Perry XLX-C and XLX Evo: Forum's Deep Water Work-Class ROV Platform

The Perry name has been in the work-class ROV industry since the 1970s, and the lineage running from the original Perry vehicles through the Triton series to the current XLX platform under Forum Energy Technologies represents one of the longer continuous development histories in the sector. The XLX-C and XLX Evo are the current expression of that heritage — hydraulic-architecture work-class vehicles designed for deep water intervention in the North Sea and Gulf of Mexico.

Forum Energy Technologies and the Perry Legacy

Perry Slingsby Systems, the UK-based ROV manufacturer responsible for the Triton work-class series, was acquired by Forum Energy Technologies in 2012. Forum consolidated the Triton product line, continued development of the XLX platform, and positioned the Perry brand alongside their broader subsea equipment portfolio. The XLX designation replaced the Triton XLX nomenclature without significant architectural change — operators who had trained on Triton XLX vehicles found the XLX-C transition familiar. Forum maintained UK manufacturing at the original Perry site in Kirkbymoorside, North Yorkshire, preserving the engineering team that had built the Triton series.

XLX-C Hydraulic Architecture

The XLX-C uses a conventional hydraulic architecture: all hydraulic power is generated by electric motors within the vehicle frame driving axial piston pumps. The vehicle receives AC power down the umbilical and generates its own hydraulic pressure onboard. This self-contained approach simplifies umbilical design — no hydraulic return lines required — and is the standard architecture for Perry-lineage vehicles. Primary circuit pressure is typically set at 207 bar, with a reduced-pressure auxiliary circuit for manipulator fine control. The vehicle's hydraulic reservoir is nitrogen-charged and compensated, maintaining positive pressure differential against ambient to prevent seawater ingestion.

Depth Ratings and Structural Design

• XLX-C standard depth rating: 3,000 metres (9,843 feet)
• XLX Evo extended depth option: available to 4,000 metres on request
• Frame construction: high-strength aluminium alloy with titanium fasteners in critical joints
• Syntactic foam: custom-density blocks rated to working depth plus 25% safety margin
• Pressure housing material: aluminium 6061-T6 for electronics enclosures, titanium for high-cycle connectors
• Umbilical connection: top-entry, compensated, with mechanical strain relief rated for dynamic lay applications
• Thruster complement: typically eight — four horizontal and four vertical — in a vectored arrangement for 6-DOF control

The Comanche Electric Variant

Forum developed the Comanche as an electrically actuated alternative to the hydraulic XLX platform, targeting operators who needed lower maintenance overhead and the efficiency advantages of electric thrusters and electric manipulators. Where the XLX-C uses hydraulic motors for all propulsion and tooling, the Comanche uses brushless DC thrusters and electrically driven manipulator joints. The trade-off is tooling compatibility: the extensive fleet of hydraulic intervention tools built for the XLX-C interface does not directly port to the Comanche without conversion. Operators running mixed fleets — Comanche for inspection and light intervention, XLX-C for construction — have reported the additional logistics overhead of maintaining both tooling ecosystems. For pure inspection campaigns, the Comanche's simpler maintenance schedule is commercially attractive.

Perry Triton Heritage

The Triton XLX was the dominant work-class platform in the North Sea through the 1990s and 2000s. Its reputation was built on hydraulic reliability and a conservative design philosophy — components were over-specified rather than minimised for weight, and the vehicle frame was designed to survive deck handling incidents that would damage lighter systems. The XLX-C carries this philosophy forward: it is heavier than some competitors, but the weight is structural robustness. Pilots who trained on Triton XLX vehicles and transitioned to XLX-C have consistently noted the control feel and hydraulic response are familiar — Forum made deliberate decisions to maintain continuity with the Triton operating experience.

North Sea vs Gulf of Mexico Deployment Profiles

The XLX-C's operational profile differs between its two primary markets. In the North Sea, where water depths on production fields typically range from 100 to 600 metres and weather windows are limited, the vehicle's deck handling robustness and rapid deployment capability are primary considerations. North Sea operators run the XLX-C on vessel-integrated systems with smaller deck footprints. In the Gulf of Mexico, where deep water fields extend beyond 2,000 metres and campaigns run longer continuous operations, the XLX-C's depth capability and sustained power output are the differentiators. Gulf of Mexico operators also specify more extensive tooling skid configurations, taking advantage of the vehicle's payload capacity for multi-tool campaigns that minimise surface recovery cycles.

Operational Logging for XLX Platform Campaigns