Ultra-Light Range
Full Cutting Power. A Fraction of the Footprint.
The C1-16UL, C1-10, and C1-24UL Chopsaws bring Decom Engineering's proven cold-cutting technology into a crane-free, ROV-deployed package — built for chain, riser, and pipe severance under tension, wherever crane access runs out.
Why Ultra-Light
Why Operators Are Going Ultra-Light
Vessel time is the single biggest cost lever in any subsea campaign. Every hour spent waiting on crane availability, repositioning heavy tooling, or working around restricted deck space is an hour added to the day rate. Decom's Ultra-Light range removes that constraint. Built for full ROV manoeuvrability and crane-free deployment, these tools bring precision cold-cutting to jobs where conventional saws simply can't reach — beneath floating structures, inside riser turret moorings, and on vessels with minimal handling equipment.
150+
Projects completed worldwide
3×
Faster than diamond wire
Yes
Jones Act compliant
The Range
Three tools, one philosophy
Lighter frames, full cutting capability, ROV-ready from day one.
| Tool | Cutting Capacity | Weight in Air | Weight in Water | Hydraulic Requirement | Deployment |
|---|---|---|---|---|---|
| C1-10 | Chain up to 120mm | Tubulars 1" – 10" | 90 kg | 70 kg | 35 lpm @ 210 bar | ROV manipulator or ROV basket |
| C1-16UL | 2" – 16" (50–406mm) | Chain 20–200mm | 220 kg | 70 kg (with buoyancy) | 60 L/min @ 210 bar | ROV manoeuvrable, crane-free |
| C1-24UL | 2" – 24" (50–610mm) | 1,200 kg | 50–100 kg (with buoyancy) | 60 L/min @ 210 bar | ROV-friendly, neutrally buoyant |

C1-10 — Decom's Most Compact Saw to Date
Deployed by ROV manipulator or ROV basket, the C1-10 reaches places larger tools can't — cutting chain up to 120mm and tubulars 1" to 10" at depths to 3,000m, with 5 to 30 cuts per blade depending on application.
View C1-10 full specification
C1-16UL — The Tool That Started the Ultra-Light Range
Purpose-built for cutting flexible risers and mooring chain under tension — beneath floating structures, in riser turret moorings, and in deepwater tensioned moorings. ROV-manoeuvrable with 5-minute blade changes and crane-free operation.
View C1-16UL full specification
C1-24UL — Field-Tested Legacy, Lighter Frame
The latest evolution of Decom's most trusted subsea Chopsaw, rebuilt for a lighter, more agile footprint. Neutrally buoyant in seawater and fully ROV-manoeuvrable, with a cutting envelope up to 24" OD.
View C1-24UL full specificationProven in the Field
Recent Projects
FPSO Mooring Severance, Brazil
CBO Group / Petrobras
C1-16UL cutting up to 120mm mooring chain at 140m water depth, averaging 18-minute cuts, secured as a 2–3 year long-term rental.
View case studyShenandoah Mooring Chain, Gulf of Mexico
Subsea 7
12 sections of 137mm studless mooring chain cut with the C1-16UL, fitted with integrated buoyancy and a bespoke "faux link" clamp system for zero dropped objects — fastest cut in 15 minutes.
View case studyScarborough FPU, North-West Australia
McDermott, on Woodside Energy's Scarborough Development
C1-10 deployed by ROV from an anchor handling tug to rectify a mooring line during FPU hook-up, cutting a 102mm studless chain link at approximately 90–100m water depth.
Mooring Chain Cutting, West Africa
C1-16UL (Ultra-Light) paired with the standard C1-16HD, first-of-a-kind project marking the C1-16HD's first field deployment. All four mooring chain cuts completed in 11 minutes.
Ongoing Projects
- Alba Ithica, North Sea — C1-16UL, cutting 156mm & 133mm chain, 18 cuts, due to finish next week.
- North Cormorant, All Seas, North Sea — C1-24UL, mooring chain cutting, due to finish next week.
- Karoon, Brauna, Brazil — C1-10, umbilical cutting.
- Brava, Brazil — C1-16UL, chain cutting.
- Canada Mooring Chain Cutting — C1-16UL x2, chain cutting.
How It Works
From Enquiry to Cut — Crane-Free
01
Enquiry & Scope Review
Share your cutting requirement — chain size, tubular diameter, water depth, and vessel/ROV spec — and Decom's engineering team confirms the right tool from the Ultra-Light range for the job.
02
Tooling & Interface Prep
The Chopsaw is configured for your ROV's manipulator or basket, with buoyancy and clamping arrangements (e.g. custom-built faux-link retention clamps) built out where the application calls for it.
03
Mobilisation
Tooling is shipped to the vessel, with no crane or heavy-lift deck equipment required for deployment.
04
ROV Deployment & Cut
The Chopsaw is deployed and manoeuvred into position by ROV. Typical cuts complete in minutes, not hours, depending on material size and water depth.
05
Recovery & Turnaround
Blade changes take around 5 minutes on the back deck: the tool is recovered, the blade swapped, and redeployed for the next cut in the sequence.
FAQs
Frequently Asked Questions

Why Ultra-Light
Ultra-Light vs Conventional Cutting Methods
Conventional subsea severance — diamond wire, abrasive cutting, explosive charges — means heavier tooling, crane-assisted deployment, and longer cut times, all adding to the day rate. Decom's Ultra-Light Chopsaws cut that overhead: cold-cutting delivers clean, controlled severance with no heat-affected zone and none of the environmental or safety considerations of explosive methods, while the ROV-deployable, crane-free footprint gets tooling into position faster — cuts complete in minutes, not hours.
Ready to Cut Vessel Time on Your Next Campaign?
Talk to our engineering team about which Ultra-Light tool fits your chain, riser, or pipe severance scope — and get a project-specific technical review.
Request a Quote