Marine Hydraulic Refurbishment Case Study: 100 Metres of Steel Tube Installed Below Deck
Updated: 19 September 2026
A marine hydraulic system operating below deck needs pipework that is correctly specified, securely installed and suitable for the demanding conditions found aboard working vessels.
In this marine engineering project, Completely Hydraulic carried out a substantial hydraulic refurbishment involving the installation of approximately 100 metres of steel hydraulic tube across the vessel’s lower decks.
The objective was to improve the hydraulic pipework infrastructure and provide a more robust long-term arrangement for the vessel’s hydraulic systems.
Completely Hydraulic installed approximately 100 metres of steel hydraulic tube through the lower decks of a vessel as part of a marine hydraulic refurbishment. The work provided renewed fixed hydraulic pipework designed around the vessel’s existing hydraulic requirements and demanding marine operating environment.
Get Priority Hydraulic Support & Trade Pricing
Jump the queue. Reduce downtime. Pay less for parts, labour and callouts.
✔ Priority response
✔ Lower rates day & night
✔ Trade discounts on parts
✔ 30-day credit terms (approved accounts)
The Marine Hydraulic Project
Hydraulic systems perform essential functions across many types of marine equipment and vessels.
Depending on the vessel, hydraulics may be used for:
- Steering systems
- Deck machinery
- Winches
- Hatches
- Ramps
- Lifting equipment
- Actuators and cylinders
- Other powered mechanical systems
Much of the associated hydraulic infrastructure can run through restricted lower-deck areas where access, routing, vibration, corrosion exposure and maintenance all need to be considered.
For this project, the existing arrangement required significant hydraulic pipework refurbishment.
What Was the Hydraulic Engineering Challenge?
Lower-deck hydraulic pipework presents a different engineering environment from an easily accessible industrial installation.
The hydraulic lines need to be routed through the available vessel structure while allowing for factors such as:
- Restricted access
- Existing equipment and services
- Pipe support
- Vibration
- Mechanical protection
- Maintenance access
- Connection points
- Marine environmental conditions
Where ageing or unsuitable hydraulic pipework becomes difficult to maintain, repeatedly leaks or no longer provides the required installation standard, replacing sections of the fixed pipework can form part of a wider refurbishment.
Installing hydraulic pipework aboard a vessel is not simply a matter of connecting two points. Routing, supports, access, movement, vibration, connections and the surrounding environment all need to be considered as part of the installation.
The Solution: Approximately 100 Metres of Steel Hydraulic Tube
The refurbishment involved installing approximately 100 metres of steel hydraulic tube through the vessel’s lower-deck areas.
Using fixed tube for suitable sections of a hydraulic installation can provide a controlled and durable routing arrangement when correctly specified and installed.
The project required the hydraulic pipework to be integrated with the vessel’s existing system rather than treated as an isolated component.
This meant considering how each new section connected with the wider hydraulic circuit and the equipment being supplied.
Why Use Steel Tube in a Hydraulic System?
Steel tube is widely used for fixed hydraulic pipework because it can provide a strong, rigid hydraulic line where the application and environment are suitable.
Potential advantages include:
- Controlled fixed routing
- Good mechanical strength
- Support for substantial hydraulic installations
- Reduced movement compared with flexible hose
- Neat installation through machinery or structural areas
- Suitability for correctly engineered hydraulic circuits
However, material selection should always reflect the actual hydraulic application and environment.
Steel is strong and widely used for hydraulic tube, but it should not simply be described as inherently corrosion-proof. In marine environments, material specification, surface protection, installation, inspection and environmental exposure all matter.
Hydraulic Tube vs Hydraulic Hose
Hydraulic tube and hydraulic hose perform different roles within a system.
| Hydraulic Tube | Hydraulic Hose |
|---|---|
| Rigid or fixed installation | Flexible connection |
| Suitable for controlled fixed routing | Useful where movement or flexibility is required |
| Requires suitable bends, supports and connections | Requires suitable bend radius, routing and movement allowance |
| Common in fixed hydraulic circuits | Common between moving or vibration-sensitive components |
A well-designed hydraulic system may use both tube and hose, selecting each according to the function and movement required at that point in the circuit.
Planning the Hydraulic Pipework Route
Installing a substantial amount of hydraulic tube requires the route to be considered before fabrication and installation.
