LARS - Diver Launch & Recovery Systems

Diver Launch and Recovery Systems (LARS)

A Launch and Recovery System, also known as LARS, is a piece of equipment that subsea and marine companies use. They’re designed to get Commercial Divers and subsea equipment into and out of the water quickly and safely.

The main features of a Launch and Recovery System are:

• Base Skid
• A-Frame (so named for its shape)
• Guide Weight
• Diving Basket / Cage
• Twin Pump / Motor Hydraulic Powerpack
• Man-riding Winches

Northern Diver makes Launch and Recovery Systems?

In partnership with DSI, in 2014, Northern Diver designed a new hydraulic diver Launch and Recovery System (LARS). We only use premium materials and highly skilled personnel to enable us to build the best quality final product for our customers. Our LARS conforms to IMCA regulations D018 and D023 and comes fully certified.

Since we brought them to market, we’ve sold several of these units into the Commercial and Military sectors including to the MOD and large offshore commercial diving contractors. We believe this is due to the high quality of the components we use in their build, our attention to detail and because of their space saving design.

UK designed and manufactured to meet the highest requirements, our LARS enable diving and ROV operations to be conducted from dynamically positioned (DP) vessels. Northern Diver’s Launch and Recovery System has been designed in order to give a compact operating footprint to minimise the deck space required on board a vessel or barge. Our Launch and Recovery Systems offer a conventional A-frame design with hydraulic arms, they’re fully moveable and fold down to fit into a standard ISO 20’ shipping container in a modular way thereby providing a cost-effective shipping and mobilisation solution. This fold-down functionality also helps to protect the LARS from the elements and enables safe storage during times when it’s not in operation.

What does a Northern Diver LARS offer?

Comprising a hydraulic A-frame, two top-mounted man-riding winches, a two-man stainless-steel dive basket with two independent hydraulic power units and a single electrical control box. Our diving LARS has been specifically designed to provide robust operation, alongside providing safety and flexibility in deployment and recovery of commercial divers. It does so while enabling easy transportation, installation, and storage. Our top mounted winches offer great stability for the diving cage and a high level of system redundancy. Locating the two man-riding winches on top of the A-frame instead of the platform eliminates the need for guide sheaves and clears the platform of equipment. The approach guarantees optimal access and a safe workspace.

On the A-frame base there are 2x guard rails that act as support and safety for the working area and protection for the hydraulic systems during operational procedures. The two-man riding winches are designed with 4x braking/ safety features, the drive gearboxes on the winches are DNV approved. Both winches have a capacity of 150m of 13mm non-rotating wire, for diving purposes, there is only 90m of wire required for the main dive basket, the second winch has a capacity of 150m of 13mm non-rotating wire for the guide weight and secondary recovery.

The winches and cylinder pilot distributor are fit in an ergonomic 3 x lever valve block that is positioned allowing full visual control of launching and recovery operations. The main winch and guide wire winch both have a compact design. They can be fitted with a meter counter, and they’re fully compliant with DNVGL lifting personnel requirements. They’re equipped with two mechanically and functionally independent brake systems on the winch drum as well as the hydraulic control valve, and a handbrake.

The LARS design has certified approval and is independently lift tested prior to dispatch and complies with IMCA regulations D018 and D023. The units are also available with an air winch option and all are supplied complete with a full certification package.

What about the build material?

All materials used are supplier certified grade 355 mild steel, and grade 316 marine grade stainless steel, all load testing and MPI, Eddy Current and Dye Pen tested on all critical support areas, and these tests are all done by industry certified third-party lifting companies, a full certification package comes with each LARS frame and a Planned Maintenance System (PMS) schedule for individual components.

Northern Diver’s LARS power information.

There are two Hydraulic power packs so there is 100% redundancy, WP 250 bar, flow rate 25 LPM, tank capacity 150 Ltrs, system working pressure 172 bar, motor power 15kw.

There is a single main electrical power box that houses all the electrical control components, the HPUs are interlocked so only one unit can be started at any one time all the hydraulic control valves operate in conjunction with the HPU that is online, there are upper limit switches on the guide wire to prevent the dive basket from going block to block with the frame pully, and a single emergency stop, each HPU has its own hour meter to keep track of running hours for PMS schedules. 2x LED overhead lights are mounted on the A-frame cross bar to illuminate the working area.