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double acting 27th May 2019 16:47

HMS Queen Elizabeth
 
According to newspaper reports they are "replacing 284 hull valves", seems a bit strange, any clues as to why?

Erimus 27th May 2019 17:59

Appears that that was one of the major reasons for the docking along with rudder cleaning and upgrading cathodic protection.

geoff

seaman38 27th May 2019 18:10

Quote:

Originally Posted by double acting (Post 2985025)
they are "replacing 284 hull valves", seems a bit strange, any clues as to why?

Perhaps they are leaking!(Whaaa)

Stephen J. Card 27th May 2019 20:20

The captain's wife has open an iron monger's shop!

Engine Serang 27th May 2019 20:32

And she'll deliver them, in small batches.

spongebob 27th May 2019 20:57

Admiralty bought them from China as a job lot, wrong hand, clockwise to open.
A bit like those Japanese prunung saws, cut on the pull stroke.!

Bob

Dickyboy 27th May 2019 21:18

Just as well they can do it now, she's no bloody good as warship at the moment anyway.
A chance to sort out the other one now they know there's a problem as well.

Farmer John 27th May 2019 21:42

Disappointing, I clicked on this in case it was an advert for a new captain.

Engine Serang 28th May 2019 07:55

Was it only upon fitting the 284th valve that someone realised that the valves were upside down.
After a long and expensive inquiry it will be concluded that Billy the Fitter was to blame and middle-managers and above will get a bonus. Fair do's.

RHP 28th May 2019 08:13

Cathodic protection and hull valves are such basic design factors, how can they get them wrong?

YM-Mundrabilla 28th May 2019 10:47

Forgive me for I am konfuzed.
Is the LH valve bit a belated April Fool's joke?
If so, on one hand, it has reached the stage that I don't know whether to believe it or not whilst, on the other hand, the concept seems so outrageous that it might just be true. (Too many hands doing we know not what, perhaps).(egg)
If true, who uses LH valves and for what purpose?

James_C 28th May 2019 11:00

Prior to this recent docking the ship had been in the water for nearly 5 years (since July 2014) so it is no surprise that her underwater paintwork and anodes needed attention. Since she is classed by Lloyds Register to their warship rules, inspection of ship side valves is a surveyable item at 5 yearly intervals, hence their removal for inspection.
So for the avoidance of doubt for those out there who are desperate to sensationalise, there has been no massive cock up, accident or poor planning which has led to this docking or the work undertaken therein.

Engine Serang 29th May 2019 06:31

#1 "replacing 284 hull valves"

#1 2 inspection of ship side valves is a surveyable item at 5 yearly intervals, hence their removal for inspection.

False news or alternative facts?

James_C 29th May 2019 09:01

Quote:

Originally Posted by Engine Serang (Post 2985239)
#1 "replacing 284 hull valves"

#1 2 inspection of ship side valves is a surveyable item at 5 yearly intervals, hence their removal for inspection.

False news or alternative facts?


Perhaps lost in translation. Although being the RN/MOD I must admit there's every possibility they'll just remove and replace rather than inspect/overhaul and replace, especially after the shambles with Endurance.

Lao Pan 29th May 2019 09:04

replacing 284 hull valves ...upgrading cathodic protection.

maybe for the last 5 years the valves have been working as sacrificial anodes (?HUH)

...Perhaps they are leaking! - I got some Wood, Cement & Washing Soda if anyone wants to fix em before Drydock or the Engine-room floods (Jester)

Burntisland Ship Yard 29th May 2019 20:00

Is there a modern version of cement boxes ???

Engine Serang 29th May 2019 22:32

Quote:

Originally Posted by Burntisland Ship Yard (Post 2985327)
Is there a modern version of cement boxes ???

My two would be Class and Port State.

dannic 29th May 2019 23:18

Quote:

Originally Posted by James_C (Post 2985133)
Prior to this recent docking the ship had been in the water for nearly 5 years (since July 2014) so it is no surprise that her underwater paintwork and anodes needed attention. Since she is classed by Lloyds Register to their warship rules, inspection of ship side valves is a surveyable item at 5 yearly intervals, hence their removal for inspection.
So for the avoidance of doubt for those out there who are desperate to sensationalise, there has been no massive cock up, accident or poor planning which has led to this docking or the work undertaken therein.

Merchant vessels open and inspect, overhaul and then submit for for survey. Government paid for, they will be renewed, and subsequently sold on.
Dannic

Olaf_the_blue 31st May 2019 03:08

Lao Pan is probably pretty close to the mark with his "maybe for the last 5 years the valves have been working as sacrificial anodes." The give-away is the reference to cathodic protection upgrade. With ICCP systems, (Impressed Current Cathodic Protection,) if not designed and operated correctly they can strip the zinc out of brass/bronze valves attached as hull fittings making them leaky and more brittle. Could be an oops at the design end or running the ICCP to aggressively.

