Rope manufacturer Samson along with the Alaska Maritime Prevention & Response Network (Alaska Network) and Norwegian Coast Guard have completed trials of its EVATS emergency towing system.

When a vessel becomes disabled at sea and requires the services of a towing vessel the task of making the actual towing connection can be one of the most challenging parts of the operation. The tug will usually prefer to use its own towline along with the various connecting elements, most tugs equipped with a towing winch with either a man-made fibre or steel wire rope main towline.

Particularly in foul weather, making the towing connection can be fraught with danger. The process will require the tug to maintain position very close to the ship’s bow or stern for the passing of a heaving line, progressively heavier messengers and pennants being hauled aboard the ship, ideally using its powered deck machinery, before the actual towing connection can be made fast on board the ship.

On some occasions manpower on the ship may be limited (or even non-existent) and a lack of power may require the use of ‘handraulics’ to handle the lines and Samson addresses these problems with its patented Emergency Vessel Attachment & Towing System (EVATS).

EVATS can be rapidly deployed from the ship’s deck, helicopter or rescue vessel and is made up from various elements and components designed to have near-universal compatibility with ships mooring arrangements with multiple attachments points on the disabled ship. The system allows the tug to maintain a safer distance from the ship, the retrieving line incorporating a pilot anchor to stream the hawser to windward when deployed.

The system has now been tested in a live sea trial to further validate its performance. The exercise was led by the Norwegian Coastal Administration in a fjord southwest of Sortland, Norway during a scheduled training exercise.

Following a briefing, Samson, Alaska Network and Kystvakte (Norwegian Coast Guard) personnel and crew members commenced the sea trial involving the Norwegian Coast Guard vessels KV Barentshav and KV Sortland using the EVATS system in an on-water towing configuration for the first time. The purpose of the exercise was to demonstrate the enhanced capabilities of the system.

Since most vessels are not fitted with dedicated strongpoints and emergency towing arrangements the EVATS system is designed for near-universal compatibility accounting for known difference in vessels. One well-known element of other emergency towing systems is the Smit Towing Bracket which is generally welded to the ship’s deck and provides a strongpoint for connecting the towline but of course still requires the presence of and establishment of the towline elements themselves.

The primary strength members, the synthetic rope designed by Samson, allow for easy handling, quick deployment and low system weight and during the test the team was able to successfully deploy, test and recover the EVATS. Tension gauges on the tow winch of the towing vessel indicated 25+ metric tonnes in tension mode and 50+ metric tonnes in brake mode.

The hawser bushing, the component connecting the main hawser with the bridle elements, described as “a unique and critical component of the system” was reported as having slid well, with the load-sharing features’ effectiveness clearly demonstrated.

Recovery and inspection of the system showed no abrading or damage that would undermine immediate reuse of the system. Following completion of the exercise a detailed debrief was held with the test team concluding that the exercise was a success, it being stated “the EVATS system demonstrated itself as effective and practical, far exceeding expectations of the Samson and Alaska Network test team.

The EVATS system development team included Glosten, a Seattle, WA-based marine engineering firm, with technical support from Samson, input from salvage engineers and the Alaska Network who provided funding and overall guidance on the project.

Buddy Custard, president and chief executive for the Alaska Maritime Prevention & Response Network stated: “Congratulations to the entire team in successfully field testing the EVATS! This is a significant milestone in demonstrating to the maritime community how this system, using cutting-edge rope technology, enhances emergency towing safety and effectiveness under the very unpredictable and hazardous nature during an emergency tow of a distressed ocean-going vessel.”

By Peter Barker