Swimming Pools

fred henderson
5th May 2006, 23:10
The reports on Freedom of the Seas include mention of a 580 ton swimming pool being fitted. This will of course include the weight of the water in the pool. I thought members may be interested in a brief history of swimming pools in passenger ships and some of the problems they create.
Many liners operating through the tropics rigged an improvised, temporary pool in a cargo hatch trunk. It is thought that the first permanent onboard swimming pool was installed in the White Star liner Olympic (the earlier sister of Titanic). This was located low down in the ship on F deck, forward on the starboard side. It was reserved for the use of First Class passengers only and had 13 changing cubicles.
Olympic started a trend and from then onwards most transatlantic liners carried an indoor swimming pool. Most occupied three decks, including one deck for the water tank. The next development came with the Hamburg America liners Reliance and Resolute (1920) where their pools were located within the superstructure at boat deck level and were covered by a large skylight, which could be opened in good weather. These ships were intended for Atlantic service in summer and cruising in winter. Generally, however, transatlantic liners were built with indoor pools, fitted low in the ship. This was because outdoor pools were unsuited to year-round Atlantic use and because of the designers’ concerns about the pools’ adverse impact on ship stability. The water in the pool is a considerable weight well above the nominal centre of gravity and provides completely unrestrained free surface effect on the movement of the ship. (As the ship rolls, the surface of the water in the tank remains approximately horizontal, with an increasing depth of water in the direction of the roll. This shifts weight onto the downward moving side of the deck, exaggerating the intensity of the roll and opposing the ship’s natural stabilising forces.)
Nevertheless outdoor pools began to be used in ship designs. The first was in the North German Lloyd liner Columbus (1922) and they were featured in the Italian superliners Rex and Conte di Savoia of 1932. The latter pair had extensive lido areas complete with sand for added effect!
Passenger demand for outside pools on cruise ships has created additional problems, especially in converted line vessels and the smaller, earlier new-built cruise ships. These problems were so severe in some of these older ships that the pool had to be emptied if the ship reached “arrival condition” (minimum fuel/water/food) after a long voyage.
I know that most of the old salts on this site do not believe me, but the big modern cruise ships are far more stable than the old smaller ships. It is a combination of factors that are responsible, including different hull forms and broader beam in relation to length. One significant change is that because the new ships are so much bigger that the swimming pool is proportionately smaller in relation to the beam of the new ships. As a result designers began to use two or three pools and then started to lengthen the pools, whilst retaining approximately the same width. This solved the pools’ adverse effect on the stability of the ship but a new problem emerged.
The first attempt at a really long pool was made in the Carnival Fantasy (1990). The main midships pool was about twice the length of a standard pool, with an offset at the midway point. Although for the first time ever, this enabled passengers to enjoy more than a couple of strokes before needing to return, it was not a success. The inevitable slight pitching motion of the ship produced a resonance in the pool that led to a build-up of large surging wave formations that made swimming at best difficult and at times dangerous. The only answer was to divide the pool with a perforated baffle plate capped with a teak bench, thus abandoning the idea of providing passengers with a facility for a longer swim.
Pitch resonance problems were also encountered in Holland America’s Statendam. In this ship the pool was standard sized but the difficulty was that the ship has such high stability that her pitching motion is far less than normal. The unfortunate result was that the period of pitch of the ship matched that of the pool. A further problem was that at one end of the pool there was a leaping dolphin sculpture set upon a circular base recessed into the forward end of the pool. As waves surged forward they collected in the dolphin base recess, which were channelled upwards in spectacular waterspouts that reached great heights. It was great fun, but not for swimmers. A Perspex sheet was placed in front of the recess, and was promptly shattered by the force of the waves.
An extensive series of model tests were undertaken at the Vienna Model Basin to solve the problem. Various combinations of pool depths, bottom contours and recess protection arrangements were tried until an optimum solution was found.
A similar problem of matching pool and ship pitch resonance was experienced in Home Lines cruise ship Homeric. Shortly after she was delivered by Meyer Werft, Home Lines was bought by Holland America, who decided to lengthen the ship. Once this work was completed the pool problem vanished. Of course, if the pitch resonance should coincide, altering the length of the ship is not the usual option!
Swimming pools on cruise ships are a necessity. They are also a major headache for designers.

