Multi-lay packages: doubling up your on-project capacity

Sometimes, the fastest way forward is not reinventing the wheel but refining it.

With global offshore activity on the rise—driven by the diversification of the energy mix and increasing operations across multiple sectors—access to specialist assets is becoming increasingly constrained. Dedicated installation vessels are in short supply, and the newbuild market isn’t keeping pace. The result? A competitive scramble for vessel availability, rising charter rates, and longer contracts just to secure a spot.

So how do you get ahead without breaking the bank?

If you’re familiar with MDL, you know that our technology and engineering expertise can temporarily transform a vessel of opportunity into a fully operational lay or retrieval solution. Our Integrated Project Solutions empower offshore operations across various marine sectors, allowing you to do more with what you have.

If you’ve worked with us before, you already appreciate the efficiency of our technology in live operations and how it minimises downtime—whether during mobilisation in port or product changeovers on deck.

But how else can MDL help you maximise vessel time and accelerate project execution without resorting to shortcuts or securing a second vessel?

Let’s take a look at two familiar systems in a new configuration.

Dual HLS Solution: Doubling Down on Efficiency

MDL’s fleet of Horizontal Lay Systems (HLS) already enables efficient flexlay operations, including the high-performance Wheeled HLS (WHLS) variant. These systems provide capabilities similar to Vertical Lay Systems (VLS) without the burden of excessive mobilisation costs or limited vessel availability.

An HLS can be deployed on a vessel of opportunity, offering an adaptable solution for operations that require vertical deployment or retrieval of products. This is particularly valuable when sea-state conditions, minimum bend radius (MBR), or the need for buoyancy and subsea components dictate a specific lay approach.

Interestingly on this project in Brazil, the Contractor was already operating a pipelay support vessel for the end client; however, for the next SURF campaign, the operator had challenged EPCI Contractors to increase their laying capacity.

MDL’s client saw the opportunity to reinforce their PLSV with a temporary lay spread – but rather than double the output, we were going to triple it.

Enter the Dual HLS: an integrated horizontal lay package that retains all the beneficial features of existing MDL HLS systems while providing a smaller overall footprint.

Designed for parallel installation of two lines (up to 51-tonne back tension per line), this package provides seamless integration with existing vessel operations while minimising disruptions. Key features include:

• MDL’s gold-standard 4-track tensioners for precise product handling.

• Adjustable outboard chute and pivoting davit arms to accommodate varying sea conditions.

• Runway beam system to assist in buoyancy module handling.

• Retractable work platforms, ensuring smooth port calls and transit.

• Integrated hang-off assembly with load cell monitoring, providing full control of product movement.

To maintain vessel functionality, the Dual HLS was designed to integrate with the existing load-out firing line, ensuring clear passage through the system, while minimising friction points that could damage the product. The complete package also includes a modular integrated deck deflector structure to efficiently manage two intersecting firing lines: from aft reels and the under-deck carousel starboard forward.

Since this dual-package design extends from MDL’s proven technology, it remains road-transportable, allowing for efficient off-site assembly and rapid mobilisation during dock time. This flexibility ensures minimal disruption to ongoing operations or booked schedules, making the Dual HLS a highly efficient and cost-effective solution.

Specifically for this client, the multi-skilled expertise of One Team MDL had further applications. As an existing OEM of an electrical back-deck equipment package on board the vessel, MDL would be able to safely interface the new unit with the vessel's SCADA system.

The Triple RDS Advantage: Maximising Reel Handling

While the Dual HLS increases the vessel’s simultaneous lay capacity, the MDL Triple Reel Drive System (RDS) takes single-trip reel handling capability to the next level.

This evolution of our Generation 3 RDS maximises the game-changing benefits of this unique design: integration of systems and compact footprint, despite many moving parts. With the reel hub and all lashing points tucked in nicely within the RDS tower (even including the HPU) there are no potential clash points outside the system, allowing to truly capitalise on available space on deck.

MDL Reel Drive Systems are already famed for the speed and efficiency of reeled lay – their automated features deliver an average saving of four hours per reel.

The Triple RDS is designed to handle two bays of reels with minimum-to-no intervention from the vessel’s crane: the three towers move up the tracks automatically; and thanks to the large clearance under the reels, these can be deployed out of sequence, still allowing for end terminations to pass underneath.

This is facilitated by the Integrated Track & Cradle System, whose other key benefit is the reduced sea-fastening: the product reels are mobilised in port directly into the cradles and secured along with the RDS itself and with a streamlined lashings solution for the remainder.

This means much less manual intervention to move onto the next row of reels during an operation, but also less welding and deck clean-up work in port during mob/demob.

The combined benefits are all about saving time: in port and at sea for non-productive operations – benefits compounded by the fact that carrying more reels on deck means fewer port calls, and all the associated charter, rental and personnel costs, port charges and fuel burn.

And just like all other MDL systems, the Triple RDS is safety-focused. From fail-safe clamps to the automated raising and lowering system which negates working at height, the system is designed to comply with PUWER/LOLER requirements and can be CE marked. The control system is designed for safe product handling with data logging as a standard feature, ensuring instant access to critical product lay information with the option to record the data.

Innovation in Action

In the competitive world of offshore operations, staying ahead requires a commitment to innovation and a willingness to embrace new approaches. At MDL, we believe that innovation is not just about creating new products but also maximising existing technology – and since ours is market leading, that’s saying something about efficient project enablement!

By revisiting our champion designs and further pushing boundaries where it is practical and safe to do so, we can develop a comprehensive solution that addresses the need for increased capability, more efficient usage of vessel time and reduced sea transits or time in port. This approach not only enhances operational efficiency, delivering a higher return on investment, but also brings reassurance from the application of already proven solutions – minimising the risk of the unknown.

The Dual HLS and MDL Triple RDS are perfect examples of how we are achieving this goal, while keeping in our signature style of pushing the boundaries of what is possible. Check out other examples in our Innovation Spotlight – and once you’re ready, get in touch with our team to discuss your winning approach to success in an ever-changing industry.