Ultra-Light Range
Full Cutting Power. A Fraction of the Footprint.
The C1-10, C1-16UL, C1-24UL, and C1-32UL Chopsaws bring Decom Engineering's proven cold-cutting technology into a lightweight, ROV-operated package — built for chain, riser, and pipe severance under tension, wherever crane access runs out. The C1-16UL, C1-24UL and C1-32UL are deployed by crane, then fully ROV-controlled for the cutting operation itself — no crane is needed for the live cut. The C1-10 goes further still, fully ROV-manoeuvrable with no crane required at any stage.
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, these tools use the vessel crane only to launch and recover — once subsea, the cutting operation itself is entirely ROV-controlled, with no crane involved. That brings 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
5×
More cuts per blade on consumables
The Range
Four 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 — fully crane-free |
| C1-16UL | 2" – 16" (50–406mm) | Chain 20–200mm | 220 kg | 50 kg (with buoyancy) | 60 L/min @ 210 bar | Crane-launched, then ROV-controlled and operated |
| C1-24UL | 2" – 24" (50–610mm) | 1,200 kg | 50–100 kg (with buoyancy) | 120 L/min @ 210 bar | Crane-launched, then ROV-controlled and operated |
| C1-32UL | 8" – 32" (200–813mm) | 3,195 kg | 50-100 kg (with buoyancy) | 150 L/min @ 210 bar | Crane-launched, then ROV-controlled and operated |
C1-10 — Decom's Most Compact Chopsaw to Date
Deployed by ROV, 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 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. Crane-launched, then fully ROV-manoeuvrable and ROV-controlled for the cut, with blade changes in 5–10 minutes.
View C1-16UL full specification
C1-24UL — Most Versatile Chopsaw
The range's most versatile workhorse — 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 specification
C1-32UL — Decom's Largest Ultra-Light Tool
Neutrally buoyant and fully ROV-manoeuvrable, the C1-32UL extends the Ultra-Light range to its largest cutting envelope yet — 8" to 32" OD — with replaceable blade tips giving multiple cuts per blade (depending on application), and blade tip changes in around 15-20 minutes.
View C1-32UL 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 study
Shenandoah 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 study
Scarborough 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 C1-16HD (Heavy Duty), first-of-a-kind project marking the C1-16HD's first field deployment. All four mooring chain cuts completed simultaneously in 11 minutes.
Further Offshore Projects
- Alba Ithica, North Sea — C1-16UL, cutting 156mm & 133mm chain, 18 cuts.
- North Cormorant, All Seas, North Sea — C1-24UL, mooring chain cutting.
- 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-Launched, ROV-Controlled
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 to your project requirements, with buoyancy and clamping arrangements (e.g. custom-built faux-link retention clamps) built out where the application calls for it, backed by FAT (Factory Acceptance Testing) and ROV integration calls ahead of mobilisation.
03
Mobilisation
Tooling is shipped to the vessel and launched using the vessel's crane; once subsea, no further crane involvement is needed for the cutting operation itself.
04
ROV Deployment & Cut
Once lowered subsea by crane, the Chopsaw is manoeuvred into final cutting position by ROV. Typically cuts are completed in minutes, not hours, depending on material size and water depth.
05
Recovery & Turnaround
Blade changes take around 5–10 minutes for the smaller Ultra-Light tools with the full blade changed. For the larger Ultra-Light tools interchangeable blade tips are changed out, this takes around 15-20 minutes.
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 manoeuvring, 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 lightweight, ROV-controlled 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