QM2 and QE2 size comparison

[greykangaroo]

This interesting photo shows the staggering difference in sizes of the two ships.

Remember when the QE2 was a big ship back in the sixties?

The old QE2 has a gross tonnage of just 70327 .

The QM2 is much more than double that at 150000.

[guernseyguy]

I know - lets play 'Spot the ship'! ;)

 

Peter, Sydney

[greykangaroo]

Are you really a moron, or is that an act you put on?

[guernseyguy]

Are you really a moron, or is that an act you put on?

 

Oh you charmer you! Do you not think the different qualities of naval architecture exemplified by the QE2 and QM2 merit discussion? The photograph, you've so cleverly posted, (breaching someone else's copyright) illustrate their different qualities quite well. So it could invite comparisons with ships, or condominiums, say, but would you prefer discussion to remain at the level of 'one is bigger than the other'? Now while I would hesitate to describe that as 'moronic', I certainly wouldn't characterise it as 'sophisticated'.

 

Peter, Sydney

 

PS, The Gross Tonnage of the QM2 is actally 148,528, whatever Cunard say, but since you were precisely correct on the QE2 I knew you'd be happy to have the correct figure for the QM2 too....

[greykangaroo]

What makes me think that you aren't like the majority?

[travel-to-go]

Oh you charmer you! Do you not think the different qualities of naval architecture exemplified by the QE2 and QM2 merit discussion? The photograph, you've so cleverly posted, (breaching someone else's copyright) illustrate their different qualities quite well. So it could invite comparisons with ships, or condominiums, say, but would you prefer discussion to remain at the level of 'one is bigger than the other'? Now while I would hesitate to describe that as 'moronic', I certainly wouldn't characterise it as 'sophisticated'.

 

Peter, Sydney

 

PS, The Gross Tonnage of the QM2 is actally 148,528, whatever Cunard say, but since you were precisely correct on the QE2 I knew you'd be happy to have the correct figure for the QM2 too....

 

Children, children! Fight nicely, or I shall have to send you both to your rooms! And no dessert for you, Mr!

The difference in tonnage is obviously from all those fat passengers sitting in those shoddy chairs of another thread! Don't you get it?

<G>

 

No go to bed, both of you, or I shall have to cuff your ears! And you just wait 'til your father gets home, Buster!

[guernseyguy]

Are you really a moron, or is that an act you put on? What makes me think that you aren't like the majority?

 

And your point is? I know I really shouldn't respond to trolls.....but this really is too easy....now back at the QE2/QM2 - what do YOU think of the differences in naval architecture? Or do you only come to the Cunard board to post other people's pictures and your own abuse?

 

Peter

[qm2 and canberra nut]

Oh dear oh dear........what is going on here? do you two have a dislike for each other. I bet if you both met you would get on so well as you both have similar levels of humour etc...........

 

perhaps you couod both post you ages...... my guess 14 and 16 ;)

[TJL]

We could could have fun with this one!

What is the cause of this deep-rooted animosity that exists between Guernseyguy and Greykangaroo?

My guess is that they were both on a QE2 cruise and on one fateful day, Guerneyguy bagged the last spot on the last comfy sofa in the Queens Room during afternoon tea, leaving poor old Greykangaroo to the mercy of the Lido.

Now THAT'S just cause for a duel if ever there was one.

So it's Message Boards at dawn!

[guernseyguy]

What is the cause of this deep-rooted animosity that exists between Guernseyguy and Greykangaroo?

 

I don't know - best ask Graeme (Greykangaroo). I posted a mildly amusing (or so I thought) joke about the different architectural qualities of the two ships and was called a moron. When I tried to steer the thread back onto that architectural topic, other insinuations were made....so BACK ON THE TOPIC,

 

I think the QE2 looks the more elegant of the two - though from this angle the QM2's 'condo' like properties are not so pronounced. Another thing that is striking from this photo is how dominating the QM2's forward structure looks - but this also highlights the presence of forward facing public rooms, something the QE2 lacks.....so what do the rest think about what this photo says about the two ships.....

 

Peter

[TJL]

I've not travelled on QM2 so can only go by the picture, but it makes me slightly uneasy to think that the much larger and top-heavy ship has pretty much the same draft as the svelte, elegant QE2. Have stabilizers improved THAT much over the years?

 

Tim.

[travel-to-go]

We could could have fun with this one!

What is the cause of this deep-rooted animosity that exists between Guernseyguy and Greykangaroo?

My guess is that they were both on a QE2 cruise and on one fateful day, Guerneyguy bagged the last spot on the last comfy sofa in the Queens Room during afternoon tea, leaving poor old Greykangaroo to the mercy of the Lido.

Now THAT'S just cause for a duel if ever there was one.

So it's Message Boards at dawn!

 

Nah, Grey Kangaroo got the last salmon tea sandwich at afternoon tea one day!

[guernseyguy]

I've not travelled on QM2 so can only go by the picture, but it makes me slightly uneasy to think that the much larger and top-heavy ship has pretty much the same draft as the svelte, elegant QE2. Have stabilizers improved THAT much over the years? Tim.

