Design

Working in estuaries and other challenging locations in shallow waters, CMI needed a vehicle that could traverse uneven terrain and bury cables in depths of 80m, in a seabed comprising sand and clay. It trusted Royal IHC to provide it, due to its proven track record in developing innovative solutions, and its expertise in the global cable installation sector.

“What they wanted initially was a towable device, a jet plough or sled, with swords in the water,” explains Scott Mabin, currently Head of Sales and former IHC Product Lead for Subsea Technologies. “However, when we looked at the type of projects they worked on, we realised what they really needed was a tracked vehicle – and particularly an amphibious solution.”

This realisation was a lightbulb moment for Scott and his team, based in the north-east of England. “The challenges faced by CMI are like those of many other operators – so this project came at a good time for us. We were already developing a smaller jetting vehicle than the proven Hi-Traq®, so CMI’s requirements fell into place nicely.”

However, the difference between CMI’s straightforward request and Royal IHC’s more complex recommendation was vast – how could Royal IHC bridge that gap and convince CMI to see things from a new perspective? Scott and his team decided they would have to shape the new vehicle around CMI – ensuring it was lightweight, modular, reliable and cost-effective. 

Nine months of discussions between the two companies followed, on both sides of the Atlantic, before CMI made the order. Practical and pragmatic, the CMI team realised the advantages and value of the proposed Amphibious Hi-Traq® Jetter, and the benefits it would bring. It would not only significantly increase their cable burial capabilities, and enable them to approach complex projects with confidence, but also potentially open up new markets.

CMI also placed their trust in Royal IHC to deliver what they had promised – convinced by the straight-talking professionalism, sincerity and dedication shown by Scott and his colleagues. 

Once the order was given, Royal IHC had less than a year in which to deliver a bespoke machine that would change the game for CMI and usher in a new generation of trenching vehicles for the industry. Confident in their own capabilities and under Scott’s calm and steady leadership, there was little doubt this would be achieved.

Firstly, this was because the Amphibious Hi-Traq® Jetter utilises proven Royal IHC technologies, which have been tested extensively in real-life applications. It is built on the Hi-Traq® platform, a patented four-track, self-levelling system with independent steering and drive.

This gave Scott and his team the confidence in the new product’s traction capabilities, manoeuvrability and positioning in estuaries and other challenging locations in shallow waters. “This platform gives them that kind of next-generation performance,” confirms Scott. 

However, the biggest challenge for Royal IHC during the design process was maintaining the low weight of the new vehicle. While the Amphibious Hi-Traq® Jetter has the equivalent jetting capability of the Hi-Traq®, it is much lighter than its big brother – at only 20 tonnes. This is because Royal IHC designed it specifically for jetting, which is ideal for working on a seabed made of clay and sand. 

“All the fabrications are fully bespoke and designed from a blank sheet,” explains Scott. “This was further optimised through finite element analysis to ensure the weight remained low, but the strength of the vehicle was high.”

Another significant selling point is the modularity of the vehicle, which makes it easy to upgrade. It means CMI can buy an amphibious surface-fed system for the work they have today, then steadily build up its capabilities to a full deep-water jetting vehicle for the work they may have tomorrow.

The surface-fed element of the design means that components, such as the hydraulic power unit and pumps for jetting the water, remain onshore rather than subsea. This made the proposal significantly more cost-effective.

“The whole system is designed to have components pinned in and pinned out,” says Scott. “You could swap the whole central core with another that comes with all the subsea technology, enabling CMI to steadily grow with the vehicle. That was a key point for this system – to make sure it’s fully upgradable at CMI’s convenience.”

For example, CMI’s vehicle is initially designed to trench and bury cable at a water depth of about 80m. However, by changing tools, CMI will also be able to use it for de-burial scopes to recover or repair cables, opening up new opportunities. 

The modular design also has implications for easy transportation. The vehicle can be disassembled and shipped cost-effectively to different locations in conventional containers rather than using specialist transportation that would be at a significantly higher cost.

Working to a tight schedule meant that close teamwork at Royal IHC’s Port of Blyth and strong collaboration with CMI was critical. Scott reflects on this element of the project with pride and satisfaction: “I’m proud of our multi-disciplined team of nearly 50 people, who have worked incredibly well and efficiently together. We saw progress every week and it’s rewarding to see the fruits of our labour presented so quickly. It’s an exciting project, which has captured the imagination of us all. For me personally, it will be one of the projects I’ll remember going forward; I’ve been involved in many, but this one will be a high point."

Nevertheless, developing bespoke equipment at such a rapid pace must add pressure to even the most experienced. What impact would it have on the rest of the team throughout the construction, commissioning and testing processes? Had the design concept created by Scott and his colleagues set up the rest of the company to succeed? Would CMI be rewarded for having faith in an industry first? Senior Mechanical Engineer Ian Robson continues the story…