Steve Oatey 31st May 2019 08:51

Contract language is very important. Replace is not the same as renew.

Varley 31st May 2019 10:27

Quote:

Originally Posted by Olaf_the_blue (Post 2985431)
Lao Pan is probably pretty close to the mark with his "maybe for the last 5 years the valves have been working as sacrificial anodes." The .............be an oops at the design end or running the ICCP to aggressively.

I don't agree with your last ('aggressively'). The only real meaning of overprotection is to generate gas bubbles and blow off the paint. De-zincification would only occur if it were being sacrificial (ie underprotection).

Denholm's had relinquished Mr. Rappaport's fleet to Acomarit and this included two Russian built bulk carriers with enormous and unstable ICCP power unit. One each side every hatch break! Were the wielder of the terminal screwdriver to have had the touch of a midwife he would still have been hard pressed to adjust the output in the very small band between sod all and very much all.

Not long after I got a call from Dick Swindall (formerly my line manager and now deserted to Acomarit) asking innocently if I had ever seen an ICCP'd hull with a 'sort of etched look' and no paint. Havin already reported that the best use of these vessels' ICCP, if not subject to expert attention, would be to anchor-off the vessel prior to her next drydock and use it to blow the paint off and save on blasting.

Sure enough the question was about one of the subject bulkers.

uncle Ray 31st May 2019 14:28

Quote:

Originally Posted by Varley (Post 2985453)
I don't agree with your last ('aggressively'). The only real meaning of overprotection is to generate gas bubbles and blow off the paint. De-zincification would only occur if it were being sacrificial (ie underprotection).

It is possible to over protect a vessel with an ICCP system, if the voltage is too high for an excessive period of time it will cause Hydrogen embrittlement and as a result of this the likes of valve stems and spades made of lesser noble metals will suffer, reference cells are strategically placed around the vessel to monitor the voltage output but as most ICCP units are placed to the aft of the vessel the reference cells up Fwd will give a lesser reading to the aft reference cells therefore a happy medium must be reached. Once the ICCIP system has been switched on for the first time it will take many days for it to become fully effective and vice versa if it is switched off it will take just as long to UN protect the vessel, Ive heard of some vessels switching off the system from time to time to prevent any problems such as embrittlement.

Lao Pan 31st May 2019 16:01

Quote:

Originally Posted by Varley (Post 2985453)
... two Russian built bulk carriers with enormous and unstable ICCP power unit. One each side every hatch break!

Are you sure the Russians intended them for ICCP use - having sailed on a couple of Russian built ships they were just as likely originally designed for hull degaussing for passing through mine fields :rolleyes:

Varley 31st May 2019 18:20

Quote:

Originally Posted by uncle Ray (Post 2985487)
It is possible to over protect a vessel with an ICCP system, if the voltage is too high for an excessive period of time it will cause Hydrogen embrittlement and as a result of this the likes of valve stems and spades made of lesser noble metals will suffer, reference cells are strategically placed around the vessel to monitor the voltage output but as most ICCP units are placed to the aft of the vessel the reference cells up Fwd will give a lesser reading to the aft reference cells therefore a happy medium must be reached. Once the ICCIP system has been switched on for the first time it will take many days for it to become fully effective and vice versa if it is switched off it will take just as long to UN protect the vessel, Ive heard of some vessels switching off the system from time to time to prevent any problems such as embrittlement.

I think it is highly unlikely that one will come across hydrogen embrittlement on a hull unless and unusually it is made of high tensile steel. Again, even that would, I think, be more likely due to manufacturing than free hydrogen absorbed from its interface with the paint.

I did hear it talked about WRT MV Arctic and extremely cold water operations but I think that, too, was eventually discounted.

I am no metallurgist nor am I a gambler but I will take a bet that one is more likely to diagnose one's ICCP putting out too much from a side full of missing paint than waiting for the odd crack from hydrogen embrittlement. Any metallic suffering from overprotection will not involve it having been sacrificial, by definition, although with the Russian system it might well have been burned off!

Varley 31st May 2019 18:30

Quote:

Originally Posted by Lao Pan (Post 2985501)
Are you sure the Russians intended them for ICCP use - having sailed on a couple of Russian built ships they were just as likely originally designed for hull degaussing for passing through mine fields :rolleyes:

The pair had other features that might have been more to do with auxiliary duty as well as a few absolute horrors the worst being her "halon" system. This consisted of two fluids (as stored). One being slightly flammable itself and the other employed to supress the first. Unfortunately whether effective or not it was highly carcinogenic.

Almost every load was capable of being connected to the emergency switchboard via a huge changeover switch local to each starter.

The bitter ends of both cables were easily releasable with I metre diameter handwheels.

As far as I remember she did not have any degaussing gear (I have only seen this once on one of the Cenargo vessels, can't remember which). I do imagine, though that the ICCP could have provided a set of coils with enough juice to send the North Pole on its way back to Canada.


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