Our last poll of 2017 asked if there had been an overreaction to news that HMS Queen Elizabeth was taking on water during sea trials.
The leak was reported as being caused by a faulty seal in one of the ship’s propeller shafts, which was causing the ingress of 200 litres of sea water an hour.
HMS Queen Elizabeth is the first of two new UK aircraft carriers being built in the UK to enter service. These are the largest ever vessels to be built for the Royal Navy.
Much like any commissioning exercise, sea trials are carried out to ensure a vessel’s seaworthiness, prompting us to ask if it was fair or relevant for the national press to report the ‘fault’.
A total of 1,250 Engineer readers responded to the poll, with the vast majority (84 per cent) agreeing that there had been an overreaction and that such leaks and anomalies are to be expected.
Only 14 per cent agreed that — at a cost of £3bn — the carrier should not have such a fault. The remaining two per cent elected to choose the ‘none of the above option’.
To date, the poll has garnered 55 comments with many decrying national media outlets and others identifying what they see as the bigger issue, namely a lack of clarity about aircraft for the carriers.
Comments focused also on the technical elements arising from the story, including one from Tony Prince CEng who wrote: ‘As a marine engineer, I think this problem is not as trivial as it looks. Modern stern tubes are not old fashioned packed glands. They are oil filled with mechanical seals at either end. There is a header tank maintaining a positive pressure in the bearing. If there is a leaking outer seal, then oil will leak out. Sea water should never leak into the bearing, or the ship.’
Jonathan Douglas added: ‘Stern glands are always a source of issues for ships. This seems a rather serious fault, but the servicing of moving parts is what it is and can’t be ignored. I doubt many journalists have much idea what is actually involved.’
What do you think? Continue the debate using Comments below.
Typical media hype and naysaying about British industry – this is absolutely no big deal and is typical of snags to be sorted during trials. Gland seals on prop shafts always leak a little during bedding in and I’m sure the fitters will sort it in short order
As a Marine Engineer, I think this problem is not as trivial as it looks. Modern stern tubes are not old fashioned packed glands. They are oil filled with mechanical seals at either end. There is a header tank maintaining a positive pressure in the bearing. If there is a leaking outer seal, then oil will leak out. Sea water should never leak into the bearing, or the ship.
I could speculate that the entire stern tube assembly has been fitted incorrectly and that sea water is leaking around the joint on after bulkhead and not the bearing.
I wonder if we will get the truth.
Fully agree with the feedback. Another problem where the media made a story was of the “wobbly” Millenium Bridge across the Thames. All forgotten now and so will HMS QE once another more thrilling event develops. I hope some day the media can adopt a more positive stance and look to the successful resolution of the issues.
Many new items have problems, houses, factories, cars, planes and boat. That is the reason for the trials and tests. Then later on in a products life it requires maintenance. So there is no story here, there should be no embarrassment for the Navy or the manufacturers.
This is precisely why you conduct sea trials on these vessels to identify issues such as this then fix it. Pure media hype yet again.
Stern glands are always a source of issues for ships. This seems a rather serious fault, but the servicing of moving parts is what it is and can’t be ignored. I doubt many journalists have much idea what is actually involved. Anyone who feels this is symptomatic of problems in defence procurement has not grasped that our defence tools must be on the cutting edge and therefore will occasionally encounter engineering difficulties.
it really annoys me that the press focus on these issues, which, are to be expected in some form or other during sea trials… That’s what they are for, for goodness sake. Even the headlines of this article is guilty of this low brow need for sensationalism and blame culture, only to be explained properly in the text. The ship will be fixed at the expense to the contractor not the tax payer, so really: What is this story all about if not some finger pointing. We are engineers, we make things, things sometimes go wrong, that life!
200l/hour is hardly much is it, it’s just about enough to fill a couple of bathtubs to the brim.
Unless it’s an EAL lubricant, i.e. Environmentally-Acceptable biodegradable oil, then a barrel an hour does matter! Where do you think it’s going? Did you not watch Blue Planet II ?
