Frequently Asked Questions
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How long does a stern tube seal replacement take?
This always depends on the situation. In an ideal scenario with good organisation and planning, an overhaul of aft and forward seals using the bonding method will take 3 days.
However, perfect planning and organisation are not always easy.
Before a service job begins, we send you a preparation document that can work as a planning checklist. This includes topics to consider and discuss with the shipyard, crew and project manager:
- Oil draining: is the drain tank empty?
- Does the propeller shaft need to be withdrawn?
- How long will washing and blasting the vessel take?
- Will the painting of the vessel interfere with the aft seal bonding?
- How long will the shipyard need to build safe staging for the aft seal work?
Naturally, unforeseen situations or unexpected issues can arise during the job. This could include discovering extra repairs to complete that went unnoticed until the overhaul.
In these cases, RM Propulsion will work with the superintendent to adjust the schedule and help with planning. We always aim to make the process as easy as possible for everyone involved – and we will never leave you in the dark.
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Where do you offer stern tube seal services?
We offer a global service. Anywhere our service engineers can reach you without a visa, or if we can organise a visa with customer help, we can offer our service.
Our engineers are based in:
- Hoorn, The Netherlands
- Tallinn, Estonia
- Shanghai, China
- Cuidad Panama, Republic of Panama
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Is going into dry-dock mandatory for stern tube seal services?
Not necessarily.
We usually work in the dry-dock for practical reasons. However, when circumstances require us to work afloat or help with an underwater repair, we will – if it is possible for your vessel and safe for our staff.
In order to perform afloat repairs of the aft seals, the stern tube has to be trimmed at least 0,5 metres out of the water. This means trimming down the forward side and lifting the aft side out of the water.
However, this puts extra strain on the vessel’s structure. It is therefore crucial that afloat repairs can be carried out in calm water, preferably without swell or waves from passing boats.
Forward seals can be replaced with minimal or no trim, but you must be certain the aft seals are not leaking.
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Is an afloat repair possible for my vessel?
The crew of a vessel and its technical department will be able to calculate whether the vessel can trim far enough to perform the repair. In some cases, pumps are required for cooling if the sea chests are trimmed out of the water.
Many tankers and bulk carriers will be able to trim enough for an afloat repair, but this is less common for container vessels.
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I have discovered a leakage, what now?
When problems arise, you may not have time to check the manufacturer’s manual for answers. (Although your crew should always be able to refer to it.)
We know almost all manuals off by heart – so reach out to us with any questions via our contact details above.
Whether or not we have worked on your system, we are happy to help. In many cases, we will be able to guide your crew through the best way to manage the situation.
If not, we can give you transparent recommendations on what your next steps should be, based on our many years of experience.
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Do your services and spare parts come with a warranty?
Absolutely! Our stern tube seal services and parts come with a one-year warranty. Our propulsion services and parts come with a six-month warranty.
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Why is our final invoice higher then quoted
In an ideal scenario with proper organisation and planning, an overhaul of aft and forward seals using the bonding method will take 3 days. This is our standaard quote.
Propulsion quotes depend on the number of thrusters to be overhauled and any other maintenance work to be carried out.
Most important: the preparation phase and on-site planning.
There may be circumstances that prevent our service engineer from working through, such as:
- Stern tube oil not drained yet;
- Weather conditions;
- Lack of scaffolding/ staging;
- Sandblasting;
- Liner that needs to be machined due to grooving/pitting or a whole new liner needs to be ordered;
- Other damaged parts which are not immediately on site and have to be ordered;
- Lack of suitable tools and machinery;
- Not sufficient manpower /capacity of crew, yard and/or sub contractor.
- etc…. Due to the above mentioned reasons, the invoice may be higher.
Recommendations to make the job go smoother:
- Check the previous service report of your vessel if there are any recommendations for the next dry docking, so you won’t have any surprises in dry dock;
- In case of thruster overhaul, check if there are any issues/ difficulties while sailing. Please report it to us prior to the dry dock period;
- Please read our preparation document in advance so you are informed of what needs to be done in order to plan the project ahead. This will help you get the job done as smoothly as possible, minimizing or eliminating delays. (This preparation document will be sent to you by email prior to the job).
So please note our quotation is an estimate on perfect circumstances . The final invoice will be re-calculated based on actual traveling, working, and stand-by days and relevant expenses as described in the quotation and according to the signed timesheet.
