Rino Bošnjak

Procjena rizika pomorske nezgode za akvatorij luke Šibenik

Sibenik je velika i jedna od najstarijih i najbolje prirodno zasticenih luka na hrvatskoj obali Jadrana. Gradska luka je smjestena u potopljenom uscu rijeke Krke. Ograniceni raspoloživi manevarski prostor unutar gradske luke, smjestaj novog putnickog terminala te dijela luke za prekrcaj razlicitih vrsta tereta smanjuje siguran prostor za plovidbu i privez/odvez trgovackih i putnickih kruzerskih brodova. Prilazi luci Sibenik sa otvorenog mora, a posebno plovidba kanalom sv. Ante kao i manevriranje unutar akvatorija gradske luke za svakog pomorca predstavlja poseban izazov. S aspekta sigurnosti navedene okolnosti znacajno pridonose povecanju prijetnju od moguce pomorske nezgode. Stoga se ukazala potreba da se izvrsi procjena mogucih prijetnji pomorskih nesreca u podrucju sibenskog kanala sv. Ante. Za određivanje prijetnji pomorske nezgode razvijen je model određivanja prijetnji temeljena na kvalitativnoj metodi Rangiranja prijetnji. Svaka pomorska nezgoda u zatvorenom podrucju kanala sv. Ante i gradske luke Sibenik može imati nesagledive posljedice na cjelokupne privredne i svekolike druge aktivnosti luke Sibenik. Kanal Sv. Ante predstavlja jedini ulaz u srednjodalmatinski grad Sibenik i za međunarodni promet otvorenu sibensku luku. Zbog svog izgleda, duljine koja ne ide pravocrtno, potrebno je cesto mijenjanje kursa u kracim vremenskim intervalima. Sirina kanala na pojedinim mjestima je mala i problematicna, a zbog morskih struja i povremeno jakog vjetra, kanal je s aspekta sigurnosti plovidbe jako težak za navigaciju. Stovise, mimoilaženje brodova preko 50 BT-a unutar kanala je opasno. Mogucnost sudara, nasukanja i/ili potonuca veceg broda tijekom tranzita kroz kanal sv. Ante u krajnjem slucaju može dovesti do potpunog zatvaranja pomorskog putnickog i teretnog prometa za luku Sibenik. Stoga je od izuzetne važnosti izvrsiti procjenu prijetnji sudara, nasukanja i/ili potonuca broda u akvatoriju luke Sibenik.

Operability Guidelines For Product Tanker In Heavy Weather In The Adriatic Sea

Abstract This paper presents operability guidelines for seafarers on a product tanker which navigates in the Adriatic Sea during heavy weather. Tanker route starts from the Otranto strait in the south to the island Krk in the north of Adriatic Sea. Heavy weather is caused by south wind called jugo (blowing from E-SE to SS-E, sirocco family). Operability guidelines are given based on an operability criteria platform for presenting ship seakeeping characteristics. Operability criteria considered in this paper are propeller emergence, deck wetness and bow acceleration of a product tanker. Limiting values of mentioned criteria determine sustainable speed. Heavy weather is described by extreme sea state of 7.5 m wave height. Wave spectrum used in this paper is Tabain spectrum which is developed specifically for Adriatic Sea. Seafarers approach of decisions making in extreme weather is also shown and servers as a guideline for further research of the authors.

Estimation of Travel Times on Signalized Arterials

This paper describes procedure for estimation of travel time on signalized arterial roads based on multiple data sources with application of dimensionality reduction. Travel time estimation approach incorporates forecast of transportation nodes impendence and travel time on network links. Forecasting period is two hours and the estimation is based on historical data and real time data on traffic conditions. Travel time estimation combines multivariate regression, principal component analysis, KNN (k-nearest neighbours), cross validation and EWMA (exponentially weighted moving average) methods. When comparing estimation methodologies, relevantly better results were achieved by KNN method than with EWMA method. This is true for every time interval considered except for evening time interval when signalized arterial roads were uncongested.