Yes leaks do occur and I agree that’s what sea trials are for, but measures can be taken to reduce risk.
If it’s the only problem… I would call it a major success. All major projects will have a number of ‘snags’ which the contractor will have to fix prior to full acceptance by the MoD.
The sort of headline I would expect from the Sun and similar publications, but I am concerned that the BBC do not give a more in depth version. That’s our media of today, everything “dumbed down”
The BBC version includes details of how big a fishtank corresponds to 200 litres. that’s fairly in-depth.
There really is no excuse for letting the sun get a hold of this story. On a project this big it should be someones job to control the press. I think My 23 ft wooden boat could handle a leak of this size . But I don’t let people know as they will over react and avoiding panic is critical.
Agree with the sentiments here, especially Jon Bowen………my pond pump at home will cope with 200l/hr with ease. Now a real story would be if HMS QE pumps couldn’t cope!! Can one of the ‘journalists’ that covered this story do something really useful and find out how long the HMS QE pumps had to work to clear the leak?? Less than 10 seconds per hour is my opening bid!!
Should said journalists fail you, it’s easy to make a little estimate:
Since it’s a war vessel, the HMS QE probably has respectable pumps,
at minimum I’d expect 5MW. At a draft of 10m and an efficiency of 70%
such pumps can chuck out about 35m³/s.
So with this trickle it will be difficult to start the main pumps.
In a larger engine room this may evaporate and get expelled by the
ventilation 😉 Otherwise, there are auxiliary pumps.
Stability aside, with no pumping and no drying, at 5m³ a day, she’ll
sink about when due for decommissioning.
it shouldn’t leak at all, we have very advanced software that can do all the calculations needed.
someone didn’t do there job regardless, yes something going wrong IS to be expected but only because we accept it, realistically we shouldn’t get any problems ever, bring on full automation of everything.
This is a wind-up, surely?… Has this guy EVER designed anything in his life? Automating engineering design?.. REALLY?
Have you ever conducted any engineering work yourself or even have a clue whereabouts on the platform this leak is occurring? And by the way, automatons are only as good as the humans programming them!
What has software to do with a faulty or poorly bedded mechanical seal, that is subject to wear and tear? A 70,000tonne ship that accumulates 200kg per hour of water nothing to write home about, and that is precisely the purpose of the pre-handover sea trials to identify such faults.
I’m more concerned about the availability of such information, how on earth does this get out? What next?
A fantastic success story, highlighting the best of British Manufacturing, its a shame our press focus on a very minor issue rather than praising this magnificent achievement.
This is a really minor fault and a well known issue with stern glands.
If you read about the things that happened during WWII, dockyard teams who were rectifying serious delivery problems with warships actually worked through some very famous sea battles to ensure that the ships did not need to go back into dock.
Different times, different headlines.
Anything that comes out of Rosyth dockyard cannot be trusted, failed project after failed project.
Steve Bee
If it’s the only problem… I would call it a major success. All major projects will have a number of ‘snags’ which the contractor will have to fix prior to full acceptance by the MoD.
As a marine engineer, a slightly dripping seal has never been a source of major concern. Having no aircraft to carry on board seems to be a slightly more important matter to me.
I didn’t realise that the Sun was still being printed?
We have the most unsupportive press in the world all they thrive on is the negative as to them failure is a story success is not. It is surprising we have had so many engineers over the years that have pressed on through the negative press coverage and gone on to make the UK a fortune but even that would not draw the attention of the news press. And I say the news press rather than the media generally some of which have a far better idea of how success generates wealth.
If the fuel pump you used to fill your car with could only deliver 200 litres/hour you would be pretty disappointed. It is not a big leak for a ship of this size and just normal business when commissioning a new vessel.
Now …. what *are* bilge pumps for?
