HDXLPE (before/after) - TNT - FRP (before/after)

Flex-Ride Night Raider Plastic Boat: Explosives testing reveals energy absorbing superiority to FRP.

PRLog (Press Release) - Jan 09, 2012 -
ABSTRACT: Historically, boats made of wood, fiberglass or metals are rigid, providing no occupant protection from repeated wave impacts. The Widmer plastic hull flexes and absorbs impacts produced at high speeds in rough water: the impact G-forces are absorbed by the hull instead of directly translated to the occupants. The Widmer boat hull is double-wall rotationally molded out of high density cross-linked polyethylene (HDXLPE). It employs Widmer’s patented kiss-offs for strength. The kiss-offs are designed to produce a double-walled cross-section in high impact areas such as the hull bottom. Additional benefits of this polyethylene material are its toughness, the ability to absorb blunt impacts from rocks/debris, abrasion resistance and puncture resilience. Furthermore, HDXLPE resists cracking, does not corrode, does not need paint – and this material floats!

The ability of Widmer's hull to flex and absorb energy was recently tested with TNT, blasted by ATF Federal Explosive Licensed Phil Miller from Southwest Explosives, 40294 Pinewood Ct., Browerville, MN 56438 (Phone 218-639-3273). The tests were performed behind Widmer's facility in Staples, MN on Friday, January 6, 2011. Phil used 5.3 oz sticks of TNT with performance characteristics of 24,000 ft/sec detonation speed and 230 kb (3.335 million psi) of detonation pressure. Charges were placed six inches away from the rotationally molded hull and six inches away from fiberglass for comparison. The results were quite impressive. The Widmer hull absorbed and dissipated the energy without any loss of material integrity. The fiberglass failed under pressure. The photo shows before and after detonation images of Widmer's plastic hull on the left and fiberglass on the right. The fiberglass "after" explosion image is cropped out (larger area) because a significant section was destroyed.

This test demonstrates the survivability of boat hulls made from different materials when subjected to explosives. When an explosive ordinance (shell/mine) explodes in the vicinity of a military boat, the concussive forces placed upon the hull and occupants can range from injuries to hull rupture and/or failure. When craft survivability is paramount to mission success, an explosive resistant hull from Widmer is the solution.

The Flex-Ride Night Raider is the culmination of Stanley Widmer’s lifelong search for a better boat hull. Stanley’s boat racing experiences, marine industry experience and hull development are thoroughly covered in his book The Journal of a Businessman. Visit http://www.stanleywidmerassociatesinc.com/newspressrelea ... The boat’s initial success has prompted interest from military, law enforcement and Coast Guards worldwide. Commercial applications are also being designed and reviewed.
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Lightweight Shock Mitigating Chair

Lightweight rugged suspension chair: The art of Widmer's shock mitigating design.

FOR IMMEDIATE RELEASE
PRLog (Press Release) – Jul 07, 2011 – The "Lightweight Seat", (patent pending - Widmer) is designed for harsh environments where the occupant is subjected to substantial random and/or sudden dynamic forces, e.g. buffeting, pounding, bouncing and the like caused by high G-loads resulting from sudden impacts, shocks, or jarring. Examples include the seats suitable for high-speed, rugged marine craft and employ the term “shock mitigating seats”. The occupants of such seats must withstand extreme amounts of applied force while impacting waves at high speeds. At the same time, weight is always a concern in high-performance vehicles and, of course, the seat must be comfortable (and, typically, rotatable and/or adjustable vertically and/or horizontally). The seat proper is mounted on a pedestal and base which has a permanently or temporarily inflated air bag to provide cushioning and, in the preferred embodiment, approximately 4 inches of vertical clearance to absorb forces. The seat pivots around the vertical axis. Two rings help maintain the performance of the air bag.

In general, the components of the base and seat are rotationally molded polymers and marine environment suitable metals, or flexible polymers in the case of the air bag. Materials are selected based on a sufficient balance of cost, strength, weight, ease of handling, and the like. Preferred molding materials for high performance watercraft and similar applications are high density cross-linked polyethylene (HDXLPE), which are commercially available. Other materials known to be suitable for rotational molding may also be used, including the less costly (and less strong) high density polyethylene (HDPE) which is also commercially available. The air bag is generally similar to that described in U.S. Patent 4,560,145 (Widmer). In general, the air bag is an inflatable member made of a flexible material, having a uniform thickness and comprising a plurality of annular sections. The sections sequentially taper in diameter to form a generally pyramidal shape. There is also a ring, one between each pair of adjacent sections, extending around the outside of the air bag to provide annular support between the sections and to control bulges and stretching. The rings provide support without the danger of the inflatable member “thinning” in the ring area when inflated. “Thinning” of the inflatable member could result in a rupture or bulge. Each ring has a circular cross section. The air bag is inflated by conventional means. In terms of materials, the air bag is constructed from polymer such as a suitable elastomer, e.g., a vinyl plastic of about durometer on the A scale. The rings are made of elastic or elastomeric material, such as neoprene rubber, for example in the range of 35 to 50 durometer. In the preferred embodiment illustrated in the Figure, the air bag provides 4 inches of cushioned vertical travel. The seat is attached by way of the pedestal to the hull or other structure using holes or other features supporting connection.

