A1 motorway - Incremental launching of multiple viaducts Gliwice, Poland 2010-2011 | construction methods | on-site Key challenges: Two viaducts launched connected longitudinally from single casting yard. Combined length 880m and total weigh of 20 000t. 5 viaducts launched simultaneously. 165m of new deck every week. 100t. of PT installed per week.