Fred (Thumb)

John Rogers
5th May 2006, 23:23
Interesting piece Fred,question..could they design a pool on some sort of gyro/Gimbel.
John

newda898
5th May 2006, 23:27
Interesting Fred.
It was certainly fun "trying" to swim in the pool on Oceana when the boat started pitching - almost to the extent of being dangerous and the kiddy club people were starting to haul everybody out unless they were supervised by a parent.
Do ships designed for the American market have deeper pools? Aurora has small, shallow ones whereas Princess ships seem to have deeper, slightly bigger ones that you can actually swim in.

Richard Green
6th May 2006, 08:43
Back in '53 we travelled as a family out to Cuba on PSNC. I remember very well as a kid being scared to death of going into the pool that was rigged part way through the voyage on the hatch just forward of the accommodation, alarmingly close to the side of the ship. It seemed to me to be about two miles high. I remember it being made up of wooden hatch covers? lined with rather grubby brown canvas. Of course it was not possible to sit on the edge and there was nothing to hold onto if you beathed in a packet of salt water. Once in, that was it sink or swim and with the roll of the ship I was terrified of sloshing overboard...

benjidog
6th May 2006, 16:47
A very thought provoking piece Fred. I can see the logic of the problem getting less with larger ships.

I presume from the problems encountered that the designers are not able to predict whether or not resonance will be a problem and it is a matter of suck it and see. Is this still the case or are there now ways of modelling this so that the design can be modified before the ship is built?

Regards,

Brian

fred henderson
6th May 2006, 19:17
Brian
When the resonance problems first cropped up it was a case of "Oh S**t!" As a result of remedial studies the broad parameters were understood and designers tried to avoid certain size combinations. Research is continuing and the results are now more precise.
There will always be a degree of pitching beyond which pools will not be safe. The object is to ensure that they are usually usable. The depth of the pool is one of the factors in the calculations,Daniel. The available space under the pool is another constraint.

Fred

Santos
6th May 2006, 20:54
Are they easily emptied in the case of an emergency, Fred ? Do they have an emergency release system.

Chris

Bob
7th May 2006, 11:15
(Applause) Back in '53 we travelled as a family out to Cuba on PSNC. I remember very well as a kid being scared to death of going into the pool that was rigged part way through the voyage on the hatch just forward of the accommodation, alarmingly close to the side of the ship. It seemed to me to be about two miles high. I remember it being made up of wooden hatch covers? lined with rather grubby brown canvas. Of course it was not possible to sit on the edge and there was nothing to hold onto if you beathed in a packet of salt water. Once in, that was it sink or swim and with the roll of the ship I was terrified of sloshing overboard...

I was in the PSNC at that time and do remember a pool as described between the hatch combings and the rail, I think it was the chippies job to put it up.
Just checked my discharge book, was on "Salamanca" in 53 Cheers Bob

fred henderson
7th May 2006, 13:49
Are they easily emptied in the case of an emergency, Fred ? Do they have an emergency release system.

Chris

I am not aware of an emergency release system being fitted Chris. They may exist on some ships, but I think that such systems could cause problems of their own.

Fred

rstimaru
7th May 2006, 14:01
We had one on E Ds timber built with a hatch cover to fill with seawater liner it was,nt. You also burnt the soles of your feet getting to it Bob

Richard Green
7th May 2006, 18:02
Bob, Yes, the pool was between the side and the hatch and you did burn your feet getting there! Here's a list of our trips on PSNC. I'd like to get in touch with any ex PSNC guys who sailed on these boats and these trips. As you can see I sailed on the SANTANDER in '53. My Mum, now living in W. Aussie, became a life long friend of Capt. 'Geoff' Turner who sadly died about 3 weeks ago. He went on from PSNC to drive tankers. Which and for who I don't know.

R58484956
7th May 2006, 18:59
On two of the ships I sailed on Iberia & QE (1) which both had pools, at the slightest sign of pitching a big net was used to cover them, or if pitching got too bad they were emptied. as both ships had stabilizers, rolling ( or the lack of)seemed to offer no problems.

Bob S
7th May 2006, 20:14
A couple of years ago I took a cruise on an older ship, the VAN GOGH (built 1975, 15402 grt - built as the Russian GRUZIYA). Although a very nice ship to cruise in, the circular pool at the aft end was a source of amusment when the pitch took over. From my vantage point on a higher deck, we could see when the water started to "swirl", some of the passengers were quick to cotton on but there were always a few who didn't and of course, no body told them (*)) . I've never seen people move so fast when the water came over the side.
I think I may even have a photo somewhere.

