Ropes made with Dyneema®, ultra-high molecular weight polyethylene (UHMWPE), are proving a safe and secure alternative to steel wire rope for connecting barges and vessels in ‘push combinations’ working on inland waterways.
In push combinations, the barge and the unpowered vessel in front of it have to be tightly lashed together to prevent any articulation. Traditional steel wire rope (SWR) is not only labour intensive, but can also be dangerous for the crew if individual strands snap, creating so-called fish hooks. The hard and heavy SWR can also damage decks, bollards and other equipment, leading to costly repairs and paint jobs.
The push combination ‘Norma’ has been operated by Captain Grinwis and his crew on the river Rhine between Basel and Rotterdam since July 2007. With a total length of 179m, a width of 11.5m and a capability of carrying loads of up to 336 TEU (20ft equivalent units), it uses four ‘Eurolest’ ropes made with Dyneema by Lankhorst Ropes in Sneek, the Netherlands. Captain Grinwis and his crew – all of whom have had a lot of previous experience with SWR on other push combinations – say they are extremely satisfied with the new solution offered by ropes.
The connecting ropes made with Dyneema are seven times lighter than SWR, yet offer greater strength at a comparable diameter, resulting in higher handling speeds and the involvement of fewer crew members. The ropes float on water and do not damage deck equipment, considerably reducing the need for repairs and paint jobs.
“Handling the ropes with Dyneema is very simple,” says Captain Grinwis. “Connecting the barge can take just five minutes; in some cases disconnecting can take only two. Moreover, it requires just one crew member to do the job and there is no risk of fishhooks.”
The barge needs to be bound very tightly to the push vesseI in order to avoid unwanted swirling of the barge and to maintain sailing speed. Because of their very low elongation, the lines with Dyneema offer the advantage that once connected, tension within the ropes needs hardly any readjustment. “An occasional single click of the winch is often all that is required,” says Grinwis.