 

Having sailed on the QM2, I'd have to say 'yes' - the ship is very stable - though we didn't have as bad weather as I had on the QE2, those who have crossed on the QM2 in bad weather report her a very stable ride. Stability is determined in part (afaik) by something known as a ships metacentric height - which Wikipedia explains:

http://en.wikipedia.org/wiki/Metacentric_height

 

So, if I've understood that correctly, the QM2's wider beam will increase her stability. Also the ship was built a deck higher than could have otherwise been done by 'stepping back' the cabins above the boat deck...but I am sure there are more knowledgeable out there to keep us correct!

 

Peter

[rabbit85]

Fascinating discussion by Guernsey Guy, for my personal comment on a

recent voyage you might enjoy my post yesterday,Dec.3rd---------

'What I learned Nov.20th voyage to N.Y.-

 

the STABILITY was simply amazing!

[TJL]

So, if I've understood that correctly, the QM2's wider beam will increase her stability. Also the ship was built a deck higher than could have otherwise been done by 'stepping back' the cabins above the boat deck...but I am sure there are more knowledgeable out there to keep us correct!

 

Peter

 

Interesting - and thanks for all the info, Peter. I hadn't thought of QM2's wider beam. Glad she's proving to be very seaworthy. I know that one spends very little time looking at the outside of a ship (especially on a transatlantic crossing!) but it's still a shame that QM2's looks are a bit disjointed due to the demand for row upon row of balconies. The hull starts off quite promisingly, yet the superstructure is pure high-rise hotel with a funnel on top. Even my travel agent described her as "fabulous on the inside but not much to look at on the outside". But I've wittered on enough about QM2 visual appeal on previous threads and I'm sure there are many QM2-travelled Cunarders out there who would strongly disagree with me....

 

Tim.

 

PS I really really really tried to book a trip on QM2 next summer (honest), but it was no good. I just couldn't help myself. I've opted for QE2. Again. I must fight this addiction! I know I can do it! ;)

[transat_jon]

If I remember correctly, QM2s beam was increased by 3ft during her design after it was decided that the gas turbines would be located at the funnel. This was to increase the righting moment to compensate for the extra weight up top.

 

There are three main reasons for QM2 behaving so well in bad weather. Firstly she is enormous and heavy so will get pushed arround less by the weather, secondly the hull design ensures she is fairly well behaved at sea. The third reason is stabilisers, skeg and big bilge keels, never neglect the power of stabilisation!

 

******************************************************

Tim, the stabilisers don't stop ships actally capsizing, QM2 is stable because the metacentre is always above her centre of gravity, the shape of the hull, especially the beam has a alot to do with that. Her draft in relation to her beam is lower than QE2 which should increase static stability and hence allow a higher centre of gravity.

 

******************************************************

 

Peter, in answer to wider beam making the ship more stable, this is partly true. Making a ship more stable in a static condition can actualy work against dynamic stability and passenger comfort.

 

The metacentric height is an important factor in the stability of a ship.

 

It is in effect the point that the force of boyancy of the ship passes through for small angles of heel. This point for most ships will be above the waterline and MUST also be above the centre of gravity. The distance between centre of gravity and the metacentre is a factor that affects how a ship will behave in the real world. If this distance is too small the ship will be unstable and unsafe, if this distance is too high, the ship will have too high static stability that actually means it will behave very badly in the real world. It will either roll from side to side after any external force is applied or will return to upright so suddenly that crew and passengers will be thrown off their feet.

 

Have a look on the web if you want more on this, find a page with diagrams to make it as easy to understand as possible.

[greykangaroo]

EXAM QUESTION

"Describe then how to determine the height of the ship with a barometer?"

 

 

 

"You tie a long piece of string to the neck of the barometer, then lower the barometer from the tip of the mast to the sea. The length of the string plus the length of the barometer will equal the height of the ship."

 

This highly original answer so incensed the examiner that the student was failed. The student appealed on the grounds that his answer was indisputably correct, and the university appointed an independent arbiter to decide the case. The arbiter judged that the answer was indeed correct, but did not display any noticeable knowledge of physics. To resolve the problem it was decided to call the student in and allow him six minutes in which to provide a verbal answer which showed at least a minimal familiarity with the basic principles of physics.

 

For five minutes the student sat in silence, forehead creased in thought. The arbiter reminded him that time was running out, to which the student replied that he had several extremely relevant answers, but couldn't make up his mind which to use.

 

On being advised to hurry up the student replied as follows:

 

"Firstly, you could take the barometer up to the top of the mast, drop it over the edge, and measure the time it takes to reach the sea. The height of the ship can then be worked out from the formula H = 0.5g x t squared. But bad luck on the barometer after it is immersed in sea water."

 

"Or if the sun is shining you could measure the height of the barometer, then set it on end and measure the length of its shadow. Then you measure the length of the ship's shadow, and thereafter it is a simple matter of proportional arithmetic to work out the height of the ship."

