Fort Randall Custom Shallow - Water Boat and Trailer

1 DETAILED SPECIFICATION SHEET SPECIFICATION FOR CUSTOM SHALLOW-WATER BOAT: FORT RANDALL PROJECT 1. Scope Vendor shall provide and deliver to the Fort Randall Project a custom boat and trailer that will allow the Corps to navigate the shallow waters of the middle Missouri River. Vendor is responsible for all labor, tools, transportaƟon, material, equipment, and supervision necessary to construct the boat and trailer. Vendor must be registered with SAM (www.sam.gov) and have a DUNS number. All fabricaƟon shall conform to the technical specificaƟons detailed below. This solicitaƟon package includes this Unabridged Detailed SpecificaƟon and Appendix A: Visual Reference Drawings & Examples. Together, these documents illustrate the intended layout, geometry, fabricaƟon methods, and final appearance of key custom components. The drawings and pictures in Appendix A are provided to clarify design intent and provide a high-level project visual. However, the exact dimensions, materials, and fabricaƟon methods mandated in this Detailed SpecificaƟon shall govern. The builder is responsible for noƟfying the ContracƟng Officer’s RepresentaƟve (COR) of any perceived conflicts prior to bidding. 2. Technical SpecificaƟons The following specificaƟons outline the structural, mechanical, and layout requirements for the vessel. 2.1 Vessel Overview & Hull SpecificaƟons Length Overall (LOA): 24 feet (Float pods not included in this length) BoƩom Width: 72 inches Beam (Gunnel Width): 96 inches Side Wall Height: 27 inches Transom Height: 27 inches Hull Shape: Modified V-bow tapering to a flat boƩom Occupant & Carrying Capacity: Vessel design, stability, and seaƟng layout must safely accommodate a carrying capacity of 6 to 8 occupants. -- 1 of 22 -- 2 Hull BoƩom, Tunnel, & Transom Thickness: Minimum 0.190-inch (3/16“) 5086-H116 Aluminum Plate. Transom must include a 0.250-inch (1/4”) 5086-H116 doubler plate in the engine mounƟng zone. Sides, Console, & Pods Thickness: Minimum 0.125-inch (1/8") 5052-H32 Aluminum. Floor, Raised Decks, & Bench SeaƟng Thickness: Minimum 0.125-inch (1/8“) 5052-H32 Aluminum. All interior walking surfaces (main floor, raised casƟng deck, aŌ decks, and steps) must be fabricated from 0.125” Aluminum Diamond Plate (Tread-Brite) to ensure rigidity without oil-canning. 2.1.1 Longitudinal Stringers Floor Stringers (The Tapered Track): Four (4) conƟnuous 3”x3”x0.250” 6061-T6 T-Bars running the length of the hull. Two of these are “flanking stringers.” These flanking stringers must not run parallel to the centerline. They must angle inward to precisely track and hug the exact 1- inch-per-foot taper of the tunnel‘s outer verƟcal walls (starƟng at 28“ wide at the forward iniƟaƟon point and converging to 22” wide at the transom). The tunnel’s verƟcal side walls shall weld directly and conƟnuously to the inward-facing side of these flanking stringers. The other two outer floor stringers shall be spaced midway between the tunnel and the outer chines. Tunnel Roof Stringers (The Converging Spine): Two (2) 2”x2”x0.250” 6061-T6 Angle stringers shall run longitudinally along the 8” elevated tunnel roof to prevent upward flex under hydraulic pressure. To maintain equal support across the tapering 14.5" flat roof, these two roof stringers must also angle slightly inward from front to back, remaining equidistant from the tunnel’s 45- degree diagonal corner plates along the enƟre 72-inch length of the tunnel. Mandatory In-Process InspecƟon: See SecƟon 6.3, Hold Point 1 for inspecƟon and sign-off requirements prior to main deck installaƟon. 2.1.2 Transverse Ribs (The Intercostal Grid) Material & Spacing: 0.190“(3/16”) formed C-channel or 0.250“ (1/4”) 6061-T6 Angle, spaced twelve (12) inches on-center throughout the enƟre boƩom. Intercostal FabricaƟon: Ribs must be installed using the intercostal method. The longitudinal stringers must remain conƟnuous and uncut. The transverse ribs must be cut into separate segments, fiƩed Ɵghtly between the longitudinal stringers, and have their verƟcal ends welded solidly to the verƟcal webs of the T-bars to create an interlocking 12“x12” structural grid. Tunnel IntegraƟon: Rib segments must Ɵe directly into the tunnel side-walls and be physically bridged over the top of the tunnel roof to Ɵe the port and starboard halves of the hull together. -- 2 of 22 -- 3 Welding & Drainage: SƟtch welding (e.g., 2“ weld, 4” skip) must be used where the ribs meet the flat hull skin to prevent warping the 72-inch boƩom. All rib segments must feature half- moon weep/limber holes at the boƩom corners to allow water to flow to the bilge. 2.1.3 Transom Knee Braces (Engine Torque Support) QuanƟty & Purpose: Four (4) heavy-duty braces designed to support the transom against the extreme torque and leverage of the 150 HP engine and 6-inch setback jack plate. Material: 0.250” (1/4”) 5086-H116 plate. The long diagonal edge of each brace must feature a 2-inch-wide welded flange cap (creaƟng a rigid I-beam/T-beam profile to prevent the plate from buckling under compression). Dimensions & Placement: The verƟcal legs (~24“) shall weld directly to the inside of the transom bulkhead. The horizontal legs (~24”-30“) must land directly on top of the conƟnuous 3”x3" longitudinal floor stringers (never on bare hull skin) to drive the engine thrust forward into the hull. Layout: Two braces shall directly flank the tunnel (landing on the flanking stringers), and two shall sit on the outer longitudinal stringers. Stress Relief: A 2-inch radius “mouse hole” must be cut at the 90-degree corner of each brace to bridge over the transom-to-floor weld seam, prevenƟng intersecƟng weld fractures. 2.1.4 AddiƟonal Hull Components Side Frames: Tied to boƩom ribs with 0.190" chine gussets and running up the flared side walls to the gunnel on every other rib (24-inch centers). Bow Chevrons: Two to three 2”x2”x1/4” 6061-T6 Angle chevron (V-shape) braces in the forward 5 feet. AnƟ-Slide Ribs: Two 2-inch angle-aluminum rib…