The Daily Express’s headline is “EXPOSED: Queens new £3.1bn warship SINKING as critics slam MoD for getting ‘mugged off'”. I worked out that it would take about 44 years for a leak this size to leak the ship’s displacement in water (70,000 tons); so should be good for a year or so with no pumping.
Slight exaggeration by the Express.
With a project of this complexity if that is the only thing they have to worry about then they have done well !
In my first-year software engineering lectures, they showed us a curve of problems vs time for engineering projects (general, not just software). It looks like a very fat u shape, with a large number of initial problems, then a long period of small/infrequent problems, then a large number of problems before the project is decommissioned.
I think the general public do understand this intuitively, but the data is there to back it up too.
Journalists, on the other hand, want headlines, any headlines….
Its called ‘The Bath Tub Curve’ Mohammed, maybe they can use it to catch the water, the bath tub that is!
Sickened this morning to hear Humphries and some other pointless journo who’d obviously never made or project managed anything of this complexity snorting derision and giggling childishly about this on ‘Today’ this morning. I trust that their brethren in ‘Centaur Towers’ wouldn’t stoop this low, long may it continue. Sadly we engineers face the same reactions daily from similarly inexperienced operations managers…
A complete non-story. Mechanical seals have to heve a flow across the faces to provide lubrication. 200l/h is more than expected, but is “a drop in a bucket” for a ship the size of HMS QE! Agree with most of the comments – this is what you have sea trials for!
Once upon a time this story would have been subject to the Official Secrets Act…
it’s 200 ltrs/hour, the reaction of the press makes it sound like the leak is like the Titanic, no sense of proportion. Shouldn’t have happened, but its not going to sink the thing, minor fault.
It’s what tests and trials are all about. I guess if you found nothing wrong then the media would say that tests and trials are a waste of time and tax payers money.
Journalists or anyone posting comments or opinion should have to state their qualification/experience in that subject to allow the reader to evaluate the content and validity of their remarks.
Bob. HNC Mech, time served Marine engineer, specialist oilfield engineer (48 years experience as a HAZOP Leader, Offshore fire fighter, offshore crane driver………), semi retired. ;¬)
A major NON story ! As to be expected on a new, complex platform. It’s called real world engineering.
Would be better if our rubbish MSM have nothing better to do if they were to look into the F-35 programme and its problems and escalating costs. Here’s a programme that’s going to cripple our future defence capability so why aren’t the press doing serious investigative journalism into the MOD and governments culpability ?
This is not news, it is a non-issue, it is an everyday experience for those who actually imagine, design, make, commission and operate things be they warships or washing machines. The fact that there is a pump there at all demonstrates that someone thought it could possibly be a problem. Some folk in the media need to get out more and actually make something.
Following Malcolm Jennings’ comment, he may be a little misguided. The “useful” investigation work he suggested requires a certain IQ from the journalists. The pump system has far more intelligence than any journalist! BTW I have a 1930’s portable pump with a JAP 2-stroke engine which will shift 50 gallons/min, I think that would do the job!
That is the purpose of trials after all. And seals and so on are part of the wear and tear of moving parts. Why do ships have pumps and has anyone ever looked over the side of a ferry when at sea and looked at what is being pumped out all the time? Journalists are now creating news from whatever load of rubbish they hear and don’t understand.
Compared to how much water would find its way inside under normal operating conditions in heavy seas and storm conditions, through no doubt a myriad of openings, that amount is probably negligible for a ship of this size and complexity. At the end of the day, that is why a ship has bilge pumps – they leak. You just need to ensure you pump the water out faster than it comes in!
You are all missing the point. This is the 21st century. Yes, it is possible to pump the water out of the bilges, that’s why there is a bilge pump, general service pumps that can be used if the leakage gets bad. Even an emergency ‘bilge injection’ able to operated from upper levels of the engine room, if the leakage in is catastrophic. However, there are regulations as to when and where you can pump bilges. MARPOL regulations if memory serves. I would expect a new moden ship to have bilges painted a light colour. I was given a good b****cking when, I was a Junior Engineer, for putting dirty foot prints in the bilges of a steam Shell tanker in 1971.
