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| Quantity: | |
|---|---|
DF-497
HEE
CAST STEEL COLSED CHOCK
| MODEL NO. | A | B | C | D | E | WT.(lbs) |
| DF-497 | 19 3/4" | 8" | 4" | 6 3/4" | 6" | 84 |
| DF-480 | 27 3/4" | 12" | 6" | 10 1/8" | 9" | 191 |
| DF-490 | 36" | 16" | 8" | 13 3/8" | 12" | 455 |
The Cast Steel Closed Marine Chock sets the standard for secure rope management in demanding marine environments where rope containment and directional control are critical. As vessel operators face increasing challenges from extreme weather events and heavy seas, this closed-type chock provides superior rope retention compared to open designs, minimizing the risk of dislodgement during rough conditions . Constructed from ASTM A27 grade cast steel with a safe working load (SWL) of 800 kN (81.6 tons), the chock features a fully enclosed throat with a 14-inch diameter rope channel that accommodates synthetic and steel ropes from 40mm to 75mm in diameter. Its compact footprint (24 × 18 inches) makes it suitable for both deck and bulwark mounting on commercial cargo vessels, offshore supply ships, and coastal patrol boats.
The fully closed throat configuration features 360° rope enclosure with a smooth, radiused channel that prevents rope escape even during sudden load shifts or vessel roll exceeding 25° . The entry and exit ports include 15° flares that guide rope into the main channel while reducing abrasion. This design eliminates the "whipping" hazard associated with open chocks when ropes momentarily slacken.
Manufactured using lost-foam casting for dimensional precision, the chock achieves uniform grain structure throughout its 2-inch thick walls . The one-piece construction eliminates potential failure points, while heat treatment to 200 BHN hardness provides exceptional wear resistance. Critical stress areas around the mounting flange are reinforced with integral ribbing.
The chock receives a two-stage protective coating: a 120μm zinc-rich epoxy primer applied after sandblasting to SA 2.5 standards, followed by a 60μm aliphatic polyurethane topcoat . This system provides 1,800 hours of salt spray resistance per ASTM B117 testing. All surfaces in contact with mooring lines are polished to Ra 1.6μm finish to minimize rope wear.
The enclosed throat prevents ropes from jumping out of the chock during sudden load changes or vessel movement, eliminating the risk of line whip injuries to crew and damage to equipment . This feature is particularly valuable in storm conditions or during emergency mooring operations.
The polished channel with smooth radii prevents fiber degradation in high-performance synthetic ropes like Dyneema and polyester . The design avoids sharp edges that can cause internal fiber damage, extending rope service life by up to 30% compared to standard open chocks.
The Closed Marine Chock is certified to ISO 13713 standards for mooring fittings and meets SOLAS requirements for vessels operating in international waters . It is approved by major classification societies including ABS, DNV, and Lloyd’s Register.
Yes, the symmetrical design allows installation in both deck (horizontal) and bulwark (vertical) positions without compromising performance . The mounting flange includes 12 pre-drilled holes to accommodate different installation configurations.
Weekly inspections should check for rope wear patterns and debris in the channel . Monthly maintenance includes cleaning the rope path and inspecting coating integrity. Annual inspections should verify mounting welds and measure channel dimensions to detect excessive wear (maximum allowable wear is 5% of original diameter).
CAST STEEL COLSED CHOCK
| MODEL NO. | A | B | C | D | E | WT.(lbs) |
| DF-497 | 19 3/4" | 8" | 4" | 6 3/4" | 6" | 84 |
| DF-480 | 27 3/4" | 12" | 6" | 10 1/8" | 9" | 191 |
| DF-490 | 36" | 16" | 8" | 13 3/8" | 12" | 455 |
The Cast Steel Closed Marine Chock sets the standard for secure rope management in demanding marine environments where rope containment and directional control are critical. As vessel operators face increasing challenges from extreme weather events and heavy seas, this closed-type chock provides superior rope retention compared to open designs, minimizing the risk of dislodgement during rough conditions . Constructed from ASTM A27 grade cast steel with a safe working load (SWL) of 800 kN (81.6 tons), the chock features a fully enclosed throat with a 14-inch diameter rope channel that accommodates synthetic and steel ropes from 40mm to 75mm in diameter. Its compact footprint (24 × 18 inches) makes it suitable for both deck and bulwark mounting on commercial cargo vessels, offshore supply ships, and coastal patrol boats.
The fully closed throat configuration features 360° rope enclosure with a smooth, radiused channel that prevents rope escape even during sudden load shifts or vessel roll exceeding 25° . The entry and exit ports include 15° flares that guide rope into the main channel while reducing abrasion. This design eliminates the "whipping" hazard associated with open chocks when ropes momentarily slacken.
Manufactured using lost-foam casting for dimensional precision, the chock achieves uniform grain structure throughout its 2-inch thick walls . The one-piece construction eliminates potential failure points, while heat treatment to 200 BHN hardness provides exceptional wear resistance. Critical stress areas around the mounting flange are reinforced with integral ribbing.
The chock receives a two-stage protective coating: a 120μm zinc-rich epoxy primer applied after sandblasting to SA 2.5 standards, followed by a 60μm aliphatic polyurethane topcoat . This system provides 1,800 hours of salt spray resistance per ASTM B117 testing. All surfaces in contact with mooring lines are polished to Ra 1.6μm finish to minimize rope wear.
The enclosed throat prevents ropes from jumping out of the chock during sudden load changes or vessel movement, eliminating the risk of line whip injuries to crew and damage to equipment . This feature is particularly valuable in storm conditions or during emergency mooring operations.
The polished channel with smooth radii prevents fiber degradation in high-performance synthetic ropes like Dyneema and polyester . The design avoids sharp edges that can cause internal fiber damage, extending rope service life by up to 30% compared to standard open chocks.
The Closed Marine Chock is certified to ISO 13713 standards for mooring fittings and meets SOLAS requirements for vessels operating in international waters . It is approved by major classification societies including ABS, DNV, and Lloyd’s Register.
Yes, the symmetrical design allows installation in both deck (horizontal) and bulwark (vertical) positions without compromising performance . The mounting flange includes 12 pre-drilled holes to accommodate different installation configurations.
Weekly inspections should check for rope wear patterns and debris in the channel . Monthly maintenance includes cleaning the rope path and inspecting coating integrity. Annual inspections should verify mounting welds and measure channel dimensions to detect excessive wear (maximum allowable wear is 5% of original diameter).
