Lay-up of Vessel / Electric Motors

If you are talking about pretty large motors, and I would guess you are, then yes the heaters need to be on or you need some kind of climate control. If there is no power, the alternative is to pull the motors and store them somewhere that is climate controlled or where you can run the heaters.

Moisture in the stator windings is a formula for bad motor problems when you put the vessel back in service.

Are you laying up this vessel afloat or high and dry?

If it is going to be out of the water and you can dry out the machinery compartments you could dry store. To do this you need lots of silica gel. You can also nitrogen fill the compartments once they are dry and seal them with lots of warning signs to prevent entry. Nitrogen is not poisonous but wont support life of the human kind.

The heaters will keep the motors dry and the insulation in working order.

This may be the cheapest/easiest option.

BAB

Lay up?

Do you mean just taking it out of service or taking it out of service for repairs?

Because do repairs is going to require ventilation systems to remove the smoke and other things in the air on the vessel.

The cold water outside will draw condenstation to the hull espically if there is any welding or heating inside the ship.

To answer your questions how and what we are laying up: in this case it is a 100.000 dwt oil tanker, being layed up for approximately 1 year. Electric motors on board are varying in size from the smallest starting at 2 kW and the largest ones at 2500 kW. The largest ones (bowthrusters etc) will be conserved according manufacturers specifications, but for the smaller ones (<1000 kW) we are looking for an alternative. Because parts of the vessel, for instance machinery spaces, accomodation, foreship / forecastle etc will not be used entirely during this period, main power will be shut of. The vessel will be in the water (wet lay-up).

I think I agree with Steve S; I would want to keep the motor heaters running in this situation. If laid up alongside, perhaps laying in a shoreside supply would be practical; if not then a portable genset would perhaps be the best way, assuming some level of manning to maintain it.

Hello, when you mention laying up a vessel I automatically assume an ASME pressure vessel. On thing I would suggest to do besides the motor PM is to drain any tanks or vessels and purge them with nitrogen or another of the cheaper inert gases to prevent oxidation/corrosion while being down. This is especially true if you have boilers. I have seen boilers losing allot of life by letting air get to the interior surface of the tubes while they were down for longer periods. Any time we "lay up" motors in the paper mill for very long we send them out for servicing before reusing them. If you are planning to do this then the problem of keeping them heated is not as big of a concern. We cannot afford to have a motor to go out and cause unnecessary downtime so we follow this rule.

pipewelder

He is referring to laying up a ship. In this case an oil tanker.