Last minute cost-cutting on QE2

[skilly56]

There are two different types of cathodic protection.
One type has an anode and a cathode in each sea chest, and the ions released are then carried through all the sea water pipework within the hull to prevent (or, slow down is probably more accurate) corrosion and growth.
The second type is what most people are referring to - this induces an impressed current to counteract the effects of electrolysis to protect the hull. I have worked with Cathelco systems in the past and they work quite well if kept within their working parameters. Google 'Cathelco' for a more detailed explanation and a couple of animations showing how the systems work.
A few years back I posted photos of the QE2 shaft earthing system - under 'Diesel Electric Propulsion' if I recall.
Cheers
Skilly

[Lynda Bradford]

Hi Skilly

You contributed such a lot of information on the combined  QE2 Engines and QE2 Engines (diesel-electric power) topic board, which was a fantastic insight for members, even non technical people (like me).
 
On page 3 post number 97 you mentioned the propeller shaft earthing connection.  Is this the photo you were referring?

https://www.theqe2story.com/forum/index.php/topic,1039.80.html

Number 13.  Almost forgot the most important one. The propeller shaft earthing connection. As the rotating mass of the shaft is spinning it builds up a static electrical charge. If that charge is not correctly discharged to the hull structure, it will find a way to earth itself through the prop motor, pedestal bearings or the O.D. Box. I have been on a diesel electric ship where this high current-low voltage discharge from the diesel-generator installation has welded the main bearing shells to the engine crankshaft and spun them in the webs! Very messy, and the crank had to be removed & reground, and the entablature was line bored - a very major job.

[June Ingram]

If QE2's cathodic protection were serviced at the last Dubai dry docking, what would be her condition now ?  If she were not serviced then, again what would be her condition ? 

[Bruce Nicholls]

If QE2's cathodic protection were serviced at the last Dubai dry docking, what would be her condition now ?  If she were not serviced then, again what would be her condition ?

Depends on the water the vessel is in, salinity etc. Also on electrical activity around the ship.

What could happen is shown in my pics showing anodes on Lone Gerd after 12 months. The one attached to the stern gear has gone. It was the size of the one shown on a water intake and Lone Gerd is wooden with metal fittings, not all metal.

[June Ingram]

Depends on the water the vessel is in, salinity etc. Also on electrical activity around the ship.

What could happen is shown in my pics showing anodes on Lone Gerd after 12 months. The one attached to the stern gear has gone. It was the size of the one shown on a water intake and Lone Gerd is wooden with metal fittings, not all metal.

Thank you very much, Bruce for your reply and pictures.  Not an encouraging prospect considering Lone Gerd's condition is after only 12 months.

[Twynkle]

We are fast approaching the 50th anniversary of the contract being placed for QE2 on 30 December 1964.
....

Michael - thanks so much for the reminders that you kindly posted today, as well as posted earlier in this topic.

Please, would it be possible for us to think specifically about the planned 'breakwater'?
It wasn't re-instated was it?
If it had it been 'stuck' onto her foredeck, do you think the risks to the Look-out Bar and the foredeck doors, hatches etc would have been different?
It's interesting to note that the height of QM2's breakwater is considerable - I wonder if this was made higher as a direct result of QE2 not having one? (!)

Also, on reflection - do you and the engineers et al have thoughts now about any of the other things that were left off the list then?
(Hoping you will excuse so many questions!    )
Rosie