Editing Dredging (section)

====Trailing suction====
A trailing suction hopper dredger (TSHD) trails its suction pipe when working. The pipe, which is fitted with a [[dredge drag head]], loads the dredge spoil into one or more hoppers in the vessel.
When the hoppers are full, the TSHD sails to a disposal area and either dumps the material through doors in the hull or pumps the material out of the hoppers. Some dredges also self-offload using drag buckets and conveyors.{{citation needed|date=July 2018}}

{{asof|2008}} the largest trailing suction hopper dredgers in the world were [[Jan De Nul]]'s ''Cristobal Colon'' (launched 4 July 2008<ref>{{cite web|url=http://www.sandandgravel.com/news/article.asp?v1=11114 |title=Jan de Nul's mega trailer Cristóbal Colón launched - Dredging News Online |publisher=Sandandgravel.com |date=7 July 2008 |access-date=14 June 2013}}</ref>) and her sister ship ''Leiv Eriksson'' (launched 4 September 2009<ref>{{cite web|url=http://www.sandandgravel.com/news/article.asp?v1=11221 |title=Keel-laying ceremony for Jan de Nul's Leiv Eiriksson held - Dredging News Online |publisher=Sandandgravel.com |date=1 September 2008 |access-date=14 June 2013}}</ref>). Main design specifications for the ''Cristobal Colon'' and the '' Leiv Eriksson'' are: 46,000&nbsp;cubic metre hopper and a design dredging depth of 155&nbsp;m.<ref>{{cite web|url=http://www.jandenul.com |title=Jan De Nul Group |publisher=Jandenul.com |date=7 June 2013 |access-date=14 June 2013}}</ref> Next largest is ''HAM 318'' ([[Van Oord]]) with its 37,293&nbsp;cubic metre hopper and a maximum dredging depth of 101&nbsp;m.