This problem on HMS QE is pretty fundamental. It points to poor build quality. If they got this wrong, what else will turn up on sea trials?
Hello Tony,
Ex Shell Tankers (UK) R.O. here! Served on the Verconella, Arianta, Aluco & Naticina. Any of these ring a bell? – maybe our paths have crossed in the past?
Perhaps you should be a journalist?
To say that it is indicative of the build quality is just as much of a stretch as the “Express’s” comment on it sinking, or the local radio station claiming that the prop shaft is 17 metres in diameter.
Having worked on many many yachts over the years, few if any of them have had completely dry stern glands.
As others have said, a more fundamental flaw is the lack of fixed wing aircraft to fly off her flight deck. Given that as far as I’m aware there are no other aircraft available that we could purchase to use on this ship, to be completely dependant on another country for those planes seems like a far bigger fault than a shaft seal leak. I presume that you think that the F35 is somewhat worse than shoddy design and manufacture given the almost endless faults and teething problems that these aircraft have encountered on their way to active service.
Re. your suggestion that I should be a journalist, maybe I could bring my 50 years experience as a Marine Engineer to bear on the discussion. I have sailed on 23MW supertankers. I was Chief Engineer during the building, commissioning, sea trials, delivery and maiden voyage of clean oil product tanker. If I were this journalist, making a comment on this thread, I would start by saying that packed stern glands are very old technology, and that you shouldn’t listen to anyone who harps on about their yacht. Ships I sailed on built in the 50’s had them and, indeed, the water poured in. Ships that I served on built from mid-60’s have all had oil filled stern tubes with mechanical seals and no leakage. If you have water coming in through one of these, then you have a very big problem that will probably result in an emergency docking.
The problem with this thread is that we don’t know what the problem is. The speculation is intense, but because it is about the stern tube, seals and shafting I don’t think it a trivial thing. I agree the lack of aircraft is a concern, but it means they have plenty of time to fix the problem before they arrive. Unlike a merchant ship that is at sea for 300 days a year.
Like you, I look forward, with interest, to finding out what the problem really is.
codswallop, Tony Prince…..even a sound seal “leaks”, inasmuch as was pointed out above, without a modicum of water as a lubricant, the seal would not last as long-anyone would think that the bottom had fell out. The shaft revolves pretty slowly-forgotten the normal revs for a prop-60-80 RPM?-so hardly likely to burst into flames. Seem to remember bilges being pumped everyday in the good old days when we had a Merchant Navy-dear god, where did it all go wrong, what a country……
n ‘expert’ on our local radio was saying the prop. shaft is 17 metres diameter! I don’t believe it! Considering the ship was built in at least half-a-dozen sections it’s amazing that a) they all fitted perfectly and b) didn’t leak.
Oh dear oh dear……..1.7 metres circumference, perhaps, on a vessel with a prop that size that size
Different media outlets suggesting the fault is in different places (some say main prop shaft, others say azipod) so it looks like no one knows for sure but if it is a leak on the main prop shaft seal it is an issue as it will require drydocking to fix it. Under normal circumstances there should be zero leakage from a main prop shaft seal.
This is to be expected, especially in ships coming out of build or refit. If my recollection serves me correctly, it would be the rule rather than the exception that at some stage during a commission a shaft leak would occur – usually no big deal – a case of lazy journalists flying speculative kites rather than doing their research – still it all sells newspapers. Problems with shaft bearings and misalignment are an altogether more intractable challenge.
Does anyone actually know what type of seal it is? AFAIC a gland seal is SUPPOSED to leak a little, but a mechanical seal shouldn’t, if everything has been aligned perfectly
What use is an aircraft carrier (leaky or otherwise) if it doesn’t have any aircraft on it? Is 2020 still on?
