General Product Design Features

The Sea Catch Toggle Release is a new quick release device combining an old and proven four-point-toggle-linkage principle with computer-generated parts precision-cut by water jet from aerospace-grade stainless steel plate. These parts are welded together and connected by pivot pins to form the device. The first Sea Catch products were put into commercial use in November, 1994.

Product Material / Specifications - All Sea Catch parts are longitudinally cut from aerospace-grade 15-5 PH stainless steel plate. Its Rockwell hardness is between 34 & 42 after heat treat. Precipitation hardening stainless steels are chromium-nickel alloys. Pins are turned from 15-5 stainless steel round stock. All material is aircraft quality, grade XM-12 and meets the following specifications: AMS 5659, BMS 7-240, AMS 5862, and ASTM A564. For more information about 15-5 PH and other such materials, visit Metallurgical Consultants.

Manufacturing - McMillan Design, Inc. is the only manufacturer of the Sea Catch product. It is contracted to be made and assembled at Cutting Technology, Inc. and GMS Metal Works, Inc., both of Auburn, WA. Manufacturing processes follow rigid, national-level standards of precision-jet cutting, machining, welding, heat treating, and final assembly.

Welding, Heat Treatment, and Lubrication - All welding is with 17-4 SS wire only. All welded parts and pins are thoroughly cleaned and heat treated to H-1025 which increases the rating of the welding by 20-30% and the parts by 15 %. Heat treating also results in improved mechanical, fatigue and corrosion properties across the board. Final assembly of the product includes the light application of a lubricant to each pin such as AQUA Lube, to protect the pin surfaces from pitting during extended marine use and aid in smooth mechanical function of the device. For higher capacity units, an NLGI #2.5 grease with moly added and a temperature range from 0 to 425F is applied. Customer may request lubrication material of choice.

Product Testing and FEA - Initial prototype testing of the Sea Catch TR7 was conducted on September 2, 1994 by the testing engineering staff at West Coast Wire Rope & Rigging, Inc. in Seattle and was witnessed by the owner. Multiple pulls of break load occurred on three units. The final unit, made from 17-4 stainless plate, was proof loaded to 5,000 lbs and released, then to 10,000 lbs and released under load, and finally, pulled to ultimate destruction at 35,210 lbs. The effort to release the device at both the 5,000-lb and the 10,000-lb loads was about the same, around 40 lbs. Certificate of Testing No. 05611A was then issued to document this test.

-FEA was conducted in April, 1996 on the Sea Catch TR7 jaw portion, the critical, load-bearing portion of the device. This analysis was conducted to confirm the load carrying capacities of this design. The primary area of concern, as demonstrated by the lab test-to-failure, was the pin area of the jaw. All recommendations resulting from the FEA are followed in the production of each Sea Catch product.

-Product testing in the field continues throughout the world and includes heavy marine use at ocean depths of 2,500 feet and dependable cyclical uses of well over 5,000 releases over a three-year period.

Quality Control - The manufacturer assumes the responsibility of inspecting each production unit for function, specifications, and appearance. Units not meeting the above rigid requirements are rejected.

Normal Certification options are available on a case by case basis as follows: 

1. Proofload Test and Certificate: In this test the actual device is serial numbered and pull-tested to twice the Safe Working Load, then held for one minute. Test Certificate is issued after the device is found with no damages or deformations. One-time set up cost is US$200.00 plus US$45.00 per unit tested.

2. ABS Certificate: For this cert, an ABS (American Bureau of Shipping) representative witnesses the actual device being proofload tested as described above. Both the Test Certificate and ABS Certificate are issued. An additional cost is assessed for ABS cert per unit.

Contact jmcmillan@seacatch.com for further details.