Page 36: of Marine News Magazine (October 2014)

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SPECIALTY WORKBOATS design goal for our Four Leg RIB Boat Slings was to elimi- nate wire rope plus reduce weight, electronic interference, corrosion, wire fi sh hooks and to engineer an overall safer system. The stainless lift ring with hand holds is coupled with four Aracom T Maxijacketed rope legs. We know that over engineering can be crucial to mission success so each rope leg is capable of carrying 34,000 lbs (15,300 kg).”

Riverine Environments & Challenges

Riverine craft are specifi cally designed and manufac- tured for estuary, river and shallow water operations. In the extreme brown water environment, a poorly designed vessel can impact on mission effectiveness and crew safety.

Generally, a speed of 30+ knots is common for riverine craft. Greater speed and armor can give tactical advantages but this often means twin engines and a heavier craft, since weight is a critical concern for any shallow water vessel.

Modular ballistic protection enables the use of armor dur- ing specifi c missions.

By combining extensive background of operational ex- perience with task-specifi c design Massachusetts based spe- cialist boat builder ReconCraft have developed vessels for challenging applications. ReconCraft COO Joe Silkowski said, “Depending on the size of the vessel and the project- ed operating environment, deadrise angle between 5 and 10 degrees are the most common for riverine craft. We de- velop some models up to 17 degrees with a variable dead- rise if there’s a need for both coastal and riverine capabili- ties from the same platform, for example transiting from a river mouth through the coastal area to another river.”

In conventional naval architecture, chines and spray rails are incorporated for grip on the water at planing speed.

Silkowski adds, “This is very much dependent on how the vessel is desired to perform in shallow water. For example, some operators prefer some amount of slide when turning the vessel and aggressive chines can hinder this. There is no one size fi ts all solution to riverine craft in terms of hull design and performance.”

Many lessons learned from riverine will translate well to melting ice regions as they present similar hazards to navigation as those encountered in a river system. Use of ultra hard wearing keel pads and hull coatings allows craft to slide over obstructions and areas with little water. These features enable operators to patrol in previously inacces- sible areas and extend the working life of the craft. The ad- vantages with utilising successes from other sectors include short timelines from tender to build, and COTS (Com- mercial off the Shelf) procurement.

Rising Up: Hovercraft & Hydrofoils

Small hovercraft have a growing role to play in search and rescue, commercial and military operations around the world. Hovercraft can be a practical proposition for operations in areas inaccessible to other vehicles includ- ing frozen water, mud fl ats, intertidal areas, shallow rivers and fl ooded inland areas. Perceived to be environmentally sound, as they don’t exhaust into the water, create no wash and do not disturb the sea bed, they are also economical and do not endanger marine animals as there is no pro- peller in the water. UK manufacturers Griffon Hoverwork and Flying Fish Hovercraft and have formed a manufac- turers association to develop the Hovercraft Code of Prac- tice (HCoP). The objective is to address the differences in operating procedures, construction and usage relevant to these unusual vehicles.

The Griffon 380TD is a 22’-4” diesel powered hov- 4 UK RNLI Inshore Rescue Hovercraft

Credit Grif f on Ho v er w orks

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