Pity our media isn’t the same quality as this ship! I cannot describe how angry such shoddy journalism makes me. It seems that if “fake” news won’t do then garbage like this driving that idiot Humprys into a feeding frenzy is the next best thing, thank heaven that after more then 40 years of addicted listening to Today I’m cured!!
I hate to do this but with journos like this lot on our case who gives a stuff about what the EU are doing, we’re perfectly capable of handing out unwarranted criticisms and trying to wreck our economy without any assistance from those other idiots in the EU.
I have on occasions been involved with the testing of RN Shipsand the test are severe to extreme- they have to function in a war zone. If these test were applied to cruise liners they would break up not just spring a leak. One test I witnessed was for full forward to full astern. Why – if you are a pilot who as dropped in the sea you would be glad of this test. So I am not alarmed that during the the work out problems appear.
PS- I am aware of safety helios weather permitting.
Err, no…..I wouldn’t want to be a Pilot in the water if the vessel you had fell overboard from, went full astern in my direction and drew me into the props….usual procedure was to chuck a buoy overboard as a marker and launch the emergency lifeboat–never had to test the system, thank gawd
Does the leak need to be fixed?
If the press want a story about leaks (water not information) look no further than the water companies. The total leakage as a percentage of water put into the system is currently 15-25%. The regulator Ofwat currently requires water companies to fix leaks as long as the cost of doing so is less than the cost of not fixing the leak. This approach is called the sustainable economic level of leakage (SELL), which gives consumers the “best value for money”.
Could the contractor sell this solution to the Aircraft Carrier Alliance to minimise the cost?
I would think that a carrier prop shaft seal is rather important and careful consideration given to selection. In the chemical industry mechanical seals are used for closed stirred reactors. Where high vacuum is applied a double mechanical seal would be used back to back. What kind of seal would a navy carrier use?
On my twin engined trawler, Sanjune, leaking shaft glands were part of the design. The leak provided some lubrication. The only way to avoid this is to change the drive to a “Z” format but I wouldn’t like to try to run a carrier with this format. Bilge pumps are there for a purpose, you know. It is an “easy” job to disconnect the shaft from the drive and replace the over-leaking shaft seal
Certainly, in my practical experience, modern shaft seals are expected/required to leak in order to provide cooling/lubrication. Without this compromise the seal faces will wear prematurely. IF the ‘reported’ leakage rate is accurate (although I would doubt that very much), then it would be in excess of the designed rate and will be rectified easily.
The so called ‘journalists’ make themselves look very foolish to those with any Marine Engineering experience, but unfortunately those who lack any knowledge believe the poor reporting, and they are the majority of Joe Public.
These ships are cutting edge, and a little more difficult to Design and construct than say, an electric tin opener. If it were easy and straightforward, then everybody would be doing it. Issues have surfaced, and there will more, these also will be touted as dramatic failures in British Engineering ability. I would be more inclined to doubt British Journalistic ability, “Never let the truth oget in the way of a good story”.
The prop shaft leaked and the story leaked out via national press. The best course of action now is to identify the root cause (or causes) of the issue and make sure processes are put in place to prevent the recurrence of this issue. A second such error would be unforgivable.
As someone said “the meja has become the message!”
50+ comments by/from Engineers and those who obviously know much more about ships than journalists-(Last refuge of a scoundrel?) Lets just ignore their stupidity and see how long it takes for them to stop,
Stern tube seals are robust and reliable low maintenance items designed to accommodate significant shaft movement and vibration. You would not expect to experience problems on a new vessel but obviously it can happen. Stern tubes can be seawater or oil lubricated. The seals can be of a split design allowing maintenance/repair without withdrawing the tail-shafts – if the HMS QE seals are of the split type then it’s not such a big deal.
As a young engineer in the late sixties on Ellerman lines, we had to check the main shaft stern tube every hour for leaks .M y mate checked it out and told the chief engineer it’s ok ,but there was a salmon going up stream.