Bob
8th May 2006, 11:18
Bob, Yes, the pool was between the side and the hatch and you did burn your feet getting there! Here's a list of our trips on PSNC. I'd like to get in touch with any ex PSNC guys who sailed on these boats and these trips. As you can see I sailed on the SANTANDER in '53. My Mum, now living in W. Aussie, became a life long friend of Capt. 'Geoff' Turner who sadly died about 3 weeks ago. He went on from PSNC to drive tankers. Which and for who I don't know.

Hi Richard,I finished with the P.S.N.C. Jan 54 on "Salamanca" previously"Salinas"but starting Aug.51 with "Santander" must admit that i liked the Company, left it for Ellerman & Pappayanni?

sailor_boy37
12th June 2006, 12:32
Are they easily emptied in the case of an emergency, Fred ? Do they have an emergency release system.

Chris
Yes is the answer. I believe all modern ships have the facility of a quick dumping valve. In case of collision or any incident in which stability may be affected, the immdediate dumping of of the pool increaces the GM righting moment, increasing stability. (i think thats right....havent done our stability at college). There is annecdotal evidence in our fleet to suggest that using UHF walkie talkies in the Aurora's safety centre initially caused her to self-dump her pools....they were very confused.

Richard Green
12th June 2006, 15:29
Brilliant Sailor, I get this picture of twenty or so startled cruise passengers looking very sheepish as they go through the motions, waving arms and legs, flat out on the bottom of an empty pool. Pity the poor bod who has just decided to impress the girls with a cool swallow dive off the spring board....

tom e kelso
12th June 2006, 21:31
Fred,

When berthing at the red buoys at Port Said,possibly about 1951, I remember passing close to a Messageries Maritime vessel called (Marshall[?]) Joffre. Looking across onto her prom deck one could see her swiiming pool. This was at the after end of this deck and extended from outside, forward right into a public room (verandah cafe type). I remember being told by my captain (D R P Gunn-Cunninghame) that this ship had the distinction og having the (then) longest swimming pool afloat . I believe this ship which then had a single funnel , was one one of the MM class which originally had two square funnels each with a rather strange topi on the top

Reminds me of a forenoon call anchored at Gibraltar homeward bound in Kenya. While the pax were ashore, some of the Indian crew fishing over the stern got into a shoal of grey mullet. Once they had enough for the bhandaris' requirements, one wit put about a dozen into the Tourist class pool ! As per routine, the Chinese plumber had lowered the water depth so that kids could have their fun for an hour in the afternoon, after we had sailed . This they certainly did, with about 20 in about 2 feet of water trying to catch the poor fish. I think almost every adult ended up round the pool watching the fun!

Happy days!

Tom

Keith Adams
28th December 2006, 05:15
I have 2 views of "Santander" swimming pool which became a standard setup
kit with a canvas liner with end drain canvas tube (secured up by rail when full)
for all PSNC vessels... I later sailed on the "Cuzco","Salamanca"and "Salaverry"
and all pools were identical... usually Chippy and Cadets set them up. Photos.
taken West bound Panama canal January 1953.Trying to transmit them with this post. Snowy.

aleddy
29th December 2006, 04:32
I was pool attendant on Iberia during 64.
If the ship was putting on a bit of motion the thrillseekers would automatically leave the bars and come to the pools, their arrival enough to suggest to any bloods who had not already gotten out of the pools to do so. Pool atds then became party poopers when the nets had to be drawn across for saftey, on most of these occasions you had to call for assistance or be ignored.
I would not like to be the one trying to close a pool on one of todays cruise ships, to many young people seeing part of their fun spoiled.
Iberia had large inlet and outlet valves to fill or empty the pools with salt water, as I recall both operations were suitably quick.
If the pools were closed at sea it was an opportunity to clean them, if closures were for longer periods I could find myself hanging on to the handle of a rotating polishing machine in the alleyways of the passenger accomodition, if you got a bit careless with that the machine could rotate you.
Cheers,
Ted

Keith Adams
29th December 2006, 04:43
Here are the two photos of "Santander" deck swimming pool I promised.
-Snowy