The lightweight seat is particularly suitable for use with the Widmer Flex-Ride Night Raider, a boat having a plastic hull which flexes and absorbs impacts produced at high speeds in rough water because the impact G-forces are absorbed by the hull instead of directly translated to the occupants. The lightweight seat disclosed here further absorbs such forces instead of translating them to the occupants, and it does so at a substantial reduction in weight, which is a critical parameter in the design of an effective boat of this type and for this application. Visit http://www.widmerboat.com for details.

Sliding Truss

Flex-Ride Night Raider Plastic Boat: The art of Widmer’s internally molded truss.

FOR IMMEDIATE RELEASE
PRLog (Press Release) – Jun 14, 2011 – Rotationally molded plastic articles are typically limited to smaller sizes based upon the deflection characteristics of the material itself. This is why rotationally molded plastic parts have not been made larger than 25 feet. On the other hand, steel is very rigid. It's also very heavy, expensive and it corrodes. We are developing the technology to combine the strength of steel with the benefits of plastic. We have designed an internal metal truss system that can be molded inside the plastic part for exceptional strength and resistance to buckling or twisting.

In general, as the dimensions of a rotationally molded product increase, the amount of shrinkage increases, and also the amount of deflection (sag) in the finished product increases. The compressible truss addresses both of these problems by adding to the strength and rigidity of the finished product. The thermoplastic materials used in rotational molding are known to cause the molded articles to shrink upon removal from the mold by approximately 5% or less, typically approximately 3% in the case of polyethylene, the most common material. However, once shrinkage is complete, no further shrinkage or expansion is expected under normal circumstances. It is important to remember that due to the rotational molding process, all exposed surfaces of the molded-in truss will be covered with molten plastic material that will cool to direct contact with the truss. Thus, once the molded article has cooled and the compressible truss has contracted, the resulting article is extremely strong not only because of the inherent strength of the truss itself, but also because of the significant amount of surface area represented by the polymer/truss interface. Once the compressible truss is assembled to the article, the combination has significantly greater strength (from the truss) and may be relatively large (such as the 7 meter Navy test boat we produced http://www.widmerboat.com ) yet when it is exposed to substantial external forces, the compressibility of the truss keeps the assembly from being too stiff to absorb the applied forces.

Preferred applications are boats which are required to withstand blast, impact, and/or structural loads when they are used to blow up mines, when moving through rough seas at high speed and/or when they are hoisted aboard another structure (e.g. another vessel or a platform). Standard hull designs currently used by naval forces and others requiring such performance are made of aluminum or fiberglass. Aluminum hulls do not withstand successive blasts well, and fiberglass hulls break when moving through rough seas at speeds as low as 30 knots. The watercraft described here are more flexible (less breakable) and thus more resistant to impacts from blasts and waves, unsinkable, resilient to small arms fire, low maintenance and cost effective to manufacture. Although the principles above are described and illustrated primarily with respect to boats and other watercraft, docks, and the like, such articles are only examples. Components of structures could also be such articles. For example, walls or roofs of buildings and similar structures are possible, as are portions of containers, transportation vehicles, and the like. The strength and reduced weight provided by the sliding truss system permit the manufacture and use of structures previously believed to be "too big" for manufacture and use. Examples include military or civilian bridge structures. Similar examples include load bearing floors, walls, and roofs for low cost housing, and deck planks. Further examples include the connectable sections of floating platforms which could be as large as 12 feet by 50 feet. These platforms take advantage of the inherent buoyancy of hollow molded plastic articles yet because of the sliding truss(es) within them, they are strong enough to support substantial weight. Such platforms could easily be stacked or otherwise arranged to be joined together as required. They could be used as modular floating deck platforms in shipyards, ports, and other similar installations involving large marine vehicles or equipment. In any embodiment, it is possible to include molded-through or molded-in holes or channels or other features for drainage, or for attachment of other structures, accessories, etc.

Rotomolded Kiss-off

Flex-Ride Night Raider Plastic Boat: The art of Widmer’s rotationally molded kiss-offs.

FOR IMMEDIATE RELEASE

Stanley Widmer Associates, Inc. has just been announced a Semi-finalist in the 2011 Minnesota Cup Contest.

Link: http://www.breakthroughideas.org/page/1/MN-Cup-2011-Semifinalists.jsp

The Northwestern June 25, 2010

"Oshkosh native developing plastic boat for Navy"