HSS Stena Carisma – Onboard Report

August 18, 2013 by H.Forsman

Alright, the blog has been asleep for a long time now. I don’t want to blame laziness as the only reason, but also the fact that I have run out of interesting themes. A few years ago, a voyage or a quick visit onboard a vessel, combined with a few pictures were simply good enough for me to write a report. Now, about a dozen reports later, I have become a bit more picky, thus I want to gather more information before I actually grab the pen and start to write something. After all, what I’m doing is compiling information and hopefully, present it to you in a nice package.  Secondary, when I decided to create a blog, I wanted to switch to the English language, to reach out to more people. It is, however, a lot more time consuming and more of a challenge to write reports in a foreign language and still make it an interesting read.

Recently, I had the opportunity to travel with the HSS Stena Carisma as a visitor. Well, to be perfectly honest with you, I was actually traveling with the vessel as a passenger the week before, and since I was so excited, I asked a good friend of mine, who currently serves his duty as a crew member, if I could join for a day trip to Denmark and take a look behind the curtain. The answer was yes and so I made my way down to the “Denmark-Terminal” on a sunny Friday afternoon. Coincidentally this happened on the very same day as the funeral for the founder of the Stena corporation, Sten Allan Olsson.  Being born and bred in Gothenburg, I consider the man a legend. Not only did he help to put Gothenburg on the world map, but he did very likely spark my interest in ships and shipping thanks to his ferry empire. R.I.P. Sten Allan.

Inside the terminal, I met up with my friend and after I received a visitors pass, we went onboard the vessel, through the passenger gangway on the right side of the terminal. It was originally built and used for the ferry line to Kiel. Germany and later converted for the HSS (High Speed Service) crafts. For various reasons, I have not paid much attention to the HSS crafts in the past, mostly because I had and still have more passion for conventional vessels. One of the main reasons why I recently have found an interest in HSS crafts, is a book about one of the Swedish shipyards, Uddevallavarvet. The book contains interviews with a number of people, including the former head of the technical department, Stig Bystedt. This gentleman joined Stena in 1985/86 and was, according to independent sources, the brain behind the HSS project.

During his more than 20 years in the shipyard, Stig Bystedt belonged to a very skilled team of engineers, who developed some impressive type of vessels, some that put the yard several years ahead of their competitors. Vessels with shallow draft and very good maneuvering capabilities was their specialty. In times, when the world wide shipyard capacity was totally over-established and the prices for new vessels literally were at the bottom, the Swedish shipyards with considerably higher over head costs, had to compete with technically advanced solutions, rather than low prices. However, the Swedish Government decided to close down the two major shipyards in 1986/87. Uddevallavarvet was doomed in November 1984 and as a result, some of their most skilled people left the company to pursue new carriers.

The HSS project was launched in 1990 and the first ones, the bigger HSS 1500 (1500 pax – 375 cars) were ordered at Finnyards in Rauma, Finland. It should be borne in mind that Stena Line was already at this time, with the acquisition of S.M.Z. in 1989 and Sealink British Ferries in 1990, a major ferry operator with a number of routes and vessels. The HSS project was, therefore, just as much, if not more, for the overseas operations, as for the local Scandinavian routes. However, the fact that Sea Containers, the previous major shareholder of Sealink, introduced their own catamarans on the Gothenburg-Frederikshavn route, in 1993 probably added some fuel to the fire. Two units of the smaller HSS 900 (900 pax – 200 cars) type were ordered at the Norwegian shipyard Westamarine in Kristiandsand for delivery in 1996.

Westamarine were unfortunately unable to fulfill their obligations, and were subsequently filed for bankruptcy prior to the delivery of the first vessel. An agreement between Stena Line and the trustee was reached, in order to complete the first vessel. She was delivered in the late spring of 1997 and named HSS Stena Carisma, before she entered service on Gothenburg-Frederikshavn, where she replaced the smaller HSC Stena Lynx II, a catamaran built in Australia by InCat in 1994. The second unit only made it to the early pre-assembly stage of a few hull sections, thus she wasn’t ever completed and delivered, but some of the equipment was bought by Stena Line and kept as spare for the Carisma.

