Monday, September 14, 2015

INTERESTING INFORMATION FROM TECHNICAL TRAINING SEMINAR ABOARD NORDHAVN 68 – PART TWO

Envoy is currently in Lefkas marina, Greece and we’re home in New Zealand. But we arrive back in Lefkas late next week and soon after that will give an update on how Envoy's faring having been left for 11 months.

Our last posting introduced the technical seminar held aboard Nordhavn 68, Karajas, in Akuna Bay Marina north of Sydney.

View of Karaja's engine room with single John Deere main plus Northern Lights wing engine

Steve d'Antonio talks to course attendees in engine room

So what are a few key points others can learn from? Here is a flavour of some specifics.
- Always install equipment according to the manufacturer’s guidelines and insist that contractors do so,
as well as supplying a schematic diagram where needed.
- No AC power connections should be exposed or able to be accidentally touched.
- When working on AC power systems always totally isolate the inverter and remove the shore power
cable.
- Stainless steel bolts, nuts and washers should not be used in demanding applications like prop shaft couplings, steering couplings or engine mounts. Nor should they be used in electrical situations due to
the low conductivity of stainless steel.
- Although two hose clamps are supposed to be used for all raw water plumbing applications it is better
to use one properly than two improperly. Ensure hose clamps are marine grade stainless steel and have
solid not perforated bands. To avoid cuts and injuries use “Clamp-Aid” silicone covers on the sharp
exposed tail of the clamp.
- Only use correctly rated and marked hose for raw water plumbing and exhaust systems.
- Operate seacocks regularly to avoid them seizing up.
- Hydraulic steering rams and tiller arms should be regularly checked both at rest and under way while steering lock-to-lock to check for significant leaks and movement in fastenings.
- Test your emergency steering tiller before you need to use it.
- To reduce corrosion on aluminium masts, paravanes, booms, door frames etc bed fittings and hardware
in a PU bedding compound. This can be done retrospectively.
- In the event of engine room fire stop all engines and blowers (to maximise the effect of the extinguishing agent) and isolate the batteries (in case the fire is caused by a short circuit or overload).
- The prop shaft stuffing box temperature should not exceed about 30dF above the ambient sea water temperature.
- There is no need to change primary fuel filter cartridges too often, but as dictated by your vacuum gauge
(at about 5 inches of vacuum). Use 10 or 30 micron cartridges – finer is not better in the primaries.
- Bleeding of the fuel system should not be necessary if the primary and secondary filters are bled
correctly when changed. To ensure any air remaining in the system is passed through run the engine for
about 5 mins at 1200-1440 rpm, not at idle. This rpm range will reduce the chance of the engine stalling while passing air.
- Dry exhaust thermal insulation should be regularly checked using the pyrometer and for potential fire
and safety reasons no section should exceed 200dF. Wet exhaust system hoses should not exceed about 160dF.
- To maximise AGM battery life normally discharge to about 50% of its capacity and don’t routinely start charging much above that level.

I would certainly recommend any serious cruiser to attend a course run by Steve or a similarly qualified industry expert both to learn specifics and to stimulate thought.

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