Important considerations can include:
- Starting and termination points
- Available space
- Access around other vessel systems
- Pipe supports and clamps
- Protection from mechanical damage
- Connection accessibility
- Potential vibration
- Heat sources
- Maintenance requirements
- Future component access
Good hydraulic installation should not create unnecessary maintenance problems simply to achieve the shortest possible route.
Why Hydraulic Tube Support Matters
Long hydraulic tube runs need appropriate support.
Without suitable support, vibration and movement can place additional stress on:
- Tube connections
- Bends
- Fittings
- Mounting points
- Connected hydraulic components
The location and spacing of supports depends on the installation, tube specification, route and operating conditions rather than one universal rule for every system.
Hydraulic Connections Below Deck
Every additional hydraulic connection is another interface that needs to remain correctly assembled and serviceable.
Connections therefore need to be selected for the pipework and system rather than simply joined using whichever adapter happens to fit.
Correct identification can involve:
- Connection standard
- Thread
- Thread pitch
- Sealing method
- Tube size
- Pressure requirement
- Fluid compatibility
- Environmental conditions
See our Hydraulic Fittings & Adapters guide for more information about BSP, JIC, ORFS, metric and other hydraulic connections.
Protecting Against Hydraulic Leaks at Sea
Hydraulic leaks are undesirable in any system, but a leak aboard a vessel can create additional operational and environmental concerns.
A properly installed hydraulic pipework system should therefore consider:
- Connection integrity
- Pipe and hose condition
- Routing
- Abrasion
- Corrosion
- Vibration
- Support
- Fluid compatibility
- Inspection access
It is also important that leaks are investigated rather than repeatedly topping up hydraulic oil without identifying where the fluid is being lost.
Never use your hand to search for a suspected pressurised hydraulic leak. High-pressure hydraulic fluid can penetrate skin and cause serious injury. The system should be made safe and the leak located using an appropriate procedure.
Hydraulic Oil & Marine Systems
The condition and specification of the hydraulic fluid are also important to system reliability.
Hydraulic oil performs several functions, including:
- Transmitting hydraulic power
- Lubricating components
- Helping control wear
- Transferring heat
- Protecting suitable internal surfaces
The correct fluid should be selected according to the equipment and system requirements rather than simply choosing an oil based on viscosity grade alone.
For more information, see our Hydraulic Oil Guide.
Not Sure Which Hydraulic Oil You Need?
Some machines require specialist or OEM-specific hydraulic oil. Using the wrong oil can cause serious damage.
Check Your Oil NowWhat Did the Marine Refurbishment Achieve?
The project replaced a substantial section of the vessel’s hydraulic pipework infrastructure with approximately 100 metres of newly installed steel hydraulic tube.
The key practical outcomes were:
- Renewed hydraulic pipework across the lower-deck areas
- A more structured fixed hydraulic routing arrangement
- Replacement of ageing or unsuitable sections of the previous installation
- Integration with the vessel’s hydraulic system
- Improved access to newly installed hydraulic infrastructure where the route allowed
- A refreshed basis for ongoing inspection and maintenance
The strongest evidence from this case study is the engineering work itself: approximately 100 metres of steel hydraulic tube was installed across the vessel’s lower decks. We have deliberately avoided assigning unsupported percentage improvements or future cost-saving figures to the project.
Why We Removed the Old Performance Percentages
The original version of this case study included estimates for percentage improvements in efficiency, leakage reduction and projected maintenance savings.
Those figures were not supported by documented before-and-after measurement data within the project information available for this article.
For that reason, the updated case study focuses on the engineering work that was actually completed rather than presenting estimates as measured results.
This gives customers a clearer picture of Completely Hydraulic’s demonstrated marine hydraulic capability.
Marine Hydraulic Refurbishment Is More Than Replacing Pipe
A hydraulic refurbishment can involve much more than changing one damaged line.
Depending on the condition of the vessel and system, work may involve:
- Hydraulic pipework replacement
- Hydraulic hose replacement
- Fittings and adapters
- Valves
- Cylinders and actuators
- Hydraulic pumps
- System fault finding
- Fluid condition
- Filtration
- Routing modifications
- Leak investigation
The appropriate scope should be based on the actual condition and requirements of the hydraulic system.
Why Marine Hydraulic Systems Need Regular Inspection
Marine hydraulic equipment can operate in demanding conditions involving moisture, salt exposure, vibration, temperature changes and restricted access.