Back to my visit, we walked through the passenger accommodation which is all located on one single deck, and continued up through stairs that start in the middle of the restaurant, and lead to a deck below the bridge. The bridge is accessible via a couple of more stairs and is shaped like a cockpit with the nautical equipment in a “horseshoe” console, located at the front end, with two seats for the navigator and the skipper. The engineers have their own set of consoles, located further to the aft, on the PS, which also is shaped like a horseshoe, although slightly bigger than the one used by the deck officers. When I arrived, there was about 35-40 minutes left before departure and therefore, I had the opportunity to ask a few questions about the equipment and the vessel in general.

The Carisma is powered by two ABB GT35 gas turbines, one in each skeg, connected via shafts, to two KaMeWa 160 S11 water jets. Each water jet distributes about 37.000 liters of water per second at full speed, which is approximately 43-45 knots. Nowadays, when the fuel prices have risen with some 300 %, the more normal service speed is kept at around 35 knots. Still, it’s an impressive feeling to be standing on the aft deck and watch a vessel of this size (L 80 x B 30 m) making her way through the sea. One of the secrets behind the very good sailing characteristics is the hull shape. Each skeg is very narrow along the water line, with the part of the hull, located under the water, shaped like a pontoon.

Once the gas turbines are started, the water jets stir up a lot of sea behind the vessel and around the floating linkspan pontoon. However, as long as the water jets are kept in neutral position the vessel won’t move forward. With the water jets in “drive” mode and the turbines on idle, the Carisma still has a minimum speed of 12 knots, for which she holds a special certificate issued by the Swedish Maritime Administration. For conventional vessels, the maximum speed in the port of Gothenburg is limited to 8 knots. For the tight maneuvers, when the vessel is moving out from the linkspan and turns 180 degrees, the deck officers are assisted by two KaMeWa bow thrusters, one in each skeg. It should be mentioned though, that the Carisma can handle these maneuvers, without the thrusters, at wind speeds below 15 meters per second.

On our way out from the port, we went outside (nor sure if the term deck is correct here, as we were more in the “top” of the box, but anyways…) and got some great shots of the running mate, the RoPax vessel, M/V Stena Jutlandica, delivered in 1996 from the now defunct Dutch shipbuilder, Van Der Giessen Der Noord. This was just minutes before the speed was increased to 20 knots, which is the limit through the archipelago, but still the front wind was fairly hard and I had to struggle to keep the camera in position. Once the pictures were taken, we moved on to the aft, behind the funnels and further to the aft, where we could spot the passengers on the deck below. Apart from the exhaust fumes, there are air outlets from the galley which results in a peculiar smell around the funnels, somewhere between fish and chips and diesel oil.

Now it was about time to discover the Carisma on the inside, and the inside dear readers, does not mean the passenger accommodation but the technique that makes the vessel operational. The walk continued down through, the lower car deck, via the workshop, through hatches and down ladders. Literally every little hull detail is made in aluminum and the feeling you get, reminds very much of entering an aircraft. Furthermore, everything is extremely compact compared to a conventional vessel, and dare I say that you have to be in good shape to climb around this vessel on a everyday basis. Once we had reached the bottom of the SB skeg, we started our walk forward, through the different compartments. At the very aft, each skeg accommodates quite a heavy power pack, that feeds the hydraulic cylinders that controls each water jet. As with most power packs, it creates a lot of noise and this was no exception and perhaps a reason for us to proceed forward rather quickly.

We continued our walk along the shaft that connects the water jet with the turbine, which was located in a compartment further fwd. The sound level inside the turbine room was very low, actually lower than expected, but the temperature was considerably higher. To be honest, it was quite a strange feeling to be inside the turbine room. I have been visiting quite a few engine rooms on conventional vessels, with everything from small high speed marine diesels, to huge cathedral, 2-stroke engines onboard ocean going vessels, but this was something different. The fact that this little piece of equipment has an output effect of 17 MW (equivalent to approx 23.000 hp) which is more or less the same as some of the cathedral engines, is a bit strange. The efficiency of the traditional diesel engines is of course much higher, but still…

