May 6, 2020
Dynamic Load Monitoring (DLM) launch their new 1.5m De-trenching grapnel to aid the offshore industry in recovering subsea products buried in the seabed up to 1.5m.
The Southampton based load cell and load monitoring company have been supplying the offshore industry with a variety of Grapnels, including Flatfish, Rennie, Gifford and Sandpoint grapnels for hire and purchase for over 15 years. Recently, DLM saw a gap in the market and today launch the new 1.5m De trenching grapnel, designed and developed by DLM engineers.
The Grapnel is manufactured from high tensile steel, suitable for withstanding the harsh offshore environments. In order to further test the structure and material of the grapnel, finite element analysis was performed during the design phase, utilising DLM’s Solidworks 3d design suite. This simulates the various stresses and strains acting on the grapnel in a variety of different seabed conditions and allowed for optimisation of the design.
The Grapnel itself is scissor shaped at one end, which is designed to break the surface of the seabed and fitted with stabilising bars at the other end, to assist its dynamics and balance in the water column, while also for use in the seabed. In addition, there is an option to fit two Tyne’s if required either side of the grapnel, Tynes are removable and fitted with wear tips at the end, prolonging Tyne life.
The grapnel, which has recently been shipped to a customer in Asia for an offshore project, has been designed to withstand tow tensions of up to 15t. It has a built in shear pin rated to a breaking load of 15t which shears and protects the tow line and the Tyne if tension is exceeded beyond this point.
The De trenching Grapnel is typically used in conjunction with DLM’s Saddleback monitor, which measures the line tension on a cable when being towed. When set up on a ship’s deck, the Saddleback will measure the tension on the tow cable and a spike will then indicate that the cable has been caught by the de trenching grapnel.
Martin Halford, Managing Director comments ‘DLM have been working alongside the offshore industry for many years. We speak to many customers regarding their requirements and it soon became apparent that there was a need for recovering out of service cable at greater burial depth. With our in house design capabilities and our manufacturing background, we put our heads together and developed the 1.5 De trenching Grapnel.’
‘Our dynamic and dedicated design team are always keeping abreast of changes in the industry and coming up with new innovated ideas to support offshore projects. Our future plans consist of increasing the penetration depth by designing a new larger Grapnel. Furthermore, we have the option to fit load pins and load monitoring equipment on the grapnel and acoustic packages, which transmit a load signal to the surface along with the condition.’