Regular Checks of Hawsers on Viking Rosella

Work environment and safety in shipping YEAR 37 1 /13 THEME: HAWSERS AND LASHING STRAPS Regular checks of hawsers on Viking Rosella ............... 1 Research ......................................................... 4 Dirt and damage reduce strength ......................................... 2 The Transport Agency Informs .............................. 5 Rope-makers with years of experience ........................ 3 Profile: Annelie Rusth Jensen .................................. 6 Time to change the hawser .................................... 3 In brief .......................................................... 7 Sanhas the floor ................................................ 4 San tips ......................................................... 4 Regular checks of hawsers on Viking Rosella Every week the mooring equipment on Viking Rosella is checked, but it still happens that hawsers break. Sun, cold and seawater wear the materials and it is sometimes difficult to know when it is time to change the hawsers. The securing straps on the vehicle deck are used more sporadically and manage bet- ter. There are piles of hawsers coiled on the deck. Repairs can be seen here and there in the coarse ropes. ”We try to keep costs down by shorte- ning and splicing quite a lot,” says the chief mate, Anders Aspholm. ”But if something starts to look too worn we replace it directly – we don’t take any chances.” The winter sun warms slightly and the Hawsers on Viking Rosella water is still. On a day like this is not necessary to have any extra mooring ropes to keep Rosella in place at the quay once a week and equipment is replaced motorised, they are OK. But here, where in Kapellskär outside Norrtälje. But the between these checks if necessary. And they have to be pulled by hand and put weather can turn quickly and with more yet hawsers still break occasionally. ”Yes, over the bollards on the deck, it is heavy arrivals each day there is a lot of wear on they do. During a very windy autumn work.” On the quarterdeck, the haw- the equipment. a hawser may break every month if we sers are reinforced by straps in the part ”We always moor in the same place have bad luck, but as far as I know, there that runs through the hawsehole. Anders with the starboard side against the quay, is nobody here onboard who has been explains that a few years ago, a couple of and the hawsers always wear in the same injured in connection with such a break. seamen in the crew put straps into the place in the hawsehole,” says Anders. Cables may also break, but then it is most hawsers to strengthen them in places ”We have extra protection where they often inside the swab.” with a lot of wear. He lifts a hawser that have the most friction, but they still is lying loose on the deck and shows how wear.” Short crossing it is done. “It is sometimes difficult to decide Most mooring ropes used on the Rosel- ”You pull the strands apart and put the when it is time to change a hawser,” la are traditional Atlas types. strap between them,” he says and opens says Anders. He tells us that according ”Atlas hawsers are rather awkward and the hawser. ”In this way it becomes to the maintenance program, Amos, the difficult to work with,” says Anders. ”On much stronger. The guys that thought of mooring equipment is checked through more modern boats where everything is this were given a reward by the Swedish place. But there is much less lashing now difficult to keep up.” than there was before when Rosella used Anders says that they follow the instruc- to cross between Helsinki and Tallinn,” tions in the cargo securing manual, which says Anders. is available in several copies onboard. The The crossing to Åland takes two and a most recent version is dated May 2012 half hours and there is not so much open and contains everything, from descrip- sea. But the load still needs to be secured at times. ”There is not as much lashing now Anders Aspholm. ”We get weather reports all the time and if the wind approaches 13 or 14 met- as there used to be” Mercantile Marine Foundation for their res a second, it is time to do the lashing. invention.” If it has been windy for long, the sea may tions of various lashing techniques to the The vehicle deck below is empty apart be very old too. We have no stabilizers checking and maintenance of materials. from a provisions truck, which is driving and she rolls like a soap-dish in the sea,” ”There is a lot of very good information off after unloading the goods. Along the says Anders. in it,” says Anders. ”But to be frank, we bulkheads there are a few securing straps, ”At the moment it is calm, but we have don’t often look at it. Those who work but they do not need to be used on many reports that the wind may get harder here know how to do it, but of course, if crossings. towards the afternoon so we might need there is a new mate we show him where ”We have perhaps five trailers of the to lash the cargo yet. We try to secure the the manual is kept.” week, an average of four HGV trucks per load as the vehicles drive on board, but if Linda Sundgren journey and sometimes we strap stands in there are many on the crossing it can be Dirt and damage reduce strength A dirty strap has significantly less strength than a clean strap, and chains with defor- Hawsers and chains which should be med links should not be used. Tests of lashing materials show that worn equip- discarded ment does not have the strength that the marking indicates. In the past, you could count on the total capacity of the strap or chain when lashing cargo. If it was damaged or worn, on the other hand, Edge damage it would be discarded immediately. Today, it is permitted to load equipment to a maximum of 50 % of its total capacity. In contrast, the rules for when it must be replaced are more flexible and now rules state that ”only serviceable materials with the required strength” may be used. But what that means in practice can be difficult to decide. In 2009 the Swedish Trans- port Agency gave the consultancy company Knot on hawser Mariterm the task of testing the strength of used straps and chains. Their study did not give any clear answers. ”No, it is not possible to say anything in gene- ral,” says Peter Andersson at Mariterm, who took part in the testing. ”But one of the main con- Teared hawsers clusions we drew is that not only does damage affect the strength, but also dirt. On the other hand, the age of lashing straps does not seem to have any effect.” The tests were performed on lashing materials that shipping companies gathered from their ships and handed in. Most of them had already been discarded and were taken out of service, Skew chain some had major breaks and wear damage, while continues on page 8 2 San-nytt 1/13 Rope-makers with years of experience Choosing designs and materials based on the type of vessel, the traf- fic area and the equipment onboard is crucial for mooring ropes to have the longest possible service life. Three experts that SAN News has met say the same thing. A smell of tar hangs over the rope-maker’s premises just outside central Norrköping. The company has produced hawsers since the end of the 19th century and is now the only manufacturer of twisted rope on a large scale. Tore Dahlström has been in the industry since the 1980s. His business colleagues from Certex Svenska AB in Gothenburg, Mikael Jonsson and Ken- neth Johnsson, have been going since the 1970s. Over the years, they have acqui- red sound knowledge and experience of Tore Dahlström, Mikael Jonsson, Kenneth Johnsson mooring ropes. Hawsers are available in a number of variants with different charac- light? Must it float? Should it stretch or be be more expensive in the long run.” teristics, depending on the design and the inelastic? Will it be used on a mechanical On the desktop in Westerberg’s office type of fibres. winch? We need to know the priorities, there are samples of hawsers in different ”It is important to know what is wan- but we often help out to make the result materials. Some are heavy and rigid, oth- ted for the ship when ordering a new as good as possible for the customer.” ers light and flexible. In Scandinavia the hawser,” says Kenneth. ”It must be dura- ”Yes, but on the other hand many six-strand hawser in wear-resistant polya- ble, of course, but there are many other people choose hawsers only on the basis mide fibre (for example, the Atlas hawser) things to take into account. Should it be of their price,” interrupts Tore. ”But it can with a high breaking load and elasticity is continues on page 8 Time to change the hawser ference of the hawser at regular intervals. fact sunlight wears hawsers and breaks • Burned fibres. Hawsers vary in terms down the fibres. UV-exposed hawsers of heat resistance and the melting point become rough and the fibres break when may vary depending on what fibre the the hawser is bent. But a hawser that is hawser is made of. During high loads only marginally affected by UV and has in the hawse or the winch drum, heat a furry surface can even be stronger than damage may occur inside the hawser an unaffected hawser. This is because the that is not always visible on the outside.

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