A little further fwd inside the next compartment, we stopped by, to take a few pictures of the auxiliary engines. There are totally four gensets that, each consists of a MTU (Mercedes Marine) diesel engine connected to a generator, two in each skeg. For the normal electric consumption 2-3 gen sets are running, while one is in standby mode. The next compartment accommodates the electric cabinets for the auxiliary engines and a screen, for local monitoring of the system, whenever desired. We passed though a few more compartments with compressors and pumps before we entered the bunker station. One interesting feature was a traditional mechanical flow counter, where I could see the actual fuel consumption, with the liters rolling by twice as fast as when you fill your car up at the petrol station! The total fuel consumption for one return trip is approximately 30 cubic meters which is about the double quantity of the other running mate, the conventional ferry, M/V Stena Danica.

The further fwd we went the more narrow the hull shape became. In one of the final compartment we got a glimpse of the lub oil system for the bow thrusters. The bow thrusters were both overhauled at the local repair yard earlier this spring, but apparently the crew were not all satisfied with the final result. On top of these narrow sections of the skegs, on the deck above, there is a quite a big rectangular compartment with windlasses and capstans, a mooring station if you like. Through this area, we returned to the lower car deck and had a look at the provision systems, with a number of lifting platforms, located inside cages, that provide the galley and stores with food and store supplies. It goes without saying that these were all made of light weight materials as well. Fully loaded the Carisma has a total weight of approximately 1700 tons, which is incredibly low.

Back on the bridge, I had the opportunity to talk to the Cheif Engineer and his team and have a look at the screens where they can monitor each system and control most of the equipment on remote. The engineering team this day were the C/E, a 1:st and a 2nd engineer and two motor men / oilers. This is my second report from a Stena Line vessel, but I have been onboard as a visitor on quite a few more vessels, not yet presented in any report. Without any single exception, I have found the Stena Line crew members very pleasant to meet. From the lowest ranks in the catering crew to the senior officers, the Stena Line employees always keep a very professional attitude with a friendly approach and quite often with a good sense of humor. During this voyage, I was almost treated like a member of the family!

Once we arrived to the Danish port, we went ashore to have a look at the vessel and have some external shots of the Carisma, while she was moored alongside the quay. This particular berth was originally used by the competitor, Sessan Line, acquired by Stena Line in 1981. The berth was converted with a floating linkspan in the mid 90´s just before the arrival of the high speed crafts. There are, however, still some traces of the old Sessan days left, including the machinery house for the original quay flap. After a few great pictures were secured, we moved onboard the vessel again, through the stern doors. There are totally four top hinged doors, that (during the closure) rotates from horizontal to vertical position, before they slide down to achieve proper seal compression. The doors were delivered by Mongstad Engineering A/S. The SB and PS doors each leads to the lower car deck while the two doors in the C/L lead to the upper car deck, but with optional access to the lower car deck.

The port turnaround takes less than 45 minutes and the vessel can be unloaded and loaded again within only 25 min. During the return trip I stayed on the bridge for the whole time, and had a burger, brought from the restaurant below, followed by more interesting conversations with the crew. One of the deck officers explained that, unlike conventional vessels, the Carisma can actually benefit from the shallow draft nearby the Danish island Laeso, where she can “surf” on the sea bottom and actually reach a higher top speed with the same fuel consumption. However, the fuel consumption is still the weak spot and with prices that have passed beyond every worst case scenario forecasted at the time the vessels were designed, it remains to see for how long the Carisma will be kept in service. Since 2006 she does no longer operate during the off season and is laid up, while her crew members are employed on other Stena Line vessels.

For those of you who found this report interesting and haven´t traveled with the Carisma, I recommend you to do it as soon as you can. One of the HSS 1500 series have already been recycled, while one has been sold to South American operators. They vessels are unique and as mentioned in the beginning, developed by Stena’s own technical department. Some of the same people who were responsible for the design of legendary oil tankers such as T/T Nanny, M/T Polyviking and more recently, M/T Stena Vision. And the development continues with the Stena Airmax and new interesting RoRo vessels, optimized for new routes and market conditions. Make sure you travel with a HSS before it is too late.

I would also like to say thanks to the crew on Stena Carisma for making my day onboard very interesting!