 

"But if you wanted to be highly scientific about it, you could tie a short piece of string to the barometer and swing it like a pendulum, first at sea level and then at the top of the mast. The height is worked out by the difference in the gravitational restoring force T = 2 pi sqroot (l / g)."

 

"If you merely wanted to be boring and orthodox about it, of course, you could use the barometer to measure the air pressure at the top of the mast and then at sea level, and convert the difference in millibars into feet to give the height of the ship."

 

"But since we are constantly being exhorted to exercise independence of mind and apply scientific methods, undoubtedly the best way would be to knock on the purser's door and say to him 'If you would like a nice new barometer, I will give you this one if you tell me the height of this ship."

 

The student was Niels Bohr, the only person from Denmark to win the Nobel prize for Physics.

I hope this settles the arguement.

 

 

[Linerguy]

?????????????????

 

Linerguy

[Ab Ovo]

This thread started out with a nasty chin-wag -- whether by pre-pubescent lorry-louts or by just two old men slapping each other with lillies is not important -- then ended with astute observation.

 

What's not to love about CC? ;)

[Skippyyyy]

Back on topic....

 

Does anybody know the mechanics of ballast?

 

ie. Do ships (QM2 included) take on ballast to adjust their bouancy in relation to the seas? ie. More ballast for rough weather and less ballast for calm seas.

 

Considering the amount of fuel and water used from tanks in a crossing, the ship becomes considerably lighter below the waterline.

 

A rather curious situation came to our attention when last on QE2 in Guernsey - anchored off. The captain announced that as they had not been able to land people ashore owing to fog that day, they had to go out to sea to 'recharge the batteries as it were' for the night. QE2 up anchored (that's another story) and made a slow passage out to sea. Sitting in the Yacht Club, I noticed that the sound from the props was incredible. The vibration too - not as normal. So were the props running at a different pitch? Why?

 

I'm sure it's nothing to do with batteries. They've generators etc.

 

I suspect............ to flush out grey water from the holding tanks. But why the rough prop? I'll let you guess...... ;-)

 

There's much that happens below the waterline that we're not told about - it seems.....

 

I'd still be interested to hear about ballast theory.....

[transat_jon]

Your going to need someone with a good bit of experience with large ships to answer your ballast questions, I can help with the QE2 questions though.

 

QE2 uses it's motors at two different speeds, 72 and 144 rpm.

In port or during manoeuvring, combinator mode is used. This uses the lower 72rpm speed and 16knots is achievable.

Once at sea, free sailing mode is selected. This runs the motors at 144rpm.

 

I do not know all the ins and outs of the two modes, however I believe the lower prop sped is more efficient although only 29,000shp and uses a system that allows wide power changes without causing problems to the main electrical system. When using the higher prop speed the motors are connected to the main bus bar and have 130,000shp available to them.

[sailorbill]

Skippyyy - You haven't said what the QE2 did after leaving Guernsey so it is difficult to conjecture as to what was happening. If she was proceeding to Southampton at the end of a lengthly cruise she might have emptied ballast tanks in preparation for port and was riding high in the water and the noise and vibration was due to propeller cavitation. Ships propellers will cavitate when under heavy load such as trying to pick up speed quickly. When the propeller turns it pushes on the water ahead of it raising the pressure and pulls on the water behind causing a suction. Cavitation is when the water just behind the leading edge of the propeller flashes into vapor due to the suction and then collapses back into liquid under pressure. The collapse causes a bang and the sound waves strike the ships hull resulting in vibration.

 

About ballast - Nearly all ships including cruise ships have a large number of compartments along the bottom and sides of the hull that are separately used as tanks for fuel, fresh water, waste water, ballast water and other bulk liquids. The weight of the various liquids help keep the ship's center of gravity well below the water line. During a long cruise without frequent refueling, a ship will add seawater to tanks well below the waterline to replace the weight of the fuel that was burned and keep the center of gravity of the ship close to the most desirable point. This seawater ballast cannot be legally discharged close to the shoreline of most countries so must be emptied well out to sea. Cargo ships and tankers frequently add the seawater ballast to the fuel tanks since the fuel floats on top of the seawater and doesn't mix. They get in trouble sometimes when removing too much of the ballast water and pump some fuel overboard.

 

Fresh water - Cruise ships produce their own fresh water from seawater using flash evaporators. This is only done in clean open seawater and not close to shore in brackish or polluted port waters or in rivers. When in port for long periods ships will hook up to city water.

 

Bill

[Skippyyyy]

Interesting answers. Thanks.

 

QE2 left Guernsey and went 'out to sea' before returning to Guernsey the next morning. So, somewhere out into the English Channel and back.

 

I've never suffered such a long period of 'rough prop ride' as that occasion, and can only assume (from the above post) that they were for some reason not wishing to use more power.

 

I also thought, that apart from fresh water systems (from sea water) they also have tanks of fresh water fiilled whilst in port. True? Must be (I'd have thought).

[travel-to-go]

Definitely the ship uses a combination of tanks of fresh water taken on in port and water from her desalination plants.