passenger versions were in operation on routes across the Irish Sea, whilst a smaller, 900 passenger version operated a route across the Kattegat. In 2011, Stena Voyager was withdrawn from service on the Belfast-Stranraer route to be replaced by two chartered conventional ferries, MS Stena Superfast VII and MS Stena Superfast VIII. In 2015, Stena Explorer ceased to operate service between Dún Laoighaire and Holyhead.
HSS 1500 Stena Explorer: Holyhead–Dún Laoghaire (Republic of Ireland), operated one round trip each day with a 2-hour crossing time. HSS 1500 Stena Voyager: Stranraer–Belfast (Northern Ireland), operated one round trip daily with a second on peak days, 2 hours 10 minutes. HSS 900: Stena Carisma: Gothenburg (Sweden)–Frederikshavn (Denmark)
Up until November 2008 and as of August 2014, Stena Explorer had been making two return trips to Dublin per day, at a faster advertised speed of 99 minutes. Up until 2006, this had been three return services per day.
Withdrawal of Stena Discovery in 2007
Stena Discovery was taken off the Hook of Holland–Harwich route on 8 January 2007, with her final in-service trip being the 10:40 from Harwich, returning to her home port of Hook of Holland.
Taking a route via Dover and the Isle of Wight she arrived in Belfast, Northern Ireland on 24 January 2007, pending use as spare parts or possible sale. Any future use was still undecided, with Pim De Lange, Stena Line's director of North Sea operations saying that Stena Discovery had been returned to the care of Stena Ro/Ro - the Swedish-based organization's chartering arm - but that it was unlikely any other northwest European company would want to operate her.
The HSS service was replaced with twice daily - one day, one night - sailings on a pair of traditional super ferries. The Stena Hollandica and Stena Britannica vessels now accept foot-passengers and were each stretched to 240 metres in length at the Lloyd Werft shipyard in Germany in the spring of 2007. In addition to passenger traffic, the HSS service is believed to have been carrying around 25,000 units of freight per year - about 15% of the 165,000 units that Stena Line transport across the North Sea annually.
The reasons cited for the replacement by conventional ferries were decreasing passenger patronage, coupled with escalating fuel costs. A report in International Freighting Weekly following the withdrawal stated that Stena Discovery operation on the North Sea route was using more fuel than Stena's seven other conventional ferries on the North Sea put together. Fuel costs for the HSS were noted in the article to have risen 40% from 2004–2005 and again by another 15% in 2005-2006, something that was "unsustainable".