In 1997, we delivered a world-first solution that redefined underwater trenching; a bespoke, diverless jet sled capable of burying pipelines up to 5m below the seabed.
Commissioned by a major oil and gas client, this groundbreaking vehicle addressed specific operational challenges and set new standards for safety, depth, and efficiency. It is still being used to this day.
Replacing Divers: Safer, Smarter, and More Efficient
Back in the 90s, subsea pipeline burial often relied on diver-operated systems. But, with safety incidents mounting and insurance premiums soaring, our client approached us with a clear objective: to develop a remotely operated vehicle capable of trenching to greater depths.
We responded with a custom-built, 110 tonne diverless jet sled – an engineering feat that significantly increased trenching performance, unlocking operational capabilities in high-current waters up to 300m deep.
Industry-First Technology
The diverless jet sled used high-pressure water from jetting swords to trench a range of seabed surfaces, including hard clay, sand and silts. It featured industry-first adaptations to deliver exceptional results across global operations:
- Jet Pressure: Operating at up to 170 bar – far exceeding the then-industry standard jetting pressure – the vehicle jet swords delivered up to 4,500 cubic metres of water per hour through surface-fed hoses. The greater trench depths created offered better thermal insulation and protection, minimising the environmental impact of transported fluids, while securing pipelines against damage and exposure.
- Jet Swords: Thanks to remotely configurable jetting swords, trench width could be adjusted seamlessly throughout operations, offering unprecedented flexibility and accuracy.
- Two-Stage Eductors: To remove sediment and debris efficiently, an underwater transformer enabled high-pressure jetting to be combined with powerful suction. An industry-first innovation, it ensured pipelines were laid on a level trench base, preventing future damage or movement.
Seamless Launch and Recovery
Engineered for compatibility with our client’s deployment vessels, the vehicle was launched from a gantry crane at the stern of the ship and pulled using a tow line that ran from the bow to the stern. This ensured perfect alignment between the jet sled and the deployment vessel and ensured vehicle recovery could occur without repositioning. This streamlined operation saved time and reduced operational costs; an ethos we still champion for our customers today.
An Innovation Legacy
While the diverless jet sled was created as a bespoke solution, its core technologies have since influenced multiple SMD systems, including the world’s largest and most powerful free-flying jetting ROV, and the world’s largest subsea trenching vehicle, both of which we developed in 2008.
From cutting-edge pressure systems to remote configuration capabilities, this 1997 innovation laid the groundwork for decades of pioneering engineering and set the benchmark for safety and performance in global pipeline burial.
Over 25 years later, the world’s largest diverless jet sled remains a testament to SMD’s ability to solve complex client challenges with future-focused innovations.
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