One of our interns obtained his Mechanical Engineering degree at the Avans University of Applied Sciences with this graduation assignment. This assignment consists of a design of a containerized launch and recovery System (LARS). The design allows easy transportation and improves applicability and integration of a LARS which eventually saves time and money.
A Launch and Recovery System (LARS) is often used to handle a certain piece of equipment using a hinged movement and to lower it into the water with a winch. The piece of equipment can be a ROV* but also a diving basket which put divers into the sea.
Disadvantage of existing designs
Existing designs of a LARS often consist of separate components that together make up the system. Since the components are placed separately, the components must deal with interaction forces between components. This can be resolved by placing all the components on one common skid. Another disadvantage of these separate components is that the placement of a LARS is a time-consuming process. This long lead time has the consequence that the vessels will be stationary for a long time, which entails the necessary costs. This is not desirable for the installer, and especially for the customer.
Improving applicability and integration
To better serve customers, Saltwater has been looking for a general solution that improves the applicability and integration of a LARS. The LARS must be suitable for placing a piece of equipment outside the vessel and lowering it into the water by means of a winch. Generally applicable means that the LARS can be applied to various vessels and fulfil its function to deploy a ROV or diving basket.
To reduce the complexity of the forces, it is important that the components of the system are fixed in respect to each other. The design must be relatively easy to apply to various vessels to reduce installation time in port. Since users of a LARS can be located all over the world, it is important that the LARS is based on a standard container frame which makes it easy to transport.
*A ROV is an underwater robot that is controlled from a control room. ROVs are available for various purposes such as carrying out inspections, general work, and the burial of cables and pipes. In many cases, ROVs replace divers because they can operate at great depths.
The LARS complies to DNVGL-ST-0378 Standard for offshore and platform lifting appliances, DNVGL ST-E273 2.7-3 portable offshore unit’s standard, NEN-ISO 668, NEN-ISO 1496-5 and CSC.
Saltwater has designed a LARS unit that incorporates an A-frame, winch and TMS/ROV combination. All incorporated into a 20-foot container. The unit can be upgraded with a secondary winch to operate as a diving basket LARS.