Tanker Conversion
Oil-to-Bitumen Tanker Conversion
Converting a product or oil tanker to carry bitumen is one of Navtech's most repeated scopes — more than fifteen projects delivered. We provide the complete multi-discipline engineering package, from thermal system design through structure and stability to class approval.
Thermal oil and cargo heating system
Bitumen must be kept at temperature to remain pumpable, which makes the heating system the heart of the conversion. We size the thermal oil boiler against the calculated heat demand rather than a rule of thumb, design the coil layout for even tank coverage, and check the whole circuit for expansion, circulation and safety.
- Heat-loss calculations for each cargo tank at design ambient and sea conditions
- Thermal oil boiler sizing, selection support and installation design
- Heating coil layout, coil sizing and tank coverage assessment
- Thermal oil circulation, expansion tank and safety system design
- Deck and cargo line heat tracing arrangement
Insulation, structure and thermal effects
Heat is a structural problem as much as a process one. Insulation adds weight in the wrong places, coils and their supports introduce local loads, and elevated cargo temperature causes expansion that the original structure was never checked for. These are the details that generate class comments when treated as an afterthought.
- Cargo tank insulation specification and thickness calculation
- Structural assessment for elevated cargo temperature and thermal expansion
- Coil support, penetration and bulkhead detail design
- Foundations and seatings for boilers, pumps and thermal equipment
- Local reinforcement where new loads are introduced
Cargo handling, piping and machinery
Bitumen service changes what the cargo system has to do — higher viscosity, higher temperature, and no tolerance for cold spots where the cargo can set. We modify the cargo pumping and piping arrangement accordingly and update the system documentation to match.
- Cargo pump assessment and replacement specification for heated service
- Cargo line routing, insulation, lagging and drainage modification
- Updated P&IDs and system schematics for the converted arrangement
- Valve and fitting specification suitable for temperature and viscosity
- Tank cleaning, heating and discharge procedure input
Stability, electrical and class approval
Every element above changes the weight and power picture, so the conversion is only complete when the stability booklet and electrical documentation have been reworked and approved alongside the mechanical scope. Submitting these together as one coordinated package is what keeps the approval clean.
- Updated trim and stability booklet with revised lightweight
- Damage stability reassessment and revised loading conditions
- Inclining experiment where the lightweight change requires it
- Electrical load reassessment and generator adequacy verification
- Complete class submission and comment cycle management
Frequently asked questions
How many bitumen conversions has Navtech completed?
More than fifteen. That repetition is the reason the work goes smoothly — we know which details each class society questions, how the thermal system interacts with structure and stability, and where the schedule risk actually sits. It is the difference between designing a bitumen conversion and having a proven process for one.
Is every tanker suitable for conversion to bitumen service?
No, and establishing that early saves a great deal of money. Structural condition, coating and tank arrangement, existing stability margins, machinery space for the thermal plant and available electrical capacity all matter. Our feasibility study answers this before significant commitment — and occasionally the honest conclusion is that a different donor vessel is a better purchase.
How long does the engineering take?
A feasibility study is typically three to four weeks. The full basic design and class submission package generally runs eight to sixteen weeks depending on vessel size and condition, and should be complete and approved before the vessel enters the yard so the dock period is installation only.
Do you handle the class approval?
Yes. We prepare the documentation to the reviewing society’s templates, submit it, and manage the comment cycle through to stamped approval. We have delivered bitumen conversion packages to BV, RINA, IRS and Tasneef among others.
What do you need to start?
Vessel particulars and class society, the general arrangement and current stability booklet, cargo system drawings, the machinery arrangement, recent thickness measurements if available, and your intended cargo temperature and trading pattern.
Related engineering services
Have a vessel and a scope in mind?
Share your drawings, class society and target dates — we respond within 24–48 hours.