Inspection can help identify developing problems such as:
- Corrosion
- Hydraulic leaks
- Loose or damaged supports
- Hose deterioration
- Abrasion
- Damaged fittings
- Contamination
- Unusual component movement
Inspection frequency should reflect the vessel, equipment, operating duty, environment, manufacturer requirements and previous maintenance history.
Can Existing Marine Hydraulic Pipework Be Refurbished?
Yes, depending on its condition and system requirements.
A refurbishment may involve replacing selected damaged sections or carrying out a more extensive renewal of the hydraulic pipework.
Before deciding on the scope, engineers need to understand:
- Condition of existing pipework
- System layout
- Operating requirements
- Connection types
- Access
- Equipment being supplied
- Maintenance requirements
- Environmental exposure
Can Hydraulic Hoses Be Replaced During a Marine Refurbishment?
Yes. Flexible hydraulic hoses may also be inspected or replaced where appropriate during wider system work.
Hose condition should be assessed individually rather than automatically replacing every hose simply because fixed pipework is being renewed.
Where hoses are replaced, correct specification, pressure capability, fittings, routing, bend radius and movement all need to be considered.
See our Hydraulic Hose Routing Guide and Hydraulic Hose Inspection Checklist.
Marine Hydraulic Engineering Capability
Projects such as this demonstrate the difference between replacing an individual hydraulic component and working on the wider hydraulic infrastructure of a machine or vessel.
Completely Hydraulic supports hydraulic engineering projects involving:
- Fixed hydraulic pipework
- Hydraulic hose assemblies
- Hydraulic cylinders and rams
- Pumps
- Valves
- Fittings and connections
- System installation
- Hydraulic modifications
- Fault finding
- Workshop repair
For wider project support, see our Hydraulic Engineering Projects and Hydraulic Systems services.
Project Summary
| Project Detail | Marine Hydraulic Refurbishment |
|---|---|
| Environment | Vessel lower decks |
| Primary Work | Hydraulic pipework refurbishment |
| Installation | Approximately 100 metres of steel hydraulic tube |
| Key Considerations | Routing, connections, supports, access, vibration and marine operating conditions |
| Engineering Type | Marine hydraulic installation and refurbishment |
Frequently Asked Questions
What was completed during this marine hydraulic refurbishment?
Approximately 100 metres of steel hydraulic tube was installed through the vessel’s lower-deck areas as part of a substantial hydraulic pipework refurbishment.
Why is steel tube used in hydraulic systems?
Steel hydraulic tube can provide strong, fixed and controlled hydraulic routing where it is correctly specified for the application and operating environment.
Is steel hydraulic tube corrosion-proof?
No. Steel should not be treated as inherently corrosion-proof. In marine environments, material specification, surface protection, installation, inspection and exposure conditions are important.
Is hydraulic tube better than hydraulic hose?
Neither is universally better. Fixed tube and flexible hose perform different functions. A hydraulic system may use both depending on movement, routing, vibration, access and other application requirements.
Can marine hydraulic pipework be replaced without replacing the whole system?
Potentially, yes. The appropriate scope depends on the condition and design of the existing system. Individual sections or more extensive pipework can be renewed while retaining serviceable components where appropriate.
Why are hydraulic pipe supports important?
Suitable supports help control tube movement and vibration and reduce unwanted loading on connections and hydraulic components.
Can Completely Hydraulic carry out wider hydraulic engineering projects?
Yes. Completely Hydraulic supports hydraulic system installation, pipework, hoses, cylinders, valves, pumps, modifications, workshop repairs and other hydraulic engineering projects.
Does Completely Hydraulic provide emergency hydraulic support?
Yes. Completely Hydraulic provides 24/7 mobile hydraulic engineering support across its service areas in addition to planned workshop and engineering-project work.
Get Priority Hydraulic Support & Trade Pricing
Jump the queue. Reduce downtime. Pay less for parts, labour and callouts.
✔ Priority response
✔ Lower rates day & night
✔ Trade discounts on parts
✔ 30-day credit terms (approved accounts)
Planning a Hydraulic Refurbishment or Engineering Project?
From fixed hydraulic pipework and hose assemblies to cylinders, valves and wider system work, speak to Completely Hydraulic about your project requirements.